* [PATCH 1/4] new timeofday core subsystem (v. B1)
@ 2005-06-01 23:09 john stultz
2005-06-01 23:12 ` [PATCH 2/4] new timeofday i386 arch specific changes " john stultz
` (2 more replies)
0 siblings, 3 replies; 11+ messages in thread
From: john stultz @ 2005-06-01 23:09 UTC (permalink / raw)
To: Andrew Morton
Cc: lkml, Tim Schmielau, George Anzinger, albert, Ulrich Windl,
Christoph Lameter, Dominik Brodowski, David Mosberger, Andi Kleen,
paulus, schwidefsky, keith maanthey, Chris McDermott, Max Asbock,
mahuja, Nishanth Aravamudan, Darren Hart, Darrick J. Wong,
Anton Blanchard, donf, mpm, benh
Andrew, All,
I'm just re-spinning this to resolve a conflict w/ the CPUFREQ changes
Linus accepted last night.
With the goal to simplify, streamline and consolidate the time-of-day
infrastructure, I propose the following common implementation across all
arches. This will allow generic bugs to be fixed once, reduce code
duplication, and with many architectures sharing the same time source,
this allows drivers to be written once for multiple architectures.
Additionally it will better delineate the lines between the soft-timer
subsystem and the time-of-day subsystem, opening the door for more
flexible and better soft-timer management.
Features of this design:
========================
o Splits time of day management from timer interrupts
o Consolidates a large amount of code
o Generic algorithms which use time-source drivers chosen at runtime
o More consistent and readable code
o Uses nanoseconds as the kernel's base time unit
o Clearly separates the NTP code from the time code
For another description on the rework, see here:
http://lwn.net/Articles/120850/ (Many thanks to the LWN team for that
easy to understand writeup!)
This patch implements the architecture independent portion of the new
time of day subsystem. Included below is timeofday.c (which includes all
the time of day management and accessor functions), ntp.c (which
includes the ntp adjustment code, leapsecond processing, and ntp kernel
state machine code), timesource.c (for timesource specific management
functions), interface definition .h files, the example jiffies
timesource (lowest common denominator time source, mainly for use as
example code) and minimal hooks into arch independent code.
The patch does nothing without at least minimal architecture specific
hooks (i386, x86-64 to follow), and it should be able to be applied to a
tree without affecting the existing code.
Finally I'd like to thank the following people who have contributed
ideas, criticism, testing and code that has helped shape this work:
George Anzinger, Nish Aravamudan, Max Asbock, Dominik Brodowski, Darren
Hart, Christoph Lameter, Matt Mackal, Keith Mannthey, Martin
Schwidefsky, Frank Sorenson, Ulrich Windl, Darrick Wong, and any others
whom I've accidentally forgotten.
Andrew, please consider for inclusion for testing into your tree (I'd
like to target around end of July for possible inclusion into mainline).
thanks
-john
Signed-off-by: John Stultz <johnstul@us.ibm.com>
linux-2.6.12-rc5_timeofday-core_B1.patch
========================================
Index: drivers/Makefile
===================================================================
--- d414ab9a0f0995899c2e76c232714410f787b209/drivers/Makefile (mode:100644)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/drivers/Makefile (mode:100644)
@@ -64,3 +64,4 @@
obj-$(CONFIG_BLK_DEV_SGIIOC4) += sn/
obj-y += firmware/
obj-$(CONFIG_CRYPTO) += crypto/
+obj-$(CONFIG_NEWTOD) += timesource/
Index: drivers/char/hangcheck-timer.c
===================================================================
--- d414ab9a0f0995899c2e76c232714410f787b209/drivers/char/hangcheck-timer.c (mode:100644)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/drivers/char/hangcheck-timer.c (mode:100644)
@@ -49,6 +49,7 @@
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <linux/sysrq.h>
+#include <linux/timeofday.h>
#define VERSION_STR "0.9.0"
@@ -130,8 +131,12 @@
#endif
#ifdef HAVE_MONOTONIC
+#ifndef CONFIG_NEWTOD
extern unsigned long long monotonic_clock(void);
#else
+#define monotonic_clock() do_monotonic_clock()
+#endif
+#else
static inline unsigned long long monotonic_clock(void)
{
# ifdef __s390__
Index: drivers/timesource/Makefile
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/drivers/timesource/Makefile (mode:100644)
@@ -0,0 +1 @@
+obj-y += jiffies.o
Index: drivers/timesource/jiffies.c
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/drivers/timesource/jiffies.c (mode:100644)
@@ -0,0 +1,69 @@
+/***********************************************************************
+* linux/drivers/timesource/jiffies.c
+*
+* This file contains the jiffies based time source.
+*
+* Copyright (C) 2004, 2005 IBM, John Stultz (johnstul@us.ibm.com)
+*
+* This program is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation; either version 2 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program; if not, write to the Free Software
+* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*
+************************************************************************/
+#include <linux/timesource.h>
+#include <linux/jiffies.h>
+#include <linux/init.h>
+
+/* The Jiffies based timesource is the lowest common
+ * denominator time source which should function on
+ * all systems. It has the same coarse resolution as
+ * the timer interrupt frequency HZ and it suffers
+ * inaccuracies caused by missed or lost timer
+ * interrupts and the inability for the timer
+ * interrupt hardware to accuratly tick at the
+ * requested HZ value. It is also not reccomended
+ * for "tick-less" systems.
+ */
+#define NSEC_PER_JIFFY ((u32)((((u64)NSEC_PER_SEC)<<8)/ACTHZ))
+
+/* Since jiffies uses a simple NSEC_PER_JIFFY multiplier
+ * conversion, the .shift value could be zero. However
+ * this would make NTP adjustments impossible as they are
+ * in units of 1/2^.shift. Thus we use JIFFIES_SHIFT to
+ * shift both the nominator and denominator the same
+ * amount, and give ntp adjustments in units of 1/2^10
+ */
+#define JIFFIES_SHIFT 10
+
+static cycle_t jiffies_read(void)
+{
+ cycle_t ret = get_jiffies_64();
+ return ret;
+}
+
+struct timesource_t timesource_jiffies = {
+ .name = "jiffies",
+ .priority = 0, /* lowest priority*/
+ .type = TIMESOURCE_FUNCTION,
+ .read_fnct = jiffies_read,
+ .mask = (cycle_t)-1,
+ .mult = NSEC_PER_JIFFY << JIFFIES_SHIFT, /* See above for details */
+ .shift = JIFFIES_SHIFT,
+};
+
+static int __init init_jiffies_timesource(void)
+{
+ register_timesource(×ource_jiffies);
+ return 0;
+}
+module_init(init_jiffies_timesource);
Index: include/asm-generic/timeofday.h
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/include/asm-generic/timeofday.h (mode:100644)
@@ -0,0 +1,26 @@
+/* linux/include/asm-generic/timeofday.h
+ *
+ * This file contains the asm-generic interface
+ * to the arch specific calls used by the time of day subsystem
+ */
+#ifndef _ASM_GENERIC_TIMEOFDAY_H
+#define _ASM_GENERIC_TIMEOFDAY_H
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <asm/div64.h>
+#ifdef CONFIG_NEWTOD
+
+/* Required externs */
+extern nsec_t read_persistent_clock(void);
+extern void sync_persistent_clock(struct timespec ts);
+
+#ifdef CONFIG_NEWTOD_VSYSCALL
+extern void arch_update_vsyscall_gtod(nsec_t wall_time, cycle_t offset_base,
+ struct timesource_t* timesource, int ntp_adj);
+#else
+#define arch_update_vsyscall_gtod(x,y,z,w) {}
+#endif
+
+#endif /* CONFIG_NEWTOD */
+#endif
Index: include/linux/ntp.h
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/include/linux/ntp.h (mode:100644)
@@ -0,0 +1,19 @@
+/* linux/include/linux/ntp.h
+ *
+ * This file NTP state machine accessor functions.
+ */
+
+#ifndef _LINUX_NTP_H
+#define _LINUX_NTP_H
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+
+/* NTP state machine interfaces */
+int ntp_advance(nsec_t value);
+int ntp_adjtimex(struct timex*);
+int ntp_leapsecond(struct timespec now);
+void ntp_clear(void);
+int get_ntp_status(void);
+
+#endif
Index: include/linux/time.h
===================================================================
--- d414ab9a0f0995899c2e76c232714410f787b209/include/linux/time.h (mode:100644)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/include/linux/time.h (mode:100644)
@@ -27,6 +27,10 @@
#ifdef __KERNEL__
+/* timeofday base types */
+typedef u64 nsec_t;
+typedef u64 cycle_t;
+
/* Parameters used to convert the timespec values */
#ifndef USEC_PER_SEC
#define USEC_PER_SEC (1000000L)
Index: include/linux/timeofday.h
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/include/linux/timeofday.h (mode:100644)
@@ -0,0 +1,59 @@
+/* linux/include/linux/timeofday.h
+ *
+ * This file contains the interface to the time of day subsystem
+ */
+#ifndef _LINUX_TIMEOFDAY_H
+#define _LINUX_TIMEOFDAY_H
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <asm/div64.h>
+
+#ifdef CONFIG_NEWTOD
+/* Public definitions */
+extern nsec_t get_lowres_timestamp(void);
+extern nsec_t get_lowres_timeofday(void);
+extern nsec_t do_monotonic_clock(void);
+
+extern void do_gettimeofday(struct timeval *tv);
+extern void getnstimeofday(struct timespec *ts);
+extern int do_settimeofday(struct timespec *tv);
+extern int do_adjtimex(struct timex *tx);
+
+extern void timeofday_init(void);
+
+/* Inline helper functions */
+static inline struct timeval ns_to_timeval(nsec_t ns)
+{
+ struct timeval tv;
+ tv.tv_sec = div_long_long_rem(ns, NSEC_PER_SEC, &tv.tv_usec);
+ tv.tv_usec = (tv.tv_usec + NSEC_PER_USEC/2) / NSEC_PER_USEC;
+ return tv;
+}
+
+static inline struct timespec ns_to_timespec(nsec_t ns)
+{
+ struct timespec ts;
+ ts.tv_sec = div_long_long_rem(ns, NSEC_PER_SEC, &ts.tv_nsec);
+ return ts;
+}
+
+static inline nsec_t timespec_to_ns(struct timespec* ts)
+{
+ nsec_t ret;
+ ret = ((nsec_t)ts->tv_sec) * NSEC_PER_SEC;
+ ret += ts->tv_nsec;
+ return ret;
+}
+
+static inline nsec_t timeval_to_ns(struct timeval* tv)
+{
+ nsec_t ret;
+ ret = ((nsec_t)tv->tv_sec) * NSEC_PER_SEC;
+ ret += tv->tv_usec * NSEC_PER_USEC;
+ return ret;
+}
+#else /* CONFIG_NEWTOD */
+#define timeofday_init()
+#endif /* CONFIG_NEWTOD */
+#endif /* _LINUX_TIMEOFDAY_H */
Index: include/linux/timesource.h
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/include/linux/timesource.h (mode:100644)
@@ -0,0 +1,158 @@
+/* linux/include/linux/timesource.h
+ *
+ * This file contains the structure definitions for timesources.
+ *
+ * If you are not a timesource, or the time of day code, you should
+ * not be including this file!
+ */
+#ifndef _LINUX_TIMESORUCE_H
+#define _LINUX_TIMESORUCE_H
+
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <asm/io.h>
+#include <asm/div64.h>
+
+/* struct timesource_t:
+ * Provides mostly state-free accessors to the underlying hardware.
+ *
+ * name: ptr to timesource name
+ * priority: priority value for selection (higher is better)
+ * type: defines timesource type
+ * @read_fnct: returns a cycle value
+ * ptr: ptr to MMIO'ed counter
+ * mask: bitmask for two's complement
+ * subtraction of non 64 bit counters
+ * mult: cycle to nanosecond multiplier
+ * shift: cycle to nanosecond divisor (power of two)
+ * @update_callback: called when safe to alter timesource values
+ */
+struct timesource_t {
+ char* name;
+ int priority;
+ enum {
+ TIMESOURCE_FUNCTION,
+ TIMESOURCE_CYCLES,
+ TIMESOURCE_MMIO_32,
+ TIMESOURCE_MMIO_64
+ } type;
+ cycle_t (*read_fnct)(void);
+ void __iomem *mmio_ptr;
+ cycle_t mask;
+ u32 mult;
+ u32 shift;
+ void (*update_callback)(void);
+};
+
+
+/* Helper functions that converts a khz counter
+ * frequency to a timsource multiplier, given the
+ * timesource shift value
+ */
+static inline u32 timesource_khz2mult(u32 khz, u32 shift_constant)
+{
+ /* khz = cyc/(Million ns)
+ * mult/2^shift = ns/cyc
+ * mult = ns/cyc * 2^shift
+ * mult = 1Million/khz * 2^shift
+ * mult = 1000000 * 2^shift / khz
+ * mult = (1000000<<shift) / khz
+ */
+ u64 tmp = ((u64)1000000) << shift_constant;
+ tmp += khz/2; /* round for do_div */
+ do_div(tmp, khz);
+ return (u32)tmp;
+}
+
+/* Helper functions that converts a hz counter
+ * frequency to a timsource multiplier, given the
+ * timesource shift value
+ */
+static inline u32 timesource_hz2mult(u32 hz, u32 shift_constant)
+{
+ /* hz = cyc/(Billion ns)
+ * mult/2^shift = ns/cyc
+ * mult = ns/cyc * 2^shift
+ * mult = 1Billion/hz * 2^shift
+ * mult = 1000000000 * 2^shift / hz
+ * mult = (1000000000<<shift) / hz
+ */
+ u64 tmp = ((u64)1000000000) << shift_constant;
+ tmp += hz/2; /* round for do_div */
+ do_div(tmp, hz);
+ return (u32)tmp;
+}
+
+
+#ifndef readq
+/* Provide an a way to atomically read a u64 on a 32bit arch */
+static inline unsigned long long timesource_readq(void __iomem *addr)
+{
+ u32 low, high;
+ /* loop is required to make sure we get an atomic read */
+ do {
+ high = readl(addr+4);
+ low = readl(addr);
+ } while (high != readl(addr+4));
+
+ return low | (((unsigned long long)high) << 32LL);
+}
+#else
+#define timesource_readq(x) readq(x)
+#endif
+
+
+/* read_timesource():
+ * Uses the timesource to return the current cycle_t value
+ */
+static inline cycle_t read_timesource(struct timesource_t *ts)
+{
+ switch (ts->type) {
+ case TIMESOURCE_MMIO_32:
+ return (cycle_t)readl(ts->mmio_ptr);
+ case TIMESOURCE_MMIO_64:
+ return (cycle_t)timesource_readq(ts->mmio_ptr);
+ case TIMESOURCE_CYCLES:
+ return (cycle_t)get_cycles();
+ default:/* case: TIMESOURCE_FUNCTION */
+ return ts->read_fnct();
+ }
+}
+
+/* cyc2ns():
+ * Uses the timesource and ntp ajdustment interval to
+ * convert cycle_ts to nanoseconds.
+ */
+static inline nsec_t cyc2ns(struct timesource_t *ts, int ntp_adj, cycle_t cycles)
+{
+ u64 ret;
+ ret = (u64)cycles;
+ ret *= (ts->mult + ntp_adj);
+ ret >>= ts->shift;
+ return (nsec_t)ret;
+}
+
+/* cyc2ns_rem():
+ * Uses the timesource and ntp ajdustment interval to
+ * convert cycle_ts to nanoseconds. Add in remainder portion
+ * which is stored in ns<<ts->shift units and save the new
+ * remainder off.
+ */
+static inline nsec_t cyc2ns_rem(struct timesource_t *ts, int ntp_adj, cycle_t cycles, u64* rem)
+{
+ u64 ret;
+ ret = (u64)cycles;
+ ret *= (ts->mult + ntp_adj);
+ if (rem) {
+ ret += *rem;
+ *rem = ret & ((1<<ts->shift)-1);
+ }
+ ret >>= ts->shift;
+ return (nsec_t)ret;
+}
+
+/* used to install a new time source */
+void register_timesource(struct timesource_t*);
+struct timesource_t* get_next_timesource(void);
+#endif
Index: include/linux/timex.h
===================================================================
--- d414ab9a0f0995899c2e76c232714410f787b209/include/linux/timex.h (mode:100644)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/include/linux/timex.h (mode:100644)
@@ -228,6 +228,7 @@
extern unsigned long tick_nsec; /* ACTHZ period (nsec) */
extern int tickadj; /* amount of adjustment per tick */
+#ifndef CONFIG_NEWTOD
/*
* phase-lock loop variables
*/
@@ -314,6 +315,7 @@
}
#endif /* !CONFIG_TIME_INTERPOLATION */
+#endif /* !CONFIG_NEWTOD */
#endif /* KERNEL */
Index: init/main.c
===================================================================
--- d414ab9a0f0995899c2e76c232714410f787b209/init/main.c (mode:100644)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/init/main.c (mode:100644)
@@ -47,6 +47,7 @@
#include <linux/rmap.h>
#include <linux/mempolicy.h>
#include <linux/key.h>
+#include <linux/timeofday.h>
#include <asm/io.h>
#include <asm/bugs.h>
@@ -467,6 +468,7 @@
pidhash_init();
init_timers();
softirq_init();
+ timeofday_init();
time_init();
/*
Index: kernel/Makefile
===================================================================
--- d414ab9a0f0995899c2e76c232714410f787b209/kernel/Makefile (mode:100644)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/kernel/Makefile (mode:100644)
@@ -9,6 +9,7 @@
rcupdate.o intermodule.o extable.o params.o posix-timers.o \
kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o
+obj-$(CONFIG_NEWTOD) += timeofday.o timesource.o ntp.o
obj-$(CONFIG_FUTEX) += futex.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
obj-$(CONFIG_SMP) += cpu.o spinlock.o
Index: kernel/ntp.c
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/kernel/ntp.c (mode:100644)
@@ -0,0 +1,519 @@
+/********************************************************************
+* linux/kernel/ntp.c
+*
+* NTP state machine and time scaling code.
+*
+* Copyright (C) 2004, 2005 IBM, John Stultz (johnstul@us.ibm.com)
+*
+* Portions rewritten from kernel/time.c and kernel/timer.c
+* Please see those files for original copyrights.
+*
+* This program is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation; either version 2 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program; if not, write to the Free Software
+* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*
+* Notes:
+*
+* Hopefully you should never have to understand or touch
+* any of the code below. but don't let that keep you from trying!
+*
+* This code is loosely based on David Mills' RFC 1589 and its
+* updates. Please see the following for more details:
+* http://www.eecis.udel.edu/~mills/database/rfc/rfc1589.txt
+* http://www.eecis.udel.edu/~mills/database/reports/kern/kernb.pdf
+*
+* NOTE: To simplify the code, we do not implement any of
+* the PPS code, as the code that uses it never was merged.
+* -johnstul@us.ibm.com
+*
+* Revision History:
+* 2004-09-02: A0
+* o First pass sent to lkml for review.
+* 2004-12-07: A1
+* o No changes, sent to lkml for review.
+* 2005-03-11: A3
+* o yanked ntp_scale(), ntp adjustments are done in cyc2ns
+* 2005-04-29: A4
+* o Added conditional debug info
+* 2005-05-12: A5
+* o comment cleanups
+* 2005-05-31: B0
+* o comment cleanups
+* o Improved rounding
+* TODO List:
+* o Move to using ppb for frequency adjustments
+* o More documentation
+* o More testing
+* o More optimization
+*********************************************************************/
+
+#include <linux/ntp.h>
+#include <linux/errno.h>
+
+#define NTP_DEBUG 0
+
+/* NTP scaling code
+ * Functions:
+ * ----------
+ * nsec_t ntp_scale(nsec_t value):
+ * Scales the nsec_t vale using ntp kernel state
+ * void ntp_advance(nsec_t interval):
+ * Increments the NTP state machine by interval time
+ * static int ntp_hardupdate(long offset, struct timeval tv)
+ * ntp_adjtimex helper function
+ * int ntp_adjtimex(struct timex* tx):
+ * Interface to adjust NTP state machine
+ * int ntp_leapsecond(struct timespec now)
+ * Does NTP leapsecond processing. Returns number of
+ * seconds current time should be adjusted by.
+ * void ntp_clear(void):
+ * Clears the ntp kernel state
+ * int get_ntp_status(void):
+ * returns ntp_status value
+ *
+ * Variables:
+ * ----------
+ * ntp kernel state variables:
+ * See below for full list.
+ * ntp_lock:
+ * Protects ntp kernel state variables
+ */
+
+
+
+/* Chapter 5: Kernel Variables [RFC 1589 pg. 28] */
+/* 5.1 Interface Variables */
+static int ntp_status = STA_UNSYNC; /* status */
+static long ntp_offset; /* usec */
+static long ntp_constant = 2; /* ntp magic? */
+static long ntp_maxerror = NTP_PHASE_LIMIT; /* usec */
+static long ntp_esterror = NTP_PHASE_LIMIT; /* usec */
+static const long ntp_tolerance = MAXFREQ; /* shifted ppm */
+static const long ntp_precision = 1; /* constant */
+
+/* 5.2 Phase-Lock Loop Variables */
+static long ntp_freq; /* shifted ppm */
+static long ntp_reftime; /* sec */
+
+/* Extra values */
+static int ntp_state = TIME_OK; /* leapsecond state */
+static long ntp_tick = USEC_PER_SEC/USER_HZ; /* tick length */
+
+static s64 ss_offset_len; /* SINGLESHOT offset adj interval (nsec)*/
+static long singleshot_adj; /* +/- MAX_SINGLESHOT_ADJ (ppm)*/
+static long tick_adj; /* tx->tick adjustment (ppm) */
+static long offset_adj; /* offset adjustment (ppm) */
+
+
+/* lock for the above variables */
+static seqlock_t ntp_lock = SEQLOCK_UNLOCKED;
+
+#define MAX_SINGLESHOT_ADJ 500 /* (ppm) */
+#define SEC_PER_DAY 86400
+
+/* Required to safely shift negative values */
+#define shiftR(x,s) (x < 0) ? (-((-x) >> (s))) : ((x) >> (s))
+
+/**
+ * ntp_advance - Periodic hook which increments NTP state machine
+ * interval: nsecond interval value used to increment the state machine
+ *
+ * Periodic hook which increments NTP state machine by interval.
+ * Returns the signed PPM adjustment to be used for the next interval.
+ *
+ * This is ntp_hardclock in the RFC.
+ */
+int ntp_advance(nsec_t interval)
+{
+ static u64 interval_sum = 0;
+ static long ss_adj = 0;
+ unsigned long flags;
+ long ppm_sum;
+
+ /* inc interval sum */
+ interval_sum += interval;
+
+ write_seqlock_irqsave(&ntp_lock, flags);
+
+ /* decrement singleshot offset interval */
+ ss_offset_len -= interval;
+ if(ss_offset_len < 0) /* make sure it doesn't go negative */
+ ss_offset_len = 0;
+
+ /* Do second overflow code */
+ while (interval_sum > NSEC_PER_SEC) {
+ /* XXX - I'd prefer to smoothly apply this math
+ * at each call to ntp_advance() rather then each
+ * second.
+ */
+ long tmp;
+
+ /* Bump maxerror by ntp_tolerance */
+ ntp_maxerror += shiftR(ntp_tolerance, SHIFT_USEC);
+ if (ntp_maxerror > NTP_PHASE_LIMIT) {
+ ntp_maxerror = NTP_PHASE_LIMIT;
+ ntp_status |= STA_UNSYNC;
+ }
+
+ /* Calculate offset_adj for the next second */
+ tmp = ntp_offset;
+ if (!(ntp_status & STA_FLL))
+ tmp = shiftR(tmp, SHIFT_KG + ntp_constant);
+
+ /* bound the adjustment to MAXPHASE/MINSEC */
+ tmp = min(tmp, (MAXPHASE / MINSEC) << SHIFT_UPDATE);
+ tmp = max(tmp, -(MAXPHASE / MINSEC) << SHIFT_UPDATE);
+
+ offset_adj = shiftR(tmp, SHIFT_UPDATE); /* (usec/sec) = ppm */
+ ntp_offset -= tmp;
+
+ interval_sum -= NSEC_PER_SEC;
+
+ /* calculate singleshot aproximation ppm for the next second */
+ ss_adj = singleshot_adj;
+ singleshot_adj = 0;
+ }
+
+ /* calculate total ppm adjustment for the next interval */
+ ppm_sum = tick_adj;
+ ppm_sum += offset_adj;
+ ppm_sum += shiftR(ntp_freq,SHIFT_USEC);
+ ppm_sum += ss_adj;
+
+#if NTP_DEBUG
+{
+ static int dbg = 0;
+ if(!(dbg++%300000))
+ printk("tick_adj(%d) + offset_adj(%d) + ntp_freq(%d) + ss_adj(%d) = ppm_sum(%d)\n", tick_adj, offset_adj, shiftR(ntp_freq,SHIFT_USEC), ss_adj, ppm_sum);
+}
+#endif
+
+ write_sequnlock_irqrestore(&ntp_lock, flags);
+
+ return ppm_sum;
+}
+
+/**
+ * ntp_hardupdate - Calculates the offset and freq values
+ * offset: current offset
+ * tv: timeval holding the current time
+ *
+ * Private function, called only by ntp_adjtimex while holding ntp_lock
+ *
+ * This function is called when an offset adjustment is requested.
+ * It calculates the offset adjustment and manipulates the
+ * frequency adjustement accordingly.
+ */
+static int ntp_hardupdate(long offset, struct timeval tv)
+{
+ int ret;
+ long tmp, interval;
+
+ ret = 0;
+ if (!(ntp_status & STA_PLL))
+ return ret;
+
+ tmp = offset;
+ /* Make sure offset is bounded by MAXPHASE */
+ tmp = min(tmp, MAXPHASE);
+ tmp = max(tmp, -MAXPHASE);
+
+ ntp_offset = tmp << SHIFT_UPDATE;
+
+ if ((ntp_status & STA_FREQHOLD) || (ntp_reftime == 0))
+ ntp_reftime = tv.tv_sec;
+
+ /* calculate seconds since last call to hardupdate */
+ interval = tv.tv_sec - ntp_reftime;
+ ntp_reftime = tv.tv_sec;
+
+ if ((ntp_status & STA_FLL) && (interval >= MINSEC)) {
+ long damping;
+ /* calculate frequency for this interval */
+ tmp = (offset + interval/2) / interval; /* ppm (usec/sec)*/
+
+ /* calculate damping factor */
+ damping = SHIFT_KH - SHIFT_USEC;
+
+ /* convert to shifted ppm, then apply damping factor */
+ ntp_freq += shiftR(tmp,damping);
+#if NTP_DEBUG
+ printk("ntp->freq change: %ld\n",shiftR(tmp,damping));
+#endif
+
+ } else if ((ntp_status & STA_PLL) && (interval < MAXSEC)) {
+ long damping;
+ tmp = offset * interval;
+
+ /* calculate damping factor */
+ damping = (2 * ntp_constant) + SHIFT_KF - SHIFT_USEC;
+
+ /* apply damping factor */
+ ntp_freq += shiftR(tmp,damping);
+
+#if NTP_DEBUG
+ printk("ntp->freq change: %ld\n", shiftR(tmp,damping));
+#endif
+ } else { /* interval out of bounds */
+#if NTP_DEBUG
+ printk("ntp_hardupdate(): interval out of bounds: %ld status: 0x%x\n",
+ interval, ntp_status);
+#endif
+ ret = -1; /* TIME_ERROR */
+ }
+
+ /* bound ntp_freq */
+ if (ntp_freq > ntp_tolerance)
+ ntp_freq = ntp_tolerance;
+ if (ntp_freq < -ntp_tolerance)
+ ntp_freq = -ntp_tolerance;
+
+ return ret;
+}
+
+/**
+ * ntp_adjtimex - Interface to change NTP state machine
+ * @tx: timex value passed to the kernel to be used
+ */
+int ntp_adjtimex(struct timex* tx)
+{
+ long save_offset;
+ int result;
+ unsigned long flags;
+
+/* Sanity checking
+ */
+ /* frequency adjustment limited to +/- MAXFREQ */
+ if ((tx->modes & ADJ_FREQUENCY)
+ && (abs(tx->freq) > MAXFREQ))
+ return -EINVAL;
+
+ /* maxerror adjustment limited to NTP_PHASE_LIMIT */
+ if ((tx->modes & ADJ_MAXERROR)
+ && (tx->maxerror < 0
+ || tx->maxerror >= NTP_PHASE_LIMIT))
+ return -EINVAL;
+
+ /* esterror adjustment limited to NTP_PHASE_LIMIT */
+ if ((tx->modes & ADJ_ESTERROR)
+ && (tx->esterror < 0
+ || tx->esterror >= NTP_PHASE_LIMIT))
+ return -EINVAL;
+
+ /* constant adjustment must be positive */
+ if ((tx->modes & ADJ_TIMECONST)
+ && (tx->constant < 0))
+ return -EINVAL;
+
+ /* Single shot mode can only be used by itself */
+ if (((tx->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
+ && (tx->modes != ADJ_OFFSET_SINGLESHOT))
+ return -EINVAL;
+
+ /* offset adjustment limited to +/- MAXPHASE */
+ if ((tx->modes != ADJ_OFFSET_SINGLESHOT)
+ && (tx->modes & ADJ_OFFSET)
+ && (abs(tx->offset)>= MAXPHASE))
+ return -EINVAL;
+
+ /* tick adjustment limited to 10% */
+ if ((tx->modes & ADJ_TICK)
+ && ((tx->tick < 900000/USER_HZ)
+ ||(tx->tick > 11000000/USER_HZ)))
+ return -EINVAL;
+
+#if NTP_DEBUG
+ if(tx->modes) {
+ printk("adjtimex: tx->offset: %ld tx->freq: %ld\n",
+ tx->offset, tx->freq);
+ }
+#endif
+
+/* Kernel input bits
+ */
+ write_seqlock_irqsave(&ntp_lock, flags);
+
+ result = ntp_state;
+
+ /* For ADJ_OFFSET_SINGLESHOT we must return the old offset */
+ save_offset = shiftR(ntp_offset, SHIFT_UPDATE);
+
+ /* Process input parameters */
+ if (tx->modes & ADJ_STATUS) {
+ ntp_status &= STA_RONLY;
+ ntp_status |= tx->status & ~STA_RONLY;
+ }
+
+ if (tx->modes & ADJ_FREQUENCY)
+ ntp_freq = tx->freq;
+
+ if (tx->modes & ADJ_MAXERROR)
+ ntp_maxerror = tx->maxerror;
+
+ if (tx->modes & ADJ_ESTERROR)
+ ntp_esterror = tx->esterror;
+
+ if (tx->modes & ADJ_TIMECONST)
+ ntp_constant = tx->constant;
+
+ if (tx->modes & ADJ_OFFSET) {
+ /* check if we're doing a singleshot adjustment */
+ if (tx->modes == ADJ_OFFSET_SINGLESHOT)
+ singleshot_adj = tx->offset;
+ /* otherwise, call hardupdate() */
+ else if (ntp_hardupdate(tx->offset, tx->time))
+ result = TIME_ERROR;
+ }
+
+ if (tx->modes & ADJ_TICK) {
+ /* first calculate usec/user_tick offset */
+ tick_adj = ((USEC_PER_SEC + USER_HZ/2)/USER_HZ) - tx->tick;
+ /* multiply by user_hz to get usec/sec => ppm */
+ tick_adj *= USER_HZ;
+ /* save tx->tick for future calls to adjtimex */
+ ntp_tick = tx->tick;
+ }
+
+ if ((ntp_status & (STA_UNSYNC|STA_CLOCKERR)) != 0 )
+ result = TIME_ERROR;
+
+/* Kernel output bits
+ */
+ /* write kernel state to user timex values*/
+ if ((tx->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
+ tx->offset = save_offset;
+ else
+ tx->offset = shiftR(ntp_offset, SHIFT_UPDATE);
+
+ tx->freq = ntp_freq;
+ tx->maxerror = ntp_maxerror;
+ tx->esterror = ntp_esterror;
+ tx->status = ntp_status;
+ tx->constant = ntp_constant;
+ tx->precision = ntp_precision;
+ tx->tolerance = ntp_tolerance;
+
+ /* PPS is not implemented, so these are zero */
+ tx->ppsfreq = /*XXX - Not Implemented!*/ 0;
+ tx->jitter = /*XXX - Not Implemented!*/ 0;
+ tx->shift = /*XXX - Not Implemented!*/ 0;
+ tx->stabil = /*XXX - Not Implemented!*/ 0;
+ tx->jitcnt = /*XXX - Not Implemented!*/ 0;
+ tx->calcnt = /*XXX - Not Implemented!*/ 0;
+ tx->errcnt = /*XXX - Not Implemented!*/ 0;
+ tx->stbcnt = /*XXX - Not Implemented!*/ 0;
+
+ write_sequnlock_irqrestore(&ntp_lock, flags);
+
+ return result;
+}
+
+
+/**
+ * ntp_leapsecond - NTP leapsecond processing code.
+ * now: the current time
+ *
+ * Returns the number of seconds (-1, 0, or 1) that
+ * should be added to the current time to properly
+ * adjust for leapseconds.
+ */
+int ntp_leapsecond(struct timespec now)
+{
+ /*
+ * Leap second processing. If in leap-insert state at
+ * the end of the day, the system clock is set back one
+ * second; if in leap-delete state, the system clock is
+ * set ahead one second.
+ */
+ static time_t leaptime = 0;
+
+ switch (ntp_state) {
+ case TIME_OK:
+ if (ntp_status & STA_INS) {
+ ntp_state = TIME_INS;
+ /* calculate end of today (23:59:59)*/
+ leaptime = now.tv_sec + SEC_PER_DAY -
+ (now.tv_sec % SEC_PER_DAY) - 1;
+ }
+ else if (ntp_status & STA_DEL) {
+ ntp_state = TIME_DEL;
+ /* calculate end of today (23:59:59)*/
+ leaptime = now.tv_sec + SEC_PER_DAY -
+ (now.tv_sec % SEC_PER_DAY) - 1;
+ }
+ break;
+
+ case TIME_INS:
+ /* Once we are at (or past) leaptime, insert the second */
+ if (now.tv_sec > leaptime) {
+ ntp_state = TIME_OOP;
+ printk(KERN_NOTICE
+ "Clock: inserting leap second 23:59:60 UTC\n");
+ return -1;
+ }
+ break;
+
+ case TIME_DEL:
+ /* Once we are at (or past) leaptime, delete the second */
+ if (now.tv_sec >= leaptime) {
+ ntp_state = TIME_WAIT;
+ printk(KERN_NOTICE
+ "Clock: deleting leap second 23:59:59 UTC\n");
+ return 1;
+ }
+ break;
+
+ case TIME_OOP:
+ /* Wait for the end of the leap second*/
+ if (now.tv_sec > (leaptime + 1))
+ ntp_state = TIME_WAIT;
+ break;
+
+ case TIME_WAIT:
+ if (!(ntp_status & (STA_INS | STA_DEL)))
+ ntp_state = TIME_OK;
+ }
+
+ return 0;
+}
+
+/**
+ * ntp_clear - Clears the NTP state machine.
+ *
+ */
+void ntp_clear(void)
+{
+ unsigned long flags;
+ write_seqlock_irqsave(&ntp_lock, flags);
+
+ /* clear everything */
+ ntp_status |= STA_UNSYNC;
+ ntp_maxerror = NTP_PHASE_LIMIT;
+ ntp_esterror = NTP_PHASE_LIMIT;
+ ss_offset_len = 0;
+ singleshot_adj = 0;
+ tick_adj = 0;
+ offset_adj =0;
+
+ write_sequnlock_irqrestore(&ntp_lock, flags);
+}
+
+/**
+ * get_ntp_status - Returns the NTP status value
+ *
+ */
+int get_ntp_status(void)
+{
+ return ntp_status;
+}
+
Index: kernel/time.c
===================================================================
--- d414ab9a0f0995899c2e76c232714410f787b209/kernel/time.c (mode:100644)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/kernel/time.c (mode:100644)
@@ -38,6 +38,7 @@
#include <asm/uaccess.h>
#include <asm/unistd.h>
+#include <linux/timeofday.h>
/*
* The timezone where the local system is located. Used as a default by some
@@ -128,6 +129,7 @@
* as real UNIX machines always do it. This avoids all headaches about
* daylight saving times and warping kernel clocks.
*/
+#ifndef CONFIG_NEWTOD
inline static void warp_clock(void)
{
write_seqlock_irq(&xtime_lock);
@@ -137,6 +139,18 @@
write_sequnlock_irq(&xtime_lock);
clock_was_set();
}
+#else /* !CONFIG_NEWTOD */
+/* XXX - this is somewhat cracked out and should
+ be checked -johnstul@us.ibm.com
+*/
+inline static void warp_clock(void)
+{
+ struct timespec ts;
+ getnstimeofday(&ts);
+ ts.tv_sec += sys_tz.tz_minuteswest * 60;
+ do_settimeofday(&ts);
+}
+#endif /* !CONFIG_NEWTOD */
/*
* In case for some reason the CMOS clock has not already been running
@@ -227,6 +241,7 @@
/* adjtimex mainly allows reading (and writing, if superuser) of
* kernel time-keeping variables. used by xntpd.
*/
+#ifndef CONFIG_NEWTOD
int do_adjtimex(struct timex *txc)
{
long ltemp, mtemp, save_adjust;
@@ -410,6 +425,7 @@
notify_arch_cmos_timer();
return(result);
}
+#endif /* !CONFIG_NEWTOD */
asmlinkage long sys_adjtimex(struct timex __user *txc_p)
{
@@ -558,6 +574,7 @@
#else
+#ifndef CONFIG_NEWTOD
/*
* Simulate gettimeofday using do_gettimeofday which only allows a timeval
* and therefore only yields usec accuracy
@@ -570,6 +587,7 @@
tv->tv_sec = x.tv_sec;
tv->tv_nsec = x.tv_usec * NSEC_PER_USEC;
}
+#endif /* !CONFIG_NEWTOD */
#endif
#if (BITS_PER_LONG < 64)
Index: kernel/timeofday.c
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/kernel/timeofday.c (mode:100644)
@@ -0,0 +1,607 @@
+/*********************************************************************
+* linux/kernel/timeofday.c
+*
+* This file contains the functions which access and manage
+* the system's time of day functionality.
+*
+* Copyright (C) 2003, 2004, 2005 IBM, John Stultz (johnstul@us.ibm.com)
+*
+* This program is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation; either version 2 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program; if not, write to the Free Software
+* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*
+* Revision History:
+* 2004-09-02: A0
+* o First pass sent to lkml for review.
+* 2004-12-07: A1
+* o Rework of timesource structure
+* o Sent to lkml for review
+* 2005-01-24: A2
+* o write_seqlock_irq -> writeseqlock_irqsave
+* o arch generic interface for for get_cmos_time() equivalents
+* o suspend/resume hooks for sleep/hibernate (lightly tested)
+* o timesource adjust_callback hook
+* o Sent to lkml for review
+* 2005-03-11: A3
+* o periodic_hook (formerly interrupt_hook) now calle by softtimer
+* o yanked ntp_scale(), ntp adjustments are done in cyc2ns now
+* o sent to lkml for review
+* 2005-04-29: A4
+* o Improved the cyc2ns remainder handling
+* o Added getnstimeofday
+* o Cleanups from Nish Aravamudan
+* 2005-05-12: A5
+* o Added clock_was_set hooks
+* o Added suspend/resume sysfs hooks
+* o Minor code cleanups
+* o First attempt at docbook comments
+* 2005-05-31: B0
+* o Comment cleanups
+* o Rounding fixes
+*
+* TODO WishList:
+* o See XXX's below.
+**********************************************************************/
+
+#include <linux/timeofday.h>
+#include <linux/timesource.h>
+#include <linux/ntp.h>
+#include <linux/timex.h>
+#include <linux/timer.h>
+#include <linux/module.h>
+#include <linux/sched.h> /* Needed for capable() */
+#include <linux/sysdev.h>
+#include <linux/jiffies.h>
+#include <asm/timeofday.h>
+
+#define TIME_DBG 0
+#define TIME_DBG_FREQ 60000
+
+/* only run periodic_hook every 50ms */
+#define PERIODIC_INTERVAL_MS 50
+
+/*[Nanosecond based variables]
+ * system_time:
+ * Monotonically increasing counter of the number of nanoseconds
+ * since boot.
+ * wall_time_offset:
+ * Offset added to system_time to provide accurate time-of-day
+ */
+static nsec_t system_time;
+static nsec_t wall_time_offset;
+
+/*[Cycle based variables]
+ * offset_base:
+ * Value of the timesource at the last timeofday_periodic_hook()
+ * (adjusted only minorly to account for rounded off cycles)
+ */
+static cycle_t offset_base;
+
+/*[Time source data]
+ * timesource:
+ * current timesource pointer
+ */
+static struct timesource_t *timesource;
+
+/*[NTP adjustment]
+ * ntp_adj:
+ * value of the current ntp adjustment,
+ * stored in timesource multiplier units.
+ */
+int ntp_adj;
+
+/*[Locks]
+ * system_time_lock:
+ * generic lock for all locally scoped time values
+ */
+static seqlock_t system_time_lock = SEQLOCK_UNLOCKED;
+
+
+/*[Suspend/Resume info]
+ * time_suspend_state:
+ * variable that keeps track of suspend state
+ * suspend_start:
+ * start of the suspend call
+ */
+static enum {
+ TIME_RUNNING,
+ TIME_SUSPENDED
+} time_suspend_state = TIME_RUNNING;
+
+static nsec_t suspend_start;
+
+/* [Soft-Timers]
+ * timeofday_timer:
+ * soft-timer used to call timeofday_periodic_hook()
+ */
+struct timer_list timeofday_timer;
+
+
+/* [Functions]
+ */
+
+/**
+ * get_lowres_timestamp - Returns a low res timestamp
+ *
+ * Returns a low res timestamp w/ PERIODIC_INTERVAL_MS
+ * granularity. (ie: the value of system_time as
+ * calculated at the last invocation of
+ * timeofday_periodic_hook())
+ */
+nsec_t get_lowres_timestamp(void)
+{
+ nsec_t ret;
+ unsigned long seq;
+ do {
+ seq = read_seqbegin(&system_time_lock);
+
+ /* quickly grab system_time*/
+ ret = system_time;
+
+ } while (read_seqretry(&system_time_lock, seq));
+
+ return ret;
+}
+
+
+/**
+ * get_lowres_timeofday - Returns a low res time of day
+ *
+ * Returns a low res time of day, as calculated at the
+ * last invocation of timeofday_periodic_hook().
+ */
+nsec_t get_lowres_timeofday(void)
+{
+ nsec_t ret;
+ unsigned long seq;
+ do {
+ seq = read_seqbegin(&system_time_lock);
+
+ /* quickly calculate low-res time of day */
+ ret = system_time + wall_time_offset;
+
+ } while (read_seqretry(&system_time_lock, seq));
+
+ return ret;
+}
+
+
+/**
+ * update_legacy_time_values - Used to sync legacy time values
+ *
+ * Private function. Used to sync legacy time values to
+ * current timeofday. Assumes we have the system_time_lock.
+ * Hopefully someday this function can be removed.
+ */
+static void update_legacy_time_values(void)
+{
+ unsigned long flags;
+ write_seqlock_irqsave(&xtime_lock, flags);
+ xtime = ns_to_timespec(system_time + wall_time_offset);
+ wall_to_monotonic = ns_to_timespec(wall_time_offset);
+ set_normalized_timespec(&wall_to_monotonic,
+ -wall_to_monotonic.tv_sec, -wall_to_monotonic.tv_nsec);
+ /* We don't update jiffies here because it is its own time domain */
+ write_sequnlock_irqrestore(&xtime_lock, flags);
+}
+
+
+/**
+ * __monotonic_clock - Returns monotonically increasing nanoseconds
+ *
+ * private function, must hold system_time_lock lock when being
+ * called. Returns the monotonically increasing number of
+ * nanoseconds since the system booted (adjusted by NTP scaling)
+ */
+static inline nsec_t __monotonic_clock(void)
+{
+ nsec_t ret, ns_offset;
+ cycle_t now, cycle_delta;
+
+ /* read timesource */
+ now = read_timesource(timesource);
+
+ /* calculate the delta since the last timeofday_periodic_hook */
+ cycle_delta = (now - offset_base) & timesource->mask;
+
+ /* convert to nanoseconds */
+ ns_offset = cyc2ns(timesource, ntp_adj, cycle_delta);
+
+ /* add result to system time */
+ ret = system_time + ns_offset;
+
+ return ret;
+}
+
+
+/**
+ * do_monotonic_clock - Returns monotonically increasing nanoseconds
+ *
+ * Returns the monotonically increasing number of nanoseconds
+ * since the system booted via __monotonic_clock()
+ */
+nsec_t do_monotonic_clock(void)
+{
+ nsec_t ret;
+ unsigned long seq;
+
+ /* atomically read __monotonic_clock() */
+ do {
+ seq = read_seqbegin(&system_time_lock);
+
+ ret = __monotonic_clock();
+
+ } while (read_seqretry(&system_time_lock, seq));
+
+ return ret;
+}
+
+
+/**
+ * __gettimeofday - Returns the timeofday in nsec_t.
+ *
+ * Private function. Returns the timeofday in nsec_t.
+ */
+static inline nsec_t __gettimeofday(void)
+{
+ nsec_t wall, sys;
+ unsigned long seq;
+
+ /* atomically read wall and sys time */
+ do {
+ seq = read_seqbegin(&system_time_lock);
+
+ wall = wall_time_offset;
+ sys = __monotonic_clock();
+
+ } while (read_seqretry(&system_time_lock, seq));
+
+ return wall + sys;
+}
+
+
+/**
+ * getnstimeofday - Returns the time of day in a timespec
+ * @ts: pointer to the timespec to be set
+ *
+ * Returns the time of day in a timespec
+ * For consistency should be renamed
+ * later to do_getnstimeofday()
+ */
+void getnstimeofday(struct timespec *ts)
+{
+ *ts = ns_to_timespec(__gettimeofday());
+}
+EXPORT_SYMBOL(getnstimeofday);
+
+
+/**
+ * do_gettimeofday - Returns the time of day in a timeval
+ * @tv: pointer to the timeval to be set
+ *
+ */
+void do_gettimeofday(struct timeval *tv)
+{
+ *tv = ns_to_timeval(__gettimeofday());
+}
+EXPORT_SYMBOL(do_gettimeofday);
+
+
+/**
+ * do_settimeofday - Sets the time of day
+ * @tv: pointer to the timespec that will be used to set the time
+ *
+ */
+int do_settimeofday(struct timespec *tv)
+{
+ unsigned long flags;
+ nsec_t newtime = timespec_to_ns(tv);
+
+ /* atomically adjust wall_time_offset & clear ntp state machine */
+ write_seqlock_irqsave(&system_time_lock, flags);
+
+ wall_time_offset = newtime - __monotonic_clock();
+ ntp_clear();
+
+ update_legacy_time_values();
+
+ arch_update_vsyscall_gtod(system_time + wall_time_offset, offset_base,
+ timesource, ntp_adj);
+
+ write_sequnlock_irqrestore(&system_time_lock, flags);
+
+ /* signal posix-timers about time change */
+ clock_was_set();
+
+ return 0;
+}
+EXPORT_SYMBOL(do_settimeofday);
+
+
+/**
+ * do_adjtimex - interface to the kernel NTP variables
+ * @tx: pointer to the timex value that will be used
+ *
+ * Userspace NTP daemon's interface to the kernel NTP variables
+ */
+int do_adjtimex(struct timex *tx)
+{
+ /* Check capabilities if we're trying to modify something */
+ if (tx->modes && !capable(CAP_SYS_TIME))
+ return -EPERM;
+
+ /* Note: We set tx->time first,
+ * because ntp_adjtimex uses it
+ */
+ do_gettimeofday(&tx->time);
+
+ /* call out to NTP code */
+ return ntp_adjtimex(tx);
+}
+
+
+/**
+ * timeofday_suspend_hook - allows the timeofday subsystem to be shutdown
+ * @dev: unused
+ * state: unused
+ *
+ * This function allows the timeofday subsystem to
+ * be shutdown for a period of time. Usefull when
+ * going into suspend/hibernate mode. The code is
+ * very similar to the first half of
+ * timeofday_periodic_hook().
+ */
+static int timeofday_suspend_hook(struct sys_device *dev, u32 state)
+{
+ unsigned long flags;
+
+ write_seqlock_irqsave(&system_time_lock, flags);
+
+ /* Make sure time_suspend_state is sane */
+ BUG_ON(time_suspend_state != TIME_RUNNING);
+
+ /* First off, save suspend start time
+ * then quickly call __monotonic_clock.
+ * These two calls hopefully occur quickly
+ * because the difference between reads will
+ * accumulate as time drift on resume.
+ */
+ suspend_start = read_persistent_clock();
+ system_time = __monotonic_clock();
+
+ /* switch states */
+ time_suspend_state = TIME_SUSPENDED;
+
+ write_sequnlock_irqrestore(&system_time_lock, flags);
+ return 0;
+}
+
+
+/**
+ * timeofday_resume_hook - Resumes the timeofday subsystem.
+ * @dev: unused
+ *
+ * This function resumes the timeofday subsystem
+ * from a previous call to timeofday_suspend_hook.
+ */
+static int timeofday_resume_hook(struct sys_device *dev)
+{
+ nsec_t now, suspend_time;
+ unsigned long flags;
+
+ write_seqlock_irqsave(&system_time_lock, flags);
+
+ /* Make sure time_suspend_state is sane */
+ BUG_ON(time_suspend_state != TIME_SUSPENDED);
+
+ /* Read persistent clock to mark the end of
+ * the suspend interval then rebase the
+ * offset_base to current timesource value.
+ * Again, time between these two calls will
+ * not be accounted for and will show up as
+ * time drift.
+ */
+ now = read_persistent_clock();
+ offset_base = read_timesource(timesource);
+
+ /* calculate how long we were out for */
+ suspend_time = now - suspend_start;
+
+ /* update system_time */
+ system_time += suspend_time;
+
+ ntp_clear();
+
+ /* Set us back to running */
+ time_suspend_state = TIME_RUNNING;
+
+ /* finally, update legacy time values */
+ update_legacy_time_values();
+
+ write_sequnlock_irqrestore(&system_time_lock, flags);
+
+ /* signal posix-timers about time change */
+ clock_was_set();
+
+ return 0;
+}
+
+/* sysfs resume/suspend bits */
+static struct sysdev_class timeofday_sysclass = {
+ .resume = timeofday_resume_hook,
+ .suspend = timeofday_suspend_hook,
+ set_kset_name("timeofday"),
+};
+static struct sys_device device_timer = {
+ .id = 0,
+ .cls = &timeofday_sysclass,
+};
+static int timeofday_init_device(void)
+{
+ int error = sysdev_class_register(&timeofday_sysclass);
+ if (!error)
+ error = sysdev_register(&device_timer);
+ return error;
+}
+device_initcall(timeofday_init_device);
+
+/**
+ * timeofday_periodic_hook - Does periodic update of timekeeping values.
+ * unused: unused
+ *
+ * Calculates the delta since the last call,
+ * updates system time and clears the offset.
+ *
+ * Called via timeofday_timer.
+ */
+static void timeofday_periodic_hook(unsigned long unused)
+{
+ cycle_t now, cycle_delta;
+ static u64 remainder;
+ nsec_t ns, ns_ntp;
+ long leapsecond;
+ struct timesource_t* next;
+ unsigned long flags;
+ u64 tmp;
+ int ppm;
+
+ write_seqlock_irqsave(&system_time_lock, flags);
+
+ /* read time source & calc time since last call*/
+ now = read_timesource(timesource);
+ cycle_delta = (now - offset_base) & timesource->mask;
+
+ /* convert cycles to ntp adjusted ns and save remainder */
+ ns_ntp = cyc2ns_rem(timesource, ntp_adj, cycle_delta, &remainder);
+
+ /* convert cycles to raw ns for ntp advance */
+ ns = cyc2ns(timesource, 0, cycle_delta);
+
+#if TIME_DBG
+ static int dbg=0;
+ if(!(dbg++%TIME_DBG_FREQ)){
+ printk(KERN_INFO "now: %lluc - then: %lluc = delta: %lluc -> %llu ns + %llu shift_ns (ntp_adj: %i)\n",
+ (unsigned long long)now, (unsigned long long)offset_base,
+ (unsigned long long)cycle_delta, (unsigned long long)ns,
+ (unsigned long long)remainder, ntp_adj);
+ }
+}
+#endif
+
+ /* update system_time */
+ system_time += ns_ntp;
+
+ /* reset the offset_base */
+ offset_base = now;
+
+ /* advance the ntp state machine by ns interval*/
+ ppm = ntp_advance(ns);
+
+ /* do ntp leap second processing*/
+ leapsecond = ntp_leapsecond(ns_to_timespec(system_time+wall_time_offset));
+ wall_time_offset += leapsecond * NSEC_PER_SEC;
+
+ /* sync the persistent clock */
+ if (!(get_ntp_status() & STA_UNSYNC))
+ sync_persistent_clock(ns_to_timespec(system_time + wall_time_offset));
+
+ /* if necessary, switch timesources */
+ next = get_next_timesource();
+ if (next != timesource) {
+ /* immediately set new offset_base */
+ offset_base = read_timesource(next);
+ /* swap timesources */
+ timesource = next;
+ printk(KERN_INFO "Time: %s timesource has been installed.\n",
+ timesource->name);
+ ntp_clear();
+ ntp_adj = 0;
+ remainder = 0;
+ }
+
+ /* now is a safe time, so allow timesource to adjust
+ * itself (for example: to make cpufreq changes).
+ */
+ if(timesource->update_callback)
+ timesource->update_callback();
+
+
+ /* Convert the signed ppm to timesource multiplier adjustment */
+ tmp = abs(ppm);
+ tmp = tmp * timesource->mult;
+ tmp += 1000000/2; /* round for div*/
+ do_div(tmp, 1000000);
+ if (ppm < 0)
+ ntp_adj = -(int)tmp;
+ else
+ ntp_adj = (int)tmp;
+
+ /* sync legacy values */
+ update_legacy_time_values();
+
+ arch_update_vsyscall_gtod(system_time + wall_time_offset, offset_base,
+ timesource, ntp_adj);
+
+ write_sequnlock_irqrestore(&system_time_lock, flags);
+
+ /* XXX - Do we need to call clock_was_set() here? */
+
+ /* Set us up to go off on the next interval */
+ mod_timer(&timeofday_timer,
+ jiffies + msecs_to_jiffies(PERIODIC_INTERVAL_MS));
+}
+
+
+/**
+ * timeofday_init - Initializes time variables
+ *
+ */
+void __init timeofday_init(void)
+{
+ unsigned long flags;
+#if TIME_DBG
+ printk(KERN_INFO "timeofday_init: Starting up!\n");
+#endif
+ write_seqlock_irqsave(&system_time_lock, flags);
+
+ /* initialize the timesource variable */
+ timesource = get_next_timesource();
+
+ /* clear and initialize offsets*/
+ offset_base = read_timesource(timesource);
+ wall_time_offset = read_persistent_clock();
+
+ /* clear NTP scaling factor & state machine */
+ ntp_adj = 0;
+ ntp_clear();
+
+ arch_update_vsyscall_gtod(system_time + wall_time_offset, offset_base,
+ timesource, ntp_adj);
+
+ /* initialize legacy time values */
+ update_legacy_time_values();
+
+ write_sequnlock_irqrestore(&system_time_lock, flags);
+
+ /* Install timeofday_periodic_hook timer */
+ init_timer(&timeofday_timer);
+ timeofday_timer.function = timeofday_periodic_hook;
+ timeofday_timer.expires = jiffies + 1;
+ add_timer(&timeofday_timer);
+
+
+#if TIME_DBG
+ printk(KERN_INFO "timeofday_init: finished!\n");
+#endif
+ return;
+}
Index: kernel/timer.c
===================================================================
--- d414ab9a0f0995899c2e76c232714410f787b209/kernel/timer.c (mode:100644)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/kernel/timer.c (mode:100644)
@@ -577,6 +577,7 @@
int tickadj = 500/HZ ? : 1; /* microsecs */
+#ifndef CONFIG_NEWTOD
/*
* phase-lock loop variables
*/
@@ -807,6 +808,9 @@
}
} while (ticks);
}
+#else /* !CONFIG_NEWTOD */
+#define update_wall_time(x)
+#endif /* !CONFIG_NEWTOD */
/*
* Called from the timer interrupt handler to charge one tick to the current
Index: kernel/timesource.c
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/kernel/timesource.c (mode:100644)
@@ -0,0 +1,237 @@
+/*********************************************************************
+* linux/kernel/timesource.c
+*
+* This file contains the functions which manage timesource drivers.
+*
+* Copyright (C) 2004, 2005 IBM, John Stultz (johnstul@us.ibm.com)
+*
+* This program is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation; either version 2 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program; if not, write to the Free Software
+* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*
+* Revision History:
+* 2004-12-07: A1
+* o Rework of timesource structure
+* o Sent to lkml for review
+* 2005-04-29: A4
+* o Keep track of all registered timesources
+* o Add sysfs interface for overriding default selection
+* 2005-05-12: A5
+* o Add boot-time timesource= option for timesource overrides
+* TODO WishList:
+* o Allow timesource drivers to be unregistered
+* o get rid of timesource_jiffies extern
+**********************************************************************/
+
+#include <linux/timesource.h>
+#include <linux/sysdev.h>
+#include <linux/init.h>
+#include <linux/module.h>
+
+#define MAX_TIMESOURCES 10
+
+
+/* XXX - Would like a better way for initializing curr_timesource */
+extern struct timesource_t timesource_jiffies;
+
+/*[Timesource internal variables]---------
+ * curr_timesource:
+ * currently selected timesource. Initialized to timesource_jiffies.
+ * next_timesource:
+ * pending next selected timesource.
+ * timesource_list:
+ * array of pointers pointing to registered timesources
+ * timesource_list_counter:
+ * value which counts the number of registered timesources
+ * timesource_lock:
+ * protects manipulations to curr_timesource and next_timesource
+ * and the timesource_list
+ */
+static struct timesource_t *curr_timesource = ×ource_jiffies;
+static struct timesource_t *next_timesource;
+static struct timesource_t *timesource_list[MAX_TIMESOURCES];
+static int timesource_list_counter;
+static seqlock_t timesource_lock = SEQLOCK_UNLOCKED;
+
+static char override_name[32];
+
+/**
+ * get_next_timesource - Returns the selected timesource
+ *
+ */
+struct timesource_t* get_next_timesource(void)
+{
+ write_seqlock(×ource_lock);
+ if (next_timesource) {
+ curr_timesource = next_timesource;
+ next_timesource = NULL;
+ }
+ write_sequnlock(×ource_lock);
+
+ return curr_timesource;
+}
+
+/**
+ * select_timesource - Finds the best registered timesource.
+ *
+ * Private function. Must have a writelock on timesource_lock
+ * when called.
+ */
+static struct timesource_t* select_timesource(void)
+{
+ struct timesource_t* best = timesource_list[0];
+ int i;
+
+ for (i=0; i < timesource_list_counter; i++) {
+ /* Check for override */
+ if ((override_name[0] != 0) &&
+ (!strncmp(timesource_list[i]->name, override_name,
+ strlen(override_name)))) {
+ best = timesource_list[i];
+ break;
+ }
+ /* Pick the highest priority */
+ if (timesource_list[i]->priority > best->priority)
+ best = timesource_list[i];
+ }
+ return best;
+}
+
+/**
+ * register_timesource - Used to install new timesources
+ * @t: timesource to be registered
+ *
+ */
+void register_timesource(struct timesource_t* t)
+{
+ char* error_msg = 0;
+ int i;
+ write_seqlock(×ource_lock);
+
+ /* check if timesource is already registered */
+ for (i=0; i < timesource_list_counter; i++)
+ if (!strncmp(timesource_list[i]->name, t->name, strlen(t->name))){
+ error_msg = "Already registered!";
+ break;
+ }
+
+ /* check that the list isn't full */
+ if (timesource_list_counter >= MAX_TIMESOURCES)
+ error_msg = "Too many timesources!";
+
+ if(!error_msg)
+ timesource_list[timesource_list_counter++] = t;
+ else
+ printk("register_timesource: Cannot register %s. %s\n",
+ t->name, error_msg);
+
+ /* select next timesource */
+ next_timesource = select_timesource();
+
+ write_sequnlock(×ource_lock);
+}
+EXPORT_SYMBOL(register_timesource);
+
+/**
+ * sysfs_show_timesources - sysfs interface for listing timesource
+ * @dev: unused
+ * @buf: char buffer to be filled with timesource list
+ *
+ * Provides sysfs interface for listing registered timesources
+ */
+static ssize_t sysfs_show_timesources(struct sys_device *dev, char *buf)
+{
+ int i;
+ char* curr = buf;
+ write_seqlock(×ource_lock);
+ for(i=0; i < timesource_list_counter; i++) {
+ /* Mark current timesource w/ a star */
+ if (timesource_list[i] == curr_timesource)
+ curr += sprintf(curr, "*");
+ curr += sprintf(curr, "%s ",timesource_list[i]->name);
+ }
+ write_sequnlock(×ource_lock);
+
+ curr += sprintf(curr, "\n");
+ return curr - buf;
+}
+
+/**
+ * sysfs_override_timesource - interface for manually overriding timesource
+ * @dev: unused
+ * @buf: name of override timesource
+ *
+ *
+ * Takes input from sysfs interface for manually overriding
+ * the default timesource selction
+ */
+static ssize_t sysfs_override_timesource(struct sys_device *dev,
+ const char *buf, size_t count)
+{
+ /* check to avoid underflow later */
+ if (strlen(buf) == 0)
+ return count;
+
+ write_seqlock(×ource_lock);
+
+ /* copy the name given */
+ strncpy(override_name, buf, strlen(buf)-1);
+ override_name[strlen(buf)-1] = 0;
+
+ /* see if we can find it */
+ next_timesource = select_timesource();
+
+ write_sequnlock(×ource_lock);
+ return count;
+}
+
+/* Sysfs setup bits:
+ */
+static SYSDEV_ATTR(timesource, 0600, sysfs_show_timesources, sysfs_override_timesource);
+
+static struct sysdev_class timesource_sysclass = {
+ set_kset_name("timesource"),
+};
+
+static struct sys_device device_timesource = {
+ .id = 0,
+ .cls = ×ource_sysclass,
+};
+
+static int init_timesource_sysfs(void)
+{
+ int error = sysdev_class_register(×ource_sysclass);
+ if (!error) {
+ error = sysdev_register(&device_timesource);
+ if (!error)
+ error = sysdev_create_file(&device_timesource, &attr_timesource);
+ }
+ return error;
+}
+device_initcall(init_timesource_sysfs);
+
+
+/**
+ * boot_override_timesource - boot time override
+ * @str: override name
+ *
+ * Takes a timesource= boot argument and uses it
+ * as the timesource override name
+ */
+static int __init boot_override_timesource(char* str)
+{
+ if (str)
+ strlcpy(override_name, str, sizeof(override_name));
+ return 1;
+}
+__setup("timesource=", boot_override_timesource);
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 2/4] new timeofday i386 arch specific changes (v. B1)
2005-06-01 23:09 [PATCH 1/4] new timeofday core subsystem (v. B1) john stultz
@ 2005-06-01 23:12 ` john stultz
2005-06-01 23:13 ` [PATCH 3/4] new timeofday x86-64 " john stultz
2005-06-02 1:08 ` [PATCH 1/4] new timeofday core subsystem " Frank Sorenson
2005-06-03 7:29 ` Frank Sorenson
2 siblings, 1 reply; 11+ messages in thread
From: john stultz @ 2005-06-01 23:12 UTC (permalink / raw)
To: Andrew Morton
Cc: lkml, Tim Schmielau, George Anzinger, albert, Ulrich Windl,
Christoph Lameter, Dominik Brodowski, David Mosberger, Andi Kleen,
paulus, schwidefsky, keith maanthey, Chris McDermott, Max Asbock,
mahuja, Nishanth Aravamudan, Darren Hart, Darrick J. Wong,
Anton Blanchard, donf, mpm, benh
Andrew, All,
I'm just re-spinning this to resolve a conflict w/ the CPUFREQ changes
Linus accepted last night.
This patch converts the i386 arch to use the new timeofday
infrastructure. It applies on top of my timeofday-core_B1 patch. This is
a full conversion, so most of this patch is subtractions removing the
existing arch specific time keeping code. This patch does not provide
any i386 timesources, so using this patch alone on top of the timeofday-
core patch will only give you the jiffies timesource. To get full
replacements for the code being removed here, the following timeofday-
timesources-i386 patch will need to be applied.
Andrew, please consider for inclusion for testing into your tree (I'd
like to target around end of July for possible inclusion into mainline).
thanks
-john
Signed-off-by: John Stultz <johnstul@us.ibm.com>
linux-2.6.12-rc5_timeofday-arch-i386_B1.patch
=============================================
Index: arch/i386/Kconfig
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/Kconfig (mode:100644)
+++ 6f1948595e5fa374fc552a4a01fe5524530ea1dd/arch/i386/Kconfig (mode:100644)
@@ -14,6 +14,10 @@
486, 586, Pentiums, and various instruction-set-compatible chips by
AMD, Cyrix, and others.
+config NEWTOD
+ bool
+ default y
+
config MMU
bool
default y
Index: arch/i386/kernel/Makefile
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/kernel/Makefile (mode:100644)
+++ 6f1948595e5fa374fc552a4a01fe5524530ea1dd/arch/i386/kernel/Makefile (mode:100644)
@@ -7,10 +7,9 @@
obj-y := process.o semaphore.o signal.o entry.o traps.o irq.o vm86.o \
ptrace.o time.o ioport.o ldt.o setup.o i8259.o sys_i386.o \
pci-dma.o i386_ksyms.o i387.o dmi_scan.o bootflag.o \
- doublefault.o quirks.o
+ doublefault.o quirks.o tsc.o
obj-y += cpu/
-obj-y += timers/
obj-$(CONFIG_ACPI_BOOT) += acpi/
obj-$(CONFIG_X86_BIOS_REBOOT) += reboot.o
obj-$(CONFIG_MCA) += mca.o
Index: arch/i386/kernel/i8259.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/kernel/i8259.c (mode:100644)
+++ 6f1948595e5fa374fc552a4a01fe5524530ea1dd/arch/i386/kernel/i8259.c (mode:100644)
@@ -387,6 +387,48 @@
}
}
+#ifdef CONFIG_NEWTOD
+void setup_pit_timer(void)
+{
+ extern spinlock_t i8253_lock;
+ unsigned long flags;
+
+ spin_lock_irqsave(&i8253_lock, flags);
+ outb_p(0x34,PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
+ udelay(10);
+ outb_p(LATCH & 0xff , PIT_CH0); /* LSB */
+ udelay(10);
+ outb(LATCH >> 8 , PIT_CH0); /* MSB */
+ spin_unlock_irqrestore(&i8253_lock, flags);
+}
+
+static int timer_resume(struct sys_device *dev)
+{
+ setup_pit_timer();
+ return 0;
+}
+
+static struct sysdev_class timer_sysclass = {
+ set_kset_name("timer_pit"),
+ .resume = timer_resume,
+};
+
+static struct sys_device device_timer = {
+ .id = 0,
+ .cls = &timer_sysclass,
+};
+
+static int __init init_timer_sysfs(void)
+{
+ int error = sysdev_class_register(&timer_sysclass);
+ if (!error)
+ error = sysdev_register(&device_timer);
+ return error;
+}
+
+device_initcall(init_timer_sysfs);
+#endif
+
void __init init_IRQ(void)
{
int i;
Index: arch/i386/kernel/setup.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/kernel/setup.c (mode:100644)
+++ 6f1948595e5fa374fc552a4a01fe5524530ea1dd/arch/i386/kernel/setup.c (mode:100644)
@@ -1525,6 +1525,7 @@
conswitchp = &dummy_con;
#endif
#endif
+ tsc_init();
}
#include "setup_arch_post.h"
Index: arch/i386/kernel/time.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/kernel/time.c (mode:100644)
+++ 6f1948595e5fa374fc552a4a01fe5524530ea1dd/arch/i386/kernel/time.c (mode:100644)
@@ -56,6 +56,7 @@
#include <asm/uaccess.h>
#include <asm/processor.h>
#include <asm/timer.h>
+#include <asm/timeofday.h>
#include "mach_time.h"
@@ -86,8 +87,6 @@
DEFINE_SPINLOCK(i8253_lock);
EXPORT_SYMBOL(i8253_lock);
-struct timer_opts *cur_timer = &timer_none;
-
/*
* This is a special lock that is owned by the CPU and holds the index
* register we are working with. It is required for NMI access to the
@@ -117,102 +116,19 @@
}
EXPORT_SYMBOL(rtc_cmos_write);
-/*
- * This version of gettimeofday has microsecond resolution
- * and better than microsecond precision on fast x86 machines with TSC.
- */
-void do_gettimeofday(struct timeval *tv)
-{
- unsigned long seq;
- unsigned long usec, sec;
- unsigned long max_ntp_tick;
-
- do {
- unsigned long lost;
-
- seq = read_seqbegin(&xtime_lock);
-
- usec = cur_timer->get_offset();
- lost = jiffies - wall_jiffies;
-
- /*
- * If time_adjust is negative then NTP is slowing the clock
- * so make sure not to go into next possible interval.
- * Better to lose some accuracy than have time go backwards..
- */
- if (unlikely(time_adjust < 0)) {
- max_ntp_tick = (USEC_PER_SEC / HZ) - tickadj;
- usec = min(usec, max_ntp_tick);
-
- if (lost)
- usec += lost * max_ntp_tick;
- }
- else if (unlikely(lost))
- usec += lost * (USEC_PER_SEC / HZ);
-
- sec = xtime.tv_sec;
- usec += (xtime.tv_nsec / 1000);
- } while (read_seqretry(&xtime_lock, seq));
-
- while (usec >= 1000000) {
- usec -= 1000000;
- sec++;
- }
-
- tv->tv_sec = sec;
- tv->tv_usec = usec;
-}
-
-EXPORT_SYMBOL(do_gettimeofday);
-
-int do_settimeofday(struct timespec *tv)
-{
- time_t wtm_sec, sec = tv->tv_sec;
- long wtm_nsec, nsec = tv->tv_nsec;
-
- if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
- return -EINVAL;
-
- write_seqlock_irq(&xtime_lock);
- /*
- * This is revolting. We need to set "xtime" correctly. However, the
- * value in this location is the value at the most recent update of
- * wall time. Discover what correction gettimeofday() would have
- * made, and then undo it!
- */
- nsec -= cur_timer->get_offset() * NSEC_PER_USEC;
- nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
-
- wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
- wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
-
- set_normalized_timespec(&xtime, sec, nsec);
- set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
-
- time_adjust = 0; /* stop active adjtime() */
- time_status |= STA_UNSYNC;
- time_maxerror = NTP_PHASE_LIMIT;
- time_esterror = NTP_PHASE_LIMIT;
- write_sequnlock_irq(&xtime_lock);
- clock_was_set();
- return 0;
-}
-
-EXPORT_SYMBOL(do_settimeofday);
-
static int set_rtc_mmss(unsigned long nowtime)
{
int retval;
-
- WARN_ON(irqs_disabled());
+ unsigned long flags;
/* gets recalled with irq locally disabled */
- spin_lock_irq(&rtc_lock);
+ /* XXX - does irqsave resolve this? -johnstul */
+ spin_lock_irqsave(&rtc_lock, flags);
if (efi_enabled)
retval = efi_set_rtc_mmss(nowtime);
else
retval = mach_set_rtc_mmss(nowtime);
- spin_unlock_irq(&rtc_lock);
+ spin_unlock_irqrestore(&rtc_lock, flags);
return retval;
}
@@ -220,16 +136,6 @@
int timer_ack;
-/* monotonic_clock(): returns # of nanoseconds passed since time_init()
- * Note: This function is required to return accurate
- * time even in the absence of multiple timer ticks.
- */
-unsigned long long monotonic_clock(void)
-{
- return cur_timer->monotonic_clock();
-}
-EXPORT_SYMBOL(monotonic_clock);
-
#if defined(CONFIG_SMP) && defined(CONFIG_FRAME_POINTER)
unsigned long profile_pc(struct pt_regs *regs)
{
@@ -244,12 +150,21 @@
#endif
/*
- * timer_interrupt() needs to keep up the real-time clock,
- * as well as call the "do_timer()" routine every clocktick
+ * This is the same as the above, except we _also_ save the current
+ * Time Stamp Counter value at the time of the timer interrupt, so that
+ * we later on can estimate the time of day more exactly.
*/
-static inline void do_timer_interrupt(int irq, void *dev_id,
- struct pt_regs *regs)
+irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
+ /*
+ * Here we are in the timer irq handler. We just have irqs locally
+ * disabled but we don't know if the timer_bh is running on the other
+ * CPU. We need to avoid to SMP race with it. NOTE: we don' t need
+ * the irq version of write_lock because as just said we have irq
+ * locally disabled. -arca
+ */
+ write_seqlock(&xtime_lock);
+
#ifdef CONFIG_X86_IO_APIC
if (timer_ack) {
/*
@@ -282,27 +197,6 @@
irq = inb_p( 0x61 ); /* read the current state */
outb_p( irq|0x80, 0x61 ); /* reset the IRQ */
}
-}
-
-/*
- * This is the same as the above, except we _also_ save the current
- * Time Stamp Counter value at the time of the timer interrupt, so that
- * we later on can estimate the time of day more exactly.
- */
-irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
-{
- /*
- * Here we are in the timer irq handler. We just have irqs locally
- * disabled but we don't know if the timer_bh is running on the other
- * CPU. We need to avoid to SMP race with it. NOTE: we don' t need
- * the irq version of write_lock because as just said we have irq
- * locally disabled. -arca
- */
- write_seqlock(&xtime_lock);
-
- cur_timer->mark_offset();
-
- do_timer_interrupt(irq, NULL, regs);
write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
@@ -324,55 +218,35 @@
return retval;
}
-static void sync_cmos_clock(unsigned long dummy);
-
-static struct timer_list sync_cmos_timer =
- TIMER_INITIALIZER(sync_cmos_clock, 0, 0);
-static void sync_cmos_clock(unsigned long dummy)
+/* arch specific timeofday hooks */
+nsec_t read_persistent_clock(void)
{
- struct timeval now, next;
- int fail = 1;
+ return (nsec_t)get_cmos_time() * NSEC_PER_SEC;
+}
+void sync_persistent_clock(struct timespec ts)
+{
+ static unsigned long last_rtc_update;
/*
* If we have an externally synchronized Linux clock, then update
* CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
* called as close as possible to 500 ms before the new second starts.
- * This code is run on a timer. If the clock is set, that timer
- * may not expire at the correct time. Thus, we adjust...
*/
- if ((time_status & STA_UNSYNC) != 0)
- /*
- * Not synced, exit, do not restart a timer (if one is
- * running, let it run out).
- */
+ if (ts.tv_sec <= last_rtc_update + 660)
return;
- do_gettimeofday(&now);
- if (now.tv_usec >= USEC_AFTER - ((unsigned) TICK_SIZE) / 2 &&
- now.tv_usec <= USEC_BEFORE + ((unsigned) TICK_SIZE) / 2)
- fail = set_rtc_mmss(now.tv_sec);
-
- next.tv_usec = USEC_AFTER - now.tv_usec;
- if (next.tv_usec <= 0)
- next.tv_usec += USEC_PER_SEC;
-
- if (!fail)
- next.tv_sec = 659;
- else
- next.tv_sec = 0;
-
- if (next.tv_usec >= USEC_PER_SEC) {
- next.tv_sec++;
- next.tv_usec -= USEC_PER_SEC;
+ if((ts.tv_nsec / 1000) >= USEC_AFTER - ((unsigned) TICK_SIZE) / 2 &&
+ (ts.tv_nsec / 1000) <= USEC_BEFORE + ((unsigned) TICK_SIZE) / 2) {
+ /* horrible...FIXME */
+ if (set_rtc_mmss(ts.tv_sec) == 0)
+ last_rtc_update = ts.tv_sec;
+ else
+ last_rtc_update = ts.tv_sec - 600; /* do it again in 60 s */
}
- mod_timer(&sync_cmos_timer, jiffies + timeval_to_jiffies(&next));
}
-void notify_arch_cmos_timer(void)
-{
- mod_timer(&sync_cmos_timer, jiffies + 1);
-}
+
static long clock_cmos_diff, sleep_start;
@@ -389,7 +263,6 @@
static int timer_resume(struct sys_device *dev)
{
- unsigned long flags;
unsigned long sec;
unsigned long sleep_length;
@@ -399,10 +272,6 @@
#endif
sec = get_cmos_time() + clock_cmos_diff;
sleep_length = (get_cmos_time() - sleep_start) * HZ;
- write_seqlock_irqsave(&xtime_lock, flags);
- xtime.tv_sec = sec;
- xtime.tv_nsec = 0;
- write_sequnlock_irqrestore(&xtime_lock, flags);
jiffies += sleep_length;
wall_jiffies += sleep_length;
return 0;
@@ -436,17 +305,10 @@
/* Duplicate of time_init() below, with hpet_enable part added */
static void __init hpet_time_init(void)
{
- xtime.tv_sec = get_cmos_time();
- xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
- set_normalized_timespec(&wall_to_monotonic,
- -xtime.tv_sec, -xtime.tv_nsec);
-
if ((hpet_enable() >= 0) && hpet_use_timer) {
printk("Using HPET for base-timer\n");
}
- cur_timer = select_timer();
- printk(KERN_INFO "Using %s for high-res timesource\n",cur_timer->name);
time_init_hook();
}
@@ -464,13 +326,5 @@
return;
}
#endif
- xtime.tv_sec = get_cmos_time();
- xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
- set_normalized_timespec(&wall_to_monotonic,
- -xtime.tv_sec, -xtime.tv_nsec);
-
- cur_timer = select_timer();
- printk(KERN_INFO "Using %s for high-res timesource\n",cur_timer->name);
-
time_init_hook();
}
Index: arch/i386/kernel/timers/Makefile
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/kernel/timers/Makefile (mode:100644)
+++ /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
@@ -1,9 +0,0 @@
-#
-# Makefile for x86 timers
-#
-
-obj-y := timer.o timer_none.o timer_tsc.o timer_pit.o common.o
-
-obj-$(CONFIG_X86_CYCLONE_TIMER) += timer_cyclone.o
-obj-$(CONFIG_HPET_TIMER) += timer_hpet.o
-obj-$(CONFIG_X86_PM_TIMER) += timer_pm.o
Index: arch/i386/kernel/timers/common.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/kernel/timers/common.c (mode:100644)
+++ /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
@@ -1,162 +0,0 @@
-/*
- * Common functions used across the timers go here
- */
-
-#include <linux/init.h>
-#include <linux/timex.h>
-#include <linux/errno.h>
-#include <linux/jiffies.h>
-#include <linux/module.h>
-
-#include <asm/io.h>
-#include <asm/timer.h>
-#include <asm/hpet.h>
-
-#include "mach_timer.h"
-
-/* ------ Calibrate the TSC -------
- * Return 2^32 * (1 / (TSC clocks per usec)) for do_fast_gettimeoffset().
- * Too much 64-bit arithmetic here to do this cleanly in C, and for
- * accuracy's sake we want to keep the overhead on the CTC speaker (channel 2)
- * output busy loop as low as possible. We avoid reading the CTC registers
- * directly because of the awkward 8-bit access mechanism of the 82C54
- * device.
- */
-
-#define CALIBRATE_TIME (5 * 1000020/HZ)
-
-unsigned long calibrate_tsc(void)
-{
- mach_prepare_counter();
-
- {
- unsigned long startlow, starthigh;
- unsigned long endlow, endhigh;
- unsigned long count;
-
- rdtsc(startlow,starthigh);
- mach_countup(&count);
- rdtsc(endlow,endhigh);
-
-
- /* Error: ECTCNEVERSET */
- if (count <= 1)
- goto bad_ctc;
-
- /* 64-bit subtract - gcc just messes up with long longs */
- __asm__("subl %2,%0\n\t"
- "sbbl %3,%1"
- :"=a" (endlow), "=d" (endhigh)
- :"g" (startlow), "g" (starthigh),
- "0" (endlow), "1" (endhigh));
-
- /* Error: ECPUTOOFAST */
- if (endhigh)
- goto bad_ctc;
-
- /* Error: ECPUTOOSLOW */
- if (endlow <= CALIBRATE_TIME)
- goto bad_ctc;
-
- __asm__("divl %2"
- :"=a" (endlow), "=d" (endhigh)
- :"r" (endlow), "0" (0), "1" (CALIBRATE_TIME));
-
- return endlow;
- }
-
- /*
- * The CTC wasn't reliable: we got a hit on the very first read,
- * or the CPU was so fast/slow that the quotient wouldn't fit in
- * 32 bits..
- */
-bad_ctc:
- return 0;
-}
-
-#ifdef CONFIG_HPET_TIMER
-/* ------ Calibrate the TSC using HPET -------
- * Return 2^32 * (1 / (TSC clocks per usec)) for getting the CPU freq.
- * Second output is parameter 1 (when non NULL)
- * Set 2^32 * (1 / (tsc per HPET clk)) for delay_hpet().
- * calibrate_tsc() calibrates the processor TSC by comparing
- * it to the HPET timer of known frequency.
- * Too much 64-bit arithmetic here to do this cleanly in C
- */
-#define CALIBRATE_CNT_HPET (5 * hpet_tick)
-#define CALIBRATE_TIME_HPET (5 * KERNEL_TICK_USEC)
-
-unsigned long __init calibrate_tsc_hpet(unsigned long *tsc_hpet_quotient_ptr)
-{
- unsigned long tsc_startlow, tsc_starthigh;
- unsigned long tsc_endlow, tsc_endhigh;
- unsigned long hpet_start, hpet_end;
- unsigned long result, remain;
-
- hpet_start = hpet_readl(HPET_COUNTER);
- rdtsc(tsc_startlow, tsc_starthigh);
- do {
- hpet_end = hpet_readl(HPET_COUNTER);
- } while ((hpet_end - hpet_start) < CALIBRATE_CNT_HPET);
- rdtsc(tsc_endlow, tsc_endhigh);
-
- /* 64-bit subtract - gcc just messes up with long longs */
- __asm__("subl %2,%0\n\t"
- "sbbl %3,%1"
- :"=a" (tsc_endlow), "=d" (tsc_endhigh)
- :"g" (tsc_startlow), "g" (tsc_starthigh),
- "0" (tsc_endlow), "1" (tsc_endhigh));
-
- /* Error: ECPUTOOFAST */
- if (tsc_endhigh)
- goto bad_calibration;
-
- /* Error: ECPUTOOSLOW */
- if (tsc_endlow <= CALIBRATE_TIME_HPET)
- goto bad_calibration;
-
- ASM_DIV64_REG(result, remain, tsc_endlow, 0, CALIBRATE_TIME_HPET);
- if (remain > (tsc_endlow >> 1))
- result++; /* rounding the result */
-
- if (tsc_hpet_quotient_ptr) {
- unsigned long tsc_hpet_quotient;
-
- ASM_DIV64_REG(tsc_hpet_quotient, remain, tsc_endlow, 0,
- CALIBRATE_CNT_HPET);
- if (remain > (tsc_endlow >> 1))
- tsc_hpet_quotient++; /* rounding the result */
- *tsc_hpet_quotient_ptr = tsc_hpet_quotient;
- }
-
- return result;
-bad_calibration:
- /*
- * the CPU was so fast/slow that the quotient wouldn't fit in
- * 32 bits..
- */
- return 0;
-}
-#endif
-
-/* calculate cpu_khz */
-void init_cpu_khz(void)
-{
- if (cpu_has_tsc) {
- unsigned long tsc_quotient = calibrate_tsc();
- if (tsc_quotient) {
- /* report CPU clock rate in Hz.
- * The formula is (10^6 * 2^32) / (2^32 * 1 / (clocks/us)) =
- * clock/second. Our precision is about 100 ppm.
- */
- { unsigned long eax=0, edx=1000;
- __asm__("divl %2"
- :"=a" (cpu_khz), "=d" (edx)
- :"r" (tsc_quotient),
- "0" (eax), "1" (edx));
- printk("Detected %lu.%03lu MHz processor.\n", cpu_khz / 1000, cpu_khz % 1000);
- }
- }
- }
-}
-
Index: arch/i386/kernel/timers/timer.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/kernel/timers/timer.c (mode:100644)
+++ /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
@@ -1,66 +0,0 @@
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/string.h>
-#include <asm/timer.h>
-
-#ifdef CONFIG_HPET_TIMER
-/*
- * HPET memory read is slower than tsc reads, but is more dependable as it
- * always runs at constant frequency and reduces complexity due to
- * cpufreq. So, we prefer HPET timer to tsc based one. Also, we cannot use
- * timer_pit when HPET is active. So, we default to timer_tsc.
- */
-#endif
-/* list of timers, ordered by preference, NULL terminated */
-static struct init_timer_opts* __initdata timers[] = {
-#ifdef CONFIG_X86_CYCLONE_TIMER
- &timer_cyclone_init,
-#endif
-#ifdef CONFIG_HPET_TIMER
- &timer_hpet_init,
-#endif
-#ifdef CONFIG_X86_PM_TIMER
- &timer_pmtmr_init,
-#endif
- &timer_tsc_init,
- &timer_pit_init,
- NULL,
-};
-
-static char clock_override[10] __initdata;
-
-static int __init clock_setup(char* str)
-{
- if (str)
- strlcpy(clock_override, str, sizeof(clock_override));
- return 1;
-}
-__setup("clock=", clock_setup);
-
-
-/* The chosen timesource has been found to be bad.
- * Fall back to a known good timesource (the PIT)
- */
-void clock_fallback(void)
-{
- cur_timer = &timer_pit;
-}
-
-/* iterates through the list of timers, returning the first
- * one that initializes successfully.
- */
-struct timer_opts* __init select_timer(void)
-{
- int i = 0;
-
- /* find most preferred working timer */
- while (timers[i]) {
- if (timers[i]->init)
- if (timers[i]->init(clock_override) == 0)
- return timers[i]->opts;
- ++i;
- }
-
- panic("select_timer: Cannot find a suitable timer\n");
- return NULL;
-}
Index: arch/i386/kernel/timers/timer_cyclone.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/kernel/timers/timer_cyclone.c (mode:100644)
+++ /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
@@ -1,259 +0,0 @@
-/* Cyclone-timer:
- * This code implements timer_ops for the cyclone counter found
- * on IBM x440, x360, and other Summit based systems.
- *
- * Copyright (C) 2002 IBM, John Stultz (johnstul@us.ibm.com)
- */
-
-
-#include <linux/spinlock.h>
-#include <linux/init.h>
-#include <linux/timex.h>
-#include <linux/errno.h>
-#include <linux/string.h>
-#include <linux/jiffies.h>
-
-#include <asm/timer.h>
-#include <asm/io.h>
-#include <asm/pgtable.h>
-#include <asm/fixmap.h>
-#include "io_ports.h"
-
-extern spinlock_t i8253_lock;
-
-/* Number of usecs that the last interrupt was delayed */
-static int delay_at_last_interrupt;
-
-#define CYCLONE_CBAR_ADDR 0xFEB00CD0
-#define CYCLONE_PMCC_OFFSET 0x51A0
-#define CYCLONE_MPMC_OFFSET 0x51D0
-#define CYCLONE_MPCS_OFFSET 0x51A8
-#define CYCLONE_TIMER_FREQ 100000000
-#define CYCLONE_TIMER_MASK (((u64)1<<40)-1) /* 40 bit mask */
-int use_cyclone = 0;
-
-static u32* volatile cyclone_timer; /* Cyclone MPMC0 register */
-static u32 last_cyclone_low;
-static u32 last_cyclone_high;
-static unsigned long long monotonic_base;
-static seqlock_t monotonic_lock = SEQLOCK_UNLOCKED;
-
-/* helper macro to atomically read both cyclone counter registers */
-#define read_cyclone_counter(low,high) \
- do{ \
- high = cyclone_timer[1]; low = cyclone_timer[0]; \
- } while (high != cyclone_timer[1]);
-
-
-static void mark_offset_cyclone(void)
-{
- unsigned long lost, delay;
- unsigned long delta = last_cyclone_low;
- int count;
- unsigned long long this_offset, last_offset;
-
- write_seqlock(&monotonic_lock);
- last_offset = ((unsigned long long)last_cyclone_high<<32)|last_cyclone_low;
-
- spin_lock(&i8253_lock);
- read_cyclone_counter(last_cyclone_low,last_cyclone_high);
-
- /* read values for delay_at_last_interrupt */
- outb_p(0x00, 0x43); /* latch the count ASAP */
-
- count = inb_p(0x40); /* read the latched count */
- count |= inb(0x40) << 8;
-
- /*
- * VIA686a test code... reset the latch if count > max + 1
- * from timer_pit.c - cjb
- */
- if (count > LATCH) {
- outb_p(0x34, PIT_MODE);
- outb_p(LATCH & 0xff, PIT_CH0);
- outb(LATCH >> 8, PIT_CH0);
- count = LATCH - 1;
- }
- spin_unlock(&i8253_lock);
-
- /* lost tick compensation */
- delta = last_cyclone_low - delta;
- delta /= (CYCLONE_TIMER_FREQ/1000000);
- delta += delay_at_last_interrupt;
- lost = delta/(1000000/HZ);
- delay = delta%(1000000/HZ);
- if (lost >= 2)
- jiffies_64 += lost-1;
-
- /* update the monotonic base value */
- this_offset = ((unsigned long long)last_cyclone_high<<32)|last_cyclone_low;
- monotonic_base += (this_offset - last_offset) & CYCLONE_TIMER_MASK;
- write_sequnlock(&monotonic_lock);
-
- /* calculate delay_at_last_interrupt */
- count = ((LATCH-1) - count) * TICK_SIZE;
- delay_at_last_interrupt = (count + LATCH/2) / LATCH;
-
-
- /* catch corner case where tick rollover occured
- * between cyclone and pit reads (as noted when
- * usec delta is > 90% # of usecs/tick)
- */
- if (lost && abs(delay - delay_at_last_interrupt) > (900000/HZ))
- jiffies_64++;
-}
-
-static unsigned long get_offset_cyclone(void)
-{
- u32 offset;
-
- if(!cyclone_timer)
- return delay_at_last_interrupt;
-
- /* Read the cyclone timer */
- offset = cyclone_timer[0];
-
- /* .. relative to previous jiffy */
- offset = offset - last_cyclone_low;
-
- /* convert cyclone ticks to microseconds */
- /* XXX slow, can we speed this up? */
- offset = offset/(CYCLONE_TIMER_FREQ/1000000);
-
- /* our adjusted time offset in microseconds */
- return delay_at_last_interrupt + offset;
-}
-
-static unsigned long long monotonic_clock_cyclone(void)
-{
- u32 now_low, now_high;
- unsigned long long last_offset, this_offset, base;
- unsigned long long ret;
- unsigned seq;
-
- /* atomically read monotonic base & last_offset */
- do {
- seq = read_seqbegin(&monotonic_lock);
- last_offset = ((unsigned long long)last_cyclone_high<<32)|last_cyclone_low;
- base = monotonic_base;
- } while (read_seqretry(&monotonic_lock, seq));
-
-
- /* Read the cyclone counter */
- read_cyclone_counter(now_low,now_high);
- this_offset = ((unsigned long long)now_high<<32)|now_low;
-
- /* convert to nanoseconds */
- ret = base + ((this_offset - last_offset)&CYCLONE_TIMER_MASK);
- return ret * (1000000000 / CYCLONE_TIMER_FREQ);
-}
-
-static int __init init_cyclone(char* override)
-{
- u32* reg;
- u32 base; /* saved cyclone base address */
- u32 pageaddr; /* page that contains cyclone_timer register */
- u32 offset; /* offset from pageaddr to cyclone_timer register */
- int i;
-
- /* check clock override */
- if (override[0] && strncmp(override,"cyclone",7))
- return -ENODEV;
-
- /*make sure we're on a summit box*/
- if(!use_cyclone) return -ENODEV;
-
- printk(KERN_INFO "Summit chipset: Starting Cyclone Counter.\n");
-
- /* find base address */
- pageaddr = (CYCLONE_CBAR_ADDR)&PAGE_MASK;
- offset = (CYCLONE_CBAR_ADDR)&(~PAGE_MASK);
- set_fixmap_nocache(FIX_CYCLONE_TIMER, pageaddr);
- reg = (u32*)(fix_to_virt(FIX_CYCLONE_TIMER) + offset);
- if(!reg){
- printk(KERN_ERR "Summit chipset: Could not find valid CBAR register.\n");
- return -ENODEV;
- }
- base = *reg;
- if(!base){
- printk(KERN_ERR "Summit chipset: Could not find valid CBAR value.\n");
- return -ENODEV;
- }
-
- /* setup PMCC */
- pageaddr = (base + CYCLONE_PMCC_OFFSET)&PAGE_MASK;
- offset = (base + CYCLONE_PMCC_OFFSET)&(~PAGE_MASK);
- set_fixmap_nocache(FIX_CYCLONE_TIMER, pageaddr);
- reg = (u32*)(fix_to_virt(FIX_CYCLONE_TIMER) + offset);
- if(!reg){
- printk(KERN_ERR "Summit chipset: Could not find valid PMCC register.\n");
- return -ENODEV;
- }
- reg[0] = 0x00000001;
-
- /* setup MPCS */
- pageaddr = (base + CYCLONE_MPCS_OFFSET)&PAGE_MASK;
- offset = (base + CYCLONE_MPCS_OFFSET)&(~PAGE_MASK);
- set_fixmap_nocache(FIX_CYCLONE_TIMER, pageaddr);
- reg = (u32*)(fix_to_virt(FIX_CYCLONE_TIMER) + offset);
- if(!reg){
- printk(KERN_ERR "Summit chipset: Could not find valid MPCS register.\n");
- return -ENODEV;
- }
- reg[0] = 0x00000001;
-
- /* map in cyclone_timer */
- pageaddr = (base + CYCLONE_MPMC_OFFSET)&PAGE_MASK;
- offset = (base + CYCLONE_MPMC_OFFSET)&(~PAGE_MASK);
- set_fixmap_nocache(FIX_CYCLONE_TIMER, pageaddr);
- cyclone_timer = (u32*)(fix_to_virt(FIX_CYCLONE_TIMER) + offset);
- if(!cyclone_timer){
- printk(KERN_ERR "Summit chipset: Could not find valid MPMC register.\n");
- return -ENODEV;
- }
-
- /*quick test to make sure its ticking*/
- for(i=0; i<3; i++){
- u32 old = cyclone_timer[0];
- int stall = 100;
- while(stall--) barrier();
- if(cyclone_timer[0] == old){
- printk(KERN_ERR "Summit chipset: Counter not counting! DISABLED\n");
- cyclone_timer = 0;
- return -ENODEV;
- }
- }
-
- init_cpu_khz();
-
- /* Everything looks good! */
- return 0;
-}
-
-
-static void delay_cyclone(unsigned long loops)
-{
- unsigned long bclock, now;
- if(!cyclone_timer)
- return;
- bclock = cyclone_timer[0];
- do {
- rep_nop();
- now = cyclone_timer[0];
- } while ((now-bclock) < loops);
-}
-/************************************************************/
-
-/* cyclone timer_opts struct */
-static struct timer_opts timer_cyclone = {
- .name = "cyclone",
- .mark_offset = mark_offset_cyclone,
- .get_offset = get_offset_cyclone,
- .monotonic_clock = monotonic_clock_cyclone,
- .delay = delay_cyclone,
-};
-
-struct init_timer_opts __initdata timer_cyclone_init = {
- .init = init_cyclone,
- .opts = &timer_cyclone,
-};
Index: arch/i386/kernel/timers/timer_hpet.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/kernel/timers/timer_hpet.c (mode:100644)
+++ /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
@@ -1,194 +0,0 @@
-/*
- * This code largely moved from arch/i386/kernel/time.c.
- * See comments there for proper credits.
- */
-
-#include <linux/spinlock.h>
-#include <linux/init.h>
-#include <linux/timex.h>
-#include <linux/errno.h>
-#include <linux/string.h>
-#include <linux/jiffies.h>
-
-#include <asm/timer.h>
-#include <asm/io.h>
-#include <asm/processor.h>
-
-#include "io_ports.h"
-#include "mach_timer.h"
-#include <asm/hpet.h>
-
-static unsigned long hpet_usec_quotient; /* convert hpet clks to usec */
-static unsigned long tsc_hpet_quotient; /* convert tsc to hpet clks */
-static unsigned long hpet_last; /* hpet counter value at last tick*/
-static unsigned long last_tsc_low; /* lsb 32 bits of Time Stamp Counter */
-static unsigned long last_tsc_high; /* msb 32 bits of Time Stamp Counter */
-static unsigned long long monotonic_base;
-static seqlock_t monotonic_lock = SEQLOCK_UNLOCKED;
-
-/* convert from cycles(64bits) => nanoseconds (64bits)
- * basic equation:
- * ns = cycles / (freq / ns_per_sec)
- * ns = cycles * (ns_per_sec / freq)
- * ns = cycles * (10^9 / (cpu_mhz * 10^6))
- * ns = cycles * (10^3 / cpu_mhz)
- *
- * Then we use scaling math (suggested by george@mvista.com) to get:
- * ns = cycles * (10^3 * SC / cpu_mhz) / SC
- * ns = cycles * cyc2ns_scale / SC
- *
- * And since SC is a constant power of two, we can convert the div
- * into a shift.
- * -johnstul@us.ibm.com "math is hard, lets go shopping!"
- */
-static unsigned long cyc2ns_scale;
-#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
-
-static inline void set_cyc2ns_scale(unsigned long cpu_mhz)
-{
- cyc2ns_scale = (1000 << CYC2NS_SCALE_FACTOR)/cpu_mhz;
-}
-
-static inline unsigned long long cycles_2_ns(unsigned long long cyc)
-{
- return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
-}
-
-static unsigned long long monotonic_clock_hpet(void)
-{
- unsigned long long last_offset, this_offset, base;
- unsigned seq;
-
- /* atomically read monotonic base & last_offset */
- do {
- seq = read_seqbegin(&monotonic_lock);
- last_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
- base = monotonic_base;
- } while (read_seqretry(&monotonic_lock, seq));
-
- /* Read the Time Stamp Counter */
- rdtscll(this_offset);
-
- /* return the value in ns */
- return base + cycles_2_ns(this_offset - last_offset);
-}
-
-static unsigned long get_offset_hpet(void)
-{
- register unsigned long eax, edx;
-
- eax = hpet_readl(HPET_COUNTER);
- eax -= hpet_last; /* hpet delta */
- eax = min(hpet_tick, eax);
- /*
- * Time offset = (hpet delta) * ( usecs per HPET clock )
- * = (hpet delta) * ( usecs per tick / HPET clocks per tick)
- * = (hpet delta) * ( hpet_usec_quotient ) / (2^32)
- *
- * Where,
- * hpet_usec_quotient = (2^32 * usecs per tick)/HPET clocks per tick
- *
- * Using a mull instead of a divl saves some cycles in critical path.
- */
- ASM_MUL64_REG(eax, edx, hpet_usec_quotient, eax);
-
- /* our adjusted time offset in microseconds */
- return edx;
-}
-
-static void mark_offset_hpet(void)
-{
- unsigned long long this_offset, last_offset;
- unsigned long offset;
-
- write_seqlock(&monotonic_lock);
- last_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
- rdtsc(last_tsc_low, last_tsc_high);
-
- if (hpet_use_timer)
- offset = hpet_readl(HPET_T0_CMP) - hpet_tick;
- else
- offset = hpet_readl(HPET_COUNTER);
- if (unlikely(((offset - hpet_last) >= (2*hpet_tick)) && (hpet_last != 0))) {
- int lost_ticks = ((offset - hpet_last) / hpet_tick) - 1;
- jiffies_64 += lost_ticks;
- }
- hpet_last = offset;
-
- /* update the monotonic base value */
- this_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
- monotonic_base += cycles_2_ns(this_offset - last_offset);
- write_sequnlock(&monotonic_lock);
-}
-
-static void delay_hpet(unsigned long loops)
-{
- unsigned long hpet_start, hpet_end;
- unsigned long eax;
-
- /* loops is the number of cpu cycles. Convert it to hpet clocks */
- ASM_MUL64_REG(eax, loops, tsc_hpet_quotient, loops);
-
- hpet_start = hpet_readl(HPET_COUNTER);
- do {
- rep_nop();
- hpet_end = hpet_readl(HPET_COUNTER);
- } while ((hpet_end - hpet_start) < (loops));
-}
-
-static int __init init_hpet(char* override)
-{
- unsigned long result, remain;
-
- /* check clock override */
- if (override[0] && strncmp(override,"hpet",4))
- return -ENODEV;
-
- if (!is_hpet_enabled())
- return -ENODEV;
-
- printk("Using HPET for gettimeofday\n");
- if (cpu_has_tsc) {
- unsigned long tsc_quotient = calibrate_tsc_hpet(&tsc_hpet_quotient);
- if (tsc_quotient) {
- /* report CPU clock rate in Hz.
- * The formula is (10^6 * 2^32) / (2^32 * 1 / (clocks/us)) =
- * clock/second. Our precision is about 100 ppm.
- */
- { unsigned long eax=0, edx=1000;
- ASM_DIV64_REG(cpu_khz, edx, tsc_quotient,
- eax, edx);
- printk("Detected %lu.%03lu MHz processor.\n",
- cpu_khz / 1000, cpu_khz % 1000);
- }
- set_cyc2ns_scale(cpu_khz/1000);
- }
- }
-
- /*
- * Math to calculate hpet to usec multiplier
- * Look for the comments at get_offset_hpet()
- */
- ASM_DIV64_REG(result, remain, hpet_tick, 0, KERNEL_TICK_USEC);
- if (remain > (hpet_tick >> 1))
- result++; /* rounding the result */
- hpet_usec_quotient = result;
-
- return 0;
-}
-
-/************************************************************/
-
-/* tsc timer_opts struct */
-static struct timer_opts timer_hpet = {
- .name = "hpet",
- .mark_offset = mark_offset_hpet,
- .get_offset = get_offset_hpet,
- .monotonic_clock = monotonic_clock_hpet,
- .delay = delay_hpet,
-};
-
-struct init_timer_opts __initdata timer_hpet_init = {
- .init = init_hpet,
- .opts = &timer_hpet,
-};
Index: arch/i386/kernel/timers/timer_none.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/kernel/timers/timer_none.c (mode:100644)
+++ /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
@@ -1,39 +0,0 @@
-#include <linux/init.h>
-#include <asm/timer.h>
-
-static void mark_offset_none(void)
-{
- /* nothing needed */
-}
-
-static unsigned long get_offset_none(void)
-{
- return 0;
-}
-
-static unsigned long long monotonic_clock_none(void)
-{
- return 0;
-}
-
-static void delay_none(unsigned long loops)
-{
- int d0;
- __asm__ __volatile__(
- "\tjmp 1f\n"
- ".align 16\n"
- "1:\tjmp 2f\n"
- ".align 16\n"
- "2:\tdecl %0\n\tjns 2b"
- :"=&a" (d0)
- :"0" (loops));
-}
-
-/* none timer_opts struct */
-struct timer_opts timer_none = {
- .name = "none",
- .mark_offset = mark_offset_none,
- .get_offset = get_offset_none,
- .monotonic_clock = monotonic_clock_none,
- .delay = delay_none,
-};
Index: arch/i386/kernel/timers/timer_pit.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/kernel/timers/timer_pit.c (mode:100644)
+++ /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
@@ -1,206 +0,0 @@
-/*
- * This code largely moved from arch/i386/kernel/time.c.
- * See comments there for proper credits.
- */
-
-#include <linux/spinlock.h>
-#include <linux/module.h>
-#include <linux/device.h>
-#include <linux/irq.h>
-#include <linux/sysdev.h>
-#include <linux/timex.h>
-#include <asm/delay.h>
-#include <asm/mpspec.h>
-#include <asm/timer.h>
-#include <asm/smp.h>
-#include <asm/io.h>
-#include <asm/arch_hooks.h>
-
-extern spinlock_t i8259A_lock;
-extern spinlock_t i8253_lock;
-#include "do_timer.h"
-#include "io_ports.h"
-
-static int count_p; /* counter in get_offset_pit() */
-
-static int __init init_pit(char* override)
-{
- /* check clock override */
- if (override[0] && strncmp(override,"pit",3))
- printk(KERN_ERR "Warning: clock= override failed. Defaulting to PIT\n");
-
- count_p = LATCH;
- return 0;
-}
-
-static void mark_offset_pit(void)
-{
- /* nothing needed */
-}
-
-static unsigned long long monotonic_clock_pit(void)
-{
- return 0;
-}
-
-static void delay_pit(unsigned long loops)
-{
- int d0;
- __asm__ __volatile__(
- "\tjmp 1f\n"
- ".align 16\n"
- "1:\tjmp 2f\n"
- ".align 16\n"
- "2:\tdecl %0\n\tjns 2b"
- :"=&a" (d0)
- :"0" (loops));
-}
-
-
-/* This function must be called with xtime_lock held.
- * It was inspired by Steve McCanne's microtime-i386 for BSD. -- jrs
- *
- * However, the pc-audio speaker driver changes the divisor so that
- * it gets interrupted rather more often - it loads 64 into the
- * counter rather than 11932! This has an adverse impact on
- * do_gettimeoffset() -- it stops working! What is also not
- * good is that the interval that our timer function gets called
- * is no longer 10.0002 ms, but 9.9767 ms. To get around this
- * would require using a different timing source. Maybe someone
- * could use the RTC - I know that this can interrupt at frequencies
- * ranging from 8192Hz to 2Hz. If I had the energy, I'd somehow fix
- * it so that at startup, the timer code in sched.c would select
- * using either the RTC or the 8253 timer. The decision would be
- * based on whether there was any other device around that needed
- * to trample on the 8253. I'd set up the RTC to interrupt at 1024 Hz,
- * and then do some jiggery to have a version of do_timer that
- * advanced the clock by 1/1024 s. Every time that reached over 1/100
- * of a second, then do all the old code. If the time was kept correct
- * then do_gettimeoffset could just return 0 - there is no low order
- * divider that can be accessed.
- *
- * Ideally, you would be able to use the RTC for the speaker driver,
- * but it appears that the speaker driver really needs interrupt more
- * often than every 120 us or so.
- *
- * Anyway, this needs more thought.... pjsg (1993-08-28)
- *
- * If you are really that interested, you should be reading
- * comp.protocols.time.ntp!
- */
-
-static unsigned long get_offset_pit(void)
-{
- int count;
- unsigned long flags;
- static unsigned long jiffies_p = 0;
-
- /*
- * cache volatile jiffies temporarily; we have xtime_lock.
- */
- unsigned long jiffies_t;
-
- spin_lock_irqsave(&i8253_lock, flags);
- /* timer count may underflow right here */
- outb_p(0x00, PIT_MODE); /* latch the count ASAP */
-
- count = inb_p(PIT_CH0); /* read the latched count */
-
- /*
- * We do this guaranteed double memory access instead of a _p
- * postfix in the previous port access. Wheee, hackady hack
- */
- jiffies_t = jiffies;
-
- count |= inb_p(PIT_CH0) << 8;
-
- /* VIA686a test code... reset the latch if count > max + 1 */
- if (count > LATCH) {
- outb_p(0x34, PIT_MODE);
- outb_p(LATCH & 0xff, PIT_CH0);
- outb(LATCH >> 8, PIT_CH0);
- count = LATCH - 1;
- }
-
- /*
- * avoiding timer inconsistencies (they are rare, but they happen)...
- * there are two kinds of problems that must be avoided here:
- * 1. the timer counter underflows
- * 2. hardware problem with the timer, not giving us continuous time,
- * the counter does small "jumps" upwards on some Pentium systems,
- * (see c't 95/10 page 335 for Neptun bug.)
- */
-
- if( jiffies_t == jiffies_p ) {
- if( count > count_p ) {
- /* the nutcase */
- count = do_timer_overflow(count);
- }
- } else
- jiffies_p = jiffies_t;
-
- count_p = count;
-
- spin_unlock_irqrestore(&i8253_lock, flags);
-
- count = ((LATCH-1) - count) * TICK_SIZE;
- count = (count + LATCH/2) / LATCH;
-
- return count;
-}
-
-
-/* tsc timer_opts struct */
-struct timer_opts timer_pit = {
- .name = "pit",
- .mark_offset = mark_offset_pit,
- .get_offset = get_offset_pit,
- .monotonic_clock = monotonic_clock_pit,
- .delay = delay_pit,
-};
-
-struct init_timer_opts __initdata timer_pit_init = {
- .init = init_pit,
- .opts = &timer_pit,
-};
-
-void setup_pit_timer(void)
-{
- extern spinlock_t i8253_lock;
- unsigned long flags;
-
- spin_lock_irqsave(&i8253_lock, flags);
- outb_p(0x34,PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
- udelay(10);
- outb_p(LATCH & 0xff , PIT_CH0); /* LSB */
- udelay(10);
- outb(LATCH >> 8 , PIT_CH0); /* MSB */
- spin_unlock_irqrestore(&i8253_lock, flags);
-}
-
-static int timer_resume(struct sys_device *dev)
-{
- setup_pit_timer();
- return 0;
-}
-
-static struct sysdev_class timer_sysclass = {
- set_kset_name("timer_pit"),
- .resume = timer_resume,
-};
-
-static struct sys_device device_timer = {
- .id = 0,
- .cls = &timer_sysclass,
-};
-
-static int __init init_timer_sysfs(void)
-{
- int error = sysdev_class_register(&timer_sysclass);
- if (!error)
- error = sysdev_register(&device_timer);
- return error;
-}
-
-device_initcall(init_timer_sysfs);
-
Index: arch/i386/kernel/timers/timer_pm.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/kernel/timers/timer_pm.c (mode:100644)
+++ /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
@@ -1,258 +0,0 @@
-/*
- * (C) Dominik Brodowski <linux@brodo.de> 2003
- *
- * Driver to use the Power Management Timer (PMTMR) available in some
- * southbridges as primary timing source for the Linux kernel.
- *
- * Based on parts of linux/drivers/acpi/hardware/hwtimer.c, timer_pit.c,
- * timer_hpet.c, and on Arjan van de Ven's implementation for 2.4.
- *
- * This file is licensed under the GPL v2.
- */
-
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/device.h>
-#include <linux/init.h>
-#include <asm/types.h>
-#include <asm/timer.h>
-#include <asm/smp.h>
-#include <asm/io.h>
-#include <asm/arch_hooks.h>
-
-#include <linux/timex.h>
-#include "mach_timer.h"
-
-/* Number of PMTMR ticks expected during calibration run */
-#define PMTMR_TICKS_PER_SEC 3579545
-#define PMTMR_EXPECTED_RATE \
- ((CALIBRATE_LATCH * (PMTMR_TICKS_PER_SEC >> 10)) / (CLOCK_TICK_RATE>>10))
-
-
-/* The I/O port the PMTMR resides at.
- * The location is detected during setup_arch(),
- * in arch/i386/acpi/boot.c */
-u32 pmtmr_ioport = 0;
-
-
-/* value of the Power timer at last timer interrupt */
-static u32 offset_tick;
-static u32 offset_delay;
-
-static unsigned long long monotonic_base;
-static seqlock_t monotonic_lock = SEQLOCK_UNLOCKED;
-
-#define ACPI_PM_MASK 0xFFFFFF /* limit it to 24 bits */
-
-/*helper function to safely read acpi pm timesource*/
-static inline u32 read_pmtmr(void)
-{
- u32 v1=0,v2=0,v3=0;
- /* It has been reported that because of various broken
- * chipsets (ICH4, PIIX4 and PIIX4E) where the ACPI PM time
- * source is not latched, so you must read it multiple
- * times to insure a safe value is read.
- */
- do {
- v1 = inl(pmtmr_ioport);
- v2 = inl(pmtmr_ioport);
- v3 = inl(pmtmr_ioport);
- } while ((v1 > v2 && v1 < v3) || (v2 > v3 && v2 < v1)
- || (v3 > v1 && v3 < v2));
-
- /* mask the output to 24 bits */
- return v2 & ACPI_PM_MASK;
-}
-
-
-/*
- * Some boards have the PMTMR running way too fast. We check
- * the PMTMR rate against PIT channel 2 to catch these cases.
- */
-static int verify_pmtmr_rate(void)
-{
- u32 value1, value2;
- unsigned long count, delta;
-
- mach_prepare_counter();
- value1 = read_pmtmr();
- mach_countup(&count);
- value2 = read_pmtmr();
- delta = (value2 - value1) & ACPI_PM_MASK;
-
- /* Check that the PMTMR delta is within 5% of what we expect */
- if (delta < (PMTMR_EXPECTED_RATE * 19) / 20 ||
- delta > (PMTMR_EXPECTED_RATE * 21) / 20) {
- printk(KERN_INFO "PM-Timer running at invalid rate: %lu%% of normal - aborting.\n", 100UL * delta / PMTMR_EXPECTED_RATE);
- return -1;
- }
-
- return 0;
-}
-
-
-static int init_pmtmr(char* override)
-{
- u32 value1, value2;
- unsigned int i;
-
- if (override[0] && strncmp(override,"pmtmr",5))
- return -ENODEV;
-
- if (!pmtmr_ioport)
- return -ENODEV;
-
- /* we use the TSC for delay_pmtmr, so make sure it exists */
- if (!cpu_has_tsc)
- return -ENODEV;
-
- /* "verify" this timing source */
- value1 = read_pmtmr();
- for (i = 0; i < 10000; i++) {
- value2 = read_pmtmr();
- if (value2 == value1)
- continue;
- if (value2 > value1)
- goto pm_good;
- if ((value2 < value1) && ((value2) < 0xFFF))
- goto pm_good;
- printk(KERN_INFO "PM-Timer had inconsistent results: 0x%#x, 0x%#x - aborting.\n", value1, value2);
- return -EINVAL;
- }
- printk(KERN_INFO "PM-Timer had no reasonable result: 0x%#x - aborting.\n", value1);
- return -ENODEV;
-
-pm_good:
- if (verify_pmtmr_rate() != 0)
- return -ENODEV;
-
- init_cpu_khz();
- return 0;
-}
-
-static inline u32 cyc2us(u32 cycles)
-{
- /* The Power Management Timer ticks at 3.579545 ticks per microsecond.
- * 1 / PM_TIMER_FREQUENCY == 0.27936511 =~ 286/1024 [error: 0.024%]
- *
- * Even with HZ = 100, delta is at maximum 35796 ticks, so it can
- * easily be multiplied with 286 (=0x11E) without having to fear
- * u32 overflows.
- */
- cycles *= 286;
- return (cycles >> 10);
-}
-
-/*
- * this gets called during each timer interrupt
- * - Called while holding the writer xtime_lock
- */
-static void mark_offset_pmtmr(void)
-{
- u32 lost, delta, last_offset;
- static int first_run = 1;
- last_offset = offset_tick;
-
- write_seqlock(&monotonic_lock);
-
- offset_tick = read_pmtmr();
-
- /* calculate tick interval */
- delta = (offset_tick - last_offset) & ACPI_PM_MASK;
-
- /* convert to usecs */
- delta = cyc2us(delta);
-
- /* update the monotonic base value */
- monotonic_base += delta * NSEC_PER_USEC;
- write_sequnlock(&monotonic_lock);
-
- /* convert to ticks */
- delta += offset_delay;
- lost = delta / (USEC_PER_SEC / HZ);
- offset_delay = delta % (USEC_PER_SEC / HZ);
-
-
- /* compensate for lost ticks */
- if (lost >= 2)
- jiffies_64 += lost - 1;
-
- /* don't calculate delay for first run,
- or if we've got less then a tick */
- if (first_run || (lost < 1)) {
- first_run = 0;
- offset_delay = 0;
- }
-}
-
-
-static unsigned long long monotonic_clock_pmtmr(void)
-{
- u32 last_offset, this_offset;
- unsigned long long base, ret;
- unsigned seq;
-
-
- /* atomically read monotonic base & last_offset */
- do {
- seq = read_seqbegin(&monotonic_lock);
- last_offset = offset_tick;
- base = monotonic_base;
- } while (read_seqretry(&monotonic_lock, seq));
-
- /* Read the pmtmr */
- this_offset = read_pmtmr();
-
- /* convert to nanoseconds */
- ret = (this_offset - last_offset) & ACPI_PM_MASK;
- ret = base + (cyc2us(ret) * NSEC_PER_USEC);
- return ret;
-}
-
-static void delay_pmtmr(unsigned long loops)
-{
- unsigned long bclock, now;
-
- rdtscl(bclock);
- do
- {
- rep_nop();
- rdtscl(now);
- } while ((now-bclock) < loops);
-}
-
-
-/*
- * get the offset (in microseconds) from the last call to mark_offset()
- * - Called holding a reader xtime_lock
- */
-static unsigned long get_offset_pmtmr(void)
-{
- u32 now, offset, delta = 0;
-
- offset = offset_tick;
- now = read_pmtmr();
- delta = (now - offset)&ACPI_PM_MASK;
-
- return (unsigned long) offset_delay + cyc2us(delta);
-}
-
-
-/* acpi timer_opts struct */
-static struct timer_opts timer_pmtmr = {
- .name = "pmtmr",
- .mark_offset = mark_offset_pmtmr,
- .get_offset = get_offset_pmtmr,
- .monotonic_clock = monotonic_clock_pmtmr,
- .delay = delay_pmtmr,
-};
-
-struct init_timer_opts __initdata timer_pmtmr_init = {
- .init = init_pmtmr,
- .opts = &timer_pmtmr,
-};
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
-MODULE_DESCRIPTION("Power Management Timer (PMTMR) as primary timing source for x86");
Index: arch/i386/kernel/timers/timer_tsc.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/kernel/timers/timer_tsc.c (mode:100644)
+++ /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
@@ -1,580 +0,0 @@
-/*
- * This code largely moved from arch/i386/kernel/time.c.
- * See comments there for proper credits.
- *
- * 2004-06-25 Jesper Juhl
- * moved mark_offset_tsc below cpufreq_delayed_get to avoid gcc 3.4
- * failing to inline.
- */
-
-#include <linux/spinlock.h>
-#include <linux/init.h>
-#include <linux/timex.h>
-#include <linux/errno.h>
-#include <linux/cpufreq.h>
-#include <linux/string.h>
-#include <linux/jiffies.h>
-
-#include <asm/timer.h>
-#include <asm/io.h>
-/* processor.h for distable_tsc flag */
-#include <asm/processor.h>
-
-#include "io_ports.h"
-#include "mach_timer.h"
-
-#include <asm/hpet.h>
-
-#ifdef CONFIG_HPET_TIMER
-static unsigned long hpet_usec_quotient;
-static unsigned long hpet_last;
-static struct timer_opts timer_tsc;
-#endif
-
-static inline void cpufreq_delayed_get(void);
-
-int tsc_disable __initdata = 0;
-
-extern spinlock_t i8253_lock;
-
-static int use_tsc;
-/* Number of usecs that the last interrupt was delayed */
-static int delay_at_last_interrupt;
-
-static unsigned long last_tsc_low; /* lsb 32 bits of Time Stamp Counter */
-static unsigned long last_tsc_high; /* msb 32 bits of Time Stamp Counter */
-static unsigned long long monotonic_base;
-static seqlock_t monotonic_lock = SEQLOCK_UNLOCKED;
-
-/* convert from cycles(64bits) => nanoseconds (64bits)
- * basic equation:
- * ns = cycles / (freq / ns_per_sec)
- * ns = cycles * (ns_per_sec / freq)
- * ns = cycles * (10^9 / (cpu_mhz * 10^6))
- * ns = cycles * (10^3 / cpu_mhz)
- *
- * Then we use scaling math (suggested by george@mvista.com) to get:
- * ns = cycles * (10^3 * SC / cpu_mhz) / SC
- * ns = cycles * cyc2ns_scale / SC
- *
- * And since SC is a constant power of two, we can convert the div
- * into a shift.
- * -johnstul@us.ibm.com "math is hard, lets go shopping!"
- */
-static unsigned long cyc2ns_scale;
-#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
-
-static inline void set_cyc2ns_scale(unsigned long cpu_mhz)
-{
- cyc2ns_scale = (1000 << CYC2NS_SCALE_FACTOR)/cpu_mhz;
-}
-
-static inline unsigned long long cycles_2_ns(unsigned long long cyc)
-{
- return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
-}
-
-static int count2; /* counter for mark_offset_tsc() */
-
-/* Cached *multiplier* to convert TSC counts to microseconds.
- * (see the equation below).
- * Equal to 2^32 * (1 / (clocks per usec) ).
- * Initialized in time_init.
- */
-static unsigned long fast_gettimeoffset_quotient;
-
-static unsigned long get_offset_tsc(void)
-{
- register unsigned long eax, edx;
-
- /* Read the Time Stamp Counter */
-
- rdtsc(eax,edx);
-
- /* .. relative to previous jiffy (32 bits is enough) */
- eax -= last_tsc_low; /* tsc_low delta */
-
- /*
- * Time offset = (tsc_low delta) * fast_gettimeoffset_quotient
- * = (tsc_low delta) * (usecs_per_clock)
- * = (tsc_low delta) * (usecs_per_jiffy / clocks_per_jiffy)
- *
- * Using a mull instead of a divl saves up to 31 clock cycles
- * in the critical path.
- */
-
- __asm__("mull %2"
- :"=a" (eax), "=d" (edx)
- :"rm" (fast_gettimeoffset_quotient),
- "0" (eax));
-
- /* our adjusted time offset in microseconds */
- return delay_at_last_interrupt + edx;
-}
-
-static unsigned long long monotonic_clock_tsc(void)
-{
- unsigned long long last_offset, this_offset, base;
- unsigned seq;
-
- /* atomically read monotonic base & last_offset */
- do {
- seq = read_seqbegin(&monotonic_lock);
- last_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
- base = monotonic_base;
- } while (read_seqretry(&monotonic_lock, seq));
-
- /* Read the Time Stamp Counter */
- rdtscll(this_offset);
-
- /* return the value in ns */
- return base + cycles_2_ns(this_offset - last_offset);
-}
-
-/*
- * Scheduler clock - returns current time in nanosec units.
- */
-unsigned long long sched_clock(void)
-{
- unsigned long long this_offset;
-
- /*
- * In the NUMA case we dont use the TSC as they are not
- * synchronized across all CPUs.
- */
-#ifndef CONFIG_NUMA
- if (!use_tsc)
-#endif
- /* no locking but a rare wrong value is not a big deal */
- return jiffies_64 * (1000000000 / HZ);
-
- /* Read the Time Stamp Counter */
- rdtscll(this_offset);
-
- /* return the value in ns */
- return cycles_2_ns(this_offset);
-}
-
-static void delay_tsc(unsigned long loops)
-{
- unsigned long bclock, now;
-
- rdtscl(bclock);
- do
- {
- rep_nop();
- rdtscl(now);
- } while ((now-bclock) < loops);
-}
-
-#ifdef CONFIG_HPET_TIMER
-static void mark_offset_tsc_hpet(void)
-{
- unsigned long long this_offset, last_offset;
- unsigned long offset, temp, hpet_current;
-
- write_seqlock(&monotonic_lock);
- last_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
- /*
- * It is important that these two operations happen almost at
- * the same time. We do the RDTSC stuff first, since it's
- * faster. To avoid any inconsistencies, we need interrupts
- * disabled locally.
- */
- /*
- * Interrupts are just disabled locally since the timer irq
- * has the SA_INTERRUPT flag set. -arca
- */
- /* read Pentium cycle counter */
-
- hpet_current = hpet_readl(HPET_COUNTER);
- rdtsc(last_tsc_low, last_tsc_high);
-
- /* lost tick compensation */
- offset = hpet_readl(HPET_T0_CMP) - hpet_tick;
- if (unlikely(((offset - hpet_last) > hpet_tick) && (hpet_last != 0))) {
- int lost_ticks = (offset - hpet_last) / hpet_tick;
- jiffies_64 += lost_ticks;
- }
- hpet_last = hpet_current;
-
- /* update the monotonic base value */
- this_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
- monotonic_base += cycles_2_ns(this_offset - last_offset);
- write_sequnlock(&monotonic_lock);
-
- /* calculate delay_at_last_interrupt */
- /*
- * Time offset = (hpet delta) * ( usecs per HPET clock )
- * = (hpet delta) * ( usecs per tick / HPET clocks per tick)
- * = (hpet delta) * ( hpet_usec_quotient ) / (2^32)
- * Where,
- * hpet_usec_quotient = (2^32 * usecs per tick)/HPET clocks per tick
- */
- delay_at_last_interrupt = hpet_current - offset;
- ASM_MUL64_REG(temp, delay_at_last_interrupt,
- hpet_usec_quotient, delay_at_last_interrupt);
-}
-#endif
-
-
-#ifdef CONFIG_CPU_FREQ
-#include <linux/workqueue.h>
-
-static unsigned int cpufreq_delayed_issched = 0;
-static unsigned int cpufreq_init = 0;
-static struct work_struct cpufreq_delayed_get_work;
-
-static void handle_cpufreq_delayed_get(void *v)
-{
- unsigned int cpu;
- for_each_online_cpu(cpu) {
- cpufreq_get(cpu);
- }
- cpufreq_delayed_issched = 0;
-}
-
-/* if we notice lost ticks, schedule a call to cpufreq_get() as it tries
- * to verify the CPU frequency the timing core thinks the CPU is running
- * at is still correct.
- */
-static inline void cpufreq_delayed_get(void)
-{
- if (cpufreq_init && !cpufreq_delayed_issched) {
- cpufreq_delayed_issched = 1;
- printk(KERN_DEBUG "Losing some ticks... checking if CPU frequency changed.\n");
- schedule_work(&cpufreq_delayed_get_work);
- }
-}
-
-/* If the CPU frequency is scaled, TSC-based delays will need a different
- * loops_per_jiffy value to function properly.
- */
-
-static unsigned int ref_freq = 0;
-static unsigned long loops_per_jiffy_ref = 0;
-
-#ifndef CONFIG_SMP
-static unsigned long fast_gettimeoffset_ref = 0;
-static unsigned long cpu_khz_ref = 0;
-#endif
-
-static int
-time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
- void *data)
-{
- struct cpufreq_freqs *freq = data;
-
- if (val != CPUFREQ_RESUMECHANGE)
- write_seqlock_irq(&xtime_lock);
- if (!ref_freq) {
- ref_freq = freq->old;
- loops_per_jiffy_ref = cpu_data[freq->cpu].loops_per_jiffy;
-#ifndef CONFIG_SMP
- fast_gettimeoffset_ref = fast_gettimeoffset_quotient;
- cpu_khz_ref = cpu_khz;
-#endif
- }
-
- if ((val == CPUFREQ_PRECHANGE && freq->old < freq->new) ||
- (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
- (val == CPUFREQ_RESUMECHANGE)) {
- if (!(freq->flags & CPUFREQ_CONST_LOOPS))
- cpu_data[freq->cpu].loops_per_jiffy = cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new);
-#ifndef CONFIG_SMP
- if (cpu_khz)
- cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new);
- if (use_tsc) {
- if (!(freq->flags & CPUFREQ_CONST_LOOPS)) {
- fast_gettimeoffset_quotient = cpufreq_scale(fast_gettimeoffset_ref, freq->new, ref_freq);
- set_cyc2ns_scale(cpu_khz/1000);
- }
- }
-#endif
- }
-
- if (val != CPUFREQ_RESUMECHANGE)
- write_sequnlock_irq(&xtime_lock);
-
- return 0;
-}
-
-static struct notifier_block time_cpufreq_notifier_block = {
- .notifier_call = time_cpufreq_notifier
-};
-
-
-static int __init cpufreq_tsc(void)
-{
- int ret;
- INIT_WORK(&cpufreq_delayed_get_work, handle_cpufreq_delayed_get, NULL);
- ret = cpufreq_register_notifier(&time_cpufreq_notifier_block,
- CPUFREQ_TRANSITION_NOTIFIER);
- if (!ret)
- cpufreq_init = 1;
- return ret;
-}
-core_initcall(cpufreq_tsc);
-
-#else /* CONFIG_CPU_FREQ */
-static inline void cpufreq_delayed_get(void) { return; }
-#endif
-
-int recalibrate_cpu_khz(void)
-{
-#ifndef CONFIG_SMP
- unsigned long cpu_khz_old = cpu_khz;
-
- if (cpu_has_tsc) {
- init_cpu_khz();
- cpu_data[0].loops_per_jiffy =
- cpufreq_scale(cpu_data[0].loops_per_jiffy,
- cpu_khz_old,
- cpu_khz);
- return 0;
- } else
- return -ENODEV;
-#else
- return -ENODEV;
-#endif
-}
-EXPORT_SYMBOL(recalibrate_cpu_khz);
-
-static void mark_offset_tsc(void)
-{
- unsigned long lost,delay;
- unsigned long delta = last_tsc_low;
- int count;
- int countmp;
- static int count1 = 0;
- unsigned long long this_offset, last_offset;
- static int lost_count = 0;
-
- write_seqlock(&monotonic_lock);
- last_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
- /*
- * It is important that these two operations happen almost at
- * the same time. We do the RDTSC stuff first, since it's
- * faster. To avoid any inconsistencies, we need interrupts
- * disabled locally.
- */
-
- /*
- * Interrupts are just disabled locally since the timer irq
- * has the SA_INTERRUPT flag set. -arca
- */
-
- /* read Pentium cycle counter */
-
- rdtsc(last_tsc_low, last_tsc_high);
-
- spin_lock(&i8253_lock);
- outb_p(0x00, PIT_MODE); /* latch the count ASAP */
-
- count = inb_p(PIT_CH0); /* read the latched count */
- count |= inb(PIT_CH0) << 8;
-
- /*
- * VIA686a test code... reset the latch if count > max + 1
- * from timer_pit.c - cjb
- */
- if (count > LATCH) {
- outb_p(0x34, PIT_MODE);
- outb_p(LATCH & 0xff, PIT_CH0);
- outb(LATCH >> 8, PIT_CH0);
- count = LATCH - 1;
- }
-
- spin_unlock(&i8253_lock);
-
- if (pit_latch_buggy) {
- /* get center value of last 3 time lutch */
- if ((count2 >= count && count >= count1)
- || (count1 >= count && count >= count2)) {
- count2 = count1; count1 = count;
- } else if ((count1 >= count2 && count2 >= count)
- || (count >= count2 && count2 >= count1)) {
- countmp = count;count = count2;
- count2 = count1;count1 = countmp;
- } else {
- count2 = count1; count1 = count; count = count1;
- }
- }
-
- /* lost tick compensation */
- delta = last_tsc_low - delta;
- {
- register unsigned long eax, edx;
- eax = delta;
- __asm__("mull %2"
- :"=a" (eax), "=d" (edx)
- :"rm" (fast_gettimeoffset_quotient),
- "0" (eax));
- delta = edx;
- }
- delta += delay_at_last_interrupt;
- lost = delta/(1000000/HZ);
- delay = delta%(1000000/HZ);
- if (lost >= 2) {
- jiffies_64 += lost-1;
-
- /* sanity check to ensure we're not always losing ticks */
- if (lost_count++ > 100) {
- printk(KERN_WARNING "Losing too many ticks!\n");
- printk(KERN_WARNING "TSC cannot be used as a timesource. \n");
- printk(KERN_WARNING "Possible reasons for this are:\n");
- printk(KERN_WARNING " You're running with Speedstep,\n");
- printk(KERN_WARNING " You don't have DMA enabled for your hard disk (see hdparm),\n");
- printk(KERN_WARNING " Incorrect TSC synchronization on an SMP system (see dmesg).\n");
- printk(KERN_WARNING "Falling back to a sane timesource now.\n");
-
- clock_fallback();
- }
- /* ... but give the TSC a fair chance */
- if (lost_count > 25)
- cpufreq_delayed_get();
- } else
- lost_count = 0;
- /* update the monotonic base value */
- this_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
- monotonic_base += cycles_2_ns(this_offset - last_offset);
- write_sequnlock(&monotonic_lock);
-
- /* calculate delay_at_last_interrupt */
- count = ((LATCH-1) - count) * TICK_SIZE;
- delay_at_last_interrupt = (count + LATCH/2) / LATCH;
-
- /* catch corner case where tick rollover occured
- * between tsc and pit reads (as noted when
- * usec delta is > 90% # of usecs/tick)
- */
- if (lost && abs(delay - delay_at_last_interrupt) > (900000/HZ))
- jiffies_64++;
-}
-
-static int __init init_tsc(char* override)
-{
-
- /* check clock override */
- if (override[0] && strncmp(override,"tsc",3)) {
-#ifdef CONFIG_HPET_TIMER
- if (is_hpet_enabled()) {
- printk(KERN_ERR "Warning: clock= override failed. Defaulting to tsc\n");
- } else
-#endif
- {
- return -ENODEV;
- }
- }
-
- /*
- * If we have APM enabled or the CPU clock speed is variable
- * (CPU stops clock on HLT or slows clock to save power)
- * then the TSC timestamps may diverge by up to 1 jiffy from
- * 'real time' but nothing will break.
- * The most frequent case is that the CPU is "woken" from a halt
- * state by the timer interrupt itself, so we get 0 error. In the
- * rare cases where a driver would "wake" the CPU and request a
- * timestamp, the maximum error is < 1 jiffy. But timestamps are
- * still perfectly ordered.
- * Note that the TSC counter will be reset if APM suspends
- * to disk; this won't break the kernel, though, 'cuz we're
- * smart. See arch/i386/kernel/apm.c.
- */
- /*
- * Firstly we have to do a CPU check for chips with
- * a potentially buggy TSC. At this point we haven't run
- * the ident/bugs checks so we must run this hook as it
- * may turn off the TSC flag.
- *
- * NOTE: this doesn't yet handle SMP 486 machines where only
- * some CPU's have a TSC. Thats never worked and nobody has
- * moaned if you have the only one in the world - you fix it!
- */
-
- count2 = LATCH; /* initialize counter for mark_offset_tsc() */
-
- if (cpu_has_tsc) {
- unsigned long tsc_quotient;
-#ifdef CONFIG_HPET_TIMER
- if (is_hpet_enabled() && hpet_use_timer) {
- unsigned long result, remain;
- printk("Using TSC for gettimeofday\n");
- tsc_quotient = calibrate_tsc_hpet(NULL);
- timer_tsc.mark_offset = &mark_offset_tsc_hpet;
- /*
- * Math to calculate hpet to usec multiplier
- * Look for the comments at get_offset_tsc_hpet()
- */
- ASM_DIV64_REG(result, remain, hpet_tick,
- 0, KERNEL_TICK_USEC);
- if (remain > (hpet_tick >> 1))
- result++; /* rounding the result */
-
- hpet_usec_quotient = result;
- } else
-#endif
- {
- tsc_quotient = calibrate_tsc();
- }
-
- if (tsc_quotient) {
- fast_gettimeoffset_quotient = tsc_quotient;
- use_tsc = 1;
- /*
- * We could be more selective here I suspect
- * and just enable this for the next intel chips ?
- */
- /* report CPU clock rate in Hz.
- * The formula is (10^6 * 2^32) / (2^32 * 1 / (clocks/us)) =
- * clock/second. Our precision is about 100 ppm.
- */
- { unsigned long eax=0, edx=1000;
- __asm__("divl %2"
- :"=a" (cpu_khz), "=d" (edx)
- :"r" (tsc_quotient),
- "0" (eax), "1" (edx));
- printk("Detected %lu.%03lu MHz processor.\n", cpu_khz / 1000, cpu_khz % 1000);
- }
- set_cyc2ns_scale(cpu_khz/1000);
- return 0;
- }
- }
- return -ENODEV;
-}
-
-#ifndef CONFIG_X86_TSC
-/* disable flag for tsc. Takes effect by clearing the TSC cpu flag
- * in cpu/common.c */
-static int __init tsc_setup(char *str)
-{
- tsc_disable = 1;
- return 1;
-}
-#else
-static int __init tsc_setup(char *str)
-{
- printk(KERN_WARNING "notsc: Kernel compiled with CONFIG_X86_TSC, "
- "cannot disable TSC.\n");
- return 1;
-}
-#endif
-__setup("notsc", tsc_setup);
-
-
-
-/************************************************************/
-
-/* tsc timer_opts struct */
-static struct timer_opts timer_tsc = {
- .name = "tsc",
- .mark_offset = mark_offset_tsc,
- .get_offset = get_offset_tsc,
- .monotonic_clock = monotonic_clock_tsc,
- .delay = delay_tsc,
-};
-
-struct init_timer_opts __initdata timer_tsc_init = {
- .init = init_tsc,
- .opts = &timer_tsc,
-};
Index: arch/i386/kernel/tsc.c
===================================================================
--- /dev/null (tree:15eb8deaa5b22a81f97a9af307d81b0567115674)
+++ 6f1948595e5fa374fc552a4a01fe5524530ea1dd/arch/i386/kernel/tsc.c (mode:100644)
@@ -0,0 +1,190 @@
+#include <linux/init.h>
+#include <linux/timex.h>
+#include <linux/cpufreq.h>
+#include "mach_timer.h"
+
+int tsc_disable;
+
+/* convert from cycles(64bits) => nanoseconds (64bits)
+ * basic equation:
+ * ns = cycles / (freq / ns_per_sec)
+ * ns = cycles * (ns_per_sec / freq)
+ * ns = cycles * (10^9 / (cpu_mhz * 10^6))
+ * ns = cycles * (10^3 / cpu_mhz)
+ *
+ * Then we use scaling math (suggested by george@mvista.com) to get:
+ * ns = cycles * (10^3 * SC / cpu_mhz) / SC
+ * ns = cycles * cyc2ns_scale / SC
+ *
+ * And since SC is a constant power of two, we can convert the div
+ * into a shift.
+ * -johnstul@us.ibm.com "math is hard, lets go shopping!"
+ */
+static unsigned long cyc2ns_scale;
+#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
+
+static inline void set_cyc2ns_scale(unsigned long cpu_mhz)
+{
+ cyc2ns_scale = (1000 << CYC2NS_SCALE_FACTOR)/cpu_mhz;
+}
+
+static inline unsigned long long cycles_2_ns(unsigned long long cyc)
+{
+ return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
+}
+
+/*
+ * Scheduler clock - returns current time in nanosec units.
+ */
+unsigned long long sched_clock(void)
+{
+ unsigned long long this_offset;
+
+ /*
+ * In the NUMA case we dont use the TSC as they are not
+ * synchronized across all CPUs.
+ */
+#ifndef CONFIG_NUMA
+ if (!cpu_khz)
+#endif
+ /* no locking but a rare wrong value is not a big deal */
+ return jiffies_64 * (1000000000 / HZ);
+
+ /* Read the Time Stamp Counter */
+ rdtscll(this_offset);
+
+ /* return the value in ns */
+ return cycles_2_ns(this_offset);
+}
+static unsigned long calculate_cpu_khz(void)
+{
+ unsigned long long start, end;
+ unsigned long count;
+ u64 delta64;
+ int i;
+
+ /* repeat 3 times to make sure the cache is warm */
+ for(i=0; i < 3; i++) {
+ /* XXX - we need HPET based calibration too */
+ mach_prepare_counter();
+ rdtscll(start);
+ mach_countup(&count);
+ rdtscll(end);
+ }
+ delta64 = end - start;
+
+ /* cpu freq too fast */
+ if(delta64 > (1ULL<<32))
+ return 0;
+ /* cpu freq too slow */
+ if (delta64 <= CALIBRATE_TIME)
+ return 0;
+
+ delta64 *= 1000;
+ do_div(delta64,CALIBRATE_TIME);
+
+ return (unsigned long)delta64;
+}
+
+void tsc_init(void)
+{
+ if(!cpu_has_tsc)
+ return;
+ cpu_khz = calculate_cpu_khz();
+
+ if (!cpu_khz)
+ return;
+
+ printk("Detected %lu.%03lu MHz processor.\n",
+ cpu_khz / 1000, cpu_khz % 1000);
+
+ set_cyc2ns_scale(cpu_khz/1000);
+}
+
+int recalibrate_cpu_khz(void)
+{
+#ifndef CONFIG_SMP
+ unsigned long cpu_khz_old = cpu_khz;
+
+ if (cpu_has_tsc) {
+ cpu_khz = calculate_cpu_khz();
+ cpu_data[0].loops_per_jiffy =
+ cpufreq_scale(cpu_data[0].loops_per_jiffy,
+ cpu_khz_old, cpu_khz);
+ return 0;
+ } else
+ return -ENODEV;
+#else
+ return -ENODEV;
+#endif
+}
+EXPORT_SYMBOL(recalibrate_cpu_khz);
+
+/* All of the code below comes from arch/i386/kernel/timers/timer_tsc.c
+ * XXX: severly needs better comments and the ifdef's killed.
+ */
+
+#ifdef CONFIG_CPU_FREQ
+static unsigned int cpufreq_init = 0;
+
+/* If the CPU frequency is scaled, TSC-based delays will need a different
+ * loops_per_jiffy value to function properly.
+ */
+
+static unsigned int ref_freq = 0;
+static unsigned long loops_per_jiffy_ref = 0;
+
+#ifndef CONFIG_SMP
+static unsigned long cpu_khz_ref = 0;
+#endif
+
+static int time_cpufreq_notifier(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ struct cpufreq_freqs *freq = data;
+
+ if (val != CPUFREQ_RESUMECHANGE)
+ write_seqlock_irq(&xtime_lock);
+ if (!ref_freq) {
+ ref_freq = freq->old;
+ loops_per_jiffy_ref = cpu_data[freq->cpu].loops_per_jiffy;
+#ifndef CONFIG_SMP
+ cpu_khz_ref = cpu_khz;
+#endif
+ }
+
+ if ((val == CPUFREQ_PRECHANGE && freq->old < freq->new) ||
+ (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
+ (val == CPUFREQ_RESUMECHANGE)) {
+ if (!(freq->flags & CPUFREQ_CONST_LOOPS))
+ cpu_data[freq->cpu].loops_per_jiffy = cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new);
+#ifndef CONFIG_SMP
+ if (cpu_khz) {
+ cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new);
+ set_cyc2ns_scale(cpu_khz/1000);
+ }
+#endif
+ }
+
+ if (val != CPUFREQ_RESUMECHANGE)
+ write_sequnlock_irq(&xtime_lock);
+
+ return 0;
+}
+
+static struct notifier_block time_cpufreq_notifier_block = {
+ .notifier_call = time_cpufreq_notifier
+};
+
+static int __init cpufreq_tsc(void)
+{
+ int ret;
+ ret = cpufreq_register_notifier(&time_cpufreq_notifier_block,
+ CPUFREQ_TRANSITION_NOTIFIER);
+ if (!ret)
+ cpufreq_init = 1;
+ return ret;
+}
+core_initcall(cpufreq_tsc);
+#endif /* CONFIG_CPU_FREQ */
+
Index: arch/i386/lib/delay.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/lib/delay.c (mode:100644)
+++ 6f1948595e5fa374fc552a4a01fe5524530ea1dd/arch/i386/lib/delay.c (mode:100644)
@@ -13,6 +13,7 @@
#include <linux/config.h>
#include <linux/sched.h>
#include <linux/delay.h>
+#include <linux/timeofday.h>
#include <asm/processor.h>
#include <asm/delay.h>
#include <asm/timer.h>
@@ -21,11 +22,20 @@
#include <asm/smp.h>
#endif
-extern struct timer_opts* timer;
-
+/* XXX - For now just use a simple loop delay
+ * This has cpufreq issues, but so did the old method.
+ */
void __delay(unsigned long loops)
{
- cur_timer->delay(loops);
+ int d0;
+ __asm__ __volatile__(
+ "\tjmp 1f\n"
+ ".align 16\n"
+ "1:\tjmp 2f\n"
+ ".align 16\n"
+ "2:\tdecl %0\n\tjns 2b"
+ :"=&a" (d0)
+ :"0" (loops));
}
inline void __const_udelay(unsigned long xloops)
Index: include/asm-generic/timeofday.h
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/include/asm-generic/timeofday.h (mode:100644)
+++ 6f1948595e5fa374fc552a4a01fe5524530ea1dd/include/asm-generic/timeofday.h (mode:100644)
@@ -20,7 +20,7 @@
struct timesource_t* timesource, int ntp_adj);
#else
#define arch_update_vsyscall_gtod(x,y,z,w) {}
-#endif
+#endif /* CONFIG_NEWTOD_VSYSCALL */
#endif /* CONFIG_NEWTOD */
#endif
Index: include/asm-i386/mach-default/mach_timer.h
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/include/asm-i386/mach-default/mach_timer.h (mode:100644)
+++ 6f1948595e5fa374fc552a4a01fe5524530ea1dd/include/asm-i386/mach-default/mach_timer.h (mode:100644)
@@ -14,8 +14,12 @@
*/
#ifndef _MACH_TIMER_H
#define _MACH_TIMER_H
+#include <linux/jiffies.h>
+#include <asm/io.h>
-#define CALIBRATE_LATCH (5 * LATCH)
+#define CALIBRATE_ITERATION 50
+#define CALIBRATE_LATCH (CALIBRATE_ITERATION * LATCH)
+#define CALIBRATE_TIME (CALIBRATE_ITERATION * 1000020/HZ)
static inline void mach_prepare_counter(void)
{
Index: include/asm-i386/timeofday.h
===================================================================
--- /dev/null (tree:15eb8deaa5b22a81f97a9af307d81b0567115674)
+++ 6f1948595e5fa374fc552a4a01fe5524530ea1dd/include/asm-i386/timeofday.h (mode:100644)
@@ -0,0 +1,4 @@
+#ifndef _ASM_I386_TIMEOFDAY_H
+#define _ASM_I386_TIMEOFDAY_H
+#include <asm-generic/timeofday.h>
+#endif
Index: include/asm-i386/timer.h
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/include/asm-i386/timer.h (mode:100644)
+++ 6f1948595e5fa374fc552a4a01fe5524530ea1dd/include/asm-i386/timer.h (mode:100644)
@@ -2,64 +2,11 @@
#define _ASMi386_TIMER_H
#include <linux/init.h>
-/**
- * struct timer_ops - used to define a timer source
- *
- * @name: name of the timer.
- * @init: Probes and initializes the timer. Takes clock= override
- * string as an argument. Returns 0 on success, anything else
- * on failure.
- * @mark_offset: called by the timer interrupt.
- * @get_offset: called by gettimeofday(). Returns the number of microseconds
- * since the last timer interupt.
- * @monotonic_clock: returns the number of nanoseconds since the init of the
- * timer.
- * @delay: delays this many clock cycles.
- */
-struct timer_opts {
- char* name;
- void (*mark_offset)(void);
- unsigned long (*get_offset)(void);
- unsigned long long (*monotonic_clock)(void);
- void (*delay)(unsigned long);
-};
-
-struct init_timer_opts {
- int (*init)(char *override);
- struct timer_opts *opts;
-};
-
#define TICK_SIZE (tick_nsec / 1000)
-
-extern struct timer_opts* __init select_timer(void);
-extern void clock_fallback(void);
void setup_pit_timer(void);
-
/* Modifiers for buggy PIT handling */
-
extern int pit_latch_buggy;
-
-extern struct timer_opts *cur_timer;
extern int timer_ack;
-
-/* list of externed timers */
-extern struct timer_opts timer_none;
-extern struct timer_opts timer_pit;
-extern struct init_timer_opts timer_pit_init;
-extern struct init_timer_opts timer_tsc_init;
-#ifdef CONFIG_X86_CYCLONE_TIMER
-extern struct init_timer_opts timer_cyclone_init;
-#endif
-
-extern unsigned long calibrate_tsc(void);
-extern void init_cpu_khz(void);
extern int recalibrate_cpu_khz(void);
-#ifdef CONFIG_HPET_TIMER
-extern struct init_timer_opts timer_hpet_init;
-extern unsigned long calibrate_tsc_hpet(unsigned long *tsc_hpet_quotient_ptr);
-#endif
-#ifdef CONFIG_X86_PM_TIMER
-extern struct init_timer_opts timer_pmtmr_init;
-#endif
#endif
Index: include/asm-i386/timex.h
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/include/asm-i386/timex.h (mode:100644)
+++ 6f1948595e5fa374fc552a4a01fe5524530ea1dd/include/asm-i386/timex.h (mode:100644)
@@ -16,6 +16,8 @@
#endif
+/* XXX - All of this should likely move elsewhere -johnstul@us.ibm.com*/
+
/*
* Standard way to access the cycle counter on i586+ CPUs.
* Currently only used on SMP.
@@ -48,5 +50,6 @@
}
extern unsigned long cpu_khz;
+extern void tsc_init(void);
#endif
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 3/4] new timeofday x86-64 arch specific changes (v. B1)
2005-06-01 23:12 ` [PATCH 2/4] new timeofday i386 arch specific changes " john stultz
@ 2005-06-01 23:13 ` john stultz
2005-06-01 23:16 ` [PATCH 4/4] new timeofday i386 and x86-64 timesources " john stultz
2005-06-02 0:37 ` [PATCH 3/4] new timeofday x86-64 arch specific changes " Parag Warudkar
0 siblings, 2 replies; 11+ messages in thread
From: john stultz @ 2005-06-01 23:13 UTC (permalink / raw)
To: Andi Kleen
Cc: lkml, Tim Schmielau, George Anzinger, albert, Ulrich Windl,
Christoph Lameter, Dominik Brodowski, David Mosberger,
Andrew Morton, paulus, schwidefsky, keith maanthey,
Chris McDermott, Max Asbock, mahuja, Nishanth Aravamudan,
Darren Hart, Darrick J. Wong, Anton Blanchard, donf, mpm, benh
Andi, All,
I'm just re-spinning this to resolve a conflict w/ the CPUFREQ changes
Linus accepted last night.
This patch converts the x86-64 arch to use the new timeofday
infrastructure. It applies on top of my timeofday-core_B1 patch. This is
a full conversion, so most of this patch is subtractions removing the
existing arch specific time keeping code. This patch does not provide
any x86-64 timesources, so using this patch alone on top of the
timeofday-core patch will only give you the jiffies timesource. To get
full replacements for the code being removed here, the following
timeofday-timesources-i386 patch (x86-64 shares the same timesources as
i386) will need to be applied.
Andi: I'd like to submit this to Andrew for inclusion into his tree for
testing, however I'd like to get an ACK from you first. Please let me
know if you have any feedback or suggestions.
thanks
-john
Signed-off-by: John Stultz <johnstul@us.ibm.com>
linux-2.6.12-rc5_timeofday-arch-x86-64_B1.patch
===============================================
Index: arch/i386/kernel/acpi/boot.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/i386/kernel/acpi/boot.c (mode:100644)
+++ 85c83ea7c8c2d1f7e94ba65fa8d2a77d1022c973/arch/i386/kernel/acpi/boot.c (mode:100644)
@@ -547,7 +547,7 @@
#ifdef CONFIG_HPET_TIMER
-
+#include <asm/hpet.h>
static int __init acpi_parse_hpet(unsigned long phys, unsigned long size)
{
struct acpi_table_hpet *hpet_tbl;
@@ -570,18 +570,12 @@
#ifdef CONFIG_X86_64
vxtime.hpet_address = hpet_tbl->addr.addrl |
((long) hpet_tbl->addr.addrh << 32);
-
- printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n",
- hpet_tbl->id, vxtime.hpet_address);
+ hpet_address = vxtime.hpet_address;
#else /* X86 */
- {
- extern unsigned long hpet_address;
-
hpet_address = hpet_tbl->addr.addrl;
+#endif /* X86 */
printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n",
hpet_tbl->id, hpet_address);
- }
-#endif /* X86 */
return 0;
}
Index: arch/x86_64/Kconfig
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/x86_64/Kconfig (mode:100644)
+++ 85c83ea7c8c2d1f7e94ba65fa8d2a77d1022c973/arch/x86_64/Kconfig (mode:100644)
@@ -24,6 +24,14 @@
bool
default y
+config NEWTOD
+ bool
+ default y
+
+config NEWTOD_VSYSCALL
+ bool
+ default y
+
config MMU
bool
default y
Index: arch/x86_64/kernel/Makefile
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/x86_64/kernel/Makefile (mode:100644)
+++ 85c83ea7c8c2d1f7e94ba65fa8d2a77d1022c973/arch/x86_64/kernel/Makefile (mode:100644)
@@ -28,7 +28,6 @@
obj-$(CONFIG_DUMMY_IOMMU) += pci-nommu.o pci-dma.o
obj-$(CONFIG_SWIOTLB) += swiotlb.o
obj-$(CONFIG_KPROBES) += kprobes.o
-obj-$(CONFIG_X86_PM_TIMER) += pmtimer.o
obj-$(CONFIG_MODULES) += module.o
Index: arch/x86_64/kernel/pmtimer.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/x86_64/kernel/pmtimer.c (mode:100644)
+++ /dev/null (tree:85c83ea7c8c2d1f7e94ba65fa8d2a77d1022c973)
@@ -1,101 +0,0 @@
-/* Ported over from i386 by AK, original copyright was:
- *
- * (C) Dominik Brodowski <linux@brodo.de> 2003
- *
- * Driver to use the Power Management Timer (PMTMR) available in some
- * southbridges as primary timing source for the Linux kernel.
- *
- * Based on parts of linux/drivers/acpi/hardware/hwtimer.c, timer_pit.c,
- * timer_hpet.c, and on Arjan van de Ven's implementation for 2.4.
- *
- * This file is licensed under the GPL v2.
- *
- * Dropped all the hardware bug workarounds for now. Hopefully they
- * are not needed on 64bit chipsets.
- */
-
-#include <linux/jiffies.h>
-#include <linux/kernel.h>
-#include <linux/time.h>
-#include <linux/init.h>
-#include <linux/cpumask.h>
-#include <asm/io.h>
-#include <asm/proto.h>
-#include <asm/msr.h>
-#include <asm/vsyscall.h>
-
-/* The I/O port the PMTMR resides at.
- * The location is detected during setup_arch(),
- * in arch/i386/kernel/acpi/boot.c */
-u32 pmtmr_ioport;
-
-/* value of the Power timer at last timer interrupt */
-static u32 offset_delay;
-static u32 last_pmtmr_tick;
-
-#define ACPI_PM_MASK 0xFFFFFF /* limit it to 24 bits */
-
-static inline u32 cyc2us(u32 cycles)
-{
- /* The Power Management Timer ticks at 3.579545 ticks per microsecond.
- * 1 / PM_TIMER_FREQUENCY == 0.27936511 =~ 286/1024 [error: 0.024%]
- *
- * Even with HZ = 100, delta is at maximum 35796 ticks, so it can
- * easily be multiplied with 286 (=0x11E) without having to fear
- * u32 overflows.
- */
- cycles *= 286;
- return (cycles >> 10);
-}
-
-int pmtimer_mark_offset(void)
-{
- static int first_run = 1;
- unsigned long tsc;
- u32 lost;
-
- u32 tick = inl(pmtmr_ioport);
- u32 delta;
-
- delta = cyc2us((tick - last_pmtmr_tick) & ACPI_PM_MASK);
-
- last_pmtmr_tick = tick;
- monotonic_base += delta * NSEC_PER_USEC;
-
- delta += offset_delay;
-
- lost = delta / (USEC_PER_SEC / HZ);
- offset_delay = delta % (USEC_PER_SEC / HZ);
-
- rdtscll(tsc);
- vxtime.last_tsc = tsc - offset_delay * cpu_khz;
-
- /* don't calculate delay for first run,
- or if we've got less then a tick */
- if (first_run || (lost < 1)) {
- first_run = 0;
- offset_delay = 0;
- }
-
- return lost - 1;
-}
-
-unsigned int do_gettimeoffset_pm(void)
-{
- u32 now, offset, delta = 0;
-
- offset = last_pmtmr_tick;
- now = inl(pmtmr_ioport);
- delta = (now - offset) & ACPI_PM_MASK;
-
- return offset_delay + cyc2us(delta);
-}
-
-
-static int __init nopmtimer_setup(char *s)
-{
- pmtmr_ioport = 0;
- return 0;
-}
-
-__setup("nopmtimer", nopmtimer_setup);
Index: arch/x86_64/kernel/time.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/x86_64/kernel/time.c (mode:100644)
+++ 85c83ea7c8c2d1f7e94ba65fa8d2a77d1022c973/arch/x86_64/kernel/time.c (mode:100644)
@@ -26,10 +26,6 @@
#include <linux/sysdev.h>
#include <linux/bcd.h>
#include <linux/kallsyms.h>
-#include <linux/acpi.h>
-#ifdef CONFIG_ACPI
-#include <acpi/achware.h> /* for PM timer frequency */
-#endif
#include <asm/8253pit.h>
#include <asm/pgtable.h>
#include <asm/vsyscall.h>
@@ -39,6 +35,7 @@
#include <asm/sections.h>
#include <linux/cpufreq.h>
#include <linux/hpet.h>
+#include <linux/timeofday.h>
#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/apic.h>
#endif
@@ -47,9 +44,6 @@
EXPORT_SYMBOL(jiffies_64);
-#ifdef CONFIG_CPU_FREQ
-static void cpufreq_delayed_get(void);
-#endif
extern void i8254_timer_resume(void);
extern int using_apic_timer;
@@ -62,6 +56,7 @@
#undef HPET_HACK_ENABLE_DANGEROUS
unsigned int cpu_khz; /* TSC clocks / usec, not used here */
+unsigned long hpet_address;
static unsigned long hpet_period; /* fsecs / HPET clock */
unsigned long hpet_tick; /* HPET clocks / interrupt */
unsigned long vxtime_hz = PIT_TICK_RATE;
@@ -83,108 +78,6 @@
rdtscll(*tsc);
}
-/*
- * do_gettimeoffset() returns microseconds since last timer interrupt was
- * triggered by hardware. A memory read of HPET is slower than a register read
- * of TSC, but much more reliable. It's also synchronized to the timer
- * interrupt. Note that do_gettimeoffset() may return more than hpet_tick, if a
- * timer interrupt has happened already, but vxtime.trigger wasn't updated yet.
- * This is not a problem, because jiffies hasn't updated either. They are bound
- * together by xtime_lock.
- */
-
-static inline unsigned int do_gettimeoffset_tsc(void)
-{
- unsigned long t;
- unsigned long x;
- rdtscll_sync(&t);
- if (t < vxtime.last_tsc) t = vxtime.last_tsc; /* hack */
- x = ((t - vxtime.last_tsc) * vxtime.tsc_quot) >> 32;
- return x;
-}
-
-static inline unsigned int do_gettimeoffset_hpet(void)
-{
- return ((hpet_readl(HPET_COUNTER) - vxtime.last) * vxtime.quot) >> 32;
-}
-
-unsigned int (*do_gettimeoffset)(void) = do_gettimeoffset_tsc;
-
-/*
- * This version of gettimeofday() has microsecond resolution and better than
- * microsecond precision, as we're using at least a 10 MHz (usually 14.31818
- * MHz) HPET timer.
- */
-
-void do_gettimeofday(struct timeval *tv)
-{
- unsigned long seq, t;
- unsigned int sec, usec;
-
- do {
- seq = read_seqbegin(&xtime_lock);
-
- sec = xtime.tv_sec;
- usec = xtime.tv_nsec / 1000;
-
- /* i386 does some correction here to keep the clock
- monotonous even when ntpd is fixing drift.
- But they didn't work for me, there is a non monotonic
- clock anyways with ntp.
- I dropped all corrections now until a real solution can
- be found. Note when you fix it here you need to do the same
- in arch/x86_64/kernel/vsyscall.c and export all needed
- variables in vmlinux.lds. -AK */
-
- t = (jiffies - wall_jiffies) * (1000000L / HZ) +
- do_gettimeoffset();
- usec += t;
-
- } while (read_seqretry(&xtime_lock, seq));
-
- tv->tv_sec = sec + usec / 1000000;
- tv->tv_usec = usec % 1000000;
-}
-
-EXPORT_SYMBOL(do_gettimeofday);
-
-/*
- * settimeofday() first undoes the correction that gettimeofday would do
- * on the time, and then saves it. This is ugly, but has been like this for
- * ages already.
- */
-
-int do_settimeofday(struct timespec *tv)
-{
- time_t wtm_sec, sec = tv->tv_sec;
- long wtm_nsec, nsec = tv->tv_nsec;
-
- if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
- return -EINVAL;
-
- write_seqlock_irq(&xtime_lock);
-
- nsec -= do_gettimeoffset() * 1000 +
- (jiffies - wall_jiffies) * (NSEC_PER_SEC/HZ);
-
- wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
- wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
-
- set_normalized_timespec(&xtime, sec, nsec);
- set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
-
- time_adjust = 0; /* stop active adjtime() */
- time_status |= STA_UNSYNC;
- time_maxerror = NTP_PHASE_LIMIT;
- time_esterror = NTP_PHASE_LIMIT;
-
- write_sequnlock_irq(&xtime_lock);
- clock_was_set();
- return 0;
-}
-
-EXPORT_SYMBOL(do_settimeofday);
-
unsigned long profile_pc(struct pt_regs *regs)
{
unsigned long pc = instruction_pointer(regs);
@@ -284,90 +177,8 @@
spin_unlock(&rtc_lock);
}
-
-/* monotonic_clock(): returns # of nanoseconds passed since time_init()
- * Note: This function is required to return accurate
- * time even in the absence of multiple timer ticks.
- */
-unsigned long long monotonic_clock(void)
-{
- unsigned long seq;
- u32 last_offset, this_offset, offset;
- unsigned long long base;
-
- if (vxtime.mode == VXTIME_HPET) {
- do {
- seq = read_seqbegin(&xtime_lock);
-
- last_offset = vxtime.last;
- base = monotonic_base;
- this_offset = hpet_readl(HPET_T0_CMP) - hpet_tick;
-
- } while (read_seqretry(&xtime_lock, seq));
- offset = (this_offset - last_offset);
- offset *=(NSEC_PER_SEC/HZ)/hpet_tick;
- return base + offset;
- }else{
- do {
- seq = read_seqbegin(&xtime_lock);
-
- last_offset = vxtime.last_tsc;
- base = monotonic_base;
- } while (read_seqretry(&xtime_lock, seq));
- sync_core();
- rdtscll(this_offset);
- offset = (this_offset - last_offset)*1000/cpu_khz;
- return base + offset;
- }
-
-
-}
-EXPORT_SYMBOL(monotonic_clock);
-
-static noinline void handle_lost_ticks(int lost, struct pt_regs *regs)
-{
- static long lost_count;
- static int warned;
-
- if (report_lost_ticks) {
- printk(KERN_WARNING "time.c: Lost %d timer "
- "tick(s)! ", lost);
- print_symbol("rip %s)\n", regs->rip);
- }
-
- if (lost_count == 1000 && !warned) {
- printk(KERN_WARNING
- "warning: many lost ticks.\n"
- KERN_WARNING "Your time source seems to be instable or "
- "some driver is hogging interupts\n");
- print_symbol("rip %s\n", regs->rip);
- if (vxtime.mode == VXTIME_TSC && vxtime.hpet_address) {
- printk(KERN_WARNING "Falling back to HPET\n");
- vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
- vxtime.mode = VXTIME_HPET;
- do_gettimeoffset = do_gettimeoffset_hpet;
- }
- /* else should fall back to PIT, but code missing. */
- warned = 1;
- } else
- lost_count++;
-
-#ifdef CONFIG_CPU_FREQ
- /* In some cases the CPU can change frequency without us noticing
- (like going into thermal throttle)
- Give cpufreq a change to catch up. */
- if ((lost_count+1) % 25 == 0) {
- cpufreq_delayed_get();
- }
-#endif
-}
-
static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
- static unsigned long rtc_update = 0;
- unsigned long tsc;
- int delay, offset = 0, lost = 0;
-
/*
* Here we are in the timer irq handler. We have irqs locally disabled (so we
* don't need spin_lock_irqsave()) but we don't know if the timer_bh is running
@@ -377,60 +188,6 @@
write_seqlock(&xtime_lock);
- if (vxtime.hpet_address) {
- offset = hpet_readl(HPET_T0_CMP) - hpet_tick;
- delay = hpet_readl(HPET_COUNTER) - offset;
- } else {
- spin_lock(&i8253_lock);
- outb_p(0x00, 0x43);
- delay = inb_p(0x40);
- delay |= inb(0x40) << 8;
- spin_unlock(&i8253_lock);
- delay = LATCH - 1 - delay;
- }
-
- rdtscll_sync(&tsc);
-
- if (vxtime.mode == VXTIME_HPET) {
- if (offset - vxtime.last > hpet_tick) {
- lost = (offset - vxtime.last) / hpet_tick - 1;
- }
-
- monotonic_base +=
- (offset - vxtime.last)*(NSEC_PER_SEC/HZ) / hpet_tick;
-
- vxtime.last = offset;
-#ifdef CONFIG_X86_PM_TIMER
- } else if (vxtime.mode == VXTIME_PMTMR) {
- lost = pmtimer_mark_offset();
-#endif
- } else {
- offset = (((tsc - vxtime.last_tsc) *
- vxtime.tsc_quot) >> 32) - (USEC_PER_SEC / HZ);
-
- if (offset < 0)
- offset = 0;
-
- if (offset > (USEC_PER_SEC / HZ)) {
- lost = offset / (USEC_PER_SEC / HZ);
- offset %= (USEC_PER_SEC / HZ);
- }
-
- monotonic_base += (tsc - vxtime.last_tsc)*1000000/cpu_khz ;
-
- vxtime.last_tsc = tsc - vxtime.quot * delay / vxtime.tsc_quot;
-
- if ((((tsc - vxtime.last_tsc) *
- vxtime.tsc_quot) >> 32) < offset)
- vxtime.last_tsc = tsc -
- (((long) offset << 32) / vxtime.tsc_quot) - 1;
- }
-
- if (lost > 0) {
- handle_lost_ticks(lost, regs);
- jiffies += lost;
- }
-
/*
* Do the timer stuff.
*/
@@ -453,20 +210,6 @@
smp_local_timer_interrupt(regs);
#endif
-/*
- * If we have an externally synchronized Linux clock, then update CMOS clock
- * accordingly every ~11 minutes. set_rtc_mmss() will be called in the jiffy
- * closest to exactly 500 ms before the next second. If the update fails, we
- * don't care, as it'll be updated on the next turn, and the problem (time way
- * off) isn't likely to go away much sooner anyway.
- */
-
- if ((~time_status & STA_UNSYNC) && xtime.tv_sec > rtc_update &&
- abs(xtime.tv_nsec - 500000000) <= tick_nsec / 2) {
- set_rtc_mmss(xtime.tv_sec);
- rtc_update = xtime.tv_sec + 660;
- }
-
write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
@@ -567,6 +310,30 @@
return mktime(year, mon, day, hour, min, sec);
}
+/* arch specific timeofday hooks */
+nsec_t read_persistent_clock(void)
+{
+ return (nsec_t)get_cmos_time() * NSEC_PER_SEC;
+}
+
+void sync_persistent_clock(struct timespec ts)
+{
+ static unsigned long rtc_update = 0;
+ /*
+ * If we have an externally synchronized Linux clock, then update
+ * CMOS clock accordingly every ~11 minutes. set_rtc_mmss() will
+ * be called in the jiffy closest to exactly 500 ms before the
+ * next second. If the update fails, we don't care, as it'll be
+ * updated on the next turn, and the problem (time way off) isn't
+ * likely to go away much sooner anyway.
+ */
+ if (ts.tv_sec > rtc_update &&
+ abs(ts.tv_nsec - 500000000) <= tick_nsec / 2) {
+ set_rtc_mmss(xtime.tv_sec);
+ rtc_update = xtime.tv_sec + 660;
+ }
+}
+
#ifdef CONFIG_CPU_FREQ
/* Frequency scaling support. Adjust the TSC based timer when the cpu frequency
@@ -594,23 +361,6 @@
cpufreq_delayed_issched = 0;
}
-/* if we notice lost ticks, schedule a call to cpufreq_get() as it tries
- * to verify the CPU frequency the timing core thinks the CPU is running
- * at is still correct.
- */
-static void cpufreq_delayed_get(void)
-{
- static int warned;
- if (cpufreq_init && !cpufreq_delayed_issched) {
- cpufreq_delayed_issched = 1;
- if (!warned) {
- warned = 1;
- printk(KERN_DEBUG "Losing some ticks... checking if CPU frequency changed.\n");
- }
- schedule_work(&cpufreq_delayed_get_work);
- }
-}
-
static unsigned int ref_freq = 0;
static unsigned long loops_per_jiffy_ref = 0;
@@ -906,13 +656,6 @@
hpet_period;
cpu_khz = hpet_calibrate_tsc();
timename = "HPET";
-#ifdef CONFIG_X86_PM_TIMER
- } else if (pmtmr_ioport) {
- vxtime_hz = PM_TIMER_FREQUENCY;
- timename = "PM";
- pit_init();
- cpu_khz = pit_calibrate_tsc();
-#endif
} else {
pit_init();
cpu_khz = pit_calibrate_tsc();
@@ -963,31 +706,8 @@
*/
void __init time_init_gtod(void)
{
- char *timetype;
-
if (unsynchronized_tsc())
notsc = 1;
- if (vxtime.hpet_address && notsc) {
- timetype = "HPET";
- vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
- vxtime.mode = VXTIME_HPET;
- do_gettimeoffset = do_gettimeoffset_hpet;
-#ifdef CONFIG_X86_PM_TIMER
- /* Using PM for gettimeofday is quite slow, but we have no other
- choice because the TSC is too unreliable on some systems. */
- } else if (pmtmr_ioport && !vxtime.hpet_address && notsc) {
- timetype = "PM";
- do_gettimeoffset = do_gettimeoffset_pm;
- vxtime.mode = VXTIME_PMTMR;
- sysctl_vsyscall = 0;
- printk(KERN_INFO "Disabling vsyscall due to use of PM timer\n");
-#endif
- } else {
- timetype = vxtime.hpet_address ? "HPET/TSC" : "PIT/TSC";
- vxtime.mode = VXTIME_TSC;
- }
-
- printk(KERN_INFO "time.c: Using %s based timekeeping.\n", timetype);
}
__setup("report_lost_ticks", time_setup);
@@ -1010,7 +730,6 @@
static int timer_resume(struct sys_device *dev)
{
- unsigned long flags;
unsigned long sec;
unsigned long ctime = get_cmos_time();
unsigned long sleep_length = (ctime - sleep_start) * HZ;
@@ -1021,10 +740,6 @@
i8254_timer_resume();
sec = ctime + clock_cmos_diff;
- write_seqlock_irqsave(&xtime_lock,flags);
- xtime.tv_sec = sec;
- xtime.tv_nsec = 0;
- write_sequnlock_irqrestore(&xtime_lock,flags);
jiffies += sleep_length;
wall_jiffies += sleep_length;
return 0;
Index: arch/x86_64/kernel/vmlinux.lds.S
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/x86_64/kernel/vmlinux.lds.S (mode:100644)
+++ 85c83ea7c8c2d1f7e94ba65fa8d2a77d1022c973/arch/x86_64/kernel/vmlinux.lds.S (mode:100644)
@@ -71,6 +71,13 @@
. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
.jiffies : AT CACHE_ALIGN(AFTER(.xtime)) { *(.jiffies) }
jiffies = LOADADDR(.jiffies);
+
+ .vsyscall_gtod_data : AT AFTER(.jiffies) { *(.vsyscall_gtod_data) }
+ vsyscall_gtod_data = LOADADDR(.vsyscall_gtod_data);
+ .vsyscall_gtod_lock : AT AFTER(.vsyscall_gtod_data) { *(.vsyscall_gtod_lock) }
+ vsyscall_gtod_lock = LOADADDR(.vsyscall_gtod_lock);
+
+
.vsyscall_1 ADDR(.vsyscall_0) + 1024: AT (LOADADDR(.vsyscall_0) + 1024) { *(.vsyscall_1) }
. = LOADADDR(.vsyscall_0) + 4096;
Index: arch/x86_64/kernel/vsyscall.c
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/arch/x86_64/kernel/vsyscall.c (mode:100644)
+++ 85c83ea7c8c2d1f7e94ba65fa8d2a77d1022c973/arch/x86_64/kernel/vsyscall.c (mode:100644)
@@ -19,6 +19,8 @@
* want per guest time just set the kernel.vsyscall64 sysctl to 0.
*/
+#include <linux/timeofday.h>
+#include <linux/timesource.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/kernel.h>
@@ -40,6 +42,21 @@
int __sysctl_vsyscall __section_sysctl_vsyscall = 1;
seqlock_t __xtime_lock __section_xtime_lock = SEQLOCK_UNLOCKED;
+
+struct vsyscall_gtod_data_t {
+ struct timeval wall_time_tv;
+ struct timezone sys_tz;
+ cycle_t offset_base;
+ struct timesource_t timesource;
+};
+
+extern struct vsyscall_gtod_data_t vsyscall_gtod_data;
+struct vsyscall_gtod_data_t __vsyscall_gtod_data __section_vsyscall_gtod_data;
+
+extern seqlock_t vsyscall_gtod_lock;
+seqlock_t __vsyscall_gtod_lock __section_vsyscall_gtod_lock = SEQLOCK_UNLOCKED;
+
+
#include <asm/unistd.h>
static force_inline void timeval_normalize(struct timeval * tv)
@@ -53,40 +70,54 @@
}
}
-static force_inline void do_vgettimeofday(struct timeval * tv)
+/* XXX - this is ugly. gettimeofday() has a label in it so we can't
+ call it twice.
+ */
+static force_inline int syscall_gtod(struct timeval *tv, struct timezone *tz)
{
- long sequence, t;
- unsigned long sec, usec;
-
+ int ret;
+ asm volatile("syscall"
+ : "=a" (ret)
+ : "0" (__NR_gettimeofday),"D" (tv),"S" (tz) : __syscall_clobber );
+ return ret;
+}
+static force_inline void do_vgettimeofday(struct timeval* tv)
+{
+ cycle_t now, cycle_delta;
+ nsec_t nsec_delta;
+ unsigned long seq;
do {
- sequence = read_seqbegin(&__xtime_lock);
-
- sec = __xtime.tv_sec;
- usec = (__xtime.tv_nsec / 1000) +
- (__jiffies - __wall_jiffies) * (1000000 / HZ);
-
- if (__vxtime.mode != VXTIME_HPET) {
- sync_core();
- rdtscll(t);
- if (t < __vxtime.last_tsc)
- t = __vxtime.last_tsc;
- usec += ((t - __vxtime.last_tsc) *
- __vxtime.tsc_quot) >> 32;
- /* See comment in x86_64 do_gettimeofday. */
- } else {
- usec += ((readl((void *)fix_to_virt(VSYSCALL_HPET) + 0xf0) -
- __vxtime.last) * __vxtime.quot) >> 32;
+ seq = read_seqbegin(&__vsyscall_gtod_lock);
+
+ if (__vsyscall_gtod_data.timesource.type == TIMESOURCE_FUNCTION) {
+ syscall_gtod(tv, NULL);
+ return;
}
- } while (read_seqretry(&__xtime_lock, sequence));
- tv->tv_sec = sec + usec / 1000000;
- tv->tv_usec = usec % 1000000;
+ /* read the timeosurce and calc cycle_delta */
+ now = read_timesource(&__vsyscall_gtod_data.timesource);
+ cycle_delta = (now - __vsyscall_gtod_data.offset_base)
+ & __vsyscall_gtod_data.timesource.mask;
+
+ /* convert cycles to nsecs */
+ nsec_delta = cycle_delta * __vsyscall_gtod_data.timesource.mult;
+ nsec_delta = nsec_delta >> __vsyscall_gtod_data.timesource.shift;
+
+ /* add nsec offset to wall_time_tv */
+ *tv = __vsyscall_gtod_data.wall_time_tv;
+ do_div(nsec_delta, NSEC_PER_USEC);
+ tv->tv_usec += (unsigned long) nsec_delta;
+ while (tv->tv_usec > USEC_PER_SEC) {
+ tv->tv_sec += 1;
+ tv->tv_usec -= USEC_PER_SEC;
+ }
+ } while (read_seqretry(&__vsyscall_gtod_lock, seq));
}
/* RED-PEN may want to readd seq locking, but then the variable should be write-once. */
static force_inline void do_get_tz(struct timezone * tz)
{
- *tz = __sys_tz;
+ *tz = __vsyscall_gtod_data.sys_tz;
}
static force_inline int gettimeofday(struct timeval *tv, struct timezone *tz)
@@ -118,15 +149,15 @@
return 0;
}
-/* This will break when the xtime seconds get inaccurate, but that is
- * unlikely */
static time_t __vsyscall(1) vtime(time_t *t)
{
+ struct timeval tv;
if (unlikely(!__sysctl_vsyscall))
return time_syscall(t);
- else if (t)
- *t = __xtime.tv_sec;
- return __xtime.tv_sec;
+ vgettimeofday(&tv, 0);
+ if (t)
+ *t = tv.tv_sec;
+ return tv.tv_sec;
}
static long __vsyscall(2) venosys_0(void)
@@ -139,6 +170,48 @@
return -ENOSYS;
}
+struct timesource_t* curr_timesource;
+
+void arch_update_vsyscall_gtod(nsec_t wall_time, cycle_t offset_base,
+ struct timesource_t* timesource, int ntp_adj)
+{
+ unsigned long flags;
+
+ write_seqlock_irqsave(&vsyscall_gtod_lock, flags);
+
+ /* XXX - hackitty hack hack. this is terrible! */
+ if (curr_timesource != timesource) {
+ if ((timesource->type == TIMESOURCE_MMIO_32)
+ || (timesource->type == TIMESOURCE_MMIO_64)) {
+ unsigned long vaddr = (unsigned long)timesource->mmio_ptr;
+ pgd_t *pgd = pgd_offset_k(vaddr);
+ pud_t *pud = pud_offset(pgd, vaddr);
+ pmd_t *pmd = pmd_offset(pud,vaddr);
+ pte_t *pte = pte_offset_kernel(pmd, vaddr);
+ *pte = pte_mkread(*pte);
+ }
+ curr_timesource = timesource;
+ }
+
+ /* save off wall time as timeval */
+ vsyscall_gtod_data.wall_time_tv = ns_to_timeval(wall_time);
+
+ /* save offset_base */
+ vsyscall_gtod_data.offset_base = offset_base;
+
+ /* copy current timesource */
+ vsyscall_gtod_data.timesource = *timesource;
+
+ /* apply ntp adjustment to timesource mult */
+ vsyscall_gtod_data.timesource.mult += ntp_adj;
+
+ /* save off current timezone */
+ vsyscall_gtod_data.sys_tz = sys_tz;
+
+ write_sequnlock_irqrestore(&vsyscall_gtod_lock, flags);
+
+}
+
#ifdef CONFIG_SYSCTL
#define SYSCALL 0x050f
@@ -217,6 +290,7 @@
BUG_ON((unsigned long) &vtime != VSYSCALL_ADDR(__NR_vtime));
BUG_ON((VSYSCALL_ADDR(0) != __fix_to_virt(VSYSCALL_FIRST_PAGE)));
map_vsyscall();
+ sysctl_vsyscall = 1;
#ifdef CONFIG_SYSCTL
register_sysctl_table(kernel_root_table2, 0);
#endif
Index: include/asm-generic/div64.h
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/include/asm-generic/div64.h (mode:100644)
+++ 85c83ea7c8c2d1f7e94ba65fa8d2a77d1022c973/include/asm-generic/div64.h (mode:100644)
@@ -55,4 +55,13 @@
#endif /* BITS_PER_LONG */
+#ifndef div_long_long_rem
+#define div_long_long_rem(dividend,divisor,remainder) \
+({ \
+ u64 result = dividend; \
+ *remainder = do_div(result,divisor); \
+ result; \
+})
+#endif
+
#endif /* _ASM_GENERIC_DIV64_H */
Index: include/asm-x86_64/hpet.h
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/include/asm-x86_64/hpet.h (mode:100644)
+++ 85c83ea7c8c2d1f7e94ba65fa8d2a77d1022c973/include/asm-x86_64/hpet.h (mode:100644)
@@ -1,6 +1,6 @@
#ifndef _ASM_X8664_HPET_H
#define _ASM_X8664_HPET_H 1
-
+#include <asm/fixmap.h>
/*
* Documentation on HPET can be found at:
* http://www.intel.com/ial/home/sp/pcmmspec.htm
@@ -44,6 +44,7 @@
#define HPET_TN_SETVAL 0x040
#define HPET_TN_32BIT 0x100
+extern unsigned long hpet_address; /* hpet memory map physical address */
extern int is_hpet_enabled(void);
extern int hpet_rtc_timer_init(void);
extern int oem_force_hpet_timer(void);
Index: include/asm-x86_64/timeofday.h
===================================================================
--- /dev/null (tree:15eb8deaa5b22a81f97a9af307d81b0567115674)
+++ 85c83ea7c8c2d1f7e94ba65fa8d2a77d1022c973/include/asm-x86_64/timeofday.h (mode:100644)
@@ -0,0 +1,4 @@
+#ifndef _ASM_X86_64_TIMEOFDAY_H
+#define _ASM_X86_64_TIMEOFDAY_H
+#include <asm-generic/timeofday.h>
+#endif
Index: include/asm-x86_64/vsyscall.h
===================================================================
--- 15eb8deaa5b22a81f97a9af307d81b0567115674/include/asm-x86_64/vsyscall.h (mode:100644)
+++ 85c83ea7c8c2d1f7e94ba65fa8d2a77d1022c973/include/asm-x86_64/vsyscall.h (mode:100644)
@@ -22,6 +22,8 @@
#define __section_sysctl_vsyscall __attribute__ ((unused, __section__ (".sysctl_vsyscall"), aligned(16)))
#define __section_xtime __attribute__ ((unused, __section__ (".xtime"), aligned(16)))
#define __section_xtime_lock __attribute__ ((unused, __section__ (".xtime_lock"), aligned(16)))
+#define __section_vsyscall_gtod_data __attribute__ ((unused, __section__ (".vsyscall_gtod_data"),aligned(16)))
+#define __section_vsyscall_gtod_lock __attribute__ ((unused, __section__ (".vsyscall_gtod_lock"),aligned(16)))
#define VXTIME_TSC 1
#define VXTIME_HPET 2
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 4/4] new timeofday i386 and x86-64 timesources (v. B1)
2005-06-01 23:13 ` [PATCH 3/4] new timeofday x86-64 " john stultz
@ 2005-06-01 23:16 ` john stultz
2005-06-02 0:37 ` [PATCH 3/4] new timeofday x86-64 arch specific changes " Parag Warudkar
1 sibling, 0 replies; 11+ messages in thread
From: john stultz @ 2005-06-01 23:16 UTC (permalink / raw)
To: Andrew Morton
Cc: lkml, Tim Schmielau, George Anzinger, albert, Ulrich Windl,
Christoph Lameter, Dominik Brodowski, David Mosberger, Andi Kleen,
paulus, schwidefsky, keith maanthey, Chris McDermott, Max Asbock,
mahuja, Nishanth Aravamudan, Darren Hart, Darrick J. Wong,
Anton Blanchard, donf, mpm, benh
Andrew, All,
I'm just respinning this to resolve a conflict w/ the CPUFREQ changes
Linus accepted last night.
This patch implements the time sources shared between i386 and x86-64
(acpi_pm, cyclone, hpet, pit, tsc and tsc-interp). The patch should
apply on top of the timeofday-arch-i386_B1.patch as well as the arch-
x86-64_B1.patch.
The patch should be fairly straight forward, only adding the new
timesources.
Andrew, please consider for inclusion for testing into your tree (I'd
like to target around end of July for possible inclusion into mainline).
thanks
-john
linux-2.6.12-rc5_timeofday-timesources-i386_B1.patch
====================================================
Index: drivers/acpi/processor_idle.c
===================================================================
--- 6f1948595e5fa374fc552a4a01fe5524530ea1dd/drivers/acpi/processor_idle.c (mode:100644)
+++ d863b75b6ce09943359e994eed96c5ee8e72dc81/drivers/acpi/processor_idle.c (mode:100644)
@@ -162,6 +162,7 @@
return;
}
+extern void tsc_c3_compensate(unsigned long usecs);
static void acpi_processor_idle (void)
{
@@ -309,6 +310,10 @@
t2 = inl(acpi_fadt.xpm_tmr_blk.address);
/* Enable bus master arbitration */
acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0, ACPI_MTX_DO_NOT_LOCK);
+
+ /* compensate for TSC pause */
+ tsc_c3_compensate((((t2-t1)&0xFFFFFF)*286)>>10);
+
/* Re-enable interrupts */
local_irq_enable();
/* Compute time (ticks) that we were actually asleep */
Index: drivers/timesource/Makefile
===================================================================
--- 6f1948595e5fa374fc552a4a01fe5524530ea1dd/drivers/timesource/Makefile (mode:100644)
+++ d863b75b6ce09943359e994eed96c5ee8e72dc81/drivers/timesource/Makefile (mode:100644)
@@ -1 +1,8 @@
obj-y += jiffies.o
+
+obj-$(CONFIG_X86) += tsc.o
+obj-$(CONFIG_X86) += i386_pit.o
+obj-$(CONFIG_X86) += tsc-interp.o
+obj-$(CONFIG_X86_CYCLONE_TIMER) += cyclone.o
+obj-$(CONFIG_X86_PM_TIMER) += acpi_pm.o
+obj-$(CONFIG_HPET_TIMER) += hpet.o
Index: drivers/timesource/acpi_pm.c
===================================================================
--- /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
+++ d863b75b6ce09943359e994eed96c5ee8e72dc81/drivers/timesource/acpi_pm.c (mode:100644)
@@ -0,0 +1,140 @@
+/*
+ * linux/drivers/timesource/acpi_pm.c
+ *
+ * This file contains the ACPI PM based time source.
+ *
+ * This code was largely moved from the i386 timer_pm.c file
+ * which was (C) Dominik Brodowski <linux@brodo.de> 2003
+ * and contained the following comments:
+ *
+ * Driver to use the Power Management Timer (PMTMR) available in some
+ * southbridges as primary timing source for the Linux kernel.
+ *
+ * Based on parts of linux/drivers/acpi/hardware/hwtimer.c, timer_pit.c,
+ * timer_hpet.c, and on Arjan van de Ven's implementation for 2.4.
+ *
+ * This file is licensed under the GPL v2.
+ */
+
+
+#include <linux/timesource.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <asm/io.h>
+
+/* Number of PMTMR ticks expected during calibration run */
+#define PMTMR_TICKS_PER_SEC 3579545
+
+#if (CONFIG_X86 && (!CONFIG_X86_64))
+#include "mach_timer.h"
+#define PMTMR_EXPECTED_RATE \
+ ((CALIBRATE_LATCH * (PMTMR_TICKS_PER_SEC >> 10)) / (CLOCK_TICK_RATE>>10))
+#endif
+
+/* The I/O port the PMTMR resides at.
+ * The location is detected during setup_arch(),
+ * in arch/i386/acpi/boot.c */
+u32 pmtmr_ioport = 0;
+
+#define ACPI_PM_MASK 0xFFFFFF /* limit it to 24 bits */
+
+static inline u32 read_pmtmr(void)
+{
+ u32 v1=0,v2=0,v3=0;
+ /* It has been reported that because of various broken
+ * chipsets (ICH4, PIIX4 and PIIX4E) where the ACPI PM time
+ * source is not latched, so you must read it multiple
+ * times to insure a safe value is read.
+ */
+ do {
+ v1 = inl(pmtmr_ioport);
+ v2 = inl(pmtmr_ioport);
+ v3 = inl(pmtmr_ioport);
+ } while ((v1 > v2 && v1 < v3) || (v2 > v3 && v2 < v1)
+ || (v3 > v1 && v3 < v2));
+
+ /* mask the output to 24 bits */
+ return v2 & ACPI_PM_MASK;
+}
+
+
+static cycle_t acpi_pm_read(void)
+{
+ return (cycle_t)read_pmtmr();
+}
+
+struct timesource_t timesource_acpi_pm = {
+ .name = "acpi_pm",
+ .priority = 200,
+ .type = TIMESOURCE_FUNCTION,
+ .read_fnct = acpi_pm_read,
+ .mask = (cycle_t)ACPI_PM_MASK,
+ .mult = 0, /*to be caluclated*/
+ .shift = 22,
+};
+
+#if (CONFIG_X86 && (!CONFIG_X86_64))
+/*
+ * Some boards have the PMTMR running way too fast. We check
+ * the PMTMR rate against PIT channel 2 to catch these cases.
+ */
+static int __init verify_pmtmr_rate(void)
+{
+ u32 value1, value2;
+ unsigned long count, delta;
+
+ mach_prepare_counter();
+ value1 = read_pmtmr();
+ mach_countup(&count);
+ value2 = read_pmtmr();
+ delta = (value2 - value1) & ACPI_PM_MASK;
+
+ /* Check that the PMTMR delta is within 5% of what we expect */
+ if (delta < (PMTMR_EXPECTED_RATE * 19) / 20 ||
+ delta > (PMTMR_EXPECTED_RATE * 21) / 20) {
+ printk(KERN_INFO "PM-Timer running at invalid rate: %lu%% of normal - aborting.\n", 100UL * delta / PMTMR_EXPECTED_RATE);
+ return -1;
+ }
+
+ return 0;
+}
+#else
+#define verify_pmtmr_rate() (0)
+#endif
+
+static int __init init_acpi_pm_timesource(void)
+{
+ u32 value1, value2;
+ unsigned int i;
+
+ if (!pmtmr_ioport)
+ return -ENODEV;
+
+ timesource_acpi_pm.mult = timesource_hz2mult(PMTMR_TICKS_PER_SEC,
+ timesource_acpi_pm.shift);
+
+ /* "verify" this timing source */
+ value1 = read_pmtmr();
+ for (i = 0; i < 10000; i++) {
+ value2 = read_pmtmr();
+ if (value2 == value1)
+ continue;
+ if (value2 > value1)
+ goto pm_good;
+ if ((value2 < value1) && ((value2) < 0xFFF))
+ goto pm_good;
+ printk(KERN_INFO "PM-Timer had inconsistent results: 0x%#x, 0x%#x - aborting.\n", value1, value2);
+ return -EINVAL;
+ }
+ printk(KERN_INFO "PM-Timer had no reasonable result: 0x%#x - aborting.\n", value1);
+ return -ENODEV;
+
+pm_good:
+ if (verify_pmtmr_rate() != 0)
+ return -ENODEV;
+
+ register_timesource(×ource_acpi_pm);
+ return 0;
+}
+
+module_init(init_acpi_pm_timesource);
Index: drivers/timesource/cyclone.c
===================================================================
--- /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
+++ d863b75b6ce09943359e994eed96c5ee8e72dc81/drivers/timesource/cyclone.c (mode:100644)
@@ -0,0 +1,135 @@
+#include <linux/timesource.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/timex.h>
+#include <linux/init.h>
+
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include "mach_timer.h"
+
+#define CYCLONE_CBAR_ADDR 0xFEB00CD0 /* base address ptr*/
+#define CYCLONE_PMCC_OFFSET 0x51A0 /* offset to control register */
+#define CYCLONE_MPCS_OFFSET 0x51A8 /* offset to select register */
+#define CYCLONE_MPMC_OFFSET 0x51D0 /* offset to count register */
+#define CYCLONE_TIMER_FREQ 100000000
+#define CYCLONE_TIMER_MASK (0xFFFFFFFF) /* 32 bit mask */
+
+int use_cyclone = 0;
+
+struct timesource_t timesource_cyclone = {
+ .name = "cyclone",
+ .priority = 100,
+ .type = TIMESOURCE_MMIO_32,
+ .mmio_ptr = NULL, /* to be set */
+ .mask = (cycle_t)CYCLONE_TIMER_MASK,
+ .mult = 10,
+ .shift = 0,
+};
+
+static unsigned long __init calibrate_cyclone(void)
+{
+ unsigned long start, end, delta;
+ unsigned long i, count;
+ unsigned long cyclone_freq_khz;
+
+ /* repeat 3 times to make sure the cache is warm */
+ for(i=0; i < 3; i++) {
+ mach_prepare_counter();
+ start = readl(timesource_cyclone.mmio_ptr);
+ mach_countup(&count);
+ end = readl(timesource_cyclone.mmio_ptr);
+ }
+
+ delta = end - start;
+ printk("cyclone delta: %lu\n", delta);
+ delta *= (ACTHZ/1000)>>8;
+ printk("delta*hz = %lu\n", delta);
+ cyclone_freq_khz = delta/CALIBRATE_ITERATION;
+ printk("calculated cyclone_freq: %lu khz\n", cyclone_freq_khz);
+ return cyclone_freq_khz;
+}
+
+static int __init init_cyclone_timesource(void)
+{
+ unsigned long base; /* saved value from CBAR */
+ unsigned long offset;
+ u32 __iomem* reg;
+ u32 __iomem* volatile cyclone_timer; /* Cyclone MPMC0 register */
+ unsigned long khz;
+ int i;
+
+ /*make sure we're on a summit box*/
+ if (!use_cyclone) return -ENODEV;
+
+ printk(KERN_INFO "Summit chipset: Starting Cyclone Counter.\n");
+
+ /* find base address */
+ offset = CYCLONE_CBAR_ADDR;
+ reg = ioremap_nocache(offset, sizeof(reg));
+ if(!reg){
+ printk(KERN_ERR "Summit chipset: Could not find valid CBAR register.\n");
+ return -ENODEV;
+ }
+ /* even on 64bit systems, this is only 32bits */
+ base = readl(reg);
+ if(!base){
+ printk(KERN_ERR "Summit chipset: Could not find valid CBAR value.\n");
+ return -ENODEV;
+ }
+ iounmap(reg);
+
+ /* setup PMCC */
+ offset = base + CYCLONE_PMCC_OFFSET;
+ reg = ioremap_nocache(offset, sizeof(reg));
+ if(!reg){
+ printk(KERN_ERR "Summit chipset: Could not find valid PMCC register.\n");
+ return -ENODEV;
+ }
+ writel(0x00000001,reg);
+ iounmap(reg);
+
+ /* setup MPCS */
+ offset = base + CYCLONE_MPCS_OFFSET;
+ reg = ioremap_nocache(offset, sizeof(reg));
+ if(!reg){
+ printk(KERN_ERR "Summit chipset: Could not find valid MPCS register.\n");
+ return -ENODEV;
+ }
+ writel(0x00000001,reg);
+ iounmap(reg);
+
+ /* map in cyclone_timer */
+ offset = base + CYCLONE_MPMC_OFFSET;
+ cyclone_timer = ioremap_nocache(offset, sizeof(u64));
+ if(!cyclone_timer){
+ printk(KERN_ERR "Summit chipset: Could not find valid MPMC register.\n");
+ return -ENODEV;
+ }
+
+ /*quick test to make sure its ticking*/
+ for(i=0; i<3; i++){
+ u32 old = readl(cyclone_timer);
+ int stall = 100;
+ while(stall--) barrier();
+ if(readl(cyclone_timer) == old){
+ printk(KERN_ERR "Summit chipset: Counter not counting! DISABLED\n");
+ iounmap(cyclone_timer);
+ cyclone_timer = NULL;
+ return -ENODEV;
+ }
+ }
+ timesource_cyclone.mmio_ptr = cyclone_timer;
+
+ /* sort out mult/shift values */
+ khz = calibrate_cyclone();
+ timesource_cyclone.shift = 22;
+ timesource_cyclone.mult = timesource_khz2mult(khz,
+ timesource_cyclone.shift);
+
+ register_timesource(×ource_cyclone);
+
+ return 0;
+}
+
+module_init(init_cyclone_timesource);
Index: drivers/timesource/hpet.c
===================================================================
--- /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
+++ d863b75b6ce09943359e994eed96c5ee8e72dc81/drivers/timesource/hpet.c (mode:100644)
@@ -0,0 +1,59 @@
+#include <linux/timesource.h>
+#include <linux/hpet.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <asm/io.h>
+#include <asm/hpet.h>
+
+#define HPET_MASK (0xFFFFFFFF)
+#define HPET_SHIFT 22
+
+/* FSEC = 10^-15 NSEC = 10^-9 */
+#define FSEC_PER_NSEC 1000000
+
+struct timesource_t timesource_hpet = {
+ .name = "hpet",
+ .priority = 300,
+ .type = TIMESOURCE_MMIO_32,
+ .mmio_ptr = NULL,
+ .mask = (cycle_t)HPET_MASK,
+ .mult = 0, /* set below */
+ .shift = HPET_SHIFT,
+};
+
+static int __init init_hpet_timesource(void)
+{
+ unsigned long hpet_period;
+ void __iomem* hpet_base;
+ u64 tmp;
+
+ if (!hpet_address)
+ return -ENODEV;
+
+ /* calculate the hpet address */
+ hpet_base =
+ (void __iomem*)ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
+ timesource_hpet.mmio_ptr = hpet_base + HPET_COUNTER;
+
+ /* calculate the frequency */
+ hpet_period = readl(hpet_base + HPET_PERIOD);
+
+
+ /* hpet period is in femto seconds per cycle
+ * so we need to convert this to ns/cyc units
+ * aproximated by mult/2^shift
+ *
+ * fsec/cyc * 1nsec/1000000fsec = nsec/cyc = mult/2^shift
+ * fsec/cyc * 1ns/1000000fsec * 2^shift = mult
+ * fsec/cyc * 2^shift * 1nsec/1000000fsec = mult
+ * (fsec/cyc << shift)/1000000 = mult
+ * (hpet_period << shift)/FSEC_PER_NSEC = mult
+ */
+ tmp = (u64)hpet_period << HPET_SHIFT;
+ do_div(tmp, FSEC_PER_NSEC);
+ timesource_hpet.mult = (u32)tmp;
+
+ register_timesource(×ource_hpet);
+ return 0;
+}
+module_init(init_hpet_timesource);
Index: drivers/timesource/i386_pit.c
===================================================================
--- /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
+++ d863b75b6ce09943359e994eed96c5ee8e72dc81/drivers/timesource/i386_pit.c (mode:100644)
@@ -0,0 +1,64 @@
+#include <linux/timesource.h>
+#include <linux/jiffies.h>
+#include <linux/init.h>
+/* pit timesource does not build on x86-64 */
+#ifndef CONFIG_X86_64
+#include <asm/io.h>
+#include "io_ports.h"
+
+extern spinlock_t i8253_lock;
+
+/* Since the PIT overflows every tick, its not very useful
+ * to just read by itself. So use jiffies to emulate a free
+ * running counter.
+ */
+
+static cycle_t pit_read(void)
+{
+ unsigned long flags, seq;
+ int count;
+ u64 jifs;
+
+ do {
+ seq = read_seqbegin(&xtime_lock);
+
+ spin_lock_irqsave(&i8253_lock, flags);
+
+ outb_p(0x00, PIT_MODE); /* latch the count ASAP */
+ count = inb_p(PIT_CH0); /* read the latched count */
+ count |= inb_p(PIT_CH0) << 8;
+
+ /* VIA686a test code... reset the latch if count > max + 1 */
+ if (count > LATCH) {
+ outb_p(0x34, PIT_MODE);
+ outb_p(LATCH & 0xff, PIT_CH0);
+ outb(LATCH >> 8, PIT_CH0);
+ count = LATCH - 1;
+ }
+ spin_unlock_irqrestore(&i8253_lock, flags);
+ jifs = get_jiffies_64() - INITIAL_JIFFIES;
+ } while (read_seqretry(&xtime_lock, seq));
+
+ count = (LATCH-1) - count;
+
+ return (cycle_t)(jifs * LATCH) + count;
+}
+
+static struct timesource_t timesource_pit = {
+ .name = "pit",
+ .priority = 0,
+ .type = TIMESOURCE_FUNCTION,
+ .read_fnct = pit_read,
+ .mask = (cycle_t)-1,
+ .mult = 0,
+ .shift = 20,
+};
+
+static int __init init_pit_timesource(void)
+{
+ timesource_pit.mult = timesource_hz2mult(CLOCK_TICK_RATE, 20);
+ register_timesource(×ource_pit);
+ return 0;
+}
+module_init(init_pit_timesource);
+#endif
Index: drivers/timesource/tsc-interp.c
===================================================================
--- /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
+++ d863b75b6ce09943359e994eed96c5ee8e72dc81/drivers/timesource/tsc-interp.c (mode:100644)
@@ -0,0 +1,112 @@
+/* TSC-Jiffies Interpolation timesource
+ Example interpolation timesource.
+TODO:
+ o per-cpu TSC offsets
+*/
+#include <linux/timesource.h>
+#include <linux/timer.h>
+#include <linux/timex.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/threads.h>
+#include <linux/smp.h>
+
+static unsigned long current_cpu_khz = 0;
+
+static seqlock_t tsc_interp_lock = SEQLOCK_UNLOCKED;
+static cycle_t tsc_then;
+static cycle_t jiffies_then;
+struct timer_list tsc_interp_timer;
+
+static unsigned long mult, shift;
+
+#define NSEC_PER_JIFFY ((((unsigned long long)NSEC_PER_SEC)<<8)/ACTHZ)
+#define SHIFT_VAL 22
+
+static cycle_t read_tsc_interp(void);
+static void tsc_interp_update_callback(void);
+
+static struct timesource_t timesource_tsc_interp = {
+ .name = "tsc-interp",
+ .priority = 20,
+ .type = TIMESOURCE_FUNCTION,
+ .read_fnct = read_tsc_interp,
+ .mask = (cycle_t)-1,
+ .mult = 1<<SHIFT_VAL,
+ .shift = SHIFT_VAL,
+ .update_callback = tsc_interp_update_callback,
+};
+
+static void tsc_interp_sync(unsigned long unused)
+{
+ cycle_t tsc_now;
+ u64 jiffies_now;
+
+ do {
+ jiffies_now = get_jiffies_64() - INITIAL_JIFFIES;
+ rdtscll(tsc_now);
+ } while (jiffies_now != (get_jiffies_64() - INITIAL_JIFFIES));
+
+ write_seqlock(&tsc_interp_lock);
+ jiffies_then = jiffies_now;
+ tsc_then = tsc_now;
+ write_sequnlock(&tsc_interp_lock);
+
+ mod_timer(&tsc_interp_timer, jiffies+1);
+}
+
+
+static cycle_t read_tsc_interp(void)
+{
+ cycle_t ret;
+ cycle_t now, then;
+ u64 jiffs_now, jiffs_then;
+ unsigned long seq;
+
+ do {
+ seq = read_seqbegin(&tsc_interp_lock);
+
+ jiffs_now = get_jiffies_64() - INITIAL_JIFFIES;
+ jiffs_then = jiffies_then;
+ then = tsc_then;
+
+ } while (read_seqretry(&tsc_interp_lock, seq));
+
+ rdtscll(now);
+ ret = jiffs_then * NSEC_PER_JIFFY;
+ if (jiffs_then == jiffs_now)
+ ret += min((cycle_t)NSEC_PER_JIFFY,(cycle_t)((now - then)*mult)>> shift);
+ else
+ ret += (jiffs_now - jiffs_then)*NSEC_PER_JIFFY;
+
+ return ret;
+}
+
+static void tsc_interp_update_callback(void)
+{
+ /* only update if cpu_khz has changed */
+ if (current_cpu_khz != cpu_khz){
+ current_cpu_khz = cpu_khz;
+ mult = timesource_khz2mult(current_cpu_khz, shift);
+ }
+}
+
+
+static int __init init_tsc_interp_timesource(void)
+{
+ /* TSC initialization is done in arch/i386/kernel/tsc.c */
+ if (cpu_has_tsc && cpu_khz) {
+ current_cpu_khz = cpu_khz;
+ shift = SHIFT_VAL;
+ mult = timesource_khz2mult(current_cpu_khz, shift);
+ /* setup periodic soft-timer */
+ init_timer(&tsc_interp_timer);
+ tsc_interp_timer.function = tsc_interp_sync;
+ tsc_interp_timer.expires = jiffies;
+ add_timer(&tsc_interp_timer);
+
+ register_timesource(×ource_tsc_interp);
+ }
+ return 0;
+}
+module_init(init_tsc_interp_timesource);
Index: drivers/timesource/tsc.c
===================================================================
--- /dev/null (tree:6f1948595e5fa374fc552a4a01fe5524530ea1dd)
+++ d863b75b6ce09943359e994eed96c5ee8e72dc81/drivers/timesource/tsc.c (mode:100644)
@@ -0,0 +1,95 @@
+/* TODO:
+ * o better calibration
+ */
+
+#include <linux/timesource.h>
+#include <linux/timex.h>
+#include <linux/init.h>
+
+static unsigned long current_cpu_khz = 0;
+static cycle_t tsc_c3_offset;
+
+static cycle_t read_safe_tsc(void);
+static void tsc_update_callback(void);
+
+static struct timesource_t timesource_safe_tsc = {
+ .name = "c3tsc",
+ .priority = 26,
+ .type = TIMESOURCE_FUNCTION,
+ .read_fnct = read_safe_tsc,
+ .mask = (cycle_t)-1,
+ .mult = 0, /* to be set */
+ .shift = 22,
+ .update_callback = tsc_update_callback,
+};
+
+static struct timesource_t timesource_raw_tsc = {
+ .name = "tsc",
+ .priority = 25,
+ .type = TIMESOURCE_CYCLES,
+ .mask = (cycle_t)-1,
+ .mult = 0, /* to be set */
+ .shift = 22,
+ .update_callback = tsc_update_callback,
+};
+
+static struct timesource_t timesource_tsc;
+
+static int use_safe_tsc = 0;
+
+static cycle_t read_safe_tsc(void)
+{
+ cycle_t ret;
+ rdtscll(ret);
+ return ret + tsc_c3_offset;
+}
+
+void tsc_c3_compensate(unsigned long usecs)
+{
+ u64 nsecs = (u64)usecs * 1000;
+ cycle_t offset = nsecs << timesource_tsc.shift;
+
+ if (!timesource_tsc.mult)
+ return;
+
+ if(!use_safe_tsc)
+ use_safe_tsc = 1;
+
+ do_div(offset, timesource_tsc.mult);
+ tsc_c3_offset += offset;
+}
+
+
+static void tsc_update_callback(void)
+{
+ /* check to see if we should switch to the safe timesource */
+ if (use_safe_tsc &&
+ strncmp(timesource_tsc.name, "c3tsc", 5)) {
+ printk("Falling back to C3 safe TSC\n");
+ timesource_safe_tsc.mult = timesource_tsc.mult;
+ timesource_tsc = timesource_safe_tsc;
+ }
+
+ /* only update if cpu_khz has changed */
+ if (current_cpu_khz != cpu_khz){
+ current_cpu_khz = cpu_khz;
+ timesource_tsc.mult = timesource_khz2mult(current_cpu_khz,
+ timesource_tsc.shift);
+ }
+}
+
+static int __init init_tsc_timesource(void)
+{
+ timesource_tsc = timesource_raw_tsc;
+ /* TSC initialization is done in arch/i386/kernel/tsc.c */
+ if (cpu_has_tsc && cpu_khz) {
+ current_cpu_khz = cpu_khz;
+ timesource_tsc.mult = timesource_khz2mult(current_cpu_khz,
+ timesource_tsc.shift);
+ register_timesource(×ource_tsc);
+ }
+ return 0;
+}
+
+module_init(init_tsc_timesource);
+
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 3/4] new timeofday x86-64 arch specific changes (v. B1)
2005-06-01 23:13 ` [PATCH 3/4] new timeofday x86-64 " john stultz
2005-06-01 23:16 ` [PATCH 4/4] new timeofday i386 and x86-64 timesources " john stultz
@ 2005-06-02 0:37 ` Parag Warudkar
2005-06-02 17:34 ` john stultz
1 sibling, 1 reply; 11+ messages in thread
From: Parag Warudkar @ 2005-06-02 0:37 UTC (permalink / raw)
To: john stultz
Cc: Andi Kleen, lkml, Tim Schmielau, George Anzinger, albert,
Ulrich Windl, Christoph Lameter, Dominik Brodowski,
David Mosberger, Andrew Morton, paulus, schwidefsky,
keith maanthey, Chris McDermott, Max Asbock, mahuja,
Nishanth Aravamudan, Darren Hart, Darrick J. Wong,
Anton Blanchard, donf, mpm, benh
[-- Attachment #1: Type: text/plain, Size: 257 bytes --]
On Wednesday 01 June 2005 19:13, john stultz wrote:
> This patch converts the x86-64 arch to use the new timeofday
> infrastructure. It applies on top of my timeofday-core_B1 patch.
This one fails to apply - time.c HUNK #1 gets rejected. (Attached)
Parag
[-- Attachment #2: time.c.rej --]
[-- Type: text/x-csrc, Size: 489 bytes --]
***************
*** 26,35 ****
#include <linux/sysdev.h>
#include <linux/bcd.h>
#include <linux/kallsyms.h>
- #include <linux/acpi.h>
- #ifdef CONFIG_ACPI
- #include <acpi/achware.h> /* for PM timer frequency */
- #endif
#include <asm/8253pit.h>
#include <asm/pgtable.h>
#include <asm/vsyscall.h>
--- 26,31 ----
#include <linux/sysdev.h>
#include <linux/bcd.h>
#include <linux/kallsyms.h>
#include <asm/8253pit.h>
#include <asm/pgtable.h>
#include <asm/vsyscall.h>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 1/4] new timeofday core subsystem (v. B1)
2005-06-01 23:09 [PATCH 1/4] new timeofday core subsystem (v. B1) john stultz
2005-06-01 23:12 ` [PATCH 2/4] new timeofday i386 arch specific changes " john stultz
@ 2005-06-02 1:08 ` Frank Sorenson
2005-06-02 18:00 ` john stultz
2005-06-03 7:29 ` Frank Sorenson
2 siblings, 1 reply; 11+ messages in thread
From: Frank Sorenson @ 2005-06-02 1:08 UTC (permalink / raw)
To: john stultz
Cc: Andrew Morton, lkml, Tim Schmielau, George Anzinger, albert,
Ulrich Windl, Christoph Lameter, Dominik Brodowski,
David Mosberger, Andi Kleen, paulus, schwidefsky, keith maanthey,
Chris McDermott, Max Asbock, mahuja, Nishanth Aravamudan,
Darren Hart, Darrick J. Wong, Anton Blanchard, donf, mpm, benh
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Patch 1 appears to be truncated, so here's an updated patch, completed
from version B0.
Frank
- --
Frank Sorenson - KD7TZK
Systems Manager, Computer Science Department
Brigham Young University
frank@tuxrocks.com
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[-- Attachment #2: TOD-B1-1.patch --]
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Andrew, All,
I'm just re-spinning this to resolve a conflict w/ the CPUFREQ changes
Linus accepted last night.
With the goal to simplify, streamline and consolidate the time-of-day
infrastructure, I propose the following common implementation across all
arches. This will allow generic bugs to be fixed once, reduce code
duplication, and with many architectures sharing the same time source,
this allows drivers to be written once for multiple architectures.
Additionally it will better delineate the lines between the soft-timer
subsystem and the time-of-day subsystem, opening the door for more
flexible and better soft-timer management.
Features of this design:
========================
o Splits time of day management from timer interrupts
o Consolidates a large amount of code
o Generic algorithms which use time-source drivers chosen at runtime
o More consistent and readable code
o Uses nanoseconds as the kernel's base time unit
o Clearly separates the NTP code from the time code
For another description on the rework, see here:
http://lwn.net/Articles/120850/ (Many thanks to the LWN team for that
easy to understand writeup!)
This patch implements the architecture independent portion of the new
time of day subsystem. Included below is timeofday.c (which includes all
the time of day management and accessor functions), ntp.c (which
includes the ntp adjustment code, leapsecond processing, and ntp kernel
state machine code), timesource.c (for timesource specific management
functions), interface definition .h files, the example jiffies
timesource (lowest common denominator time source, mainly for use as
example code) and minimal hooks into arch independent code.
The patch does nothing without at least minimal architecture specific
hooks (i386, x86-64 to follow), and it should be able to be applied to a
tree without affecting the existing code.
Finally I'd like to thank the following people who have contributed
ideas, criticism, testing and code that has helped shape this work:
George Anzinger, Nish Aravamudan, Max Asbock, Dominik Brodowski, Darren
Hart, Christoph Lameter, Matt Mackal, Keith Mannthey, Martin
Schwidefsky, Frank Sorenson, Ulrich Windl, Darrick Wong, and any others
whom I've accidentally forgotten.
Andrew, please consider for inclusion for testing into your tree (I'd
like to target around end of July for possible inclusion into mainline).
thanks
-john
Signed-off-by: John Stultz <johnstul@us.ibm.com>
linux-2.6.12-rc5_timeofday-core_B1.patch
========================================
Index: drivers/Makefile
===================================================================
--- d414ab9a0f0995899c2e76c232714410f787b209/drivers/Makefile (mode:100644)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/drivers/Makefile (mode:100644)
@@ -64,3 +64,4 @@
obj-$(CONFIG_BLK_DEV_SGIIOC4) += sn/
obj-y += firmware/
obj-$(CONFIG_CRYPTO) += crypto/
+obj-$(CONFIG_NEWTOD) += timesource/
Index: drivers/char/hangcheck-timer.c
===================================================================
--- d414ab9a0f0995899c2e76c232714410f787b209/drivers/char/hangcheck-timer.c (mode:100644)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/drivers/char/hangcheck-timer.c (mode:100644)
@@ -49,6 +49,7 @@
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <linux/sysrq.h>
+#include <linux/timeofday.h>
#define VERSION_STR "0.9.0"
@@ -130,8 +131,12 @@
#endif
#ifdef HAVE_MONOTONIC
+#ifndef CONFIG_NEWTOD
extern unsigned long long monotonic_clock(void);
#else
+#define monotonic_clock() do_monotonic_clock()
+#endif
+#else
static inline unsigned long long monotonic_clock(void)
{
# ifdef __s390__
Index: drivers/timesource/Makefile
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/drivers/timesource/Makefile (mode:100644)
@@ -0,0 +1 @@
+obj-y += jiffies.o
Index: drivers/timesource/jiffies.c
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/drivers/timesource/jiffies.c (mode:100644)
@@ -0,0 +1,69 @@
+/***********************************************************************
+* linux/drivers/timesource/jiffies.c
+*
+* This file contains the jiffies based time source.
+*
+* Copyright (C) 2004, 2005 IBM, John Stultz (johnstul@us.ibm.com)
+*
+* This program is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation; either version 2 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program; if not, write to the Free Software
+* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*
+************************************************************************/
+#include <linux/timesource.h>
+#include <linux/jiffies.h>
+#include <linux/init.h>
+
+/* The Jiffies based timesource is the lowest common
+ * denominator time source which should function on
+ * all systems. It has the same coarse resolution as
+ * the timer interrupt frequency HZ and it suffers
+ * inaccuracies caused by missed or lost timer
+ * interrupts and the inability for the timer
+ * interrupt hardware to accuratly tick at the
+ * requested HZ value. It is also not reccomended
+ * for "tick-less" systems.
+ */
+#define NSEC_PER_JIFFY ((u32)((((u64)NSEC_PER_SEC)<<8)/ACTHZ))
+
+/* Since jiffies uses a simple NSEC_PER_JIFFY multiplier
+ * conversion, the .shift value could be zero. However
+ * this would make NTP adjustments impossible as they are
+ * in units of 1/2^.shift. Thus we use JIFFIES_SHIFT to
+ * shift both the nominator and denominator the same
+ * amount, and give ntp adjustments in units of 1/2^10
+ */
+#define JIFFIES_SHIFT 10
+
+static cycle_t jiffies_read(void)
+{
+ cycle_t ret = get_jiffies_64();
+ return ret;
+}
+
+struct timesource_t timesource_jiffies = {
+ .name = "jiffies",
+ .priority = 0, /* lowest priority*/
+ .type = TIMESOURCE_FUNCTION,
+ .read_fnct = jiffies_read,
+ .mask = (cycle_t)-1,
+ .mult = NSEC_PER_JIFFY << JIFFIES_SHIFT, /* See above for details */
+ .shift = JIFFIES_SHIFT,
+};
+
+static int __init init_jiffies_timesource(void)
+{
+ register_timesource(×ource_jiffies);
+ return 0;
+}
+module_init(init_jiffies_timesource);
Index: include/asm-generic/timeofday.h
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/include/asm-generic/timeofday.h (mode:100644)
@@ -0,0 +1,26 @@
+/* linux/include/asm-generic/timeofday.h
+ *
+ * This file contains the asm-generic interface
+ * to the arch specific calls used by the time of day subsystem
+ */
+#ifndef _ASM_GENERIC_TIMEOFDAY_H
+#define _ASM_GENERIC_TIMEOFDAY_H
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <asm/div64.h>
+#ifdef CONFIG_NEWTOD
+
+/* Required externs */
+extern nsec_t read_persistent_clock(void);
+extern void sync_persistent_clock(struct timespec ts);
+
+#ifdef CONFIG_NEWTOD_VSYSCALL
+extern void arch_update_vsyscall_gtod(nsec_t wall_time, cycle_t offset_base,
+ struct timesource_t* timesource, int ntp_adj);
+#else
+#define arch_update_vsyscall_gtod(x,y,z,w) {}
+#endif
+
+#endif /* CONFIG_NEWTOD */
+#endif
Index: include/linux/ntp.h
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/include/linux/ntp.h (mode:100644)
@@ -0,0 +1,19 @@
+/* linux/include/linux/ntp.h
+ *
+ * This file NTP state machine accessor functions.
+ */
+
+#ifndef _LINUX_NTP_H
+#define _LINUX_NTP_H
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+
+/* NTP state machine interfaces */
+int ntp_advance(nsec_t value);
+int ntp_adjtimex(struct timex*);
+int ntp_leapsecond(struct timespec now);
+void ntp_clear(void);
+int get_ntp_status(void);
+
+#endif
Index: include/linux/time.h
===================================================================
--- d414ab9a0f0995899c2e76c232714410f787b209/include/linux/time.h (mode:100644)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/include/linux/time.h (mode:100644)
@@ -27,6 +27,10 @@
#ifdef __KERNEL__
+/* timeofday base types */
+typedef u64 nsec_t;
+typedef u64 cycle_t;
+
/* Parameters used to convert the timespec values */
#ifndef USEC_PER_SEC
#define USEC_PER_SEC (1000000L)
Index: include/linux/timeofday.h
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/include/linux/timeofday.h (mode:100644)
@@ -0,0 +1,59 @@
+/* linux/include/linux/timeofday.h
+ *
+ * This file contains the interface to the time of day subsystem
+ */
+#ifndef _LINUX_TIMEOFDAY_H
+#define _LINUX_TIMEOFDAY_H
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <asm/div64.h>
+
+#ifdef CONFIG_NEWTOD
+/* Public definitions */
+extern nsec_t get_lowres_timestamp(void);
+extern nsec_t get_lowres_timeofday(void);
+extern nsec_t do_monotonic_clock(void);
+
+extern void do_gettimeofday(struct timeval *tv);
+extern void getnstimeofday(struct timespec *ts);
+extern int do_settimeofday(struct timespec *tv);
+extern int do_adjtimex(struct timex *tx);
+
+extern void timeofday_init(void);
+
+/* Inline helper functions */
+static inline struct timeval ns_to_timeval(nsec_t ns)
+{
+ struct timeval tv;
+ tv.tv_sec = div_long_long_rem(ns, NSEC_PER_SEC, &tv.tv_usec);
+ tv.tv_usec = (tv.tv_usec + NSEC_PER_USEC/2) / NSEC_PER_USEC;
+ return tv;
+}
+
+static inline struct timespec ns_to_timespec(nsec_t ns)
+{
+ struct timespec ts;
+ ts.tv_sec = div_long_long_rem(ns, NSEC_PER_SEC, &ts.tv_nsec);
+ return ts;
+}
+
+static inline nsec_t timespec_to_ns(struct timespec* ts)
+{
+ nsec_t ret;
+ ret = ((nsec_t)ts->tv_sec) * NSEC_PER_SEC;
+ ret += ts->tv_nsec;
+ return ret;
+}
+
+static inline nsec_t timeval_to_ns(struct timeval* tv)
+{
+ nsec_t ret;
+ ret = ((nsec_t)tv->tv_sec) * NSEC_PER_SEC;
+ ret += tv->tv_usec * NSEC_PER_USEC;
+ return ret;
+}
+#else /* CONFIG_NEWTOD */
+#define timeofday_init()
+#endif /* CONFIG_NEWTOD */
+#endif /* _LINUX_TIMEOFDAY_H */
Index: include/linux/timesource.h
===================================================================
--- /dev/null (tree:d414ab9a0f0995899c2e76c232714410f787b209)
+++ 15eb8deaa5b22a81f97a9af307d81b0567115674/include/linux/timesource.h (mode:100644)
@@ -0,0 +1,158 @@
+/* linux/include/linux/timesource.h
+ *
+ * This file contains the structure definitions for timesources.
+ *
+ * If you are not a timesource, or the time of day code, you should
+ * not be including this file!
+ */
+#ifndef _LINUX_TIMESORUCE_H
+#define _LINUX_TIMESORUCE_H
+
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <asm/io.h>
+#include <asm/div64.h>
+
+/* struct timesource_t:
+ * Provides mostly state-free accessors to the underlying hardware.
+ *
+ * name: ptr to timesource name
+ * priority: priority value for selection (higher is better)
+ * type: defines timesource type
+ * @read_fnct: returns a cycle value
+ * ptr: ptr to MMIO'ed counter
+ * mask: bitmask for two's complement
+ * subtraction of non 64 bit counters
+ * mult: cycle to nanosecond multiplier
+ * shift: cycle to nanosecond divisor (power of two)
+ * @update_callback: called when safe to alter timesource values
+ */
+struct timesource_t {
+ char* name;
+ int priority;
+ enum {
+ TIMESOURCE_FUNCTION,
+ TIMESOURCE_CYCLES,
+ TIMESOURCE_MMIO_32,
+ TIMESOURCE_MMIO_64
+ } type;
+ cycle_t (*read_fnct)(void);
+ void __iomem *mmio_ptr;
+ cycle_t mask;
+ u32 mult;
+ u32 shift;
+ void (*update_callback)(void);
+};
+
+
+/* Helper functions that converts a khz counter
+ * frequency to a timsource multiplier, given the
+ * timesource shift value
+ */
+static inline u32 timesource_khz2mult(u32 khz, u32 shift_constant)
+{
+ /* khz = cyc/(Million ns)
+ * mult/2^shift = ns/cyc
+ * mult = ns/cyc * 2^shift
+ * mult = 1Million/khz * 2^shift
+ * mult = 1000000 * 2^shift / khz
+ * mult = (1000000<<shift) / khz
+ */
+ u64 tmp = ((u64)1000000) << shift_constant;
+ tmp += khz/2; /* round for do_div */
+ do_div(tmp, khz);
+ return (u32)tmp;
+}
+
+/* Helper functions that converts a hz counter
+ * frequency to a timsource multiplier, given the
+ * timesource shift value
+ */
+static inline u32 timesource_hz2mult(u32 hz, u32 shift_constant)
+{
+ /* hz = cyc/(Billion ns)
+ * mult/2^shift = ns/cyc
+ * mult = ns/cyc * 2^shift
+ * mult = 1Billion/hz * 2^shift
+ * mult = 1000000000 * 2^shift / hz
+ * mult = (1000000000<<shift) / hz
+ */
+ u64 tmp = ((u64)1000000000) << shift_constant;
+ tmp += hz/2; /* round for do_div */
+ do_div(tmp, hz);
+ return (u32)tmp;
+}
+
+
+#ifndef readq
+/* Provide an a way to atomically read a u64 on a 32bit arch */
+static inline unsigned long long timesource_readq(void __iomem *addr)
+{
+ u32 low, high;
+ /* loop is required to make sure we get an atomic read */
+ do {
+ high = readl(addr+4);
+ low = readl(addr);
+ } while (high != readl(addr+4));
+
+ return low | (((unsigned long long)high) << 32LL);
+}
+#else
+#define timesource_readq(x) readq(x)
+#endif
+
+
+/* read_timesource():
+ * Uses the timesource to return the current cycle_t value
+ */
+static inline cycle_t read_timesource(struct timesource_t *ts)
+{
+ switch (ts->type) {
+ case TIMESOURCE_MMIO_32:
+ return (cycle_t)readl(ts->mmio_ptr);
+ case TIMESOURCE_MMIO_64:
+ return (cycle_t)timesource_readq(ts->mmio_ptr);
+ case TIMESOURCE_CYCLES:
+ return (cycle_t)get_cycles();
+ default:/* case: TIMESOURCE_FUNCTION */
+ return ts->read_fnct();
+ }
+}
+
+/* cyc2ns():
+ * Uses the timesource and ntp ajdustment interval to
+ * convert cycle_ts to nanoseconds.
+ */
+static inline nsec_t cyc2ns(struct timesource_t *ts, int ntp_adj, cycle_t cycles)
+{
+ u64 ret;
+ ret = (u64)cycles;
+ ret *= (ts->mult + ntp_adj);
+ ret >>= ts->shift;
+ return (nsec_t)ret;
+}
+
+/* cyc2ns_rem():
+ * Uses the timesource and ntp ajdustment interval to
+ * convert cycle_ts to nanoseconds. Add in remainder portion
+ * which is stored in ns<<ts->shift units and save the new
+ * remainder off.
+ */
+static inline nsec_t cyc2ns_rem(struct timesource_t *ts, int ntp_adj, cycle_t cycles, u64* rem)
+{
+ u64 ret;
+ ret = (u64)cycles;
+ ret *= (ts->mult + ntp_adj);
+ if (rem) {
+ ret += *rem;
+ *rem = ret & ((1<<ts->shift)-1);
+ }
+ ret >>= ts->shift;
+ return (nsec_t)ret;
+}
+
+/* used to install a new time source */
+void register_timesource(struct timesource_t*);
+struct timesource_t* get_next_timesource(void);
+#endif
Index: include/linux/timex.h
===================================================================
--- 9b7fa103dfb222f809bf277668d9ac0636c060ee/include/linux/timex.h (mode:100644)
+++ 6e3d9e6298413e0aed3157cd848724bb12c42554/include/linux/timex.h (mode:100644)
@@ -228,6 +228,7 @@
extern unsigned long tick_nsec; /* ACTHZ period (nsec) */
extern int tickadj; /* amount of adjustment per tick */
+#ifndef CONFIG_NEWTOD
/*
* phase-lock loop variables
*/
@@ -314,6 +315,7 @@
}
#endif /* !CONFIG_TIME_INTERPOLATION */
+#endif /* !CONFIG_NEWTOD */
#endif /* KERNEL */
Index: init/main.c
===================================================================
--- 9b7fa103dfb222f809bf277668d9ac0636c060ee/init/main.c (mode:100644)
+++ 6e3d9e6298413e0aed3157cd848724bb12c42554/init/main.c (mode:100644)
@@ -47,6 +47,7 @@
#include <linux/rmap.h>
#include <linux/mempolicy.h>
#include <linux/key.h>
+#include <linux/timeofday.h>
#include <asm/io.h>
#include <asm/bugs.h>
@@ -467,6 +468,7 @@
pidhash_init();
init_timers();
softirq_init();
+ timeofday_init();
time_init();
/*
Index: kernel/Makefile
===================================================================
--- 9b7fa103dfb222f809bf277668d9ac0636c060ee/kernel/Makefile (mode:100644)
+++ 6e3d9e6298413e0aed3157cd848724bb12c42554/kernel/Makefile (mode:100644)
@@ -9,6 +9,7 @@
rcupdate.o intermodule.o extable.o params.o posix-timers.o \
kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o
+obj-$(CONFIG_NEWTOD) += timeofday.o timesource.o ntp.o
obj-$(CONFIG_FUTEX) += futex.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
obj-$(CONFIG_SMP) += cpu.o spinlock.o
Index: kernel/ntp.c
===================================================================
--- /dev/null (tree:9b7fa103dfb222f809bf277668d9ac0636c060ee)
+++ 6e3d9e6298413e0aed3157cd848724bb12c42554/kernel/ntp.c (mode:100644)
@@ -0,0 +1,519 @@
+/********************************************************************
+* linux/kernel/ntp.c
+*
+* NTP state machine and time scaling code.
+*
+* Copyright (C) 2004, 2005 IBM, John Stultz (johnstul@us.ibm.com)
+*
+* Portions rewritten from kernel/time.c and kernel/timer.c
+* Please see those files for original copyrights.
+*
+* This program is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation; either version 2 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program; if not, write to the Free Software
+* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*
+* Notes:
+*
+* Hopefully you should never have to understand or touch
+* any of the code below. but don't let that keep you from trying!
+*
+* This code is loosely based on David Mills' RFC 1589 and its
+* updates. Please see the following for more details:
+* http://www.eecis.udel.edu/~mills/database/rfc/rfc1589.txt
+* http://www.eecis.udel.edu/~mills/database/reports/kern/kernb.pdf
+*
+* NOTE: To simplify the code, we do not implement any of
+* the PPS code, as the code that uses it never was merged.
+* -johnstul@us.ibm.com
+*
+* Revision History:
+* 2004-09-02: A0
+* o First pass sent to lkml for review.
+* 2004-12-07: A1
+* o No changes, sent to lkml for review.
+* 2005-03-11: A3
+* o yanked ntp_scale(), ntp adjustments are done in cyc2ns
+* 2005-04-29: A4
+* o Added conditional debug info
+* 2005-05-12: A5
+* o comment cleanups
+* 2005-05-31: B0
+* o comment cleanups
+* o Improved rounding
+* TODO List:
+* o Move to using ppb for frequency adjustments
+* o More documentation
+* o More testing
+* o More optimization
+*********************************************************************/
+
+#include <linux/ntp.h>
+#include <linux/errno.h>
+
+#define NTP_DEBUG 0
+
+/* NTP scaling code
+ * Functions:
+ * ----------
+ * nsec_t ntp_scale(nsec_t value):
+ * Scales the nsec_t vale using ntp kernel state
+ * void ntp_advance(nsec_t interval):
+ * Increments the NTP state machine by interval time
+ * static int ntp_hardupdate(long offset, struct timeval tv)
+ * ntp_adjtimex helper function
+ * int ntp_adjtimex(struct timex* tx):
+ * Interface to adjust NTP state machine
+ * int ntp_leapsecond(struct timespec now)
+ * Does NTP leapsecond processing. Returns number of
+ * seconds current time should be adjusted by.
+ * void ntp_clear(void):
+ * Clears the ntp kernel state
+ * int get_ntp_status(void):
+ * returns ntp_status value
+ *
+ * Variables:
+ * ----------
+ * ntp kernel state variables:
+ * See below for full list.
+ * ntp_lock:
+ * Protects ntp kernel state variables
+ */
+
+
+
+/* Chapter 5: Kernel Variables [RFC 1589 pg. 28] */
+/* 5.1 Interface Variables */
+static int ntp_status = STA_UNSYNC; /* status */
+static long ntp_offset; /* usec */
+static long ntp_constant = 2; /* ntp magic? */
+static long ntp_maxerror = NTP_PHASE_LIMIT; /* usec */
+static long ntp_esterror = NTP_PHASE_LIMIT; /* usec */
+static const long ntp_tolerance = MAXFREQ; /* shifted ppm */
+static const long ntp_precision = 1; /* constant */
+
+/* 5.2 Phase-Lock Loop Variables */
+static long ntp_freq; /* shifted ppm */
+static long ntp_reftime; /* sec */
+
+/* Extra values */
+static int ntp_state = TIME_OK; /* leapsecond state */
+static long ntp_tick = USEC_PER_SEC/USER_HZ; /* tick length */
+
+static s64 ss_offset_len; /* SINGLESHOT offset adj interval (nsec)*/
+static long singleshot_adj; /* +/- MAX_SINGLESHOT_ADJ (ppm)*/
+static long tick_adj; /* tx->tick adjustment (ppm) */
+static long offset_adj; /* offset adjustment (ppm) */
+
+
+/* lock for the above variables */
+static seqlock_t ntp_lock = SEQLOCK_UNLOCKED;
+
+#define MAX_SINGLESHOT_ADJ 500 /* (ppm) */
+#define SEC_PER_DAY 86400
+
+/* Required to safely shift negative values */
+#define shiftR(x,s) (x < 0) ? (-((-x) >> (s))) : ((x) >> (s))
+
+/**
+ * ntp_advance - Periodic hook which increments NTP state machine
+ * interval: nsecond interval value used to increment the state machine
+ *
+ * Periodic hook which increments NTP state machine by interval.
+ * Returns the signed PPM adjustment to be used for the next interval.
+ *
+ * This is ntp_hardclock in the RFC.
+ */
+int ntp_advance(nsec_t interval)
+{
+ static u64 interval_sum = 0;
+ static long ss_adj = 0;
+ unsigned long flags;
+ long ppm_sum;
+
+ /* inc interval sum */
+ interval_sum += interval;
+
+ write_seqlock_irqsave(&ntp_lock, flags);
+
+ /* decrement singleshot offset interval */
+ ss_offset_len -= interval;
+ if(ss_offset_len < 0) /* make sure it doesn't go negative */
+ ss_offset_len = 0;
+
+ /* Do second overflow code */
+ while (interval_sum > NSEC_PER_SEC) {
+ /* XXX - I'd prefer to smoothly apply this math
+ * at each call to ntp_advance() rather then each
+ * second.
+ */
+ long tmp;
+
+ /* Bump maxerror by ntp_tolerance */
+ ntp_maxerror += shiftR(ntp_tolerance, SHIFT_USEC);
+ if (ntp_maxerror > NTP_PHASE_LIMIT) {
+ ntp_maxerror = NTP_PHASE_LIMIT;
+ ntp_status |= STA_UNSYNC;
+ }
+
+ /* Calculate offset_adj for the next second */
+ tmp = ntp_offset;
+ if (!(ntp_status & STA_FLL))
+ tmp = shiftR(tmp, SHIFT_KG + ntp_constant);
+
+ /* bound the adjustment to MAXPHASE/MINSEC */
+ tmp = min(tmp, (MAXPHASE / MINSEC) << SHIFT_UPDATE);
+ tmp = max(tmp, -(MAXPHASE / MINSEC) << SHIFT_UPDATE);
+
+ offset_adj = shiftR(tmp, SHIFT_UPDATE); /* (usec/sec) = ppm */
+ ntp_offset -= tmp;
+
+ interval_sum -= NSEC_PER_SEC;
+
+ /* calculate singleshot aproximation ppm for the next second */
+ ss_adj = singleshot_adj;
+ singleshot_adj = 0;
+ }
+
+ /* calculate total ppm adjustment for the next interval */
+ ppm_sum = tick_adj;
+ ppm_sum += offset_adj;
+ ppm_sum += shiftR(ntp_freq,SHIFT_USEC);
+ ppm_sum += ss_adj;
+
+#if NTP_DEBUG
+{
+ static int dbg = 0;
+ if(!(dbg++%300000))
+ printk("tick_adj(%d) + offset_adj(%d) + ntp_freq(%d) + ss_adj(%d) = ppm_sum(%d)\n", tick_adj, offset_adj, shiftR(ntp_freq,SHIFT_USEC), ss_adj, ppm_sum);
+}
+#endif
+
+ write_sequnlock_irqrestore(&ntp_lock, flags);
+
+ return ppm_sum;
+}
+
+/**
+ * ntp_hardupdate - Calculates the offset and freq values
+ * offset: current offset
+ * tv: timeval holding the current time
+ *
+ * Private function, called only by ntp_adjtimex while holding ntp_lock
+ *
+ * This function is called when an offset adjustment is requested.
+ * It calculates the offset adjustment and manipulates the
+ * frequency adjustement accordingly.
+ */
+static int ntp_hardupdate(long offset, struct timeval tv)
+{
+ int ret;
+ long tmp, interval;
+
+ ret = 0;
+ if (!(ntp_status & STA_PLL))
+ return ret;
+
+ tmp = offset;
+ /* Make sure offset is bounded by MAXPHASE */
+ tmp = min(tmp, MAXPHASE);
+ tmp = max(tmp, -MAXPHASE);
+
+ ntp_offset = tmp << SHIFT_UPDATE;
+
+ if ((ntp_status & STA_FREQHOLD) || (ntp_reftime == 0))
+ ntp_reftime = tv.tv_sec;
+
+ /* calculate seconds since last call to hardupdate */
+ interval = tv.tv_sec - ntp_reftime;
+ ntp_reftime = tv.tv_sec;
+
+ if ((ntp_status & STA_FLL) && (interval >= MINSEC)) {
+ long damping;
+ /* calculate frequency for this interval */
+ tmp = (offset + interval/2) / interval; /* ppm (usec/sec)*/
+
+ /* calculate damping factor */
+ damping = SHIFT_KH - SHIFT_USEC;
+
+ /* convert to shifted ppm, then apply damping factor */
+ ntp_freq += shiftR(tmp,damping);
+#if NTP_DEBUG
+ printk("ntp->freq change: %ld\n",shiftR(tmp,damping));
+#endif
+
+ } else if ((ntp_status & STA_PLL) && (interval < MAXSEC)) {
+ long damping;
+ tmp = offset * interval;
+
+ /* calculate damping factor */
+ damping = (2 * ntp_constant) + SHIFT_KF - SHIFT_USEC;
+
+ /* apply damping factor */
+ ntp_freq += shiftR(tmp,damping);
+
+#if NTP_DEBUG
+ printk("ntp->freq change: %ld\n", shiftR(tmp,damping));
+#endif
+ } else { /* interval out of bounds */
+#if NTP_DEBUG
+ printk("ntp_hardupdate(): interval out of bounds: %ld status: 0x%x\n",
+ interval, ntp_status);
+#endif
+ ret = -1; /* TIME_ERROR */
+ }
+
+ /* bound ntp_freq */
+ if (ntp_freq > ntp_tolerance)
+ ntp_freq = ntp_tolerance;
+ if (ntp_freq < -ntp_tolerance)
+ ntp_freq = -ntp_tolerance;
+
+ return ret;
+}
+
+/**
+ * ntp_adjtimex - Interface to change NTP state machine
+ * @tx: timex value passed to the kernel to be used
+ */
+int ntp_adjtimex(struct timex* tx)
+{
+ long save_offset;
+ int result;
+ unsigned long flags;
+
+/* Sanity checking
+ */
+ /* frequency adjustment limited to +/- MAXFREQ */
+ if ((tx->modes & ADJ_FREQUENCY)
+ && (abs(tx->freq) > MAXFREQ))
+ return -EINVAL;
+
+ /* maxerror adjustment limited to NTP_PHASE_LIMIT */
+ if ((tx->modes & ADJ_MAXERROR)
+ && (tx->maxerror < 0
+ || tx->maxerror >= NTP_PHASE_LIMIT))
+ return -EINVAL;
+
+ /* esterror adjustment limited to NTP_PHASE_LIMIT */
+ if ((tx->modes & ADJ_ESTERROR)
+ && (tx->esterror < 0
+ || tx->esterror >= NTP_PHASE_LIMIT))
+ return -EINVAL;
+
+ /* constant adjustment must be positive */
+ if ((tx->modes & ADJ_TIMECONST)
+ && (tx->constant < 0))
+ return -EINVAL;
+
+ /* Single shot mode can only be used by itself */
+ if (((tx->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
+ && (tx->modes != ADJ_OFFSET_SINGLESHOT))
+ return -EINVAL;
+
+ /* offset adjustment limited to +/- MAXPHASE */
+ if ((tx->modes != ADJ_OFFSET_SINGLESHOT)
+ && (tx->modes & ADJ_OFFSET)
+ && (abs(tx->offset)>= MAXPHASE))
+ return -EINVAL;
+
+ /* tick adjustment limited to 10% */
+ if ((tx->modes & ADJ_TICK)
+ && ((tx->tick < 900000/USER_HZ)
+ ||(tx->tick > 11000000/USER_HZ)))
+ return -EINVAL;
+
+#if NTP_DEBUG
+ if(tx->modes) {
+ printk("adjtimex: tx->offset: %ld tx->freq: %ld\n",
+ tx->offset, tx->freq);
+ }
+#endif
+
+/* Kernel input bits
+ */
+ write_seqlock_irqsave(&ntp_lock, flags);
+
+ result = ntp_state;
+
+ /* For ADJ_OFFSET_SINGLESHOT we must return the old offset */
+ save_offset = shiftR(ntp_offset, SHIFT_UPDATE);
+
+ /* Process input parameters */
+ if (tx->modes & ADJ_STATUS) {
+ ntp_status &= STA_RONLY;
+ ntp_status |= tx->status & ~STA_RONLY;
+ }
+
+ if (tx->modes & ADJ_FREQUENCY)
+ ntp_freq = tx->freq;
+
+ if (tx->modes & ADJ_MAXERROR)
+ ntp_maxerror = tx->maxerror;
+
+ if (tx->modes & ADJ_ESTERROR)
+ ntp_esterror = tx->esterror;
+
+ if (tx->modes & ADJ_TIMECONST)
+ ntp_constant = tx->constant;
+
+ if (tx->modes & ADJ_OFFSET) {
+ /* check if we're doing a singleshot adjustment */
+ if (tx->modes == ADJ_OFFSET_SINGLESHOT)
+ singleshot_adj = tx->offset;
+ /* otherwise, call hardupdate() */
+ else if (ntp_hardupdate(tx->offset, tx->time))
+ result = TIME_ERROR;
+ }
+
+ if (tx->modes & ADJ_TICK) {
+ /* first calculate usec/user_tick offset */
+ tick_adj = ((USEC_PER_SEC + USER_HZ/2)/USER_HZ) - tx->tick;
+ /* multiply by user_hz to get usec/sec => ppm */
+ tick_adj *= USER_HZ;
+ /* save tx->tick for future calls to adjtimex */
+ ntp_tick = tx->tick;
+ }
+
+ if ((ntp_status & (STA_UNSYNC|STA_CLOCKERR)) != 0 )
+ result = TIME_ERROR;
+
+/* Kernel output bits
+ */
+ /* write kernel state to user timex values*/
+ if ((tx->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
+ tx->offset = save_offset;
+ else
+ tx->offset = shiftR(ntp_offset, SHIFT_UPDATE);
+
+ tx->freq = ntp_freq;
+ tx->maxerror = ntp_maxerror;
+ tx->esterror = ntp_esterror;
+ tx->status = ntp_status;
+ tx->constant = ntp_constant;
+ tx->precision = ntp_precision;
+ tx->tolerance = ntp_tolerance;
+
+ /* PPS is not implemented, so these are zero */
+ tx->ppsfreq = /*XXX - Not Implemented!*/ 0;
+ tx->jitter = /*XXX - Not Implemented!*/ 0;
+ tx->shift = /*XXX - Not Implemented!*/ 0;
+ tx->stabil = /*XXX - Not Implemented!*/ 0;
+ tx->jitcnt = /*XXX - Not Implemented!*/ 0;
+ tx->calcnt = /*XXX - Not Implemented!*/ 0;
+ tx->errcnt = /*XXX - Not Implemented!*/ 0;
+ tx->stbcnt = /*XXX - Not Implemented!*/ 0;
+
+ write_sequnlock_irqrestore(&ntp_lock, flags);
+
+ return result;
+}
+
+
+/**
+ * ntp_leapsecond - NTP leapsecond processing code.
+ * now: the current time
+ *
+ * Returns the number of seconds (-1, 0, or 1) that
+ * should be added to the current time to properly
+ * adjust for leapseconds.
+ */
+int ntp_leapsecond(struct timespec now)
+{
+ /*
+ * Leap second processing. If in leap-insert state at
+ * the end of the day, the system clock is set back one
+ * second; if in leap-delete state, the system clock is
+ * set ahead one second.
+ */
+ static time_t leaptime = 0;
+
+ switch (ntp_state) {
+ case TIME_OK:
+ if (ntp_status & STA_INS) {
+ ntp_state = TIME_INS;
+ /* calculate end of today (23:59:59)*/
+ leaptime = now.tv_sec + SEC_PER_DAY -
+ (now.tv_sec % SEC_PER_DAY) - 1;
+ }
+ else if (ntp_status & STA_DEL) {
+ ntp_state = TIME_DEL;
+ /* calculate end of today (23:59:59)*/
+ leaptime = now.tv_sec + SEC_PER_DAY -
+ (now.tv_sec % SEC_PER_DAY) - 1;
+ }
+ break;
+
+ case TIME_INS:
+ /* Once we are at (or past) leaptime, insert the second */
+ if (now.tv_sec > leaptime) {
+ ntp_state = TIME_OOP;
+ printk(KERN_NOTICE
+ "Clock: inserting leap second 23:59:60 UTC\n");
+ return -1;
+ }
+ break;
+
+ case TIME_DEL:
+ /* Once we are at (or past) leaptime, delete the second */
+ if (now.tv_sec >= leaptime) {
+ ntp_state = TIME_WAIT;
+ printk(KERN_NOTICE
+ "Clock: deleting leap second 23:59:59 UTC\n");
+ return 1;
+ }
+ break;
+
+ case TIME_OOP:
+ /* Wait for the end of the leap second*/
+ if (now.tv_sec > (leaptime + 1))
+ ntp_state = TIME_WAIT;
+ break;
+
+ case TIME_WAIT:
+ if (!(ntp_status & (STA_INS | STA_DEL)))
+ ntp_state = TIME_OK;
+ }
+
+ return 0;
+}
+
+/**
+ * ntp_clear - Clears the NTP state machine.
+ *
+ */
+void ntp_clear(void)
+{
+ unsigned long flags;
+ write_seqlock_irqsave(&ntp_lock, flags);
+
+ /* clear everything */
+ ntp_status |= STA_UNSYNC;
+ ntp_maxerror = NTP_PHASE_LIMIT;
+ ntp_esterror = NTP_PHASE_LIMIT;
+ ss_offset_len = 0;
+ singleshot_adj = 0;
+ tick_adj = 0;
+ offset_adj =0;
+
+ write_sequnlock_irqrestore(&ntp_lock, flags);
+}
+
+/**
+ * get_ntp_status - Returns the NTP status value
+ *
+ */
+int get_ntp_status(void)
+{
+ return ntp_status;
+}
+
Index: kernel/time.c
===================================================================
--- 9b7fa103dfb222f809bf277668d9ac0636c060ee/kernel/time.c (mode:100644)
+++ 6e3d9e6298413e0aed3157cd848724bb12c42554/kernel/time.c (mode:100644)
@@ -38,6 +38,7 @@
#include <asm/uaccess.h>
#include <asm/unistd.h>
+#include <linux/timeofday.h>
/*
* The timezone where the local system is located. Used as a default by some
@@ -128,6 +129,7 @@
* as real UNIX machines always do it. This avoids all headaches about
* daylight saving times and warping kernel clocks.
*/
+#ifndef CONFIG_NEWTOD
inline static void warp_clock(void)
{
write_seqlock_irq(&xtime_lock);
@@ -137,6 +139,18 @@
write_sequnlock_irq(&xtime_lock);
clock_was_set();
}
+#else /* !CONFIG_NEWTOD */
+/* XXX - this is somewhat cracked out and should
+ be checked -johnstul@us.ibm.com
+*/
+inline static void warp_clock(void)
+{
+ struct timespec ts;
+ getnstimeofday(&ts);
+ ts.tv_sec += sys_tz.tz_minuteswest * 60;
+ do_settimeofday(&ts);
+}
+#endif /* !CONFIG_NEWTOD */
/*
* In case for some reason the CMOS clock has not already been running
@@ -227,6 +241,7 @@
/* adjtimex mainly allows reading (and writing, if superuser) of
* kernel time-keeping variables. used by xntpd.
*/
+#ifndef CONFIG_NEWTOD
int do_adjtimex(struct timex *txc)
{
long ltemp, mtemp, save_adjust;
@@ -410,6 +425,7 @@
notify_arch_cmos_timer();
return(result);
}
+#endif /* !CONFIG_NEWTOD */
asmlinkage long sys_adjtimex(struct timex __user *txc_p)
{
@@ -558,6 +574,7 @@
#else
+#ifndef CONFIG_NEWTOD
/*
* Simulate gettimeofday using do_gettimeofday which only allows a timeval
* and therefore only yields usec accuracy
@@ -570,6 +587,7 @@
tv->tv_sec = x.tv_sec;
tv->tv_nsec = x.tv_usec * NSEC_PER_USEC;
}
+#endif /* !CONFIG_NEWTOD */
#endif
#if (BITS_PER_LONG < 64)
Index: kernel/timeofday.c
===================================================================
--- /dev/null (tree:9b7fa103dfb222f809bf277668d9ac0636c060ee)
+++ 6e3d9e6298413e0aed3157cd848724bb12c42554/kernel/timeofday.c (mode:100644)
@@ -0,0 +1,607 @@
+/*********************************************************************
+* linux/kernel/timeofday.c
+*
+* This file contains the functions which access and manage
+* the system's time of day functionality.
+*
+* Copyright (C) 2003, 2004, 2005 IBM, John Stultz (johnstul@us.ibm.com)
+*
+* This program is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation; either version 2 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program; if not, write to the Free Software
+* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*
+* Revision History:
+* 2004-09-02: A0
+* o First pass sent to lkml for review.
+* 2004-12-07: A1
+* o Rework of timesource structure
+* o Sent to lkml for review
+* 2005-01-24: A2
+* o write_seqlock_irq -> writeseqlock_irqsave
+* o arch generic interface for for get_cmos_time() equivalents
+* o suspend/resume hooks for sleep/hibernate (lightly tested)
+* o timesource adjust_callback hook
+* o Sent to lkml for review
+* 2005-03-11: A3
+* o periodic_hook (formerly interrupt_hook) now calle by softtimer
+* o yanked ntp_scale(), ntp adjustments are done in cyc2ns now
+* o sent to lkml for review
+* 2005-04-29: A4
+* o Improved the cyc2ns remainder handling
+* o Added getnstimeofday
+* o Cleanups from Nish Aravamudan
+* 2005-05-12: A5
+* o Added clock_was_set hooks
+* o Added suspend/resume sysfs hooks
+* o Minor code cleanups
+* o First attempt at docbook comments
+* 2005-05-31: B0
+* o Comment cleanups
+* o Rounding fixes
+*
+* TODO WishList:
+* o See XXX's below.
+**********************************************************************/
+
+#include <linux/timeofday.h>
+#include <linux/timesource.h>
+#include <linux/ntp.h>
+#include <linux/timex.h>
+#include <linux/timer.h>
+#include <linux/module.h>
+#include <linux/sched.h> /* Needed for capable() */
+#include <linux/sysdev.h>
+#include <linux/jiffies.h>
+#include <asm/timeofday.h>
+
+#define TIME_DBG 0
+#define TIME_DBG_FREQ 60000
+
+/* only run periodic_hook every 50ms */
+#define PERIODIC_INTERVAL_MS 50
+
+/*[Nanosecond based variables]
+ * system_time:
+ * Monotonically increasing counter of the number of nanoseconds
+ * since boot.
+ * wall_time_offset:
+ * Offset added to system_time to provide accurate time-of-day
+ */
+static nsec_t system_time;
+static nsec_t wall_time_offset;
+
+/*[Cycle based variables]
+ * offset_base:
+ * Value of the timesource at the last timeofday_periodic_hook()
+ * (adjusted only minorly to account for rounded off cycles)
+ */
+static cycle_t offset_base;
+
+/*[Time source data]
+ * timesource:
+ * current timesource pointer
+ */
+static struct timesource_t *timesource;
+
+/*[NTP adjustment]
+ * ntp_adj:
+ * value of the current ntp adjustment,
+ * stored in timesource multiplier units.
+ */
+int ntp_adj;
+
+/*[Locks]
+ * system_time_lock:
+ * generic lock for all locally scoped time values
+ */
+static seqlock_t system_time_lock = SEQLOCK_UNLOCKED;
+
+
+/*[Suspend/Resume info]
+ * time_suspend_state:
+ * variable that keeps track of suspend state
+ * suspend_start:
+ * start of the suspend call
+ */
+static enum {
+ TIME_RUNNING,
+ TIME_SUSPENDED
+} time_suspend_state = TIME_RUNNING;
+
+static nsec_t suspend_start;
+
+/* [Soft-Timers]
+ * timeofday_timer:
+ * soft-timer used to call timeofday_periodic_hook()
+ */
+struct timer_list timeofday_timer;
+
+
+/* [Functions]
+ */
+
+/**
+ * get_lowres_timestamp - Returns a low res timestamp
+ *
+ * Returns a low res timestamp w/ PERIODIC_INTERVAL_MS
+ * granularity. (ie: the value of system_time as
+ * calculated at the last invocation of
+ * timeofday_periodic_hook())
+ */
+nsec_t get_lowres_timestamp(void)
+{
+ nsec_t ret;
+ unsigned long seq;
+ do {
+ seq = read_seqbegin(&system_time_lock);
+
+ /* quickly grab system_time*/
+ ret = system_time;
+
+ } while (read_seqretry(&system_time_lock, seq));
+
+ return ret;
+}
+
+
+/**
+ * get_lowres_timeofday - Returns a low res time of day
+ *
+ * Returns a low res time of day, as calculated at the
+ * last invocation of timeofday_periodic_hook().
+ */
+nsec_t get_lowres_timeofday(void)
+{
+ nsec_t ret;
+ unsigned long seq;
+ do {
+ seq = read_seqbegin(&system_time_lock);
+
+ /* quickly calculate low-res time of day */
+ ret = system_time + wall_time_offset;
+
+ } while (read_seqretry(&system_time_lock, seq));
+
+ return ret;
+}
+
+
+/**
+ * update_legacy_time_values - Used to sync legacy time values
+ *
+ * Private function. Used to sync legacy time values to
+ * current timeofday. Assumes we have the system_time_lock.
+ * Hopefully someday this function can be removed.
+ */
+static void update_legacy_time_values(void)
+{
+ unsigned long flags;
+ write_seqlock_irqsave(&xtime_lock, flags);
+ xtime = ns_to_timespec(system_time + wall_time_offset);
+ wall_to_monotonic = ns_to_timespec(wall_time_offset);
+ set_normalized_timespec(&wall_to_monotonic,
+ -wall_to_monotonic.tv_sec, -wall_to_monotonic.tv_nsec);
+ /* We don't update jiffies here because it is its own time domain */
+ write_sequnlock_irqrestore(&xtime_lock, flags);
+}
+
+
+/**
+ * __monotonic_clock - Returns monotonically increasing nanoseconds
+ *
+ * private function, must hold system_time_lock lock when being
+ * called. Returns the monotonically increasing number of
+ * nanoseconds since the system booted (adjusted by NTP scaling)
+ */
+static inline nsec_t __monotonic_clock(void)
+{
+ nsec_t ret, ns_offset;
+ cycle_t now, cycle_delta;
+
+ /* read timesource */
+ now = read_timesource(timesource);
+
+ /* calculate the delta since the last timeofday_periodic_hook */
+ cycle_delta = (now - offset_base) & timesource->mask;
+
+ /* convert to nanoseconds */
+ ns_offset = cyc2ns(timesource, ntp_adj, cycle_delta);
+
+ /* add result to system time */
+ ret = system_time + ns_offset;
+
+ return ret;
+}
+
+
+/**
+ * do_monotonic_clock - Returns monotonically increasing nanoseconds
+ *
+ * Returns the monotonically increasing number of nanoseconds
+ * since the system booted via __monotonic_clock()
+ */
+nsec_t do_monotonic_clock(void)
+{
+ nsec_t ret;
+ unsigned long seq;
+
+ /* atomically read __monotonic_clock() */
+ do {
+ seq = read_seqbegin(&system_time_lock);
+
+ ret = __monotonic_clock();
+
+ } while (read_seqretry(&system_time_lock, seq));
+
+ return ret;
+}
+
+
+/**
+ * __gettimeofday - Returns the timeofday in nsec_t.
+ *
+ * Private function. Returns the timeofday in nsec_t.
+ */
+static inline nsec_t __gettimeofday(void)
+{
+ nsec_t wall, sys;
+ unsigned long seq;
+
+ /* atomically read wall and sys time */
+ do {
+ seq = read_seqbegin(&system_time_lock);
+
+ wall = wall_time_offset;
+ sys = __monotonic_clock();
+
+ } while (read_seqretry(&system_time_lock, seq));
+
+ return wall + sys;
+}
+
+
+/**
+ * getnstimeofday - Returns the time of day in a timespec
+ * @ts: pointer to the timespec to be set
+ *
+ * Returns the time of day in a timespec
+ * For consistency should be renamed
+ * later to do_getnstimeofday()
+ */
+void getnstimeofday(struct timespec *ts)
+{
+ *ts = ns_to_timespec(__gettimeofday());
+}
+EXPORT_SYMBOL(getnstimeofday);
+
+
+/**
+ * do_gettimeofday - Returns the time of day in a timeval
+ * @tv: pointer to the timeval to be set
+ *
+ */
+void do_gettimeofday(struct timeval *tv)
+{
+ *tv = ns_to_timeval(__gettimeofday());
+}
+EXPORT_SYMBOL(do_gettimeofday);
+
+
+/**
+ * do_settimeofday - Sets the time of day
+ * @tv: pointer to the timespec that will be used to set the time
+ *
+ */
+int do_settimeofday(struct timespec *tv)
+{
+ unsigned long flags;
+ nsec_t newtime = timespec_to_ns(tv);
+
+ /* atomically adjust wall_time_offset & clear ntp state machine */
+ write_seqlock_irqsave(&system_time_lock, flags);
+
+ wall_time_offset = newtime - __monotonic_clock();
+ ntp_clear();
+
+ update_legacy_time_values();
+
+ arch_update_vsyscall_gtod(system_time + wall_time_offset, offset_base,
+ timesource, ntp_adj);
+
+ write_sequnlock_irqrestore(&system_time_lock, flags);
+
+ /* signal posix-timers about time change */
+ clock_was_set();
+
+ return 0;
+}
+EXPORT_SYMBOL(do_settimeofday);
+
+
+/**
+ * do_adjtimex - interface to the kernel NTP variables
+ * @tx: pointer to the timex value that will be used
+ *
+ * Userspace NTP daemon's interface to the kernel NTP variables
+ */
+int do_adjtimex(struct timex *tx)
+{
+ /* Check capabilities if we're trying to modify something */
+ if (tx->modes && !capable(CAP_SYS_TIME))
+ return -EPERM;
+
+ /* Note: We set tx->time first,
+ * because ntp_adjtimex uses it
+ */
+ do_gettimeofday(&tx->time);
+
+ /* call out to NTP code */
+ return ntp_adjtimex(tx);
+}
+
+
+/**
+ * timeofday_suspend_hook - allows the timeofday subsystem to be shutdown
+ * @dev: unused
+ * state: unused
+ *
+ * This function allows the timeofday subsystem to
+ * be shutdown for a period of time. Usefull when
+ * going into suspend/hibernate mode. The code is
+ * very similar to the first half of
+ * timeofday_periodic_hook().
+ */
+static int timeofday_suspend_hook(struct sys_device *dev, u32 state)
+{
+ unsigned long flags;
+
+ write_seqlock_irqsave(&system_time_lock, flags);
+
+ /* Make sure time_suspend_state is sane */
+ BUG_ON(time_suspend_state != TIME_RUNNING);
+
+ /* First off, save suspend start time
+ * then quickly call __monotonic_clock.
+ * These two calls hopefully occur quickly
+ * because the difference between reads will
+ * accumulate as time drift on resume.
+ */
+ suspend_start = read_persistent_clock();
+ system_time = __monotonic_clock();
+
+ /* switch states */
+ time_suspend_state = TIME_SUSPENDED;
+
+ write_sequnlock_irqrestore(&system_time_lock, flags);
+ return 0;
+}
+
+
+/**
+ * timeofday_resume_hook - Resumes the timeofday subsystem.
+ * @dev: unused
+ *
+ * This function resumes the timeofday subsystem
+ * from a previous call to timeofday_suspend_hook.
+ */
+static int timeofday_resume_hook(struct sys_device *dev)
+{
+ nsec_t now, suspend_time;
+ unsigned long flags;
+
+ write_seqlock_irqsave(&system_time_lock, flags);
+
+ /* Make sure time_suspend_state is sane */
+ BUG_ON(time_suspend_state != TIME_SUSPENDED);
+
+ /* Read persistent clock to mark the end of
+ * the suspend interval then rebase the
+ * offset_base to current timesource value.
+ * Again, time between these two calls will
+ * not be accounted for and will show up as
+ * time drift.
+ */
+ now = read_persistent_clock();
+ offset_base = read_timesource(timesource);
+
+ /* calculate how long we were out for */
+ suspend_time = now - suspend_start;
+
+ /* update system_time */
+ system_time += suspend_time;
+
+ ntp_clear();
+
+ /* Set us back to running */
+ time_suspend_state = TIME_RUNNING;
+
+ /* finally, update legacy time values */
+ update_legacy_time_values();
+
+ write_sequnlock_irqrestore(&system_time_lock, flags);
+
+ /* signal posix-timers about time change */
+ clock_was_set();
+
+ return 0;
+}
+
+/* sysfs resume/suspend bits */
+static struct sysdev_class timeofday_sysclass = {
+ .resume = timeofday_resume_hook,
+ .suspend = timeofday_suspend_hook,
+ set_kset_name("timeofday"),
+};
+static struct sys_device device_timer = {
+ .id = 0,
+ .cls = &timeofday_sysclass,
+};
+static int timeofday_init_device(void)
+{
+ int error = sysdev_class_register(&timeofday_sysclass);
+ if (!error)
+ error = sysdev_register(&device_timer);
+ return error;
+}
+device_initcall(timeofday_init_device);
+
+/**
+ * timeofday_periodic_hook - Does periodic update of timekeeping values.
+ * unused: unused
+ *
+ * Calculates the delta since the last call,
+ * updates system time and clears the offset.
+ *
+ * Called via timeofday_timer.
+ */
+static void timeofday_periodic_hook(unsigned long unused)
+{
+ cycle_t now, cycle_delta;
+ static u64 remainder;
+ nsec_t ns, ns_ntp;
+ long leapsecond;
+ struct timesource_t* next;
+ unsigned long flags;
+ u64 tmp;
+ int ppm;
+
+ write_seqlock_irqsave(&system_time_lock, flags);
+
+ /* read time source & calc time since last call*/
+ now = read_timesource(timesource);
+ cycle_delta = (now - offset_base) & timesource->mask;
+
+ /* convert cycles to ntp adjusted ns and save remainder */
+ ns_ntp = cyc2ns_rem(timesource, ntp_adj, cycle_delta, &remainder);
+
+ /* convert cycles to raw ns for ntp advance */
+ ns = cyc2ns(timesource, 0, cycle_delta);
+
+#if TIME_DBG
+ static int dbg=0;
+ if(!(dbg++%TIME_DBG_FREQ)){
+ printk(KERN_INFO "now: %lluc - then: %lluc = delta: %lluc -> %llu ns + %llu shift_ns (ntp_adj: %i)\n",
+ (unsigned long long)now, (unsigned long long)offset_base,
+ (unsigned long long)cycle_delta, (unsigned long long)ns,
+ (unsigned long long)remainder, ntp_adj);
+ }
+}
+#endif
+
+ /* update system_time */
+ system_time += ns_ntp;
+
+ /* reset the offset_base */
+ offset_base = now;
+
+ /* advance the ntp state machine by ns interval*/
+ ppm = ntp_advance(ns);
+
+ /* do ntp leap second processing*/
+ leapsecond = ntp_leapsecond(ns_to_timespec(system_time+wall_time_offset));
+ wall_time_offset += leapsecond * NSEC_PER_SEC;
+
+ /* sync the persistent clock */
+ if (!(get_ntp_status() & STA_UNSYNC))
+ sync_persistent_clock(ns_to_timespec(system_time + wall_time_offset));
+
+ /* if necessary, switch timesources */
+ next = get_next_timesource();
+ if (next != timesource) {
+ /* immediately set new offset_base */
+ offset_base = read_timesource(next);
+ /* swap timesources */
+ timesource = next;
+ printk(KERN_INFO "Time: %s timesource has been installed.\n",
+ timesource->name);
+ ntp_clear();
+ ntp_adj = 0;
+ remainder = 0;
+ }
+
+ /* now is a safe time, so allow timesource to adjust
+ * itself (for example: to make cpufreq changes).
+ */
+ if(timesource->update_callback)
+ timesource->update_callback();
+
+
+ /* Convert the signed ppm to timesource multiplier adjustment */
+ tmp = abs(ppm);
+ tmp = tmp * timesource->mult;
+ tmp += 1000000/2; /* round for div*/
+ do_div(tmp, 1000000);
+ if (ppm < 0)
+ ntp_adj = -(int)tmp;
+ else
+ ntp_adj = (int)tmp;
+
+ /* sync legacy values */
+ update_legacy_time_values();
+
+ arch_update_vsyscall_gtod(system_time + wall_time_offset, offset_base,
+ timesource, ntp_adj);
+
+ write_sequnlock_irqrestore(&system_time_lock, flags);
+
+ /* XXX - Do we need to call clock_was_set() here? */
+
+ /* Set us up to go off on the next interval */
+ mod_timer(&timeofday_timer,
+ jiffies + msecs_to_jiffies(PERIODIC_INTERVAL_MS));
+}
+
+
+/**
+ * timeofday_init - Initializes time variables
+ *
+ */
+void __init timeofday_init(void)
+{
+ unsigned long flags;
+#if TIME_DBG
+ printk(KERN_INFO "timeofday_init: Starting up!\n");
+#endif
+ write_seqlock_irqsave(&system_time_lock, flags);
+
+ /* initialize the timesource variable */
+ timesource = get_next_timesource();
+
+ /* clear and initialize offsets*/
+ offset_base = read_timesource(timesource);
+ wall_time_offset = read_persistent_clock();
+
+ /* clear NTP scaling factor & state machine */
+ ntp_adj = 0;
+ ntp_clear();
+
+ arch_update_vsyscall_gtod(system_time + wall_time_offset, offset_base,
+ timesource, ntp_adj);
+
+ /* initialize legacy time values */
+ update_legacy_time_values();
+
+ write_sequnlock_irqrestore(&system_time_lock, flags);
+
+ /* Install timeofday_periodic_hook timer */
+ init_timer(&timeofday_timer);
+ timeofday_timer.function = timeofday_periodic_hook;
+ timeofday_timer.expires = jiffies + 1;
+ add_timer(&timeofday_timer);
+
+
+#if TIME_DBG
+ printk(KERN_INFO "timeofday_init: finished!\n");
+#endif
+ return;
+}
Index: kernel/timer.c
===================================================================
--- 9b7fa103dfb222f809bf277668d9ac0636c060ee/kernel/timer.c (mode:100644)
+++ 6e3d9e6298413e0aed3157cd848724bb12c42554/kernel/timer.c (mode:100644)
@@ -577,6 +577,7 @@
int tickadj = 500/HZ ? : 1; /* microsecs */
+#ifndef CONFIG_NEWTOD
/*
* phase-lock loop variables
*/
@@ -807,6 +808,9 @@
}
} while (ticks);
}
+#else /* !CONFIG_NEWTOD */
+#define update_wall_time(x)
+#endif /* !CONFIG_NEWTOD */
/*
* Called from the timer interrupt handler to charge one tick to the current
Index: kernel/timesource.c
===================================================================
--- /dev/null (tree:9b7fa103dfb222f809bf277668d9ac0636c060ee)
+++ 6e3d9e6298413e0aed3157cd848724bb12c42554/kernel/timesource.c (mode:100644)
@@ -0,0 +1,237 @@
+/*********************************************************************
+* linux/kernel/timesource.c
+*
+* This file contains the functions which manage timesource drivers.
+*
+* Copyright (C) 2004, 2005 IBM, John Stultz (johnstul@us.ibm.com)
+*
+* This program is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation; either version 2 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program; if not, write to the Free Software
+* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*
+* Revision History:
+* 2004-12-07: A1
+* o Rework of timesource structure
+* o Sent to lkml for review
+* 2005-04-29: A4
+* o Keep track of all registered timesources
+* o Add sysfs interface for overriding default selection
+* 2005-05-12: A5
+* o Add boot-time timesource= option for timesource overrides
+* TODO WishList:
+* o Allow timesource drivers to be unregistered
+* o get rid of timesource_jiffies extern
+**********************************************************************/
+
+#include <linux/timesource.h>
+#include <linux/sysdev.h>
+#include <linux/init.h>
+#include <linux/module.h>
+
+#define MAX_TIMESOURCES 10
+
+
+/* XXX - Would like a better way for initializing curr_timesource */
+extern struct timesource_t timesource_jiffies;
+
+/*[Timesource internal variables]---------
+ * curr_timesource:
+ * currently selected timesource. Initialized to timesource_jiffies.
+ * next_timesource:
+ * pending next selected timesource.
+ * timesource_list:
+ * array of pointers pointing to registered timesources
+ * timesource_list_counter:
+ * value which counts the number of registered timesources
+ * timesource_lock:
+ * protects manipulations to curr_timesource and next_timesource
+ * and the timesource_list
+ */
+static struct timesource_t *curr_timesource = ×ource_jiffies;
+static struct timesource_t *next_timesource;
+static struct timesource_t *timesource_list[MAX_TIMESOURCES];
+static int timesource_list_counter;
+static seqlock_t timesource_lock = SEQLOCK_UNLOCKED;
+
+static char override_name[32];
+
+/**
+ * get_next_timesource - Returns the selected timesource
+ *
+ */
+struct timesource_t* get_next_timesource(void)
+{
+ write_seqlock(×ource_lock);
+ if (next_timesource) {
+ curr_timesource = next_timesource;
+ next_timesource = NULL;
+ }
+ write_sequnlock(×ource_lock);
+
+ return curr_timesource;
+}
+
+/**
+ * select_timesource - Finds the best registered timesource.
+ *
+ * Private function. Must have a writelock on timesource_lock
+ * when called.
+ */
+static struct timesource_t* select_timesource(void)
+{
+ struct timesource_t* best = timesource_list[0];
+ int i;
+
+ for (i=0; i < timesource_list_counter; i++) {
+ /* Check for override */
+ if ((override_name[0] != 0) &&
+ (!strncmp(timesource_list[i]->name, override_name,
+ strlen(override_name)))) {
+ best = timesource_list[i];
+ break;
+ }
+ /* Pick the highest priority */
+ if (timesource_list[i]->priority > best->priority)
+ best = timesource_list[i];
+ }
+ return best;
+}
+
+/**
+ * register_timesource - Used to install new timesources
+ * @t: timesource to be registered
+ *
+ */
+void register_timesource(struct timesource_t* t)
+{
+ char* error_msg = 0;
+ int i;
+ write_seqlock(×ource_lock);
+
+ /* check if timesource is already registered */
+ for (i=0; i < timesource_list_counter; i++)
+ if (!strncmp(timesource_list[i]->name, t->name, strlen(t->name))){
+ error_msg = "Already registered!";
+ break;
+ }
+
+ /* check that the list isn't full */
+ if (timesource_list_counter >= MAX_TIMESOURCES)
+ error_msg = "Too many timesources!";
+
+ if(!error_msg)
+ timesource_list[timesource_list_counter++] = t;
+ else
+ printk("register_timesource: Cannot register %s. %s\n",
+ t->name, error_msg);
+
+ /* select next timesource */
+ next_timesource = select_timesource();
+
+ write_sequnlock(×ource_lock);
+}
+EXPORT_SYMBOL(register_timesource);
+
+/**
+ * sysfs_show_timesources - sysfs interface for listing timesource
+ * @dev: unused
+ * @buf: char buffer to be filled with timesource list
+ *
+ * Provides sysfs interface for listing registered timesources
+ */
+static ssize_t sysfs_show_timesources(struct sys_device *dev, char *buf)
+{
+ int i;
+ char* curr = buf;
+ write_seqlock(×ource_lock);
+ for(i=0; i < timesource_list_counter; i++) {
+ /* Mark current timesource w/ a star */
+ if (timesource_list[i] == curr_timesource)
+ curr += sprintf(curr, "*");
+ curr += sprintf(curr, "%s ",timesource_list[i]->name);
+ }
+ write_sequnlock(×ource_lock);
+
+ curr += sprintf(curr, "\n");
+ return curr - buf;
+}
+
+/**
+ * sysfs_override_timesource - interface for manually overriding timesource
+ * @dev: unused
+ * @buf: name of override timesource
+ *
+ *
+ * Takes input from sysfs interface for manually overriding
+ * the default timesource selction
+ */
+static ssize_t sysfs_override_timesource(struct sys_device *dev,
+ const char *buf, size_t count)
+{
+ /* check to avoid underflow later */
+ if (strlen(buf) == 0)
+ return count;
+
+ write_seqlock(×ource_lock);
+
+ /* copy the name given */
+ strncpy(override_name, buf, strlen(buf)-1);
+ override_name[strlen(buf)-1] = 0;
+
+ /* see if we can find it */
+ next_timesource = select_timesource();
+
+ write_sequnlock(×ource_lock);
+ return count;
+}
+
+/* Sysfs setup bits:
+ */
+static SYSDEV_ATTR(timesource, 0600, sysfs_show_timesources, sysfs_override_timesource);
+
+static struct sysdev_class timesource_sysclass = {
+ set_kset_name("timesource"),
+};
+
+static struct sys_device device_timesource = {
+ .id = 0,
+ .cls = ×ource_sysclass,
+};
+
+static int init_timesource_sysfs(void)
+{
+ int error = sysdev_class_register(×ource_sysclass);
+ if (!error) {
+ error = sysdev_register(&device_timesource);
+ if (!error)
+ error = sysdev_create_file(&device_timesource, &attr_timesource);
+ }
+ return error;
+}
+device_initcall(init_timesource_sysfs);
+
+
+/**
+ * boot_override_timesource - boot time override
+ * @str: override name
+ *
+ * Takes a timesource= boot argument and uses it
+ * as the timesource override name
+ */
+static int __init boot_override_timesource(char* str)
+{
+ if (str)
+ strlcpy(override_name, str, sizeof(override_name));
+ return 1;
+}
+__setup("timesource=", boot_override_timesource);
-
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Please read the FAQ at http://www.tux.org/lkml/
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 3/4] new timeofday x86-64 arch specific changes (v. B1)
2005-06-02 0:37 ` [PATCH 3/4] new timeofday x86-64 arch specific changes " Parag Warudkar
@ 2005-06-02 17:34 ` john stultz
0 siblings, 0 replies; 11+ messages in thread
From: john stultz @ 2005-06-02 17:34 UTC (permalink / raw)
To: Parag Warudkar
Cc: Andi Kleen, lkml, Tim Schmielau, George Anzinger, albert,
Ulrich Windl, Christoph Lameter, Dominik Brodowski,
David Mosberger, Andrew Morton, paulus, schwidefsky,
keith maanthey, Chris McDermott, Max Asbock, mahuja,
Nishanth Aravamudan, Darren Hart, Darrick J. Wong,
Anton Blanchard, donf, mpm, benh
On Wed, 2005-06-01 at 20:37 -0400, Parag Warudkar wrote:
> On Wednesday 01 June 2005 19:13, john stultz wrote:
> > This patch converts the x86-64 arch to use the new timeofday
> > infrastructure. It applies on top of my timeofday-core_B1 patch.
>
> This one fails to apply - time.c HUNK #1 gets rejected. (Attached)
Yea, sorry. My naming scheme isn't quite granular enough. The patch is
against Linus' git tree as of yesterday, not -rc5 vanilla.
If you grab Linus' current tree it should apply.
Sorry about the confusion.
-john
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 1/4] new timeofday core subsystem (v. B1)
2005-06-02 1:08 ` [PATCH 1/4] new timeofday core subsystem " Frank Sorenson
@ 2005-06-02 18:00 ` john stultz
0 siblings, 0 replies; 11+ messages in thread
From: john stultz @ 2005-06-02 18:00 UTC (permalink / raw)
To: Frank Sorenson
Cc: Andrew Morton, lkml, Tim Schmielau, George Anzinger, albert,
Ulrich Windl, Christoph Lameter, Dominik Brodowski,
David Mosberger, Andi Kleen, paulus, schwidefsky, keith maanthey,
Chris McDermott, Max Asbock, mahuja, Nishanth Aravamudan,
Darren Hart, Darrick J. Wong, Anton Blanchard, donf, mpm, benh
On Wed, 2005-06-01 at 19:08 -0600, Frank Sorenson wrote:
> Patch 1 appears to be truncated, so here's an updated patch, completed
> from version B0.
Hmm. The archives seem to have the full B1 patch. Are you sure it didn't
just get lost on your end?
thanks
-john
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 1/4] new timeofday core subsystem (v. B1)
2005-06-01 23:09 [PATCH 1/4] new timeofday core subsystem (v. B1) john stultz
2005-06-01 23:12 ` [PATCH 2/4] new timeofday i386 arch specific changes " john stultz
2005-06-02 1:08 ` [PATCH 1/4] new timeofday core subsystem " Frank Sorenson
@ 2005-06-03 7:29 ` Frank Sorenson
2005-06-03 16:13 ` john stultz
2005-06-07 18:28 ` john stultz
2 siblings, 2 replies; 11+ messages in thread
From: Frank Sorenson @ 2005-06-03 7:29 UTC (permalink / raw)
To: john stultz
Cc: Andrew Morton, lkml, Tim Schmielau, George Anzinger, albert,
Ulrich Windl, Christoph Lameter, Dominik Brodowski,
David Mosberger, Andi Kleen, paulus, schwidefsky, keith maanthey,
Chris McDermott, Max Asbock, mahuja, Nishanth Aravamudan,
Darren Hart, Darrick J. Wong, Anton Blanchard, donf, mpm, benh
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
john stultz wrote:
> Andrew, All,
> I'm just re-spinning this to resolve a conflict w/ the CPUFREQ changes
> Linus accepted last night.
<snip>
John,
I have found an issue with these TOD subsystem patches, and I
think it's only an issue on systems that use CPUFREQ. Whenever
the frequency changes, at least some portions of the kernel
get confused about their notion of time. Here are some
example entries from my syslog:
Jun 3 00:33:40 moebius kernel: [ 145.023201] cpufreq-core: target for CPU 0: 800000 kHz, relation 0
Jun 3 00:33:47 moebius kernel: [ 114.838909] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0
Jun 3 00:33:47 moebius kernel: [ 114.838977] freq-table: request for target 1000000 kHz (relation: 0) for cpu 0
Jun 3 00:33:47 moebius kernel: [ 92.161872] codec_semaphore: semaphore is not ready [0x1][0x700300]
Jun 3 00:33:52 moebius kernel: [ 97.433279] cpufreq-core: target for CPU 0: 1200000 kHz, relation 0
Jun 3 00:33:58 moebius kernel: [ 66.352233] cpufreq-core: target for CPU 0: 1400000 kHz, relation 0
Jun 3 00:34:08 moebius kernel: [ 85.547260] cpufreq-core: target for CPU 0: 1200000 kHz, relation 0
Jun 3 00:34:16 moebius kernel: [ 211.791738] cpufreq-core: target for CPU 0: 800000 kHz, relation 0
Jun 3 00:34:27 moebius kernel: [ 112.941898] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0
Jun 3 00:34:31 moebius kernel: [ 231.793121] cpufreq-core: target for CPU 0: 800000 kHz, relation 0
Jun 3 00:34:41 moebius kernel: [ 147.122593] cpufreq-core: target for CPU 0: 1200000 kHz, relation 0
Jun 3 00:34:42 moebius kernel: [ 123.906802] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0
Jun 3 00:34:46 moebius kernel: [ 251.342116] cpufreq-core: target for CPU 0: 800000 kHz, relation 0
Jun 3 00:34:51 moebius kernel: [ 192.985214] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0
The printk times are taken from sched_clock(), which now
varies depending on the cpu frequency. Without these patches,
the printk times appear to consistently increase at the right rate.
I'm not sure what other portions of the kernel are affected by
this (watchdogs firing, or other issues?).
Thanks,
Frank
- --
Frank Sorenson - KD7TZK
Systems Manager, Computer Science Department
Brigham Young University
frank@tuxrocks.com
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^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 1/4] new timeofday core subsystem (v. B1)
2005-06-03 7:29 ` Frank Sorenson
@ 2005-06-03 16:13 ` john stultz
2005-06-07 18:28 ` john stultz
1 sibling, 0 replies; 11+ messages in thread
From: john stultz @ 2005-06-03 16:13 UTC (permalink / raw)
To: Frank Sorenson
Cc: Andrew Morton, lkml, Tim Schmielau, George Anzinger, albert,
Ulrich Windl, Christoph Lameter, Dominik Brodowski,
David Mosberger, Andi Kleen, paulus, schwidefsky, keith maanthey,
Chris McDermott, Max Asbock, mahuja, Nishanth Aravamudan,
Darren Hart, Darrick J. Wong, Anton Blanchard, donf, mpm, benh
On Fri, 2005-06-03 at 01:29 -0600, Frank Sorenson wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> john stultz wrote:
> > Andrew, All,
> > I'm just re-spinning this to resolve a conflict w/ the CPUFREQ changes
> > Linus accepted last night.
> <snip>
>
> John,
>
> I have found an issue with these TOD subsystem patches, and I
> think it's only an issue on systems that use CPUFREQ. Whenever
> the frequency changes, at least some portions of the kernel
> get confused about their notion of time. Here are some
> example entries from my syslog:
>
> Jun 3 00:33:40 moebius kernel: [ 145.023201] cpufreq-core: target for CPU 0: 800000 kHz, relation 0
> Jun 3 00:33:47 moebius kernel: [ 114.838909] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0
> Jun 3 00:33:47 moebius kernel: [ 114.838977] freq-table: request for target 1000000 kHz (relation: 0) for cpu 0
> Jun 3 00:33:47 moebius kernel: [ 92.161872] codec_semaphore: semaphore is not ready [0x1][0x700300]
> Jun 3 00:33:52 moebius kernel: [ 97.433279] cpufreq-core: target for CPU 0: 1200000 kHz, relation 0
> Jun 3 00:33:58 moebius kernel: [ 66.352233] cpufreq-core: target for CPU 0: 1400000 kHz, relation 0
> Jun 3 00:34:08 moebius kernel: [ 85.547260] cpufreq-core: target for CPU 0: 1200000 kHz, relation 0
> Jun 3 00:34:16 moebius kernel: [ 211.791738] cpufreq-core: target for CPU 0: 800000 kHz, relation 0
> Jun 3 00:34:27 moebius kernel: [ 112.941898] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0
> Jun 3 00:34:31 moebius kernel: [ 231.793121] cpufreq-core: target for CPU 0: 800000 kHz, relation 0
> Jun 3 00:34:41 moebius kernel: [ 147.122593] cpufreq-core: target for CPU 0: 1200000 kHz, relation 0
> Jun 3 00:34:42 moebius kernel: [ 123.906802] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0
> Jun 3 00:34:46 moebius kernel: [ 251.342116] cpufreq-core: target for CPU 0: 800000 kHz, relation 0
> Jun 3 00:34:51 moebius kernel: [ 192.985214] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0
>
> The printk times are taken from sched_clock(), which now
> varies depending on the cpu frequency. Without these patches,
> the printk times appear to consistently increase at the right rate.
> I'm not sure what other portions of the kernel are affected by
> this (watchdogs firing, or other issues?).
Yep, looks like something isn't right between sched_clock and the
cpufreq changes. I'll let you know when I've sorted it out.
Thanks for the great testing!
-john
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 1/4] new timeofday core subsystem (v. B1)
2005-06-03 7:29 ` Frank Sorenson
2005-06-03 16:13 ` john stultz
@ 2005-06-07 18:28 ` john stultz
1 sibling, 0 replies; 11+ messages in thread
From: john stultz @ 2005-06-07 18:28 UTC (permalink / raw)
To: Frank Sorenson
Cc: Andrew Morton, lkml, Tim Schmielau, George Anzinger, albert,
Ulrich Windl, Christoph Lameter, Dominik Brodowski,
David Mosberger, Andi Kleen, paulus, schwidefsky, keith maanthey,
Chris McDermott, Max Asbock, mahuja, Nishanth Aravamudan,
Darren Hart, Darrick J. Wong, Anton Blanchard, donf, mpm, benh
On Fri, 2005-06-03 at 01:29 -0600, Frank Sorenson wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> john stultz wrote:
> > Andrew, All,
> > I'm just re-spinning this to resolve a conflict w/ the CPUFREQ changes
> > Linus accepted last night.
> <snip>
>
> I have found an issue with these TOD subsystem patches, and I
> think it's only an issue on systems that use CPUFREQ. Whenever
> the frequency changes, at least some portions of the kernel
> get confused about their notion of time. Here are some
> example entries from my syslog:
>
> Jun 3 00:33:40 moebius kernel: [ 145.023201] cpufreq-core: target for CPU 0: 800000 kHz, relation 0
> Jun 3 00:33:47 moebius kernel: [ 114.838909] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0
> Jun 3 00:33:47 moebius kernel: [ 114.838977] freq-table: request for target 1000000 kHz (relation: 0) for cpu 0
> Jun 3 00:33:47 moebius kernel: [ 92.161872] codec_semaphore: semaphore is not ready [0x1][0x700300]
> Jun 3 00:33:52 moebius kernel: [ 97.433279] cpufreq-core: target for CPU 0: 1200000 kHz, relation 0
> Jun 3 00:33:58 moebius kernel: [ 66.352233] cpufreq-core: target for CPU 0: 1400000 kHz, relation 0
> Jun 3 00:34:08 moebius kernel: [ 85.547260] cpufreq-core: target for CPU 0: 1200000 kHz, relation 0
> Jun 3 00:34:16 moebius kernel: [ 211.791738] cpufreq-core: target for CPU 0: 800000 kHz, relation 0
> Jun 3 00:34:27 moebius kernel: [ 112.941898] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0
> Jun 3 00:34:31 moebius kernel: [ 231.793121] cpufreq-core: target for CPU 0: 800000 kHz, relation 0
> Jun 3 00:34:41 moebius kernel: [ 147.122593] cpufreq-core: target for CPU 0: 1200000 kHz, relation 0
> Jun 3 00:34:42 moebius kernel: [ 123.906802] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0
> Jun 3 00:34:46 moebius kernel: [ 251.342116] cpufreq-core: target for CPU 0: 800000 kHz, relation 0
> Jun 3 00:34:51 moebius kernel: [ 192.985214] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0
>
> The printk times are taken from sched_clock(), which now
> varies depending on the cpu frequency. Without these patches,
> the printk times appear to consistently increase at the right rate.
> I'm not sure what other portions of the kernel are affected by
> this (watchdogs firing, or other issues?).
Hrm. So, I've been looking into this and I'm a bit stumped, as I'm not
really changing the behavior of sched_clock().
sched_clock() is a pretty bad interface as it just takes the current TSC
value (relative to zero) and scales it using the current cpukhz value
(well, indirectly using cycles_2_ns). Since it doesn't ever accumulate
the past time, frequency changes affect the full interval (since the TSC
was reset) which can cause large errors. The rational for this was that
sched_clock() was supposed to be as fast as possible just to give a
quick guide to the scheduler and occasional incorrect values are
acceptable.
I'm looking further into it, but could you send me privately the dmesg
output for both with and without the TOD patch?
thanks
-john
^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2005-06-07 18:28 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2005-06-01 23:09 [PATCH 1/4] new timeofday core subsystem (v. B1) john stultz
2005-06-01 23:12 ` [PATCH 2/4] new timeofday i386 arch specific changes " john stultz
2005-06-01 23:13 ` [PATCH 3/4] new timeofday x86-64 " john stultz
2005-06-01 23:16 ` [PATCH 4/4] new timeofday i386 and x86-64 timesources " john stultz
2005-06-02 0:37 ` [PATCH 3/4] new timeofday x86-64 arch specific changes " Parag Warudkar
2005-06-02 17:34 ` john stultz
2005-06-02 1:08 ` [PATCH 1/4] new timeofday core subsystem " Frank Sorenson
2005-06-02 18:00 ` john stultz
2005-06-03 7:29 ` Frank Sorenson
2005-06-03 16:13 ` john stultz
2005-06-07 18:28 ` john stultz
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