[RFC][PATCH 0/10] Convert the remaining !GENERIC_TIME architectures to use the generic timekeeping core.

[RFC][PATCH 0/10] Convert the remaining !GENERIC_TIME architectures to use the generic timekeeping core.

[john stultz]

Hello,
	Its been two and a half years since the GENERIC_TIME infrastructure
landed. It allowed architectures that have free running counters to only
have to provide a clocksource driver and leave the rest of the
timekeeping management to generic code.

So far out of the 23 architectures we've fully converted 15 of them over
to GENERIC_TIME. The remaining 8 have in some cases been able to
convert, but not fully. The issue that keeps most architectures from
converting is that they do not have free running counters. They instead
use the counter on their tick timer to determine their inter-tick time.
This counter usually wraps every interrupt, so its not really efficient
to use as a clocksource.

This has created some difficulty as the generic timekeeping core has had
to deal with both GENERIC_TIME arches as well as !GENERIC_TIME arches,
and since it didn't manage 100% of the calculation in the !GENERIC_TIME
case, we've been limited in some of the changes we could make.

So since these last remaining architectures are unlikely to be able to
fully convert to GENERIC_TIME as it stands, the generic core should try
to adopt to their needs so we can bring them into the fold and reduce
code duplication.

The solution is to provide a arch callout from the generic timekeeping
core: arch_gettimeoffset().  On architectures that do not provide a
clocksource, the jiffies clocksource is used, and arch_gettimeoffset is
added in to create finer grained inter-tick time.

The patchset is split up into three parts.
1) Introducing the arch_gettimeoffset infrastructure to the timekeeping
core.
2) 8 patches to convert the remaining arches over to use
arch_gettimeoffset()
3) Finally, Removing all conditionals and references to GENERIC_TIME.

The full patchset reduces the kernel by about 550 lines.

 42 files changed, 139 insertions(+), 684 deletions(-)

Any thoughts or feedback would be appreciated. I've been unable to test
the arch conversions, so any help in getting those right would be
appreciated. I expect this will probably take a few tries.

And credits to Roman for initially suggesting the idea quite awhile
back.

thanks
-john

[RFC][PATCH 1/10] Create arch_gettimeoffset infrastructure for use in the generic timekeeping core.

[john stultz]

Some arches don't supply their own clocksource. This is mainly the case
in architectures that get their inter-tick times by reading the counter
on their interval timer. Since these timers wrap every tick, they're not
really useful as clocksources. Wrapping them to act like one is possible
but not very efficient. So we provide a callout these arches  can
implement for use with the jiffies clocksource to provide finer then
tick granular time.

Signed-off-by: John Stultz <johnstul@us.ibm.com>

diff --git a/include/linux/time.h b/include/linux/time.h
index fbbd2a1..4768f16 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -113,6 +113,21 @@ struct timespec current_kernel_time(void);
 #define CURRENT_TIME		(current_kernel_time())
 #define CURRENT_TIME_SEC	((struct timespec) { get_seconds(), 0 })
 
+/* Some architectures do not supply their own clocksource.
+ * This is mainly the case in architectures that get their
+ * inter-tick times by reading the counter on their interval
+ * timer. Since these timers wrap every tick, they're not really
+ * useful as clocksources. Wrapping them to act like one is possible
+ * but not very efficient. So we provide a callout these arches
+ * can implement for use with the jiffies clocksource to provide
+ * finer then tick granular time.
+ */
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
+extern u32 arch_gettimeoffset(void);
+#else
+#define arch_gettimeoffset() (0)
+#endif
+
 extern void do_gettimeofday(struct timeval *tv);
 extern int do_settimeofday(struct timespec *tv);
 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 900f1b6..45d777f 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -77,6 +77,10 @@ static void clocksource_forward_now(void)
 	clock->cycle_last = cycle_now;
 
 	nsec = cyc2ns(clock, cycle_delta);
+
+	/* If arch requires, add in gettimeoffset() */
+	nsec += arch_gettimeoffset();
+
 	timespec_add_ns(&xtime, nsec);
 
 	nsec = ((s64)cycle_delta * clock->mult_orig) >> clock->shift;
@@ -111,6 +115,9 @@ void getnstimeofday(struct timespec *ts)
 		/* convert to nanoseconds: */
 		nsecs = cyc2ns(clock, cycle_delta);
 
+		/* If arch requires, add in gettimeoffset() */
+		nsecs += arch_gettimeoffset();
+
 	} while (read_seqretry(&xtime_lock, seq));
 
 	timespec_add_ns(ts, nsecs);

[RFC][PATCH 2/10] Convert arm to use arch_getoffset() infrastructure.

[john stultz]

This patch converts arm to use GENERIC_TIME via the arch_getoffset()
infrastructure 

I do not have cross compilers for these architectures, and in some cases
the architectures can be compiles both with and without clocksources. So
I've taken my best swing at converting this, but I'm not confident I got
it right. Any assistance from arch maintainers or testers would be
great.

Signed-off-by: John Stultz <johnstul@us.ibm.com>


diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index dbfdf87..3c04f80 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -38,7 +38,7 @@ config GENERIC_GPIO
 
 config GENERIC_TIME
 	bool
-	default n
+	default y
 
 config GENERIC_CLOCKEVENTS
 	bool
@@ -203,6 +203,7 @@ config ARCH_AAEC2000
 	select CPU_ARM920T
 	select ARM_AMBA
 	select HAVE_CLK
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  This enables support for systems based on the Agilent AAEC-2000
 
@@ -212,6 +213,7 @@ config ARCH_INTEGRATOR
 	select HAVE_CLK
 	select COMMON_CLKDEV
 	select ICST525
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  Support for ARM's Integrator platform.
 
@@ -221,7 +223,6 @@ config ARCH_REALVIEW
 	select HAVE_CLK
 	select COMMON_CLKDEV
 	select ICST307
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	help
 	  This enables support for ARM Ltd RealView boards.
@@ -233,7 +234,6 @@ config ARCH_VERSATILE
 	select HAVE_CLK
 	select COMMON_CLKDEV
 	select ICST307
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	help
 	  This enables support for ARM Ltd Versatile board.
@@ -242,6 +242,7 @@ config ARCH_AT91
 	bool "Atmel AT91"
 	select GENERIC_GPIO
 	select HAVE_CLK
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  This enables support for systems based on the Atmel AT91RM9200,
 	  AT91SAM9 and AT91CAP9 processors.
@@ -257,6 +258,7 @@ config ARCH_EBSA110
 	select CPU_SA110
 	select ISA
 	select NO_IOPORT
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  This is an evaluation board for the StrongARM processor available
 	  from Digital. It has limited hardware on-board, including an
@@ -272,6 +274,7 @@ config ARCH_EP93XX
 	select HAVE_CLK
 	select COMMON_CLKDEV
 	select ARCH_REQUIRE_GPIOLIB
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  This enables support for the Cirrus EP93xx series of CPUs.
 
@@ -279,6 +282,7 @@ config ARCH_FOOTBRIDGE
 	bool "FootBridge"
 	select CPU_SA110
 	select FOOTBRIDGE
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  Support for systems based on the DC21285 companion chip
 	  ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
@@ -288,7 +292,6 @@ config ARCH_NETX
 	select CPU_ARM926T
 	select ARM_VIC
 	select GENERIC_CLOCKEVENTS
-	select GENERIC_TIME
 	help
 	  This enables support for systems based on the Hilscher NetX Soc
 
@@ -296,6 +299,7 @@ config ARCH_H720X
 	bool "Hynix HMS720x-based"
 	select CPU_ARM720T
 	select ISA_DMA_API
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  This enables support for systems based on the Hynix HMS720x
 
@@ -303,7 +307,6 @@ config ARCH_IMX
 	bool "IMX"
 	select CPU_ARM920T
 	select GENERIC_GPIO
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	help
 	  Support for Motorola's i.MX family of processors (MX1, MXL).
@@ -316,6 +319,7 @@ config ARCH_IOP13XX
 	select PCI
 	select ARCH_SUPPORTS_MSI
 	select VMSPLIT_1G
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  Support for Intel's IOP13XX (XScale) family of processors.
 
@@ -327,6 +331,7 @@ config ARCH_IOP32X
 	select PCI
 	select GENERIC_GPIO
 	select ARCH_REQUIRE_GPIOLIB
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  Support for Intel's 80219 and IOP32X (XScale) family of
 	  processors.
@@ -339,6 +344,7 @@ config ARCH_IOP33X
 	select PCI
 	select GENERIC_GPIO
 	select ARCH_REQUIRE_GPIOLIB
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  Support for Intel's IOP33X (XScale) family of processors.
 
@@ -347,6 +353,7 @@ config ARCH_IXP23XX
 	depends on MMU
 	select CPU_XSC3
  	select PCI
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  Support for Intel's IXP23xx (XScale) family of processors.
 
@@ -355,6 +362,7 @@ config ARCH_IXP2000
 	depends on MMU
 	select CPU_XSCALE
 	select PCI
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  Support for Intel's IXP2400/2800 (XScale) family of processors.
 
@@ -363,7 +371,6 @@ config ARCH_IXP4XX
 	depends on MMU
 	select CPU_XSCALE
 	select GENERIC_GPIO
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	select DMABOUNCE if PCI
 	help
@@ -373,6 +380,7 @@ config ARCH_L7200
 	bool "LinkUp-L7200"
 	select CPU_ARM720T
 	select FIQ
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  Say Y here if you intend to run this kernel on a LinkUp Systems
 	  L7200 Software Development Board which uses an ARM720T processor.
@@ -388,7 +396,6 @@ config ARCH_KIRKWOOD
 	select CPU_FEROCEON
 	select PCI
 	select GENERIC_GPIO
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	select PLAT_ORION
 	help
@@ -400,6 +407,7 @@ config ARCH_KS8695
 	select CPU_ARM922T
 	select GENERIC_GPIO
         select ARCH_REQUIRE_GPIOLIB
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
 	  System-on-Chip devices.
@@ -408,7 +416,6 @@ config ARCH_NS9XXX
 	bool "NetSilicon NS9xxx"
 	select CPU_ARM926T
 	select GENERIC_GPIO
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	select HAVE_CLK
 	help
@@ -420,7 +427,6 @@ config ARCH_NS9XXX
 config ARCH_LOKI
 	bool "Marvell Loki (88RC8480)"
 	select CPU_FEROCEON
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	select PLAT_ORION
 	help
@@ -431,7 +437,6 @@ config ARCH_MV78XX0
 	select CPU_FEROCEON
 	select PCI
 	select GENERIC_GPIO
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	select PLAT_ORION
 	help
@@ -440,7 +445,6 @@ config ARCH_MV78XX0
 
 config ARCH_MXC
 	bool "Freescale MXC/iMX-based"
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	select ARCH_MTD_XIP
 	select GENERIC_GPIO
@@ -454,7 +458,6 @@ config ARCH_ORION5X
 	select CPU_FEROCEON
 	select PCI
 	select GENERIC_GPIO
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	select PLAT_ORION
 	help
@@ -466,6 +469,7 @@ config ARCH_PNX4008
 	bool "Philips Nexperia PNX4008 Mobile"
 	select CPU_ARM926T
 	select HAVE_CLK
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  This enables support for Philips PNX4008 mobile platform.
 
@@ -477,7 +481,6 @@ config ARCH_PXA
 	select HAVE_CLK
 	select COMMON_CLKDEV
 	select ARCH_REQUIRE_GPIOLIB
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	select TICK_ONESHOT
 	help
@@ -493,6 +496,7 @@ config ARCH_RPC
 	select ISA_DMA_API
 	select NO_IOPORT
 	select ARCH_SPARSEMEM_ENABLE
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  On the Acorn Risc-PC, Linux can support the internal IDE disk and
 	  CD-ROM interface, serial and parallel port, and the floppy drive.
@@ -504,7 +508,6 @@ config ARCH_SA1100
 	select ARCH_SPARSEMEM_ENABLE
 	select ARCH_MTD_XIP
 	select GENERIC_GPIO
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	select HAVE_CLK
 	select TICK_ONESHOT
@@ -516,6 +519,7 @@ config ARCH_S3C2410
 	bool "Samsung S3C2410, S3C2412, S3C2413, S3C2440, S3C2442, S3C2443"
 	select GENERIC_GPIO
 	select HAVE_CLK
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  Samsung S3C2410X CPU based systems, such as the Simtec Electronics
 	  BAST (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or
@@ -525,6 +529,7 @@ config ARCH_S3C64XX
 	bool "Samsung S3C64XX"
 	select GENERIC_GPIO
 	select HAVE_CLK
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  Samsung S3C64XX series based systems
 
@@ -535,6 +540,7 @@ config ARCH_SHARK
 	select ISA_DMA
 	select ZONE_DMA
 	select PCI
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  Support for the StrongARM based Digital DNARD machine, also known
 	  as "Shark" (<http://www.shark-linux.de/shark.html>).
@@ -544,6 +550,7 @@ config ARCH_LH7A40X
 	select CPU_ARM922T
 	select ARCH_DISCONTIGMEM_ENABLE if !LH7A40X_CONTIGMEM
 	select ARCH_SPARSEMEM_ENABLE if !LH7A40X_CONTIGMEM
+	select ARCH_USES_GETTIMEOFFSET
 	help
 	  Say Y here for systems based on one of the Sharp LH7A40X
 	  System on a Chip processors.  These CPUs include an ARM922T
@@ -553,7 +560,6 @@ config ARCH_LH7A40X
 config ARCH_DAVINCI
 	bool "TI DaVinci"
 	select CPU_ARM926T
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_GPIO
 	select ARCH_REQUIRE_GPIOLIB
@@ -567,7 +573,6 @@ config ARCH_OMAP
 	select GENERIC_GPIO
 	select HAVE_CLK
 	select ARCH_REQUIRE_GPIOLIB
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	help
 	  Support for TI's OMAP platform (OMAP1 and OMAP2).
@@ -575,7 +580,6 @@ config ARCH_OMAP
 config ARCH_MSM
 	bool "Qualcomm MSM"
 	select CPU_V6
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	help
 	  Support for Qualcomm MSM7K based systems.  This runs on the ARM11
@@ -586,6 +590,7 @@ config ARCH_MSM
 config ARCH_W90X900
 	bool "Nuvoton W90X900 CPU"
 	select CPU_ARM926T
+	select ARCH_USES_GETTIMEOFFSET
 	help
 		Support for Nuvoton (Winbond logic dept.) ARM9 processor,You
 		can login www.mcuos.com or www.nuvoton.com to know more.
@@ -1338,3 +1343,6 @@ source "security/Kconfig"
 source "crypto/Kconfig"
 
 source "lib/Kconfig"
+
+
+
diff --git a/arch/arm/include/asm/mach/time.h b/arch/arm/include/asm/mach/time.h
index b2cc1fc..20c1d84 100644
--- a/arch/arm/include/asm/mach/time.h
+++ b/arch/arm/include/asm/mach/time.h
@@ -38,7 +38,7 @@ struct sys_timer {
 	void			(*init)(void);
 	void			(*suspend)(void);
 	void			(*resume)(void);
-#ifndef CONFIG_GENERIC_TIME
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 	unsigned long		(*offset)(void);
 #endif
 };
diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c
index c68b44a..49cdcc7 100644
--- a/arch/arm/kernel/time.c
+++ b/arch/arm/kernel/time.c
@@ -72,7 +72,7 @@ EXPORT_SYMBOL(profile_pc);
  */
 int (*set_rtc)(void);
 
-#ifndef CONFIG_GENERIC_TIME
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 static unsigned long dummy_gettimeoffset(void)
 {
 	return 0;
@@ -227,63 +227,12 @@ static inline void do_leds(void)
 #define	do_leds()
 #endif
 
-#ifndef CONFIG_GENERIC_TIME
-void do_gettimeofday(struct timeval *tv)
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
+u32 arch_gettimeoffset(void)
 {
-	unsigned long flags;
-	unsigned long seq;
-	unsigned long usec, sec;
-
-	do {
-		seq = read_seqbegin_irqsave(&xtime_lock, flags);
-		usec = system_timer->offset();
-		sec = xtime.tv_sec;
-		usec += xtime.tv_nsec / 1000;
-	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
-
-	/* usec may have gone up a lot: be safe */
-	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
-	 * done, and then undo it!
-	 */
-	nsec -= system_timer->offset() * NSEC_PER_USEC;
-
-	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);
-
-	ntp_clear();
-	write_sequnlock_irq(&xtime_lock);
-	clock_was_set();
-	return 0;
+	return system_timer->offset() * 1000;
 }
-
-EXPORT_SYMBOL(do_settimeofday);
-#endif /* !CONFIG_GENERIC_TIME */
+#endif /* CONFIG_ARCH_USES_GETTIMEOFFSET */
 
 /**
  * save_time_delta - Save the offset between system time and RTC time
@@ -382,7 +331,7 @@ device_initcall(timer_init_sysfs);
 
 void __init time_init(void)
 {
-#ifndef CONFIG_GENERIC_TIME
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 	if (system_timer->offset == NULL)
 		system_timer->offset = dummy_gettimeoffset;
 #endif
diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index 323b47f..e82979c 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -8,47 +8,41 @@ choice
 config ARCH_AT91RM9200
 	bool "AT91RM9200"
 	select CPU_ARM920T
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 
 config ARCH_AT91SAM9260
 	bool "AT91SAM9260 or AT91SAM9XE"
 	select CPU_ARM926T
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 
 config ARCH_AT91SAM9261
 	bool "AT91SAM9261"
 	select CPU_ARM926T
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 
 config ARCH_AT91SAM9263
 	bool "AT91SAM9263"
 	select CPU_ARM926T
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 
 config ARCH_AT91SAM9RL
 	bool "AT91SAM9RL"
 	select CPU_ARM926T
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 
 config ARCH_AT91SAM9G20
 	bool "AT91SAM9G20"
 	select CPU_ARM926T
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 
 config ARCH_AT91CAP9
 	bool "AT91CAP9"
 	select CPU_ARM926T
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 
 config ARCH_AT91X40
 	bool "AT91x40"
+	select ARCH_USES_GETTIMEOFFSET
 
 endchoice
 

[RFC][PATCH 3/10] Convert blackfin to use arch_getoffset() infrastructure.

[john stultz]

This patch converts blackfin to use GENERIC_TIME via the
arch_getoffset() infrastructure 

I do not have cross compilers for these architectures, and in some cases
the architectures can be compiles both with and without clocksources. So
I've taken my best swing at converting this, but I'm not confident I got
it right. Any assistance from arch maintainers or testers would be
great.

Signed-off-by: John Stultz <johnstul@us.ibm.com>


diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index a949c4f..ebe5e28 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -576,9 +576,7 @@ comment "Kernel Timer/Scheduler"
 source kernel/Kconfig.hz
 
 config GENERIC_TIME
-	bool "Generic time"
-	depends on !SMP
-	default y
+	def_bool y
 
 config GENERIC_CLOCKEVENTS
 	bool "Generic clock events"
@@ -598,6 +596,10 @@ config CYCLES_CLOCKSOURCE
 	  still be able to read it (such as for performance monitoring), but
 	  writing the registers will most likely crash the kernel.
 
+config ARCH_USES_GETTIMEOFFSET
+	depends on !CYCLES_CLOCKSOURCE
+	def_bool y
+
 source kernel/time/Kconfig
 
 comment "Misc"
diff --git a/arch/blackfin/kernel/time.c b/arch/blackfin/kernel/time.c
index 172b4c5..20870f7 100644
--- a/arch/blackfin/kernel/time.c
+++ b/arch/blackfin/kernel/time.c
@@ -85,11 +85,11 @@ time_sched_init(irqreturn_t(*timer_routine) (int, void *))
 #endif
 }
 
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 /*
  * Should return useconds since last timer tick
  */
-#ifndef CONFIG_GENERIC_TIME
-static unsigned long gettimeoffset(void)
+u32 arch_gettimeoffset(void)
 {
 	unsigned long offset;
 	unsigned long clocks_per_jiffy;
@@ -196,64 +196,29 @@ void __init time_init(void)
 	time_sched_init(timer_interrupt);
 }
 
-#ifndef CONFIG_GENERIC_TIME
-void do_gettimeofday(struct timeval *tv)
-{
-	unsigned long flags;
-	unsigned long seq;
-	unsigned long usec, sec;
-
-	do {
-		seq = read_seqbegin_irqsave(&xtime_lock, flags);
-		usec = gettimeoffset();
-		sec = xtime.tv_sec;
-		usec += (xtime.tv_nsec / NSEC_PER_USEC);
-	}
-	while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
-
-	while (usec >= USEC_PER_SEC) {
-		usec -= USEC_PER_SEC;
-		sec++;
-	}
-
-	tv->tv_sec = sec;
-	tv->tv_usec = usec;
-}
-EXPORT_SYMBOL(do_gettimeofday);
-
-int do_settimeofday(struct timespec *tv)
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
+/*
+ * Should return nseconds since last timer tick
+ */
+u32 arch_gettimeoffset(void)
 {
-	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 the xtime.tv_usec
-	 * correctly. However, the value in this location is
-	 * is value at the last tick.
-	 * Discover what correction gettimeofday
-	 * would have done, and then undo it!
-	 */
-	nsec -= (gettimeoffset() * NSEC_PER_USEC);
-
-	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);
+	unsigned long offset;
+	unsigned long clocks_per_jiffy;
 
-	ntp_clear();
+	clocks_per_jiffy = bfin_read_TPERIOD();
+	offset =
+	    (clocks_per_jiffy -
+	     bfin_read_TCOUNT()) / (((clocks_per_jiffy + 1) * HZ) /
+				    USEC_PER_SEC);
 
-	write_sequnlock_irq(&xtime_lock);
-	clock_was_set();
+	/* Check if we just wrapped the counters and maybe missed a tick */
+	if ((bfin_read_ILAT() & (1 << IRQ_CORETMR))
+	    && (offset < (100000 / HZ / 2)))
+		offset += (USEC_PER_SEC / HZ);
 
-	return 0;
+	return offset*1000;
 }
-EXPORT_SYMBOL(do_settimeofday);
-#endif /* !CONFIG_GENERIC_TIME */
+#endif /* !CONFIG_ARCH_USES_GETTIMEOFFSET */
 
 /*
  * Scheduler clock - returns current time in nanosec units.

[RFC][PATCH 4/10] Convert cris to use arch_getoffset() infrastructure.

[john stultz]

This patch converts cris to use GENERIC_TIME via the arch_getoffset()
infrastructure 

I do not have cross compilers for these architectures, and in some cases
the architectures can be compiles both with and without clocksources. So
I've taken my best swing at converting this, but I'm not confident I got
it right. Any assistance from arch maintainers or testers would be
great.

Signed-off-by: John Stultz <johnstul@us.ibm.com>


diff --git a/arch/cris/Kconfig b/arch/cris/Kconfig
index 3462245..8082352 100644
--- a/arch/cris/Kconfig
+++ b/arch/cris/Kconfig
@@ -20,6 +20,12 @@ config RWSEM_GENERIC_SPINLOCK
 config RWSEM_XCHGADD_ALGORITHM
 	bool
 
+config GENERIC_TIME
+	def_bool y
+
+config ARCH_USES_GETTIMEOFFSET
+	def_bool y
+
 config GENERIC_IOMAP
        bool
        default y
diff --git a/arch/cris/kernel/time.c b/arch/cris/kernel/time.c
index 074fe7d..a05dd31 100644
--- a/arch/cris/kernel/time.c
+++ b/arch/cris/kernel/time.c
@@ -42,75 +42,11 @@ unsigned long loops_per_usec;
 extern unsigned long do_slow_gettimeoffset(void);
 static unsigned long (*do_gettimeoffset)(void) = do_slow_gettimeoffset;
 
-/*
- * This version of gettimeofday has near microsecond resolution.
- *
- * Note: Division is quite slow on CRIS and do_gettimeofday is called
- *       rather often. Maybe we should do some kind of approximation here
- *       (a naive approximation would be to divide by 1024).
- */
-void do_gettimeofday(struct timeval *tv)
-{
-	unsigned long flags;
-	signed long usec, sec;
-	local_irq_save(flags);
-	usec = do_gettimeoffset();
-
-        /*
-	 * 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) && usec > tickadj)
-		usec = tickadj;
-
-	sec = xtime.tv_sec;
-	usec += xtime.tv_nsec / 1000;
-	local_irq_restore(flags);
-
-	while (usec >= 1000000) {
-		usec -= 1000000;
-		sec++;
-	}
-
-	tv->tv_sec = sec;
-	tv->tv_usec = usec;
-}
-
-EXPORT_SYMBOL(do_gettimeofday);
-
-int do_settimeofday(struct timespec *tv)
+u32 arch_gettimeoffset(void)
 {
-	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 -= do_gettimeoffset() * NSEC_PER_USEC;
-
-	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);
-
-	ntp_clear();
-	write_sequnlock_irq(&xtime_lock);
-	clock_was_set();
-	return 0;
+	return do_gettimeoffset() * 1000;
 }
 
-EXPORT_SYMBOL(do_settimeofday);
-
-
 /*
  * BUG: This routine does not handle hour overflow properly; it just
  *      sets the minutes. Usually you'll only notice that after reboot!

[RFC][PATCH 5/10] Convert m32r to use arch_getoffset() infrastructure.

[john stultz]

This patch converts m32r to use GENERIC_TIME via the arch_getoffset()
infrastructure 

I do not have cross compilers for these architectures, and in some cases
the architectures can be compiles both with and without clocksources. So
I've taken my best swing at converting this, but I'm not confident I got
it right. Any assistance from arch maintainers or testers would be
great.

Signed-off-by: John Stultz <johnstul@us.ibm.com>


diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index cabba33..c41234f 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -41,6 +41,12 @@ config HZ
 	int
 	default 100
 
+config GENERIC_TIME
+	def_bool y
+
+config ARCH_USES_GETTIMEOFFSET
+	def_bool y
+
 source "init/Kconfig"
 
 source "kernel/Kconfig.freezer"
diff --git a/arch/m32r/kernel/time.c b/arch/m32r/kernel/time.c
index 6ea0177..01b67d0 100644
--- a/arch/m32r/kernel/time.c
+++ b/arch/m32r/kernel/time.c
@@ -48,7 +48,7 @@ extern void smp_local_timer_interrupt(void);
 
 static unsigned long latch;
 
-static unsigned long do_gettimeoffset(void)
+u32 arch_gettimeoffset(void)
 {
 	unsigned long  elapsed_time = 0;  /* [us] */
 
@@ -93,79 +93,10 @@ static unsigned long do_gettimeoffset(void)
 #error no chip configuration
 #endif
 
-	return elapsed_time;
+	return elapsed_time * 1000;
 }
 
 /*
- * This version of gettimeofday has near microsecond resolution.
- */
-void do_gettimeofday(struct timeval *tv)
-{
-	unsigned long seq;
-	unsigned long usec, sec;
-	unsigned long max_ntp_tick = tick_usec - tickadj;
-
-	do {
-		seq = read_seqbegin(&xtime_lock);
-
-		usec = do_gettimeoffset();
-
-		/*
-		 * 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))
-			usec = min(usec, max_ntp_tick);
-
-		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 -= do_gettimeoffset() * NSEC_PER_USEC;
-
-	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);
-
-	ntp_clear();
-	write_sequnlock_irq(&xtime_lock);
-	clock_was_set();
-
-	return 0;
-}
-
-EXPORT_SYMBOL(do_settimeofday);
-
-/*
  * In order to set the CMOS clock precisely, set_rtc_mmss has to be
  * called 500 ms after the second nowtime has started, because when
  * nowtime is written into the registers of the CMOS clock, it will
@@ -192,6 +123,7 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id)
 #ifndef CONFIG_SMP
 	profile_tick(CPU_PROFILING);
 #endif
+	/* XXX FIXME. Uh, the xtime_lock should be held here, no? */
 	do_timer(1);
 
 #ifndef CONFIG_SMP

[RFC][PATCH 6/10] Convert m68k to use arch_getoffset() infrastructure.

[john stultz]

This patch converts m68k to use GENERIC_TIME via the arch_getoffset()
infrastructure 

I do not have cross compilers for these architectures, and in some cases
the architectures can be compiles both with and without clocksources. So
I've taken my best swing at converting this, but I'm not confident I got
it right. Any assistance from arch maintainers or testers would be
great.

Signed-off-by: John Stultz <johnstul@us.ibm.com>


diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index fb87c08..29dd848 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -58,6 +58,12 @@ config HZ
 	int
 	default 100
 
+config GENERIC_TIME
+	def_bool y
+
+config ARCH_USES_GETTIMEOFFSET
+	def_bool y
+
 mainmenu "Linux/68k Kernel Configuration"
 
 source "init/Kconfig"
diff --git a/arch/m68k/kernel/time.c b/arch/m68k/kernel/time.c
index 7db4159..0b1ecf3 100644
--- a/arch/m68k/kernel/time.c
+++ b/arch/m68k/kernel/time.c
@@ -90,72 +90,7 @@ void __init time_init(void)
 	mach_sched_init(timer_interrupt);
 }
 
-/*
- * This version of gettimeofday has near microsecond resolution.
- */
-void do_gettimeofday(struct timeval *tv)
-{
-	unsigned long flags;
-	unsigned long seq;
-	unsigned long usec, sec;
-	unsigned long max_ntp_tick = tick_usec - tickadj;
-
-	do {
-		seq = read_seqbegin_irqsave(&xtime_lock, flags);
-
-		usec = mach_gettimeoffset();
-
-		/*
-		 * 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))
-			usec = min(usec, max_ntp_tick);
-
-		sec = xtime.tv_sec;
-		usec += xtime.tv_nsec/1000;
-	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
-
-
-	while (usec >= 1000000) {
-		usec -= 1000000;
-		sec++;
-	}
-
-	tv->tv_sec = sec;
-	tv->tv_usec = usec;
-}
-
-EXPORT_SYMBOL(do_gettimeofday);
-
-int do_settimeofday(struct timespec *tv)
+u32 arch_gettimeoffset(void)
 {
-	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 the xtime.tv_nsec
-	 * correctly. However, the value in this location is
-	 * is value at the last tick.
-	 * Discover what correction gettimeofday
-	 * would have done, and then undo it!
-	 */
-	nsec -= 1000 * mach_gettimeoffset();
-
-	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);
-
-	ntp_clear();
-	write_sequnlock_irq(&xtime_lock);
-	clock_was_set();
-	return 0;
+	return mach_gettimeoffset() * 1000;
 }
-
-EXPORT_SYMBOL(do_settimeofday);

[RFC][PATCH 7/10] Convert sh to use arch_getoffset() infrastructure.

[john stultz]

This patch converts sh to use GENERIC_TIME via the arch_getoffset()
infrastructure 

I do not have cross compilers for these architectures, and in some cases
the architectures can be compiles both with and without clocksources. So
I've taken my best swing at converting this, but I'm not confident I got
it right. Any assistance from arch maintainers or testers would be
great.

Signed-off-by: John Stultz <johnstul@us.ibm.com>


diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index ebabe51..c48ab20 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -72,7 +72,7 @@ config GENERIC_IOMAP
 	bool
 
 config GENERIC_TIME
-	def_bool n
+	def_bool y
 
 config GENERIC_CLOCKEVENTS
 	def_bool n
@@ -406,6 +406,10 @@ config SH_TMU
 	help
 	  This enables the use of the TMU as the system timer.
 
+config ARCH_USES_GETTIMEOFFSET
+	def_bool y
+	depends on !SH_TMU
+
 config SH_CMT
 	def_bool y
 	prompt "CMT timer support"
diff --git a/arch/sh/include/asm/timer.h b/arch/sh/include/asm/timer.h
index a7ca3a1..da122a3 100644
--- a/arch/sh/include/asm/timer.h
+++ b/arch/sh/include/asm/timer.h
@@ -10,7 +10,7 @@ struct sys_timer_ops {
 	int (*start)(void);
 	int (*stop)(void);
 	cycle_t (*read)(void);
-#ifndef CONFIG_GENERIC_TIME
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 	unsigned long (*get_offset)(void);
 #endif
 };
@@ -27,7 +27,7 @@ struct sys_timer {
 extern struct sys_timer tmu_timer, cmt_timer, mtu2_timer;
 extern struct sys_timer *sys_timer;
 
-#ifndef CONFIG_GENERIC_TIME
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 static inline unsigned long get_timer_offset(void)
 {
 	return sys_timer->ops->get_offset();
diff --git a/arch/sh/kernel/time_32.c b/arch/sh/kernel/time_32.c
index 8457f83..8e9827a 100644
--- a/arch/sh/kernel/time_32.c
+++ b/arch/sh/kernel/time_32.c
@@ -52,65 +52,12 @@ static cycle_t null_hpt_read(void)
 void (*rtc_sh_get_time)(struct timespec *) = null_rtc_get_time;
 int (*rtc_sh_set_time)(const time_t) = null_rtc_set_time;
 
-#ifndef CONFIG_GENERIC_TIME
-void do_gettimeofday(struct timeval *tv)
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
+u32 arch_gettimeoffset(void)
 {
-	unsigned long flags;
-	unsigned long seq;
-	unsigned long usec, sec;
-
-	do {
-		/*
-		 * Turn off IRQs when grabbing xtime_lock, so that
-		 * the sys_timer get_offset code doesn't have to handle it.
-		 */
-		seq = read_seqbegin_irqsave(&xtime_lock, flags);
-		usec = get_timer_offset();
-		sec = xtime.tv_sec;
-		usec += xtime.tv_nsec / NSEC_PER_USEC;
-	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
-
-	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 -= get_timer_offset() * NSEC_PER_USEC;
-
-	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);
-
-	ntp_clear();
-	write_sequnlock_irq(&xtime_lock);
-	clock_was_set();
-
-	return 0;
+	return get_timer_offset() * 1000;
 }
-EXPORT_SYMBOL(do_settimeofday);
-#endif /* !CONFIG_GENERIC_TIME */
+#endif /* CONFIG_ARCH_USES_GETTIMEOFFSET */
 
 #ifndef CONFIG_GENERIC_CLOCKEVENTS
 /* last time the RTC clock got updated */
@@ -231,7 +178,7 @@ static void __init init_sh_clocksource(void)
 	clocksource_register(&clocksource_sh);
 }
 
-#ifdef CONFIG_GENERIC_TIME
+#ifndef CONFIG_ARCH_USES_GETTIMEOFFSET
 unsigned long long sched_clock(void)
 {
 	unsigned long long ticks = clocksource_sh.read();
diff --git a/arch/sh/kernel/time_64.c b/arch/sh/kernel/time_64.c
index 59d2a03..cfd75d8 100644
--- a/arch/sh/kernel/time_64.c
+++ b/arch/sh/kernel/time_64.c
@@ -144,59 +144,10 @@ static unsigned long usecs_since_tick(void)
 	return result;
 }
 
-void do_gettimeofday(struct timeval *tv)
+u32 arch_gettimeoffset(void)
 {
-	unsigned long flags;
-	unsigned long seq;
-	unsigned long usec, sec;
-
-	do {
-		seq = read_seqbegin_irqsave(&xtime_lock, flags);
-		usec = usecs_since_tick();
-		sec = xtime.tv_sec;
-		usec += xtime.tv_nsec / 1000;
-	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
-
-	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 -= 1000 * usecs_since_tick();
-
-	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);
-
-	ntp_clear();
-	write_sequnlock_irq(&xtime_lock);
-	clock_was_set();
-
-	return 0;
+	return usecs_since_tick() * 1000;
 }
-EXPORT_SYMBOL(do_settimeofday);
 
 /* Dummy RTC ops */
 static void null_rtc_get_time(struct timespec *tv)
diff --git a/arch/sh/kernel/timers/timer-cmt.c b/arch/sh/kernel/timers/timer-cmt.c
index c127293..6c729db 100644
--- a/arch/sh/kernel/timers/timer-cmt.c
+++ b/arch/sh/kernel/timers/timer-cmt.c
@@ -178,7 +178,7 @@ static struct sys_timer_ops cmt_timer_ops = {
 	.init		= cmt_timer_init,
 	.start		= cmt_timer_start,
 	.stop		= cmt_timer_stop,
-#ifndef CONFIG_GENERIC_TIME
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 	.get_offset	= cmt_timer_get_offset,
 #endif
 };
diff --git a/arch/sh/kernel/timers/timer-mtu2.c b/arch/sh/kernel/timers/timer-mtu2.c
index c3d237e..acf6a96 100644
--- a/arch/sh/kernel/timers/timer-mtu2.c
+++ b/arch/sh/kernel/timers/timer-mtu2.c
@@ -191,7 +191,7 @@ struct sys_timer_ops mtu2_timer_ops = {
 	.init		= mtu2_timer_init,
 	.start		= mtu2_timer_start,
 	.stop		= mtu2_timer_stop,
-#ifndef CONFIG_GENERIC_TIME
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 	.get_offset	= mtu2_timer_get_offset,
 #endif
 };

[RFC][PATCH 8/10] Convert sparc to use arch_getoffset() infrastructure.

[john stultz]

This patch converts sparc to use GENERIC_TIME via the arch_getoffset()
infrastructure 

I do not have cross compilers for these architectures, and in some cases
the architectures can be compiles both with and without clocksources. So
I've taken my best swing at converting this, but I'm not confident I got
it right. Any assistance from arch maintainers or testers would be
great.

Signed-off-by: John Stultz <johnstul@us.ibm.com>


diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index c3ea215..a5b465f 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -55,8 +55,11 @@ config BITS
 	default 64 if SPARC64
 
 config GENERIC_TIME
+	def_bool y
+
+config ARCH_USES_GETTIMEOFFSET
 	bool
-	default y if SPARC64
+	default y if SPARC32
 
 config GENERIC_CMOS_UPDATE
 	bool
diff --git a/arch/sparc/kernel/time_32.c b/arch/sparc/kernel/time_32.c
index 614ac7b..e946b55 100644
--- a/arch/sparc/kernel/time_32.c
+++ b/arch/sparc/kernel/time_32.c
@@ -227,7 +227,7 @@ void __init time_init(void)
 	sbus_time_init();
 }
 
-static inline unsigned long do_gettimeoffset(void)
+u32 arch_gettimeoffset(void)
 {
 	unsigned long val = *master_l10_counter;
 	unsigned long usec = (val >> 10) & 0x1fffff;
@@ -236,84 +236,7 @@ static inline unsigned long do_gettimeoffset(void)
 	if (val & 0x80000000)
 		usec += 1000000 / HZ;
 
-	return usec;
-}
-
-/* Ok, my cute asm atomicity trick doesn't work anymore.
- * There are just too many variables that need to be protected
- * now (both members of xtime, et al.)
- */
-void do_gettimeofday(struct timeval *tv)
-{
-	unsigned long flags;
-	unsigned long seq;
-	unsigned long usec, sec;
-	unsigned long max_ntp_tick = tick_usec - tickadj;
-
-	do {
-		seq = read_seqbegin_irqsave(&xtime_lock, flags);
-		usec = do_gettimeoffset();
-
-		/*
-		 * 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))
-			usec = min(usec, max_ntp_tick);
-
-		sec = xtime.tv_sec;
-		usec += (xtime.tv_nsec / 1000);
-	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
-
-	while (usec >= 1000000) {
-		usec -= 1000000;
-		sec++;
-	}
-
-	tv->tv_sec = sec;
-	tv->tv_usec = usec;
-}
-
-EXPORT_SYMBOL(do_gettimeofday);
-
-int do_settimeofday(struct timespec *tv)
-{
-	int ret;
-
-	write_seqlock_irq(&xtime_lock);
-	ret = bus_do_settimeofday(tv);
-	write_sequnlock_irq(&xtime_lock);
-	clock_was_set();
-	return ret;
-}
-
-EXPORT_SYMBOL(do_settimeofday);
-
-static int sbus_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;
-
-	/*
-	 * 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 -= 1000 * do_gettimeoffset();
-
-	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);
-
-	ntp_clear();
-	return 0;
+	return usec * 1000;
 }
 
 static int set_rtc_mmss(unsigned long secs)

[RFC][PATCH 9/10] Convert xtensa to use arch_getoffset() infrastructure.

[john stultz]

This patch converts xtensa to use GENERIC_TIME via the arch_getoffset()
infrastructure 

I do not have cross compilers for these architectures, and in some cases
the architectures can be compiles both with and without clocksources. So
I've taken my best swing at converting this, but I'm not confident I got
it right. Any assistance from arch maintainers or testers would be
great.

Signed-off-by: John Stultz <johnstul@us.ibm.com>


diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 6c873dc..ea3fdfe 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -54,6 +54,12 @@ config HZ
 	int
 	default 100
 
+config GENERIC_TIME
+	def_bool y
+
+config ARCH_USES_GETTIMEOFFSET
+	def_bool y
+
 source "init/Kconfig"
 source "kernel/Kconfig.freezer"
 
diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c
index 8df1e84..d49eb9d 100644
--- a/arch/xtensa/kernel/time.c
+++ b/arch/xtensa/kernel/time.c
@@ -88,68 +88,13 @@ void __init time_init(void)
 }
 
 
-int do_settimeofday(struct timespec *tv)
+u32 arch_gettimeoffset(void)
 {
-	time_t wtm_sec, sec = tv->tv_sec;
-	long wtm_nsec, nsec = tv->tv_nsec;
-	unsigned long delta;
-
-	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!
-	 */
-
-	delta = CCOUNT_PER_JIFFY;
-	delta += get_ccount() - get_linux_timer();
-	nsec -= delta * NSEC_PER_CCOUNT;
-
-	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);
-
-	ntp_clear();
-	write_sequnlock_irq(&xtime_lock);
-	return 0;
+	u32 delta = get_linux_timer() - get_ccount();
+	return ((unsigned long) CCOUNT_PER_JIFFY - delta)
+		 * (unsigned long) NSEC_PER_CCOUNT;
 }
 
-EXPORT_SYMBOL(do_settimeofday);
-
-
-void do_gettimeofday(struct timeval *tv)
-{
-	unsigned long flags;
-	unsigned long volatile sec, usec, delta, seq;
-
-	do {
-		seq = read_seqbegin_irqsave(&xtime_lock, flags);
-
-		sec = xtime.tv_sec;
-		usec = (xtime.tv_nsec / NSEC_PER_USEC);
-
-		delta = get_linux_timer() - get_ccount();
-
-	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
-
-	usec += (((unsigned long) CCOUNT_PER_JIFFY - delta)
-		 * (unsigned long) NSEC_PER_CCOUNT) / NSEC_PER_USEC;
-
-	for (; usec >= 1000000; sec++, usec -= 1000000)
-		;
-
-	tv->tv_sec = sec;
-	tv->tv_usec = usec;
-}
-
-EXPORT_SYMBOL(do_gettimeofday);
-
 /*
  * The timer interrupt is called HZ times per second.
  */

[RFC][PATCH 10/10] Remove CONFIG_GENERIC_TIME

[john stultz]

This removes all references to CONFIG_GENERIC_TIME in the timekeeping
core as well as the arch Kconfig files.

Arch defconfig files were left alone.

Signed-off-by: John Stultz <johnstul@us.ibm.com>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 3c04f80..00774f8 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -36,10 +36,6 @@ config GENERIC_GPIO
 	bool
 	default n
 
-config GENERIC_TIME
-	bool
-	default y
-
 config GENERIC_CLOCKEVENTS
 	bool
 	default n
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index b189680..905f5cf 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -45,9 +45,6 @@ config GENERIC_IRQ_PROBE
 config RWSEM_GENERIC_SPINLOCK
 	def_bool y
 
-config GENERIC_TIME
-	def_bool y
-
 config GENERIC_CLOCKEVENTS
 	def_bool y
 
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index ebe5e28..1754b80 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -575,12 +575,8 @@ comment "Kernel Timer/Scheduler"
 
 source kernel/Kconfig.hz
 
-config GENERIC_TIME
-	def_bool y
-
 config GENERIC_CLOCKEVENTS
 	bool "Generic clock events"
-	depends on GENERIC_TIME
 	default y
 
 config CYCLES_CLOCKSOURCE
diff --git a/arch/cris/Kconfig b/arch/cris/Kconfig
index 8082352..8265e78 100644
--- a/arch/cris/Kconfig
+++ b/arch/cris/Kconfig
@@ -20,9 +20,6 @@ config RWSEM_GENERIC_SPINLOCK
 config RWSEM_XCHGADD_ALGORITHM
 	bool
 
-config GENERIC_TIME
-	def_bool y
-
 config ARCH_USES_GETTIMEOFFSET
 	def_bool y
 
diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index 9d1552a..42c3497 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -38,10 +38,6 @@ config GENERIC_HARDIRQS_NO__DO_IRQ
 	bool
 	default y
 
-config GENERIC_TIME
-	bool
-	default y
-
 config TIME_LOW_RES
 	bool
 	default y
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index 9420648..3bf6e51 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -58,10 +58,6 @@ config GENERIC_CALIBRATE_DELAY
 	bool
 	default y
 
-config GENERIC_TIME
-	bool
-	default y
-
 config GENERIC_BUG
         bool
         depends on BUG
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 6183aec..339a368 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -77,10 +77,6 @@ config GENERIC_CALIBRATE_DELAY
 	bool
 	default y
 
-config GENERIC_TIME
-	bool
-	default y
-
 config GENERIC_TIME_VSYSCALL
 	bool
 	default y
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index c41234f..32ad821 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -41,9 +41,6 @@ config HZ
 	int
 	default 100
 
-config GENERIC_TIME
-	def_bool y
-
 config ARCH_USES_GETTIMEOFFSET
 	def_bool y
 
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 29dd848..7b0f880 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -58,9 +58,6 @@ config HZ
 	int
 	default 100
 
-config GENERIC_TIME
-	def_bool y
-
 config ARCH_USES_GETTIMEOFFSET
 	def_bool y
 
diff --git a/arch/m68knommu/Kconfig b/arch/m68knommu/Kconfig
index 4beb59d..2806400 100644
--- a/arch/m68knommu/Kconfig
+++ b/arch/m68knommu/Kconfig
@@ -58,10 +58,6 @@ config GENERIC_CALIBRATE_DELAY
 	bool
 	default y
 
-config GENERIC_TIME
-	bool
-	default y
-
 config GENERIC_CMOS_UPDATE
 	bool
 	default y
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 52c80c2..a5a4e9c 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -684,10 +684,6 @@ config GENERIC_CLOCKEVENTS
 	bool
 	default y
 
-config GENERIC_TIME
-	bool
-	default y
-
 config GENERIC_CMOS_UPDATE
 	bool
 	default y
diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig
index 9a9f433..0792a47 100644
--- a/arch/mn10300/Kconfig
+++ b/arch/mn10300/Kconfig
@@ -41,9 +41,6 @@ config GENERIC_FIND_NEXT_BIT
 config GENERIC_HWEIGHT
 	def_bool y
 
-config GENERIC_TIME
-	def_bool y
-
 config GENERIC_BUG
 	def_bool y
 
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index aacf11d..36d0e9d 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -60,10 +60,6 @@ config GENERIC_CALIBRATE_DELAY
 	bool
 	default y
 
-config GENERIC_TIME
-	bool
-	default y
-
 config TIME_LOW_RES
 	bool
 	depends on SMP
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 74cc312..dcbabd8 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -29,9 +29,6 @@ config MMU
 config GENERIC_CMOS_UPDATE
 	def_bool y
 
-config GENERIC_TIME
-	def_bool y
-
 config GENERIC_TIME_VSYSCALL
 	def_bool y
 
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 6b0a353..11eeb9b 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -40,9 +40,6 @@ config ARCH_HAS_ILOG2_U64
 config GENERIC_HWEIGHT
 	def_bool y
 
-config GENERIC_TIME
-	def_bool y
-
 config GENERIC_TIME_VSYSCALL
 	def_bool y
 
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index c48ab20..390f13c 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -71,9 +71,6 @@ config GENERIC_CALIBRATE_DELAY
 config GENERIC_IOMAP
 	bool
 
-config GENERIC_TIME
-	def_bool y
-
 config GENERIC_CLOCKEVENTS
 	def_bool n
 
@@ -401,7 +398,6 @@ config SH_TMU
 	def_bool y
 	prompt "TMU timer support"
 	depends on CPU_SH3 || CPU_SH4
-	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	help
 	  This enables the use of the TMU as the system timer.
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index a5b465f..eeba45a 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -54,9 +54,6 @@ config BITS
 	default 32 if SPARC32
 	default 64 if SPARC64
 
-config GENERIC_TIME
-	def_bool y
-
 config ARCH_USES_GETTIMEOFFSET
 	bool
 	default y if SPARC32
diff --git a/arch/um/Kconfig.common b/arch/um/Kconfig.common
index 0d207e7..7c8e277 100644
--- a/arch/um/Kconfig.common
+++ b/arch/um/Kconfig.common
@@ -55,10 +55,6 @@ config GENERIC_BUG
 	default y
 	depends on BUG
 
-config GENERIC_TIME
-	bool
-	default y
-
 config GENERIC_CLOCKEVENTS
 	bool
 	default y
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 73f7fe8..a110cd2 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -46,9 +46,6 @@ config ARCH_DEFCONFIG
 	default "arch/x86/configs/i386_defconfig" if X86_32
 	default "arch/x86/configs/x86_64_defconfig" if X86_64
 
-config GENERIC_TIME
-	def_bool y
-
 config GENERIC_CMOS_UPDATE
 	def_bool y
 
@@ -1892,7 +1889,7 @@ config SCx200
 
 config SCx200HR_TIMER
 	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
-	depends on SCx200 && GENERIC_TIME
+	depends on SCx200
 	default y
 	help
 	  This driver provides a clocksource built upon the on-chip
@@ -1904,7 +1901,7 @@ config SCx200HR_TIMER
 config GEODE_MFGPT_TIMER
 	def_bool y
 	prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
-	depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
+	depends on MGEODE_LX && GENERIC_CLOCKEVENTS
 	help
 	  This driver provides a clock event source based on the MFGPT
 	  timer(s) in the CS5535 and CS5536 companion chip for the geode.
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index ea3fdfe..95b6061 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -54,9 +54,6 @@ config HZ
 	int
 	default 100
 
-config GENERIC_TIME
-	def_bool y
-
 config ARCH_USES_GETTIMEOFFSET
 	def_bool y
 
diff --git a/drivers/Makefile b/drivers/Makefile
index c1bf417..7703ae5 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -96,7 +96,9 @@ obj-$(CONFIG_SGI_SN)		+= sn/
 obj-y				+= firmware/
 obj-$(CONFIG_CRYPTO)		+= crypto/
 obj-$(CONFIG_SUPERH)		+= sh/
-obj-$(CONFIG_GENERIC_TIME)	+= clocksource/
+ifndef CONFIG_ARCH_USES_GETTIMEOFFSET
+obj-y				+= clocksource/
+endif
 obj-$(CONFIG_DMA_ENGINE)	+= dma/
 obj-$(CONFIG_DCA)		+= dca/
 obj-$(CONFIG_HID)		+= hid/
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 66a9d81..3a17f3d 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -370,7 +370,7 @@ int acpi_processor_resume(struct acpi_device * device)
 	return 0;
 }
 
-#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
+#if defined(CONFIG_X86)
 static int tsc_halts_in_c(int state)
 {
 	switch (boot_cpu_data.x86_vendor) {
@@ -553,7 +553,7 @@ static void acpi_processor_idle(void)
 		/* Get end time (ticks) */
 		t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 
-#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
+#if defined(CONFIG_X86)
 		/* TSC halts in C2, so notify users */
 		if (tsc_halts_in_c(ACPI_STATE_C2))
 			mark_tsc_unstable("possible TSC halt in C2");
@@ -618,7 +618,7 @@ static void acpi_processor_idle(void)
 			acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
 		}
 
-#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
+#if defined(CONFIG_X86)
 		/* TSC halts in C3, so notify users */
 		if (tsc_halts_in_c(ACPI_STATE_C3))
 			mark_tsc_unstable("TSC halts in C3");
@@ -1539,7 +1539,7 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 	acpi_idle_do_entry(cx);
 	t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 
-#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
+#if defined(CONFIG_X86)
 	/* TSC could halt in idle, so notify users */
 	if (tsc_halts_in_c(cx->type))
 		mark_tsc_unstable("TSC halts in idle");;
@@ -1656,7 +1656,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 		spin_unlock(&c3_lock);
 	}
 
-#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
+#if defined(CONFIG_X86)
 	/* TSC could halt in idle, so notify users */
 	if (tsc_halts_in_c(ACPI_STATE_C3))
 		mark_tsc_unstable("TSC halts in idle");
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 5607319..72baa20 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -32,7 +32,7 @@ config ATMEL_TCLIB
 
 config ATMEL_TCB_CLKSRC
 	bool "TC Block Clocksource"
-	depends on ATMEL_TCLIB && GENERIC_TIME
+	depends on ATMEL_TCLIB
 	default y
 	help
 	  Select this to get a high precision clocksource based on a
diff --git a/kernel/time.c b/kernel/time.c
index 2951194..f001888 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -302,22 +302,6 @@ struct timespec timespec_trunc(struct timespec t, unsigned gran)
 }
 EXPORT_SYMBOL(timespec_trunc);
 
-#ifndef CONFIG_GENERIC_TIME
-/*
- * Simulate gettimeofday using do_gettimeofday which only allows a timeval
- * and therefore only yields usec accuracy
- */
-void getnstimeofday(struct timespec *tv)
-{
-	struct timeval x;
-
-	do_gettimeofday(&x);
-	tv->tv_sec = x.tv_sec;
-	tv->tv_nsec = x.tv_usec * NSEC_PER_USEC;
-}
-EXPORT_SYMBOL_GPL(getnstimeofday);
-#endif
-
 /* Converts Gregorian date to seconds since 1970-01-01 00:00:00.
  * Assumes input in normal date format, i.e. 1980-12-31 23:59:59
  * => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index 95ed429..f06a8a3 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -6,7 +6,7 @@ config TICK_ONESHOT
 
 config NO_HZ
 	bool "Tickless System (Dynamic Ticks)"
-	depends on GENERIC_TIME && GENERIC_CLOCKEVENTS
+	depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS
 	select TICK_ONESHOT
 	help
 	  This option enables a tickless system: timer interrupts will
@@ -15,7 +15,7 @@ config NO_HZ
 
 config HIGH_RES_TIMERS
 	bool "High Resolution Timer Support"
-	depends on GENERIC_TIME && GENERIC_CLOCKEVENTS
+	depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS
 	select TICK_ONESHOT
 	help
 	  This option enables high resolution timer support. If your
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 45d777f..7b0575c 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -59,7 +59,6 @@ void update_xtime_cache(u64 nsec)
 struct clocksource *clock;
 
 
-#ifdef CONFIG_GENERIC_TIME
 /**
  * clocksource_forward_now - update clock to the current time
  *
@@ -182,6 +181,7 @@ int do_settimeofday(struct timespec *tv)
 
 EXPORT_SYMBOL(do_settimeofday);
 
+#ifndef CONFIG_ARCH_USES_GETTIMEOFFSET
 /**
  * change_clocksource - Swaps clocksources if a new one is available
  *
@@ -217,7 +217,6 @@ static void change_clocksource(void)
 	 */
 }
 #else
-static inline void clocksource_forward_now(void) { }
 static inline void change_clocksource(void) { }
 #endif
 
@@ -492,10 +491,10 @@ void update_wall_time(void)
 	if (unlikely(timekeeping_suspended))
 		return;
 
-#ifdef CONFIG_GENERIC_TIME
-	offset = (clocksource_read(clock) - clock->cycle_last) & clock->mask;
-#else
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 	offset = clock->cycle_interval;
+#else
+	offset = (clocksource_read(clock) - clock->cycle_last) & clock->mask;
 #endif
 	clock->xtime_nsec = (s64)xtime.tv_nsec << clock->shift;
 
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index e2a4ff6..3adb233 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -81,7 +81,7 @@ config IRQSOFF_TRACER
 	bool "Interrupts-off Latency Tracer"
 	default n
 	depends on TRACE_IRQFLAGS_SUPPORT
-	depends on GENERIC_TIME
+	depends on !ARCH_USES_GETTIMEOFFSET
 	depends on DEBUG_KERNEL
 	select TRACE_IRQFLAGS
 	select TRACING
@@ -103,7 +103,7 @@ config IRQSOFF_TRACER
 config PREEMPT_TRACER
 	bool "Preemption-off Latency Tracer"
 	default n
-	depends on GENERIC_TIME
+	depends on !ARCH_USES_GETTIMEOFFSET
 	depends on PREEMPT
 	depends on DEBUG_KERNEL
 	select TRACING

Re: [RFC][PATCH 8/10] Convert sparc to use arch_getoffset() infrastructure.

[David Miller]

From: john stultz <johnstul@us.ibm.com>
Date: Wed, 28 Jan 2009 20:10:41 -0800

> This patch converts sparc to use GENERIC_TIME via the arch_getoffset()
> infrastructure 
> 
> I do not have cross compilers for these architectures, and in some cases
> the architectures can be compiles both with and without clocksources. So
> I've taken my best swing at converting this, but I'm not confident I got
> it right. Any assistance from arch maintainers or testers would be
> great.
> 
> Signed-off-by: John Stultz <johnstul@us.ibm.com>

Acked-by: David S. Miller <davem@davemloft.net>

Re: [RFC][PATCH 7/10] Convert sh to use arch_getoffset() infrastructure.

[Paul Mundt]

On Wed, Jan 28, 2009 at 08:10:06PM -0800, john stultz wrote:
> This patch converts sh to use GENERIC_TIME via the arch_getoffset()
> infrastructure 
> 
> I do not have cross compilers for these architectures, and in some cases
> the architectures can be compiles both with and without clocksources. So
> I've taken my best swing at converting this, but I'm not confident I got
> it right. Any assistance from arch maintainers or testers would be
> great.
> 
> Signed-off-by: John Stultz <johnstul@us.ibm.com>
> 
Acked-by: Paul Mundt <lethal@linux-sh.org>