[PATCH 0/3] fix ia64 clocksource

[PATCH 0/3] fix ia64 clocksource

[Hidetoshi Seto]

Hi all,

This is a set of patch for ia64 clocksource to improve performance
of fsys_gettimeofday (and also normal gettimeofday).

 [1/3] copy time structures into fsys_gtod_data
 [2/3] separate data for jitter compensation
 [3/3] remove cmpxchg loop in gettimeofday

Finally, the results of my test at start:

> # clocksource (Bob's) : default
> CPU  0:  4.66 (usecs) (0 errors / 2145680 iterations)
> CPU  1:  4.65 (usecs) (493 errors / 2148438 iterations)
> CPU  2:  4.63 (usecs) (668 errors / 2159461 iterations)
> CPU  3:  4.62 (usecs) (654 errors / 2163997 iterations)
> # clocksource (Bob's) : nojitter
> CPU  0:  0.14 (usecs) (0 errors / 70945550 iterations)
> CPU  1:  0.14 (usecs) (470 errors / 71640889 iterations)
> CPU  2:  0.14 (usecs) (664 errors / 70960917 iterations)
> CPU  3:  0.14 (usecs) (571 errors / 70956121 iterations)
> # clocksource (Bob's) : nolwsys
> CPU  0:  2.88 (usecs) (0 errors / 3475147 iterations)
> CPU  1:  2.88 (usecs) (0 errors / 3474881 iterations)
> CPU  2:  2.96 (usecs) (0 errors / 3382229 iterations)
> CPU  3:  2.97 (usecs) (0 errors / 3371004 iterations)

are now refined to:

> # clocksource (fixed) : default
> CPU  0:  1.33 (usecs) (0 errors / 7507837 iterations)
> CPU  1:  1.31 (usecs) (0 errors / 7621659 iterations)
> CPU  2:  1.27 (usecs) (0 errors / 7865412 iterations)
> CPU  3:  1.27 (usecs) (0 errors / 7863362 iterations)
> # clocksource (fixed) : nojitter
> CPU  0:  0.14 (usecs) (0 errors / 69608888 iterations)
> CPU  1:  0.14 (usecs) (0 errors / 70277433 iterations)
> CPU  2:  0.14 (usecs) (0 errors / 69632925 iterations)
> CPU  3:  0.14 (usecs) (0 errors / 69606531 iterations)
> # clocksource (fixed) : nolwsys
> CPU  0:  1.48 (usecs) (0 errors / 6770870 iterations)
> CPU  1:  1.48 (usecs) (0 errors / 6777897 iterations)
> CPU  2:  1.49 (usecs) (0 errors / 6728101 iterations)
> CPU  3:  1.49 (usecs) (0 errors / 6703961 iterations)

Thanks,
H.Seto

Re: [PATCH 0/3] fix ia64 clocksource

[Bob Picco]

Hi,

Sorry for the delay in response.
Hidetoshi Seto wrote:	[Wed Jul 18 2007, 10:58:55AM EDT]
> Hi all,
> 
> This is a set of patch for ia64 clocksource to improve performance
> of fsys_gettimeofday (and also normal gettimeofday).
> 
>  [1/3] copy time structures into fsys_gtod_data
>  [2/3] separate data for jitter compensation
>  [3/3] remove cmpxchg loop in gettimeofday
> 
> Finally, the results of my test at start:
First I'd like to thank you for your work.

I recently inherited Pete's code because of his departure. We (HP) are puzzled
by the poor performance and non monotonically increasing errors. Pete's results
are in conflict with your results. Perhaps you could forward your test
program. Unfortunately I don't have a clue what Pete used for testing.

Your analysis is very thorough and quite comprehendible. I also finally
read your thread:
http://marc.info/?l=linux-ia64&m\x118362166319438&w=2

I need to make the cleanups Tony identified. After that how would you like to
proceed? Combining your patch 1/3 and my 1/2 seems logical.

thanks again,

bob

[snip]

RE: [PATCH 0/3] fix ia64 clocksource

[Luck, Tony]

> I need to make the cleanups Tony identified. After that how would you like to
> proceed? Combining your patch 1/3 and my 1/2 seems logical.

I've done the cleanup, and merged Seto-san's parts 1,2,3 with your part 1, and
updated it all for the tip of Linus' tree.  Result is below.

Part 2 stayed the same, except that I also deleted Documentation/time_interpolators.txt

I'm going to send both to Linus later today ... so read fast and shout if
I botched the merge.

Time taken for a single gettimeofday() call via the fsys.S path has increased
by about 8 cycles, but this would only be significant for applications doing
> 1,000,000 gettimeofday calls per second.  The scalability problems are so
bad that I can't even get close to that rate on 4 cpus (peak cumulative rate
is about 600,000).  The patched system still has problems, but scalabilty is
better (4 cpus can get to 1,100,000 cumulative calls per second).

-Tony

commit 89f8d0677c72742767f98b9f5fcfbd575e73d0ae
Author: Tony Luck <tony.luck@intel.com>
Date:   Wed Jul 18 15:38:51 2007 -0700

    [IA64] Convert to generic timekeeping/clocksource
    
    This is a merge of Peter Keilty's initial patch for this with
    Hidetoshi Seto's fixes and scaling improvements.
    
    Signed-off-by: Tony Luck <tony.luck@intel.com>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 9a54148..68115d7 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1154,6 +1154,8 @@ and is between 256 and 4096 characters. It is defined in the file
 
 	nointroute	[IA-64]
 
+	nojitter	[IA64] Disables jitter checking for ITC timers.
+
 	nolapic		[IA-32,APIC] Do not enable or use the local APIC.
 
 	nolapic_timer	[IA-32,APIC] Do not use the local APIC timer.
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 616c96e..36c7b96 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -62,7 +62,11 @@ config GENERIC_CALIBRATE_DELAY
 	bool
 	default y
 
-config TIME_INTERPOLATION
+config GENERIC_TIME
+	bool
+	default y
+
+config GENERIC_TIME_VSYSCALL
 	bool
 	default y
 
diff --git a/arch/ia64/configs/bigsur_defconfig b/arch/ia64/configs/bigsur_defconfig
index 90e9c2e..9eb48c0 100644
--- a/arch/ia64/configs/bigsur_defconfig
+++ b/arch/ia64/configs/bigsur_defconfig
@@ -85,7 +85,7 @@ CONFIG_MMU=y
 CONFIG_SWIOTLB=y
 CONFIG_RWSEM_XCHGADD_ALGORITHM=y
 CONFIG_GENERIC_CALIBRATE_DELAY=y
-CONFIG_TIME_INTERPOLATION=y
+CONFIG_GENERIC_TIME=y
 CONFIG_EFI=y
 CONFIG_GENERIC_IOMAP=y
 CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER=y
diff --git a/arch/ia64/configs/gensparse_defconfig b/arch/ia64/configs/gensparse_defconfig
index 0d29aa2..3a9ed95 100644
--- a/arch/ia64/configs/gensparse_defconfig
+++ b/arch/ia64/configs/gensparse_defconfig
@@ -86,7 +86,7 @@ CONFIG_MMU=y
 CONFIG_SWIOTLB=y
 CONFIG_RWSEM_XCHGADD_ALGORITHM=y
 CONFIG_GENERIC_CALIBRATE_DELAY=y
-CONFIG_TIME_INTERPOLATION=y
+CONFIG_GENERIC_TIME=y
 CONFIG_EFI=y
 CONFIG_GENERIC_IOMAP=y
 CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER=y
diff --git a/arch/ia64/configs/sim_defconfig b/arch/ia64/configs/sim_defconfig
index d9146c3..c420d9f 100644
--- a/arch/ia64/configs/sim_defconfig
+++ b/arch/ia64/configs/sim_defconfig
@@ -86,7 +86,7 @@ CONFIG_MMU=y
 CONFIG_SWIOTLB=y
 CONFIG_RWSEM_XCHGADD_ALGORITHM=y
 CONFIG_GENERIC_CALIBRATE_DELAY=y
-CONFIG_TIME_INTERPOLATION=y
+CONFIG_GENERIC_TIME=y
 CONFIG_EFI=y
 CONFIG_GENERIC_IOMAP=y
 CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER=y
diff --git a/arch/ia64/configs/sn2_defconfig b/arch/ia64/configs/sn2_defconfig
index 64e951d..4c9ffc4 100644
--- a/arch/ia64/configs/sn2_defconfig
+++ b/arch/ia64/configs/sn2_defconfig
@@ -93,7 +93,7 @@ CONFIG_SWIOTLB=y
 CONFIG_RWSEM_XCHGADD_ALGORITHM=y
 CONFIG_GENERIC_FIND_NEXT_BIT=y
 CONFIG_GENERIC_CALIBRATE_DELAY=y
-CONFIG_TIME_INTERPOLATION=y
+CONFIG_GENERIC_TIME=y
 CONFIG_DMI=y
 CONFIG_EFI=y
 CONFIG_GENERIC_IOMAP=y
diff --git a/arch/ia64/configs/tiger_defconfig b/arch/ia64/configs/tiger_defconfig
index a144693..e208747 100644
--- a/arch/ia64/configs/tiger_defconfig
+++ b/arch/ia64/configs/tiger_defconfig
@@ -98,7 +98,7 @@ CONFIG_RWSEM_XCHGADD_ALGORITHM=y
 # CONFIG_ARCH_HAS_ILOG2_U64 is not set
 CONFIG_GENERIC_FIND_NEXT_BIT=y
 CONFIG_GENERIC_CALIBRATE_DELAY=y
-CONFIG_TIME_INTERPOLATION=y
+CONFIG_GENERIC_TIME=y
 CONFIG_DMI=y
 CONFIG_EFI=y
 CONFIG_GENERIC_IOMAP=y
diff --git a/arch/ia64/configs/zx1_defconfig b/arch/ia64/configs/zx1_defconfig
index 1c7955c..4a060fc 100644
--- a/arch/ia64/configs/zx1_defconfig
+++ b/arch/ia64/configs/zx1_defconfig
@@ -96,7 +96,7 @@ CONFIG_RWSEM_XCHGADD_ALGORITHM=y
 # CONFIG_ARCH_HAS_ILOG2_U64 is not set
 CONFIG_GENERIC_FIND_NEXT_BIT=y
 CONFIG_GENERIC_CALIBRATE_DELAY=y
-CONFIG_TIME_INTERPOLATION=y
+CONFIG_GENERIC_TIME=y
 CONFIG_DMI=y
 CONFIG_EFI=y
 CONFIG_GENERIC_IOMAP=y
diff --git a/arch/ia64/defconfig b/arch/ia64/defconfig
index 90bd960..461f8ee 100644
--- a/arch/ia64/defconfig
+++ b/arch/ia64/defconfig
@@ -98,7 +98,7 @@ CONFIG_RWSEM_XCHGADD_ALGORITHM=y
 # CONFIG_ARCH_HAS_ILOG2_U64 is not set
 CONFIG_GENERIC_FIND_NEXT_BIT=y
 CONFIG_GENERIC_CALIBRATE_DELAY=y
-CONFIG_TIME_INTERPOLATION=y
+CONFIG_GENERIC_TIME=y
 CONFIG_DMI=y
 CONFIG_EFI=y
 CONFIG_GENERIC_IOMAP=y
diff --git a/arch/ia64/kernel/asm-offsets.c b/arch/ia64/kernel/asm-offsets.c
index 2236fab..0aebc6f 100644
--- a/arch/ia64/kernel/asm-offsets.c
+++ b/arch/ia64/kernel/asm-offsets.c
@@ -7,6 +7,7 @@
 #define ASM_OFFSETS_C 1
 
 #include <linux/sched.h>
+#include <linux/clocksource.h>
 
 #include <asm-ia64/processor.h>
 #include <asm-ia64/ptrace.h>
@@ -15,6 +16,7 @@
 #include <asm-ia64/mca.h>
 
 #include "../kernel/sigframe.h"
+#include "../kernel/fsyscall_gtod_data.h"
 
 #define DEFINE(sym, val) \
         asm volatile("\n->" #sym " %0 " #val : : "i" (val))
@@ -256,17 +258,24 @@ void foo(void)
 	BLANK();
 
 	/* used by fsys_gettimeofday in arch/ia64/kernel/fsys.S */
-	DEFINE(IA64_TIME_INTERPOLATOR_ADDRESS_OFFSET, offsetof (struct time_interpolator, addr));
-	DEFINE(IA64_TIME_INTERPOLATOR_SOURCE_OFFSET, offsetof (struct time_interpolator, source));
-	DEFINE(IA64_TIME_INTERPOLATOR_SHIFT_OFFSET, offsetof (struct time_interpolator, shift));
-	DEFINE(IA64_TIME_INTERPOLATOR_NSEC_OFFSET, offsetof (struct time_interpolator, nsec_per_cyc));
-	DEFINE(IA64_TIME_INTERPOLATOR_OFFSET_OFFSET, offsetof (struct time_interpolator, offset));
-	DEFINE(IA64_TIME_INTERPOLATOR_LAST_CYCLE_OFFSET, offsetof (struct time_interpolator, last_cycle));
-	DEFINE(IA64_TIME_INTERPOLATOR_LAST_COUNTER_OFFSET, offsetof (struct time_interpolator, last_counter));
-	DEFINE(IA64_TIME_INTERPOLATOR_JITTER_OFFSET, offsetof (struct time_interpolator, jitter));
-	DEFINE(IA64_TIME_INTERPOLATOR_MASK_OFFSET, offsetof (struct time_interpolator, mask));
-	DEFINE(IA64_TIME_SOURCE_CPU, TIME_SOURCE_CPU);
-	DEFINE(IA64_TIME_SOURCE_MMIO64, TIME_SOURCE_MMIO64);
-	DEFINE(IA64_TIME_SOURCE_MMIO32, TIME_SOURCE_MMIO32);
-	DEFINE(IA64_TIMESPEC_TV_NSEC_OFFSET, offsetof (struct timespec, tv_nsec));
+	DEFINE(IA64_GTOD_LOCK_OFFSET,
+		offsetof (struct fsyscall_gtod_data_t, lock));
+	DEFINE(IA64_GTOD_WALL_TIME_OFFSET,
+		offsetof (struct fsyscall_gtod_data_t, wall_time));
+	DEFINE(IA64_GTOD_MONO_TIME_OFFSET,
+		offsetof (struct fsyscall_gtod_data_t, monotonic_time));
+	DEFINE(IA64_CLKSRC_MASK_OFFSET,
+		offsetof (struct fsyscall_gtod_data_t, clk_mask));
+	DEFINE(IA64_CLKSRC_MULT_OFFSET,
+		offsetof (struct fsyscall_gtod_data_t, clk_mult));
+	DEFINE(IA64_CLKSRC_SHIFT_OFFSET,
+		offsetof (struct fsyscall_gtod_data_t, clk_shift));
+	DEFINE(IA64_CLKSRC_MMIO_OFFSET,
+		offsetof (struct fsyscall_gtod_data_t, clk_fsys_mmio));
+	DEFINE(IA64_CLKSRC_CYCLE_LAST_OFFSET,
+		offsetof (struct fsyscall_gtod_data_t, clk_cycle_last));
+	DEFINE(IA64_ITC_JITTER_OFFSET,
+		offsetof (struct itc_jitter_data_t, itc_jitter));
+	DEFINE(IA64_ITC_LASTCYCLE_OFFSET,
+		offsetof (struct itc_jitter_data_t, itc_lastcycle));
 }
diff --git a/arch/ia64/kernel/cyclone.c b/arch/ia64/kernel/cyclone.c
index e00b215..2fd96d9 100644
--- a/arch/ia64/kernel/cyclone.c
+++ b/arch/ia64/kernel/cyclone.c
@@ -3,6 +3,7 @@
 #include <linux/time.h>
 #include <linux/errno.h>
 #include <linux/timex.h>
+#include <linux/clocksource.h>
 #include <asm/io.h>
 
 /* IBM Summit (EXA) Cyclone counter code*/
@@ -18,13 +19,21 @@ void __init cyclone_setup(void)
 	use_cyclone = 1;
 }
 
+static void __iomem *cyclone_mc;
 
-struct time_interpolator cyclone_interpolator = {
-	.source =	TIME_SOURCE_MMIO64,
-	.shift =	16,
-	.frequency =	CYCLONE_TIMER_FREQ,
-	.drift =	-100,
-	.mask =		(1LL << 40) - 1
+static cycle_t read_cyclone(void)
+{
+	return (cycle_t)readq((void __iomem *)cyclone_mc);
+}
+
+static struct clocksource clocksource_cyclone = {
+        .name           = "cyclone",
+        .rating         = 300,
+        .read           = read_cyclone,
+        .mask           = (1LL << 40) - 1,
+        .mult           = 0, /*to be caluclated*/
+        .shift          = 16,
+        .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
 int __init init_cyclone_clock(void)
@@ -44,13 +53,15 @@ int __init init_cyclone_clock(void)
 	offset = (CYCLONE_CBAR_ADDR);
 	reg = (u64*)ioremap_nocache(offset, sizeof(u64));
 	if(!reg){
-		printk(KERN_ERR "Summit chipset: Could not find valid CBAR register.\n");
+		printk(KERN_ERR "Summit chipset: Could not find valid CBAR"
+				" register.\n");
 		use_cyclone = 0;
 		return -ENODEV;
 	}
 	base = readq(reg);
 	if(!base){
-		printk(KERN_ERR "Summit chipset: Could not find valid CBAR value.\n");
+		printk(KERN_ERR "Summit chipset: Could not find valid CBAR"
+				" value.\n");
 		use_cyclone = 0;
 		return -ENODEV;
 	}
@@ -60,7 +71,8 @@ int __init init_cyclone_clock(void)
 	offset = (base + CYCLONE_PMCC_OFFSET);
 	reg = (u64*)ioremap_nocache(offset, sizeof(u64));
 	if(!reg){
-		printk(KERN_ERR "Summit chipset: Could not find valid PMCC register.\n");
+		printk(KERN_ERR "Summit chipset: Could not find valid PMCC"
+				" register.\n");
 		use_cyclone = 0;
 		return -ENODEV;
 	}
@@ -71,7 +83,8 @@ int __init init_cyclone_clock(void)
 	offset = (base + CYCLONE_MPCS_OFFSET);
 	reg = (u64*)ioremap_nocache(offset, sizeof(u64));
 	if(!reg){
-		printk(KERN_ERR "Summit chipset: Could not find valid MPCS register.\n");
+		printk(KERN_ERR "Summit chipset: Could not find valid MPCS"
+				" register.\n");
 		use_cyclone = 0;
 		return -ENODEV;
 	}
@@ -82,7 +95,8 @@ int __init init_cyclone_clock(void)
 	offset = (base + CYCLONE_MPMC_OFFSET);
 	cyclone_timer = (u32*)ioremap_nocache(offset, sizeof(u32));
 	if(!cyclone_timer){
-		printk(KERN_ERR "Summit chipset: Could not find valid MPMC register.\n");
+		printk(KERN_ERR "Summit chipset: Could not find valid MPMC"
+				" register.\n");
 		use_cyclone = 0;
 		return -ENODEV;
 	}
@@ -93,7 +107,8 @@ int __init init_cyclone_clock(void)
 		int stall = 100;
 		while(stall--) barrier();
 		if(readl(cyclone_timer) = old){
-			printk(KERN_ERR "Summit chipset: Counter not counting! DISABLED\n");
+			printk(KERN_ERR "Summit chipset: Counter not counting!"
+					" DISABLED\n");
 			iounmap(cyclone_timer);
 			cyclone_timer = 0;
 			use_cyclone = 0;
@@ -101,8 +116,11 @@ int __init init_cyclone_clock(void)
 		}
 	}
 	/* initialize last tick */
-	cyclone_interpolator.addr = cyclone_timer;
-	register_time_interpolator(&cyclone_interpolator);
+	cyclone_mc = cyclone_timer;
+	clocksource_cyclone.fsys_mmio = cyclone_timer;
+	clocksource_cyclone.mult = clocksource_hz2mult(CYCLONE_TIMER_FREQ,
+						clocksource_cyclone.shift);
+	clocksource_register(&clocksource_cyclone);
 
 	return 0;
 }
diff --git a/arch/ia64/kernel/fsys.S b/arch/ia64/kernel/fsys.S
index 3f926c2..4484197 100644
--- a/arch/ia64/kernel/fsys.S
+++ b/arch/ia64/kernel/fsys.S
@@ -147,12 +147,11 @@ ENTRY(fsys_set_tid_address)
 	FSYS_RETURN
 END(fsys_set_tid_address)
 
-/*
- * Ensure that the time interpolator structure is compatible with the asm code
- */
-#if IA64_TIME_INTERPOLATOR_SOURCE_OFFSET !=0 || IA64_TIME_INTERPOLATOR_SHIFT_OFFSET != 2 \
-	|| IA64_TIME_INTERPOLATOR_JITTER_OFFSET != 3 || IA64_TIME_INTERPOLATOR_NSEC_OFFSET != 4
-#error fsys_gettimeofday incompatible with changes to struct time_interpolator
+#if IA64_GTOD_LOCK_OFFSET !=0
+#error fsys_gettimeofday incompatible with changes to struct fsyscall_gtod_data_t
+#endif
+#if IA64_ITC_JITTER_OFFSET !=0
+#error fsys_gettimeofday incompatible with changes to struct itc_jitter_data_t
 #endif
 #define CLOCK_REALTIME 0
 #define CLOCK_MONOTONIC 1
@@ -179,126 +178,124 @@ ENTRY(fsys_gettimeofday)
 	// r11 = preserved: saved ar.pfs
 	// r12 = preserved: memory stack
 	// r13 = preserved: thread pointer
-	// r14 = address of mask / mask
+	// r14 = address of mask / mask value
 	// r15 = preserved: system call number
 	// r16 = preserved: current task pointer
-	// r17 = wall to monotonic use
-	// r18 = time_interpolator->offset
-	// r19 = address of wall_to_monotonic
-	// r20 = pointer to struct time_interpolator / pointer to time_interpolator->address
-	// r21 = shift factor
-	// r22 = address of time interpolator->last_counter
-	// r23 = address of time_interpolator->last_cycle
-	// r24 = adress of time_interpolator->offset
-	// r25 = last_cycle value
-	// r26 = last_counter value
-	// r27 = pointer to xtime
+	// r17 = (not used)
+	// r18 = (not used)
+	// r19 = address of itc_lastcycle
+	// r20 = struct fsyscall_gtod_data (= address of gtod_lock.sequence)
+	// r21 = address of mmio_ptr
+	// r22 = address of wall_time or monotonic_time
+	// r23 = address of shift / value
+	// r24 = address mult factor / cycle_last value
+	// r25 = itc_lastcycle value
+	// r26 = address clocksource cycle_last
+	// r27 = (not used)
 	// r28 = sequence number at the beginning of critcal section
-	// r29 = address of seqlock
+	// r29 = address of itc_jitter
 	// r30 = time processing flags / memory address
 	// r31 = pointer to result
 	// Predicates
 	// p6,p7 short term use
 	// p8 = timesource ar.itc
 	// p9 = timesource mmio64
-	// p10 = timesource mmio32
+	// p10 = timesource mmio32 - not used
 	// p11 = timesource not to be handled by asm code
-	// p12 = memory time source ( = p9 | p10)
-	// p13 = do cmpxchg with time_interpolator_last_cycle
+	// p12 = memory time source ( = p9 | p10) - not used
+	// p13 = do cmpxchg with itc_lastcycle
 	// p14 = Divide by 1000
 	// p15 = Add monotonic
 	//
-	// Note that instructions are optimized for McKinley. McKinley can process two
-	// bundles simultaneously and therefore we continuously try to feed the CPU
-	// two bundles and then a stop.
-	tnat.nz p6,p0 = r31	// branch deferred since it does not fit into bundle structure
+	// Note that instructions are optimized for McKinley. McKinley can
+	// process two bundles simultaneously and therefore we continuously
+	// try to feed the CPU two bundles and then a stop.
+	//
+	// Additional note that code has changed a lot. Optimization is TBD.
+	// Comments begin with "?" are maybe outdated.
+	tnat.nz p6,p0 = r31	// ? branch deferred to fit later bundle
 	mov pr = r30,0xc000	// Set predicates according to function
 	add r2 = TI_FLAGS+IA64_TASK_SIZE,r16
-	movl r20 = time_interpolator
+	movl r20 = fsyscall_gtod_data // load fsyscall gettimeofday data address
 	;;
-	ld8 r20 = [r20]		// get pointer to time_interpolator structure
-	movl r29 = xtime_lock
+	movl r29 = itc_jitter_data	// itc_jitter
+	add r22 = IA64_GTOD_WALL_TIME_OFFSET,r20	// wall_time
 	ld4 r2 = [r2]		// process work pending flags
-	movl r27 = xtime
-	;;	// only one bundle here
-	ld8 r21 = [r20]		// first quad with control information
+	;;
+(p15)	add r22 = IA64_GTOD_MONO_TIME_OFFSET,r20	// monotonic_time
+	add r21 = IA64_CLKSRC_MMIO_OFFSET,r20
+	add r19 = IA64_ITC_LASTCYCLE_OFFSET,r29
 	and r2 = TIF_ALLWORK_MASK,r2
-(p6)    br.cond.spnt.few .fail_einval	// deferred branch
+(p6)    br.cond.spnt.few .fail_einval	// ? deferred branch
 	;;
-	add r10 = IA64_TIME_INTERPOLATOR_ADDRESS_OFFSET,r20
-	extr r3 = r21,32,32	// time_interpolator->nsec_per_cyc
-	extr r8 = r21,0,16	// time_interpolator->source
+	add r26 = IA64_CLKSRC_CYCLE_LAST_OFFSET,r20 // clksrc_cycle_last
 	cmp.ne p6, p0 = 0, r2	// Fallback if work is scheduled
 (p6)    br.cond.spnt.many fsys_fallback_syscall
 	;;
-	cmp.eq p8,p12 = 0,r8	// Check for cpu timer
-	cmp.eq p9,p0 = 1,r8	// MMIO64 ?
-	extr r2 = r21,24,8	// time_interpolator->jitter
-	cmp.eq p10,p0 = 2,r8	// MMIO32 ?
-	cmp.ltu p11,p0 = 2,r8	// function or other clock
-(p11)	br.cond.spnt.many fsys_fallback_syscall
+	// Begin critical section
+.time_redo:
+	ld4.acq r28 = [r20]	// gtod_lock.sequence, Must take first
+	;;
+	and r28 = ~1,r28	// And make sequence even to force retry if odd
 	;;
-	setf.sig f7 = r3	// Setup for scaling of counter
-(p15)	movl r19 = wall_to_monotonic
-(p12)	ld8 r30 = [r10]
-	cmp.ne p13,p0 = r2,r0	// need jitter compensation?
-	extr r21 = r21,16,8	// shift factor
+	ld8 r30 = [r21]		// clocksource->mmio_ptr
+	add r24 = IA64_CLKSRC_MULT_OFFSET,r20
+	ld4 r2 = [r29]		// itc_jitter value
+	add r23 = IA64_CLKSRC_SHIFT_OFFSET,r20
+	add r14 = IA64_CLKSRC_MASK_OFFSET,r20
 	;;
-.time_redo:
-	.pred.rel.mutex p8,p9,p10
-	ld4.acq r28 = [r29]	// xtime_lock.sequence. Must come first for locking purposes
+	ld4 r3 = [r24]		// clocksource mult value
+	ld8 r14 = [r14]         // clocksource mask value
+	cmp.eq p8,p9 = 0,r30	// use cpu timer if no mmio_ptr
 	;;
-	and r28 = ~1,r28	// Make sequence even to force retry if odd
+	setf.sig f7 = r3	// Setup for mult scaling of counter
+(p8)	cmp.ne p13,p0 = r2,r0	// need itc_jitter compensation, set p13
+	ld4 r23 = [r23]		// clocksource shift value
+	ld8 r24 = [r26]		// get clksrc_cycle_last value
+(p9)	cmp.eq p13,p0 = 0,r30	// if mmio_ptr, clear p13 jitter control
 	;;
+	.pred.rel.mutex p8,p9
 (p8)	mov r2 = ar.itc		// CPU_TIMER. 36 clocks latency!!!
-	add r22 = IA64_TIME_INTERPOLATOR_LAST_COUNTER_OFFSET,r20
-(p9)	ld8 r2 = [r30]		// readq(ti->address). Could also have latency issues..
-(p10)	ld4 r2 = [r30]		// readw(ti->address)
-(p13)	add r23 = IA64_TIME_INTERPOLATOR_LAST_CYCLE_OFFSET,r20
-	;;			// could be removed by moving the last add upward
-	ld8 r26 = [r22]		// time_interpolator->last_counter
-(p13)	ld8 r25 = [r23]		// time interpolator->last_cycle
-	add r24 = IA64_TIME_INTERPOLATOR_OFFSET_OFFSET,r20
-(p15)	ld8 r17 = [r19],IA64_TIMESPEC_TV_NSEC_OFFSET
- 	ld8 r9 = [r27],IA64_TIMESPEC_TV_NSEC_OFFSET
-	add r14 = IA64_TIME_INTERPOLATOR_MASK_OFFSET, r20
-	;;
-	ld8 r18 = [r24]		// time_interpolator->offset
-	ld8 r8 = [r27],-IA64_TIMESPEC_TV_NSEC_OFFSET	// xtime.tv_nsec
-(p13)	sub r3 = r25,r2	// Diff needed before comparison (thanks davidm)
-	;;
-	ld8 r14 = [r14]		// time_interpolator->mask
-(p13)	cmp.gt.unc p6,p7 = r3,r0	// check if it is less than last. p6,p7 cleared
-	sub r10 = r2,r26	// current_counter - last_counter
-	;;
-(p6)	sub r10 = r25,r26	// time we got was less than last_cycle
+(p9)	ld8 r2 = [r30]		// MMIO_TIMER. Could also have latency issues..
+(p13)	ld8 r25 = [r19]		// get itc_lastcycle value
+	;;		// ? could be removed by moving the last add upward
+	ld8 r9 = [r22],IA64_TIMESPEC_TV_NSEC_OFFSET	// tv_sec
+	;;
+	ld8 r8 = [r22],-IA64_TIMESPEC_TV_NSEC_OFFSET	// tv_nsec
+(p13)	sub r3 = r25,r2		// Diff needed before comparison (thanks davidm)
+	;;
+(p13)	cmp.gt.unc p6,p7 = r3,r0 // check if it is less than last. p6,p7 cleared
+	sub r10 = r2,r24	// current_cycle - last_cycle
+	;;
+(p6)	sub r10 = r25,r24	// time we got was less than last_cycle
 (p7)	mov ar.ccv = r25	// more than last_cycle. Prep for cmpxchg
 	;;
+(p7)	cmpxchg8.rel r3 = [r19],r2,ar.ccv
+	;;
+(p7)	cmp.ne p7,p0 = r25,r3	// if cmpxchg not successful
+	;;
+(p7)	sub r10 = r3,r24	// then use new last_cycle instead
+	;;
 	and r10 = r10,r14	// Apply mask
 	;;
 	setf.sig f8 = r10
 	nop.i 123
 	;;
-(p7)	cmpxchg8.rel r3 = [r23],r2,ar.ccv
-EX(.fail_efault, probe.w.fault r31, 3)	// This takes 5 cycles and we have spare time
+	// fault check takes 5 cycles and we have spare time
+EX(.fail_efault, probe.w.fault r31, 3)
 	xmpy.l f8 = f8,f7	// nsec_per_cyc*(counter-last_counter)
-(p15)	add r9 = r9,r17		// Add wall to monotonic.secs to result secs
 	;;
-(p15)	ld8 r17 = [r19],-IA64_TIMESPEC_TV_NSEC_OFFSET
-(p7)	cmp.ne p7,p0 = r25,r3	// if cmpxchg not successful redo
-	// simulate tbit.nz.or p7,p0 = r28,0
+	// ? simulate tbit.nz.or p7,p0 = r28,0
 	getf.sig r2 = f8
 	mf
-	add r8 = r8,r18		// Add time interpolator offset
 	;;
-	ld4 r10 = [r29]		// xtime_lock.sequence
-(p15)	add r8 = r8, r17	// Add monotonic.nsecs to nsecs
-	shr.u r2 = r2,r21
-	;;		// overloaded 3 bundles!
-	// End critical section.
+	ld4 r10 = [r20]		// gtod_lock.sequence
+	shr.u r2 = r2,r23	// shift by factor
+	;;		// ? overloaded 3 bundles!
 	add r8 = r8,r2		// Add xtime.nsecs
-	cmp4.ne.or p7,p0 = r28,r10
-(p7)	br.cond.dpnt.few .time_redo	// sequence number changed ?
+	cmp4.ne p7,p0 = r28,r10
+(p7)	br.cond.dpnt.few .time_redo	// sequence number changed, redo
+	// End critical section.
 	// Now r8=tv->tv_nsec and r9=tv->tv_sec
 	mov r10 = r0
 	movl r2 = 1000000000
@@ -308,19 +305,19 @@ EX(.fail_efault, probe.w.fault r31, 3)	// This takes 5 cycles and we have spare
 .time_normalize:
 	mov r21 = r8
 	cmp.ge p6,p0 = r8,r2
-(p14)	shr.u r20 = r8, 3		// We can repeat this if necessary just wasting some time
+(p14)	shr.u r20 = r8, 3 // We can repeat this if necessary just wasting time
 	;;
 (p14)	setf.sig f8 = r20
 (p6)	sub r8 = r8,r2
-(p6)	add r9 = 1,r9			// two nops before the branch.
-(p14)	setf.sig f7 = r3		// Chances for repeats are 1 in 10000 for gettod
+(p6)	add r9 = 1,r9		// two nops before the branch.
+(p14)	setf.sig f7 = r3	// Chances for repeats are 1 in 10000 for gettod
 (p6)	br.cond.dpnt.few .time_normalize
 	;;
 	// Divided by 8 though shift. Now divide by 125
 	// The compiler was able to do that with a multiply
 	// and a shift and we do the same
-EX(.fail_efault, probe.w.fault r23, 3)		// This also costs 5 cycles
-(p14)	xmpy.hu f8 = f8, f7			// xmpy has 5 cycles latency so use it...
+EX(.fail_efault, probe.w.fault r23, 3)	// This also costs 5 cycles
+(p14)	xmpy.hu f8 = f8, f7		// xmpy has 5 cycles latency so use it
 	;;
 	mov r8 = r0
 (p14)	getf.sig r2 = f8
diff --git a/arch/ia64/kernel/fsyscall_gtod_data.h b/arch/ia64/kernel/fsyscall_gtod_data.h
new file mode 100644
index 0000000..490dab5
--- /dev/null
+++ b/arch/ia64/kernel/fsyscall_gtod_data.h
@@ -0,0 +1,23 @@
+/*
+ * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
+ *        Contributed by Peter Keilty <peter.keilty@hp.com>
+ *
+ * fsyscall gettimeofday data
+ */
+
+struct fsyscall_gtod_data_t {
+	seqlock_t	lock;
+	struct timespec	wall_time;
+	struct timespec monotonic_time;
+	cycle_t		clk_mask;
+	u32		clk_mult;
+	u32		clk_shift;
+	void		*clk_fsys_mmio;
+	cycle_t		clk_cycle_last;
+} __attribute__ ((aligned (L1_CACHE_BYTES)));
+
+struct itc_jitter_data_t {
+	int		itc_jitter;
+	cycle_t		itc_lastcycle;
+} __attribute__ ((aligned (L1_CACHE_BYTES)));
+
diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 3486fe7..627785c 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -19,6 +19,7 @@
 #include <linux/interrupt.h>
 #include <linux/efi.h>
 #include <linux/timex.h>
+#include <linux/clocksource.h>
 
 #include <asm/machvec.h>
 #include <asm/delay.h>
@@ -28,6 +29,16 @@
 #include <asm/sections.h>
 #include <asm/system.h>
 
+#include "fsyscall_gtod_data.h"
+
+static cycle_t itc_get_cycles(void);
+
+struct fsyscall_gtod_data_t fsyscall_gtod_data = {
+	.lock = SEQLOCK_UNLOCKED,
+};
+
+struct itc_jitter_data_t itc_jitter_data;
+
 volatile int time_keeper_id = 0; /* smp_processor_id() of time-keeper */
 
 #ifdef CONFIG_IA64_DEBUG_IRQ
@@ -37,11 +48,16 @@ EXPORT_SYMBOL(last_cli_ip);
 
 #endif
 
-static struct time_interpolator itc_interpolator = {
-	.shift = 16,
-	.mask = 0xffffffffffffffffLL,
-	.source = TIME_SOURCE_CPU
+static struct clocksource clocksource_itc = {
+        .name           = "itc",
+        .rating         = 350,
+        .read           = itc_get_cycles,
+        .mask           = 0xffffffffffffffff,
+        .mult           = 0, /*to be caluclated*/
+        .shift          = 16,
+        .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 };
+static struct clocksource *itc_clocksource;
 
 static irqreturn_t
 timer_interrupt (int irq, void *dev_id)
@@ -210,8 +226,6 @@ ia64_init_itm (void)
 					+ itc_freq/2)/itc_freq;
 
 	if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
-		itc_interpolator.frequency = local_cpu_data->itc_freq;
-		itc_interpolator.drift = itc_drift;
 #ifdef CONFIG_SMP
 		/* On IA64 in an SMP configuration ITCs are never accurately synchronized.
 		 * Jitter compensation requires a cmpxchg which may limit
@@ -223,15 +237,50 @@ ia64_init_itm (void)
 		 * even going backward) if the ITC offsets between the individual CPUs
 		 * are too large.
 		 */
-		if (!nojitter) itc_interpolator.jitter = 1;
+		if (!nojitter)
+			itc_jitter_data.itc_jitter = 1;
 #endif
-		register_time_interpolator(&itc_interpolator);
 	}
 
 	/* Setup the CPU local timer tick */
 	ia64_cpu_local_tick();
+
+	if (!itc_clocksource) {
+		/* Sort out mult/shift values: */
+		clocksource_itc.mult +			clocksource_hz2mult(local_cpu_data->itc_freq,
+						clocksource_itc.shift);
+		clocksource_register(&clocksource_itc);
+		itc_clocksource = &clocksource_itc;
+	}
 }
 
+static cycle_t itc_get_cycles()
+{
+	u64 lcycle, now, ret;
+
+	if (!itc_jitter_data.itc_jitter)
+		return get_cycles();
+
+	lcycle = itc_jitter_data.itc_lastcycle;
+	now = get_cycles();
+	if (lcycle && time_after(lcycle, now))
+		return lcycle;
+
+	/*
+	 * Keep track of the last timer value returned.
+	 * In an SMP environment, you could lose out in contention of
+	 * cmpxchg. If so, your cmpxchg returns new value which the
+	 * winner of contention updated to. Use the new value instead.
+	 */
+	ret = cmpxchg(&itc_jitter_data.itc_lastcycle, lcycle, now);
+	if (unlikely(ret != lcycle))
+		return ret;
+
+	return now;
+}
+
+
 static struct irqaction timer_irqaction = {
 	.handler =	timer_interrupt,
 	.flags =	IRQF_DISABLED | IRQF_IRQPOLL,
@@ -307,3 +356,34 @@ ia64_setup_printk_clock(void)
 	if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT))
 		ia64_printk_clock = ia64_itc_printk_clock;
 }
+
+void update_vsyscall(struct timespec *wall, struct clocksource *c)
+{
+        unsigned long flags;
+
+        write_seqlock_irqsave(&fsyscall_gtod_data.lock, flags);
+
+        /* copy fsyscall clock data */
+        fsyscall_gtod_data.clk_mask = c->mask;
+        fsyscall_gtod_data.clk_mult = c->mult;
+        fsyscall_gtod_data.clk_shift = c->shift;
+        fsyscall_gtod_data.clk_fsys_mmio = c->fsys_mmio;
+        fsyscall_gtod_data.clk_cycle_last = c->cycle_last;
+
+	/* copy kernel time structures */
+        fsyscall_gtod_data.wall_time.tv_sec = wall->tv_sec;
+        fsyscall_gtod_data.wall_time.tv_nsec = wall->tv_nsec;
+        fsyscall_gtod_data.monotonic_time.tv_sec = wall_to_monotonic.tv_sec
+							+ wall->tv_sec;
+        fsyscall_gtod_data.monotonic_time.tv_nsec = wall_to_monotonic.tv_nsec
+							+ wall->tv_nsec;
+
+	/* normalize */
+	while (fsyscall_gtod_data.monotonic_time.tv_nsec >= NSEC_PER_SEC) {
+		fsyscall_gtod_data.monotonic_time.tv_nsec -= NSEC_PER_SEC;
+		fsyscall_gtod_data.monotonic_time.tv_sec++;
+	}
+
+        write_sequnlock_irqrestore(&fsyscall_gtod_data.lock, flags);
+}
+
diff --git a/arch/ia64/sn/kernel/sn2/timer.c b/arch/ia64/sn/kernel/sn2/timer.c
index 56a88b6..19e25d2 100644
--- a/arch/ia64/sn/kernel/sn2/timer.c
+++ b/arch/ia64/sn/kernel/sn2/timer.c
@@ -11,6 +11,7 @@
 #include <linux/sched.h>
 #include <linux/time.h>
 #include <linux/interrupt.h>
+#include <linux/clocksource.h>
 
 #include <asm/hw_irq.h>
 #include <asm/system.h>
@@ -22,11 +23,21 @@
 
 extern unsigned long sn_rtc_cycles_per_second;
 
-static struct time_interpolator sn2_interpolator = {
-	.drift = -1,
-	.shift = 10,
-	.mask = (1LL << 55) - 1,
-	.source = TIME_SOURCE_MMIO64
+static void __iomem *sn2_mc;
+
+static cycle_t read_sn2(void)
+{
+	return (cycle_t)readq(sn2_mc);
+}
+
+static struct clocksource clocksource_sn2 = {
+        .name           = "sn2_rtc",
+        .rating         = 300,
+        .read           = read_sn2,
+        .mask           = (1LL << 55) - 1,
+        .mult           = 0,
+        .shift          = 10,
+        .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
 /*
@@ -47,9 +58,11 @@ ia64_sn_udelay (unsigned long usecs)
 
 void __init sn_timer_init(void)
 {
-	sn2_interpolator.frequency = sn_rtc_cycles_per_second;
-	sn2_interpolator.addr = RTC_COUNTER_ADDR;
-	register_time_interpolator(&sn2_interpolator);
+	sn2_mc = RTC_COUNTER_ADDR;
+	clocksource_sn2.fsys_mmio = RTC_COUNTER_ADDR;
+	clocksource_sn2.mult = clocksource_hz2mult(sn_rtc_cycles_per_second,
+							clocksource_sn2.shift);
+	clocksource_register(&clocksource_sn2);
 
 	ia64_udelay = &ia64_sn_udelay;
 }
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 80ffc78..bb5d23b 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -475,7 +475,7 @@ static void acpi_processor_idle(void)
 		/* Get end time (ticks) */
 		t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 
-#ifdef CONFIG_GENERIC_TIME
+#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
 		/* TSC halts in C2, so notify users */
 		mark_tsc_unstable("possible TSC halt in C2");
 #endif
@@ -517,7 +517,7 @@ static void acpi_processor_idle(void)
 			acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
 		}
 
-#ifdef CONFIG_GENERIC_TIME
+#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
 		/* TSC halts in C3, so notify users */
 		mark_tsc_unstable("TSC halts in C3");
 #endif
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index 0be700f..ba0e74a 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -29,6 +29,7 @@
 #include <linux/bcd.h>
 #include <linux/seq_file.h>
 #include <linux/bitops.h>
+#include <linux/clocksource.h>
 
 #include <asm/current.h>
 #include <asm/uaccess.h>
@@ -51,8 +52,34 @@
 
 #define HPET_RANGE_SIZE		1024	/* from HPET spec */
 
+#if BITS_PER_LONG = 64
+#define	write_counter(V, MC)	writeq(V, MC)
+#define	read_counter(MC)	readq(MC)
+#else
+#define	write_counter(V, MC)	writel(V, MC)
+#define	read_counter(MC)	readl(MC)
+#endif
+
 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
 
+static void __iomem *hpet_mctr;
+
+static cycle_t read_hpet(void)
+{
+	return (cycle_t)read_counter((void __iomem *)hpet_mctr);
+}
+
+static struct clocksource clocksource_hpet = {
+        .name           = "hpet",
+        .rating         = 250,
+        .read           = read_hpet,
+        .mask           = 0xffffffffffffffff,
+        .mult           = 0, /*to be caluclated*/
+        .shift          = 10,
+        .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+static struct clocksource *hpet_clocksource;
+
 /* A lock for concurrent access by app and isr hpet activity. */
 static DEFINE_SPINLOCK(hpet_lock);
 /* A lock for concurrent intermodule access to hpet and isr hpet activity. */
@@ -79,7 +106,7 @@ struct hpets {
 	struct hpets *hp_next;
 	struct hpet __iomem *hp_hpet;
 	unsigned long hp_hpet_phys;
-	struct time_interpolator *hp_interpolator;
+	struct clocksource *hp_clocksource;
 	unsigned long long hp_tick_freq;
 	unsigned long hp_delta;
 	unsigned int hp_ntimer;
@@ -94,13 +121,6 @@ static struct hpets *hpets;
 #define	HPET_PERIODIC		0x0004
 #define	HPET_SHARED_IRQ		0x0008
 
-#if BITS_PER_LONG = 64
-#define	write_counter(V, MC)	writeq(V, MC)
-#define	read_counter(MC)	readq(MC)
-#else
-#define	write_counter(V, MC) 	writel(V, MC)
-#define	read_counter(MC)	readl(MC)
-#endif
 
 #ifndef readq
 static inline unsigned long long readq(void __iomem *addr)
@@ -737,27 +757,6 @@ static ctl_table dev_root[] = {
 
 static struct ctl_table_header *sysctl_header;
 
-static void hpet_register_interpolator(struct hpets *hpetp)
-{
-#ifdef	CONFIG_TIME_INTERPOLATION
-	struct time_interpolator *ti;
-
-	ti = kzalloc(sizeof(*ti), GFP_KERNEL);
-	if (!ti)
-		return;
-
-	ti->source = TIME_SOURCE_MMIO64;
-	ti->shift = 10;
-	ti->addr = &hpetp->hp_hpet->hpet_mc;
-	ti->frequency = hpetp->hp_tick_freq;
-	ti->drift = HPET_DRIFT;
-	ti->mask = -1;
-
-	hpetp->hp_interpolator = ti;
-	register_time_interpolator(ti);
-#endif
-}
-
 /*
  * Adjustment for when arming the timer with
  * initial conditions.  That is, main counter
@@ -909,7 +908,16 @@ int hpet_alloc(struct hpet_data *hdp)
 	}
 
 	hpetp->hp_delta = hpet_calibrate(hpetp);
-	hpet_register_interpolator(hpetp);
+
+	if (!hpet_clocksource) {
+		hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
+		CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr);
+		clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq,
+						clocksource_hpet.shift);
+		clocksource_register(&clocksource_hpet);
+		hpetp->hp_clocksource = &clocksource_hpet;
+		hpet_clocksource = &clocksource_hpet;
+	}
 
 	return 0;
 }
@@ -995,7 +1003,7 @@ static int hpet_acpi_add(struct acpi_device *device)
 
 static int hpet_acpi_remove(struct acpi_device *device, int type)
 {
-	/* XXX need to unregister interpolator, dealloc mem, etc */
+	/* XXX need to unregister clocksource, dealloc mem, etc */
 	return -EINVAL;
 }
 
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index bf297b0..562c86a 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -67,6 +67,12 @@ struct clocksource {
 	unsigned long flags;
 	cycle_t (*vread)(void);
 	void (*resume)(void);
+#ifdef CONFIG_IA64
+	void *fsys_mmio;        /* used by fsyscall asm code */
+#define CLKSRC_FSYS_MMIO_SET(mmio, addr)      ((mmio) = (addr))
+#else
+#define CLKSRC_FSYS_MMIO_SET(mmio, addr)      (0)
+#endif
 
 	/* timekeeping specific data, ignore */
 	cycle_t cycle_interval;

Re: [PATCH 0/3] fix ia64 clocksource

[Bob Picco]

luck wrote:	[Fri Jul 20 2007, 12:33:43PM EDT]
> > I need to make the cleanups Tony identified. After that how would you like to
> > proceed? Combining your patch 1/3 and my 1/2 seems logical.
> 
> I've done the cleanup, and merged Seto-san's parts 1,2,3 with your part 1, and
> updated it all for the tip of Linus' tree.  Result is below.
> 
> Part 2 stayed the same, except that I also deleted Documentation/time_interpolators.txt
> 
> I'm going to send both to Linus later today ... so read fast and shout if
> I botched the merge.
> 
Looks good to me. Thanks!

Acked-by: Bob Picco <bob.picco@hp.com>

bob

[snip]

Re: [PATCH 0/3] fix ia64 clocksource

[Hidetoshi Seto]

Luck, Tony wrote:
>> I need to make the cleanups Tony identified. After that how would you like to
>> proceed? Combining your patch 1/3 and my 1/2 seems logical.
> 
> I've done the cleanup, and merged Seto-san's parts 1,2,3 with your part 1, and
> updated it all for the tip of Linus' tree.  Result is below.
> 
> Part 2 stayed the same, except that I also deleted Documentation/time_interpolators.txt
> 
> I'm going to send both to Linus later today ... so read fast and shout if
> I botched the merge.

No problem at all. Thanks!

Acked-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>

H.Seto