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Subject[patch 3/9] Remove the support for the VXTIME_HPET timer mode
VXTIME_HPET will be replaced by a more generic "Master Timer"

Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Index: linux-2.6.20-rc5/arch/x86_64/kernel/time.c
===================================================================
--- linux-2.6.20-rc5.orig/arch/x86_64/kernel/time.c
+++ linux-2.6.20-rc5/arch/x86_64/kernel/time.c
@@ -101,13 +101,6 @@ static inline unsigned int do_gettimeoff
return x;
}

-static inline unsigned int do_gettimeoffset_hpet(void)
-{
- /* cap counter read to one tick to avoid inconsistencies */
- unsigned long counter = hpet_readl(HPET_COUNTER) - vxtime.last;
- return (min(counter,hpet_tick) * vxtime.quot) >> US_SCALE;
-}
-
unsigned int (*do_gettimeoffset)(void) = do_gettimeoffset_tsc;

/*
@@ -278,17 +271,6 @@ unsigned long long monotonic_clock(void)
u32 last_offset, this_offset, offset;
unsigned long long base;

- if (vxtime.mode == VXTIME_HPET) {
- do {
- seq = read_seqbegin(&xtime_lock);
-
- last_offset = vxtime.last;
- base = monotonic_base;
- this_offset = hpet_readl(HPET_COUNTER);
- } while (read_seqretry(&xtime_lock, seq));
- offset = (this_offset - last_offset);
- offset *= NSEC_PER_TICK / hpet_tick;
- } else {
do {
seq = read_seqbegin(&xtime_lock);

@@ -297,7 +279,6 @@ unsigned long long monotonic_clock(void)
} while (read_seqretry(&xtime_lock, seq));
this_offset = get_cycles_sync();
offset = cycles_2_ns(this_offset - last_offset);
- }
return base + offset;
}
EXPORT_SYMBOL(monotonic_clock);
@@ -316,16 +297,6 @@ static noinline void handle_lost_ticks(i
KERN_WARNING "Your time source seems to be instable or "
"some driver is hogging interupts\n");
print_symbol("rip %s\n", get_irq_regs()->rip);
- if (vxtime.mode == VXTIME_TSC && vxtime.hpet_address) {
- printk(KERN_WARNING "Falling back to HPET\n");
- if (hpet_use_timer)
- vxtime.last = hpet_readl(HPET_T0_CMP) -
- hpet_tick;
- else
- vxtime.last = hpet_readl(HPET_COUNTER);
- vxtime.mode = VXTIME_HPET;
- do_gettimeoffset = do_gettimeoffset_hpet;
- }
/* else should fall back to PIT, but code missing. */
warned = 1;
} else
@@ -368,16 +339,6 @@ void main_timer_handler(void)

tsc = get_cycles_sync();

- if (vxtime.mode == VXTIME_HPET) {
- if (offset - vxtime.last > hpet_tick) {
- lost = (offset - vxtime.last) / hpet_tick - 1;
- }
-
- monotonic_base +=
- (offset - vxtime.last) * NSEC_PER_TICK / hpet_tick;
-
- vxtime.last = offset;
- } else {
offset = (((tsc - vxtime.last_tsc) *
vxtime.tsc_quot) >> US_SCALE) - USEC_PER_TICK;

@@ -387,7 +348,6 @@ void main_timer_handler(void)
if (offset > USEC_PER_TICK) {
lost = offset / USEC_PER_TICK;
offset %= USEC_PER_TICK;
- }

monotonic_base += cycles_2_ns(tsc - vxtime.last_tsc);

@@ -465,20 +425,6 @@ unsigned long long sched_clock(void)
{
unsigned long a = 0;

-#if 0
- /* Don't do a HPET read here. Using TSC always is much faster
- and HPET may not be mapped yet when the scheduler first runs.
- Disadvantage is a small drift between CPUs in some configurations,
- but that should be tolerable. */
- if (__vxtime.mode == VXTIME_HPET)
- return (hpet_readl(HPET_COUNTER) * vxtime.quot) >> US_SCALE;
-#endif
-
- /* Could do CPU core sync here. Opteron can execute rdtsc speculatively,
- which means it is not completely exact and may not be monotonous between
- CPUs. But the errors should be too small to matter for scheduling
- purposes. */
-
rdtscll(a);
return cycles_2_ns(a);
}
@@ -961,18 +907,8 @@ void time_init_gtod(void)
else
vgetcpu_mode = VGETCPU_LSL;

- if (vxtime.hpet_address && notsc) {
- timetype = hpet_use_timer ? "HPET" : "PIT/HPET";
- if (hpet_use_timer)
- vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
- else
- vxtime.last = hpet_readl(HPET_COUNTER);
- vxtime.mode = VXTIME_HPET;
- do_gettimeoffset = do_gettimeoffset_hpet;
- } else {
timetype = hpet_use_timer ? "HPET/TSC" : "PIT/TSC";
vxtime.mode = VXTIME_TSC;
- }

printk(KERN_INFO "time.c: Using %ld.%06ld MHz WALL %s GTOD %s timer.\n",
vxtime_hz / 1000000, vxtime_hz % 1000000, timename, timetype);
@@ -1031,12 +967,6 @@ static int timer_resume(struct sys_devic
write_seqlock_irqsave(&xtime_lock,flags);
xtime.tv_sec = sec;
xtime.tv_nsec = 0;
- if (vxtime.mode == VXTIME_HPET) {
- if (hpet_use_timer)
- vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
- else
- vxtime.last = hpet_readl(HPET_COUNTER);
- } else
vxtime.last_tsc = get_cycles_sync();
write_sequnlock_irqrestore(&xtime_lock,flags);
jiffies += sleep_length;
Index: linux-2.6.20-rc5/arch/x86_64/kernel/vsyscall.c
===================================================================
--- linux-2.6.20-rc5.orig/arch/x86_64/kernel/vsyscall.c
+++ linux-2.6.20-rc5/arch/x86_64/kernel/vsyscall.c
@@ -72,18 +72,9 @@ static __always_inline void do_vgettimeo
sec = __xtime.tv_sec;
usec = __xtime.tv_nsec / 1000;

- if (__vxtime.mode != VXTIME_HPET) {
- t = get_cycles_sync();
- if (t < __vxtime.last_tsc)
- t = __vxtime.last_tsc;
- usec += ((t - __vxtime.last_tsc) *
- __vxtime.tsc_quot) >> 32;
- /* See comment in x86_64 do_gettimeofday. */
- } else {
usec += ((readl((void __iomem *)
fix_to_virt(VSYSCALL_HPET) + 0xf0) -
__vxtime.last) * __vxtime.quot) >> 32;
- }
} while (read_seqretry(&__xtime_lock, sequence));

tv->tv_sec = sec + usec / 1000000;
Index: linux-2.6.20-rc5/include/asm-x86_64/vsyscall.h
===================================================================
--- linux-2.6.20-rc5.orig/include/asm-x86_64/vsyscall.h
+++ linux-2.6.20-rc5/include/asm-x86_64/vsyscall.h
@@ -25,7 +25,6 @@ enum vsyscall_num {
#define __section_xtime_lock __attribute__ ((unused, __section__ (".xtime_lock"), aligned(16)))

#define VXTIME_TSC 1
-#define VXTIME_HPET 2

#define VGETCPU_RDTSCP 1
#define VGETCPU_LSL 2
--
-
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