* [RFC][PATCH 1/6] x86_64: Enable arch-generic vsyscall support.
2006-08-09 2:17 [RFC][PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
@ 2006-08-09 2:17 ` john stultz
2006-08-09 2:29 ` Andi Kleen
2006-08-09 2:17 ` [RFC][PATCH 2/6] x86_64: hpet_address cleanup john stultz
` (5 subsequent siblings)
6 siblings, 1 reply; 18+ messages in thread
From: john stultz @ 2006-08-09 2:17 UTC (permalink / raw)
To: ak; +Cc: john stultz, linux-kernel
Provides generic infrastructure for vsyscall-gtod.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
include/linux/clocksource.h | 2 ++
kernel/timer.c | 7 +++++++
2 files changed, 9 insertions(+)
linux-2.6.18-rc4_timeofday-vsyscall-support_C5.patch
============================================
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index d852024..f554273 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -46,6 +46,7 @@ typedef u64 cycle_t;
* @shift: cycle to nanosecond divisor (power of two)
* @update_callback: called when safe to alter clocksource values
* @is_continuous: defines if clocksource is free-running.
+ * @vread: vsyscall based read
* @cycle_interval: Used internally by timekeeping core, please ignore.
* @xtime_interval: Used internally by timekeeping core, please ignore.
*/
@@ -59,6 +60,7 @@ struct clocksource {
u32 shift;
int (*update_callback)(void);
int is_continuous;
+ cycle_t (*vread)(void);
/* timekeeping specific data, ignore */
cycle_t cycle_last, cycle_interval;
diff --git a/kernel/timer.c b/kernel/timer.c
index b650f04..08b4a02 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1023,6 +1023,12 @@ static int __init timekeeping_init_devic
device_initcall(timekeeping_init_device);
+#ifdef CONFIG_GENERIC_TIME_VSYSCALL
+extern void update_vsyscall(struct timespec* ts, struct clocksource* c);
+#else
+#define update_vsyscall(now, c)
+#endif
+
/*
* If the error is already larger, we look ahead even further
* to compensate for late or lost adjustments.
@@ -1165,6 +1171,7 @@ static void update_wall_time(void)
clock->xtime_nsec = 0;
clocksource_calculate_interval(clock, tick_nsec);
}
+ update_vsyscall(&xtime, clock);
}
/*
^ permalink raw reply related [flat|nested] 18+ messages in thread* Re: [RFC][PATCH 1/6] x86_64: Enable arch-generic vsyscall support.
2006-08-09 2:17 ` [RFC][PATCH 1/6] x86_64: Enable arch-generic vsyscall support john stultz
@ 2006-08-09 2:29 ` Andi Kleen
2006-08-09 2:56 ` john stultz
0 siblings, 1 reply; 18+ messages in thread
From: Andi Kleen @ 2006-08-09 2:29 UTC (permalink / raw)
To: john stultz; +Cc: linux-kernel
> diff --git a/kernel/timer.c b/kernel/timer.c
> index b650f04..08b4a02 100644
> --- a/kernel/timer.c
> +++ b/kernel/timer.c
> @@ -1023,6 +1023,12 @@ static int __init timekeeping_init_devic
>
> device_initcall(timekeeping_init_device);
>
> +#ifdef CONFIG_GENERIC_TIME_VSYSCALL
> +extern void update_vsyscall(struct timespec* ts, struct clocksource* c);
> +#else
> +#define update_vsyscall(now, c)
> +#endif
Using a weak dummy function would be a bit cleaner.
-Andi
>
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [RFC][PATCH 1/6] x86_64: Enable arch-generic vsyscall support.
2006-08-09 2:29 ` Andi Kleen
@ 2006-08-09 2:56 ` john stultz
2006-08-09 2:59 ` Andi Kleen
0 siblings, 1 reply; 18+ messages in thread
From: john stultz @ 2006-08-09 2:56 UTC (permalink / raw)
To: Andi Kleen; +Cc: linux-kernel
On Wed, 2006-08-09 at 04:29 +0200, Andi Kleen wrote:
> > diff --git a/kernel/timer.c b/kernel/timer.c
> > index b650f04..08b4a02 100644
> > --- a/kernel/timer.c
> > +++ b/kernel/timer.c
> > @@ -1023,6 +1023,12 @@ static int __init timekeeping_init_devic
> >
> > device_initcall(timekeeping_init_device);
> >
> > +#ifdef CONFIG_GENERIC_TIME_VSYSCALL
> > +extern void update_vsyscall(struct timespec* ts, struct clocksource* c);
> > +#else
> > +#define update_vsyscall(now, c)
> > +#endif
>
> Using a weak dummy function would be a bit cleaner.
Will compilers optimize out the call properly?
Looking at it now, it probably should go in a .h file and the empty
define should be a proper "do { } while(0)"
thanks
-john
^ permalink raw reply [flat|nested] 18+ messages in thread* Re: [RFC][PATCH 1/6] x86_64: Enable arch-generic vsyscall support.
2006-08-09 2:56 ` john stultz
@ 2006-08-09 2:59 ` Andi Kleen
0 siblings, 0 replies; 18+ messages in thread
From: Andi Kleen @ 2006-08-09 2:59 UTC (permalink / raw)
To: john stultz; +Cc: linux-kernel
On Wednesday 09 August 2006 04:56, john stultz wrote:
> On Wed, 2006-08-09 at 04:29 +0200, Andi Kleen wrote:
> > > diff --git a/kernel/timer.c b/kernel/timer.c
> > > index b650f04..08b4a02 100644
> > > --- a/kernel/timer.c
> > > +++ b/kernel/timer.c
> > > @@ -1023,6 +1023,12 @@ static int __init timekeeping_init_devic
> > >
> > > device_initcall(timekeeping_init_device);
> > >
> > > +#ifdef CONFIG_GENERIC_TIME_VSYSCALL
> > > +extern void update_vsyscall(struct timespec* ts, struct clocksource* c);
> > > +#else
> > > +#define update_vsyscall(now, c)
> > > +#endif
> >
> > Using a weak dummy function would be a bit cleaner.
>
> Will compilers optimize out the call properly?
No, but it's just a call ; ret then.
>
> Looking at it now, it probably should go in a .h file and the empty
> define should be a proper "do { } while(0)"
Or use weak
-Andi
^ permalink raw reply [flat|nested] 18+ messages in thread
* [RFC][PATCH 2/6] x86_64: hpet_address cleanup
2006-08-09 2:17 [RFC][PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
2006-08-09 2:17 ` [RFC][PATCH 1/6] x86_64: Enable arch-generic vsyscall support john stultz
@ 2006-08-09 2:17 ` john stultz
2006-08-09 2:31 ` Andi Kleen
2006-08-09 2:17 ` [RFC][PATCH 3/6] x86_64: Remove apic_runs_main_timer john stultz
` (4 subsequent siblings)
6 siblings, 1 reply; 18+ messages in thread
From: john stultz @ 2006-08-09 2:17 UTC (permalink / raw)
To: ak; +Cc: john stultz, linux-kernel
In preparation for supporting generic timekeeping, this patch cleans up
x86-64's use of vxtime.hpet_address, changing it to just hpet_address
as is also used in i386. This is necessary since the vxtime structure
will be going away.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
arch/i386/kernel/acpi/boot.c | 19 ++++++-------------
arch/x86_64/kernel/apic.c | 3 ++-
arch/x86_64/kernel/time.c | 34 ++++++++++++++++++----------------
include/asm-x86_64/hpet.h | 1 +
4 files changed, 27 insertions(+), 30 deletions(-)
linux-2.6.18-rc4_timeofday-arch-x86-64-part1_C5.patch
============================================
diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c
index 0db6387..f2c43da 100644
--- a/arch/i386/kernel/acpi/boot.c
+++ b/arch/i386/kernel/acpi/boot.c
@@ -575,6 +575,7 @@ static int __init acpi_parse_sbf(unsigne
}
#ifdef CONFIG_HPET_TIMER
+#include <asm/hpet.h>
static int __init acpi_parse_hpet(unsigned long phys, unsigned long size)
{
@@ -595,21 +596,13 @@ static int __init acpi_parse_hpet(unsign
return -1;
}
#ifdef CONFIG_X86_64
- vxtime.hpet_address = hpet_tbl->addr.addrl |
+ hpet_address = hpet_tbl->addr.addrl |
((long)hpet_tbl->addr.addrh << 32);
-
+#else
+ hpet_address = hpet_tbl->addr.addrl;
+#endif
printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n",
- hpet_tbl->id, vxtime.hpet_address);
-#else /* X86 */
- {
- extern unsigned long hpet_address;
-
- hpet_address = hpet_tbl->addr.addrl;
- printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n",
- hpet_tbl->id, hpet_address);
- }
-#endif /* X86 */
-
+ hpet_tbl->id, hpet_address);
return 0;
}
#else
diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c
index 2b8cef0..1b9e3d3 100644
--- a/arch/x86_64/kernel/apic.c
+++ b/arch/x86_64/kernel/apic.c
@@ -36,6 +36,7 @@
#include <asm/idle.h>
#include <asm/proto.h>
#include <asm/timex.h>
+#include <asm/hpet.h>
int apic_verbosity;
int apic_runs_main_timer;
@@ -727,7 +728,7 @@ static void setup_APIC_timer(unsigned in
local_irq_save(flags);
/* wait for irq slice */
- if (vxtime.hpet_address && hpet_use_timer) {
+ if (hpet_address && hpet_use_timer) {
int trigger = hpet_readl(HPET_T0_CMP);
while (hpet_readl(HPET_COUNTER) >= trigger)
/* do nothing */ ;
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index 7a9b182..da89e60 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -67,6 +67,7 @@ static int notsc __initdata = 0;
unsigned int cpu_khz; /* TSC clocks / usec, not used here */
EXPORT_SYMBOL(cpu_khz);
+unsigned long hpet_address;
static unsigned long hpet_period; /* fsecs / HPET clock */
unsigned long hpet_tick; /* HPET clocks / interrupt */
int hpet_use_timer; /* Use counter of hpet for time keeping, otherwise PIT */
@@ -326,7 +327,7 @@ 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", regs->rip);
- if (vxtime.mode == VXTIME_TSC && vxtime.hpet_address) {
+ if (vxtime.mode == VXTIME_TSC && hpet_address) {
printk(KERN_WARNING "Falling back to HPET\n");
if (hpet_use_timer)
vxtime.last = hpet_readl(HPET_T0_CMP) -
@@ -334,6 +335,7 @@ static noinline void handle_lost_ticks(i
else
vxtime.last = hpet_readl(HPET_COUNTER);
vxtime.mode = VXTIME_HPET;
+ vxtime.hpet_address = hpet_address;
do_gettimeoffset = do_gettimeoffset_hpet;
}
/* else should fall back to PIT, but code missing. */
@@ -364,7 +366,7 @@ void main_timer_handler(struct pt_regs *
write_seqlock(&xtime_lock);
- if (vxtime.hpet_address)
+ if (hpet_address)
offset = hpet_readl(HPET_COUNTER);
if (hpet_use_timer) {
@@ -734,7 +736,7 @@ static __init int late_hpet_init(void)
struct hpet_data hd;
unsigned int ntimer;
- if (!vxtime.hpet_address)
+ if (!hpet_address)
return 0;
memset(&hd, 0, sizeof (hd));
@@ -747,7 +749,7 @@ static __init int late_hpet_init(void)
* Register with driver.
* Timer0 and Timer1 is used by platform.
*/
- hd.hd_phys_address = vxtime.hpet_address;
+ hd.hd_phys_address = hpet_address;
hd.hd_address = (void __iomem *)fix_to_virt(FIX_HPET_BASE);
hd.hd_nirqs = ntimer;
hd.hd_flags = HPET_DATA_PLATFORM;
@@ -816,10 +818,10 @@ static int hpet_init(void)
{
unsigned int id;
- if (!vxtime.hpet_address)
+ if (!hpet_address)
return -1;
- set_fixmap_nocache(FIX_HPET_BASE, vxtime.hpet_address);
- __set_fixmap(VSYSCALL_HPET, vxtime.hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE);
+ set_fixmap_nocache(FIX_HPET_BASE, hpet_address);
+ __set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE);
/*
* Read the period, compute tick and quotient.
@@ -873,7 +875,7 @@ void __init pit_stop_interrupt(void)
void __init stop_timer_interrupt(void)
{
char *name;
- if (vxtime.hpet_address) {
+ if (hpet_address) {
name = "HPET";
hpet_timer_stop_set_go(0);
} else {
@@ -899,8 +901,7 @@ void __init time_init(void)
char *gtod;
if (nohpet)
- vxtime.hpet_address = 0;
-
+ hpet_address = 0;
xtime.tv_sec = get_cmos_time();
xtime.tv_nsec = 0;
@@ -910,7 +911,7 @@ void __init time_init(void)
if (!hpet_init())
vxtime_hz = (FSEC_PER_SEC + hpet_period / 2) / hpet_period;
else
- vxtime.hpet_address = 0;
+ hpet_address = 0;
if (hpet_use_timer) {
/* set tick_nsec to use the proper rate for HPET */
@@ -918,7 +919,7 @@ void __init time_init(void)
cpu_khz = hpet_calibrate_tsc();
timename = "HPET";
#ifdef CONFIG_X86_PM_TIMER
- } else if (pmtmr_ioport && !vxtime.hpet_address) {
+ } else if (pmtmr_ioport && !hpet_address) {
vxtime_hz = PM_TIMER_FREQUENCY;
timename = "PM";
pit_init();
@@ -979,18 +980,19 @@ __init static char *time_init_gtod(void)
if (unsynchronized_tsc())
notsc = 1;
- if (vxtime.hpet_address && notsc) {
+ if (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;
+ vxtime.hpet_address = hpet_address;
do_gettimeoffset = do_gettimeoffset_hpet;
#ifdef CONFIG_X86_PM_TIMER
/* Using PM for gettimeofday is quite slow, but we have no other
choice because the TSC is too unreliable on some systems. */
- } else if (pmtmr_ioport && !vxtime.hpet_address && notsc) {
+ } else if (pmtmr_ioport && !hpet_address && notsc) {
timetype = "PM";
do_gettimeoffset = do_gettimeoffset_pm;
vxtime.mode = VXTIME_PMTMR;
@@ -1033,7 +1035,7 @@ static int timer_resume(struct sys_devic
unsigned long ctime = get_cmos_time();
unsigned long sleep_length = (ctime - sleep_start) * HZ;
- if (vxtime.hpet_address)
+ if (hpet_address)
hpet_reenable();
else
i8254_timer_resume();
@@ -1118,7 +1120,7 @@ static unsigned int hpet_t1_cmp; /* cach
int is_hpet_enabled(void)
{
- return vxtime.hpet_address != 0;
+ return hpet_address != 0;
}
/*
diff --git a/include/asm-x86_64/hpet.h b/include/asm-x86_64/hpet.h
index b390984..60d5127 100644
--- a/include/asm-x86_64/hpet.h
+++ b/include/asm-x86_64/hpet.h
@@ -58,6 +58,7 @@ extern int hpet_rtc_timer_init(void);
extern int apic_is_clustered_box(void);
extern int hpet_use_timer;
+extern unsigned long hpet_address;
#ifdef CONFIG_HPET_EMULATE_RTC
extern int hpet_mask_rtc_irq_bit(unsigned long bit_mask);
^ permalink raw reply related [flat|nested] 18+ messages in thread* Re: [RFC][PATCH 2/6] x86_64: hpet_address cleanup
2006-08-09 2:17 ` [RFC][PATCH 2/6] x86_64: hpet_address cleanup john stultz
@ 2006-08-09 2:31 ` Andi Kleen
2006-08-09 3:08 ` john stultz
0 siblings, 1 reply; 18+ messages in thread
From: Andi Kleen @ 2006-08-09 2:31 UTC (permalink / raw)
To: john stultz; +Cc: linux-kernel
On Wednesday 09 August 2006 04:17, john stultz wrote:
> In preparation for supporting generic timekeeping, this patch cleans up
> x86-64's use of vxtime.hpet_address, changing it to just hpet_address
> as is also used in i386. This is necessary since the vxtime structure
> will be going away.
Does the kernel still boot with that patch only?
Your new variable doesn't seem to be exported to vsyscalls
-Andi
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [RFC][PATCH 2/6] x86_64: hpet_address cleanup
2006-08-09 2:31 ` Andi Kleen
@ 2006-08-09 3:08 ` john stultz
0 siblings, 0 replies; 18+ messages in thread
From: john stultz @ 2006-08-09 3:08 UTC (permalink / raw)
To: Andi Kleen; +Cc: linux-kernel
On Wed, 2006-08-09 at 04:31 +0200, Andi Kleen wrote:
> On Wednesday 09 August 2006 04:17, john stultz wrote:
> > In preparation for supporting generic timekeeping, this patch cleans up
> > x86-64's use of vxtime.hpet_address, changing it to just hpet_address
> > as is also used in i386. This is necessary since the vxtime structure
> > will be going away.
>
> Does the kernel still boot with that patch only?
Just tested, and yes it still boots, but my box doesn't have HPET so
that isn't much of a test. :(
As I said in the announce mail, I've not boot tested each step, I
suspect patches 4/6 and 5/6 will have troubles (vsyscall isn't disabled,
but the updating is). I'll try to address that in the next release.
> Your new variable doesn't seem to be exported to vsyscalls
The vxtime structure hasn't yet been removed and we set
vxtime.hpet_address = hpet_address in necessary spots, so it should be
ok.
thanks
-john
^ permalink raw reply [flat|nested] 18+ messages in thread
* [RFC][PATCH 3/6] x86_64: Remove apic_runs_main_timer
2006-08-09 2:17 [RFC][PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
2006-08-09 2:17 ` [RFC][PATCH 1/6] x86_64: Enable arch-generic vsyscall support john stultz
2006-08-09 2:17 ` [RFC][PATCH 2/6] x86_64: hpet_address cleanup john stultz
@ 2006-08-09 2:17 ` john stultz
2006-08-09 2:31 ` Andi Kleen
2006-08-09 2:17 ` [RFC][PATCH 4/6] x86_64: Enable CONFIG_GENERIC_TIME john stultz
` (3 subsequent siblings)
6 siblings, 1 reply; 18+ messages in thread
From: john stultz @ 2006-08-09 2:17 UTC (permalink / raw)
To: ak; +Cc: john stultz, linux-kernel
Part of the x86-64 cleanup for generic timekeeping.
Remove apic_runs_main_timer, on request from Andi, since it doesn't
work on many systems.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
arch/x86_64/kernel/apic.c | 30 +-----------------------------
arch/x86_64/kernel/time.c | 2 --
include/asm-x86_64/apic.h | 1 -
3 files changed, 1 insertion(+), 32 deletions(-)
linux-2.6.18-rc4_timeofday-arch-x86-64-part2_C5.patch
============================================
diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c
index 1b9e3d3..6173b2f 100644
--- a/arch/x86_64/kernel/apic.c
+++ b/arch/x86_64/kernel/apic.c
@@ -39,7 +39,6 @@
#include <asm/hpet.h>
int apic_verbosity;
-int apic_runs_main_timer;
int apic_calibrate_pmtmr __initdata;
int disable_apic_timer __initdata;
@@ -747,16 +746,6 @@ static void setup_APIC_timer(unsigned in
} while (c2 - c1 < 300);
}
__setup_APIC_LVTT(clocks);
- /* Turn off PIT interrupt if we use APIC timer as main timer.
- Only works with the PM timer right now
- TBD fix it for HPET too. */
- if (vxtime.mode == VXTIME_PMTMR &&
- smp_processor_id() == boot_cpu_id &&
- apic_runs_main_timer == 1 &&
- !cpu_isset(boot_cpu_id, timer_interrupt_broadcast_ipi_mask)) {
- stop_timer_interrupt();
- apic_runs_main_timer++;
- }
local_irq_restore(flags);
}
@@ -946,8 +935,6 @@ void smp_local_timer_interrupt(struct pt
#ifdef CONFIG_SMP
update_process_times(user_mode(regs));
#endif
- if (apic_runs_main_timer > 1 && smp_processor_id() == boot_cpu_id)
- main_timer_handler(regs);
/*
* We take the 'long' return path, and there every subsystem
* grabs the appropriate locks (kernel lock/ irq lock).
@@ -1162,26 +1149,11 @@ static __init int setup_noapictimer(char
return 1;
}
-static __init int setup_apicmaintimer(char *str)
-{
- apic_runs_main_timer = 1;
- nohpet = 1;
- return 1;
-}
-__setup("apicmaintimer", setup_apicmaintimer);
-
-static __init int setup_noapicmaintimer(char *str)
-{
- apic_runs_main_timer = -1;
- return 1;
-}
-__setup("noapicmaintimer", setup_noapicmaintimer);
-
static __init int setup_apicpmtimer(char *s)
{
apic_calibrate_pmtmr = 1;
notsc_setup(NULL);
- return setup_apicmaintimer(NULL);
+ return 1;
}
__setup("apicpmtimer", setup_apicpmtimer);
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index da89e60..a4aef4e 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -469,8 +469,6 @@ void main_timer_handler(struct pt_regs *
static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
- if (apic_runs_main_timer > 1)
- return IRQ_HANDLED;
main_timer_handler(regs);
#ifdef CONFIG_X86_LOCAL_APIC
if (using_apic_timer)
diff --git a/include/asm-x86_64/apic.h b/include/asm-x86_64/apic.h
index 9c96a0a..06fcdc2 100644
--- a/include/asm-x86_64/apic.h
+++ b/include/asm-x86_64/apic.h
@@ -16,7 +16,6 @@
#define APIC_DEBUG 2
extern int apic_verbosity;
-extern int apic_runs_main_timer;
/*
* Define the default level of output to be very little
^ permalink raw reply related [flat|nested] 18+ messages in thread* [RFC][PATCH 4/6] x86_64: Enable CONFIG_GENERIC_TIME
2006-08-09 2:17 [RFC][PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
` (2 preceding siblings ...)
2006-08-09 2:17 ` [RFC][PATCH 3/6] x86_64: Remove apic_runs_main_timer john stultz
@ 2006-08-09 2:17 ` john stultz
2006-08-09 2:17 ` [RFC][PATCH 5/6] x86_64: Clocksources for x86-64 john stultz
` (2 subsequent siblings)
6 siblings, 0 replies; 18+ messages in thread
From: john stultz @ 2006-08-09 2:17 UTC (permalink / raw)
To: ak; +Cc: john stultz, linux-kernel
Enable CONFIG_GENERIC_TIME on x86_64 and remove arch specific
timekeeping code.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
arch/x86_64/Kconfig | 4
arch/x86_64/kernel/pmtimer.c | 58 -------
arch/x86_64/kernel/time.c | 354 +------------------------------------------
include/asm-x86_64/proto.h | 1
4 files changed, 19 insertions(+), 398 deletions(-)
linux-2.6.18-rc4_timeofday-arch-x86-64-part3_C5.patch
============================================
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 28df7d8..fabb174 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -24,6 +24,10 @@ config X86
bool
default y
+config GENERIC_TIME
+ bool
+ default y
+
config LOCKDEP_SUPPORT
bool
default y
diff --git a/arch/x86_64/kernel/pmtimer.c b/arch/x86_64/kernel/pmtimer.c
index 7554458..ae8f912 100644
--- a/arch/x86_64/kernel/pmtimer.c
+++ b/arch/x86_64/kernel/pmtimer.c
@@ -24,15 +24,6 @@
#include <asm/msr.h>
#include <asm/vsyscall.h>
-/* The I/O port the PMTMR resides at.
- * The location is detected during setup_arch(),
- * in arch/i386/kernel/acpi/boot.c */
-u32 pmtmr_ioport __read_mostly;
-
-/* value of the Power timer at last timer interrupt */
-static u32 offset_delay;
-static u32 last_pmtmr_tick;
-
#define ACPI_PM_MASK 0xFFFFFF /* limit it to 24 bits */
static inline u32 cyc2us(u32 cycles)
@@ -48,38 +39,6 @@ static inline u32 cyc2us(u32 cycles)
return (cycles >> 10);
}
-int pmtimer_mark_offset(void)
-{
- static int first_run = 1;
- unsigned long tsc;
- u32 lost;
-
- u32 tick = inl(pmtmr_ioport);
- u32 delta;
-
- delta = cyc2us((tick - last_pmtmr_tick) & ACPI_PM_MASK);
-
- last_pmtmr_tick = tick;
- monotonic_base += delta * NSEC_PER_USEC;
-
- delta += offset_delay;
-
- lost = delta / (USEC_PER_SEC / HZ);
- offset_delay = delta % (USEC_PER_SEC / HZ);
-
- rdtscll(tsc);
- vxtime.last_tsc = tsc - offset_delay * (u64)cpu_khz / 1000;
-
- /* don't calculate delay for first run,
- or if we've got less then a tick */
- if (first_run || (lost < 1)) {
- first_run = 0;
- offset_delay = 0;
- }
-
- return lost - 1;
-}
-
static unsigned pmtimer_wait_tick(void)
{
u32 a, b;
@@ -101,23 +60,6 @@ void pmtimer_wait(unsigned us)
} while (cyc2us(b - a) < us);
}
-void pmtimer_resume(void)
-{
- last_pmtmr_tick = inl(pmtmr_ioport);
-}
-
-unsigned int do_gettimeoffset_pm(void)
-{
- u32 now, offset, delta = 0;
-
- offset = last_pmtmr_tick;
- now = inl(pmtmr_ioport);
- delta = (now - offset) & ACPI_PM_MASK;
-
- return offset_delay + cyc2us(delta);
-}
-
-
static int __init nopmtimer_setup(char *s)
{
pmtmr_ioport = 0;
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index a4aef4e..d18230a 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -43,14 +43,9 @@
#include <asm/apic.h>
#endif
-#ifdef CONFIG_CPU_FREQ
-static void cpufreq_delayed_get(void);
-#endif
extern void i8254_timer_resume(void);
extern int using_apic_timer;
-static char *time_init_gtod(void);
-
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);
DEFINE_SPINLOCK(i8253_lock);
@@ -82,108 +77,6 @@ unsigned long __wall_jiffies __section_w
struct timespec __xtime __section_xtime;
struct timezone __sys_tz __section_sys_tz;
-/*
- * do_gettimeoffset() returns microseconds since last timer interrupt was
- * triggered by hardware. A memory read of HPET is slower than a register read
- * of TSC, but much more reliable. It's also synchronized to the timer
- * interrupt. Note that do_gettimeoffset() may return more than hpet_tick, if a
- * timer interrupt has happened already, but vxtime.trigger wasn't updated yet.
- * This is not a problem, because jiffies hasn't updated either. They are bound
- * together by xtime_lock.
- */
-
-static inline unsigned int do_gettimeoffset_tsc(void)
-{
- unsigned long t;
- unsigned long x;
- t = get_cycles_sync();
- if (t < vxtime.last_tsc)
- t = vxtime.last_tsc; /* hack */
- x = ((t - vxtime.last_tsc) * vxtime.tsc_quot) >> US_SCALE;
- 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;
-
-/*
- * This version of gettimeofday() has microsecond resolution and better than
- * microsecond precision, as we're using at least a 10 MHz (usually 14.31818
- * MHz) HPET timer.
- */
-
-void do_gettimeofday(struct timeval *tv)
-{
- unsigned long seq, t;
- unsigned int sec, usec;
-
- do {
- seq = read_seqbegin(&xtime_lock);
-
- sec = xtime.tv_sec;
- usec = xtime.tv_nsec / NSEC_PER_USEC;
-
- /* i386 does some correction here to keep the clock
- monotonous even when ntpd is fixing drift.
- But they didn't work for me, there is a non monotonic
- clock anyways with ntp.
- I dropped all corrections now until a real solution can
- be found. Note when you fix it here you need to do the same
- in arch/x86_64/kernel/vsyscall.c and export all needed
- variables in vmlinux.lds. -AK */
-
- t = (jiffies - wall_jiffies) * USEC_PER_TICK +
- do_gettimeoffset();
- usec += t;
-
- } while (read_seqretry(&xtime_lock, seq));
-
- tv->tv_sec = sec + usec / USEC_PER_SEC;
- tv->tv_usec = usec % USEC_PER_SEC;
-}
-
-EXPORT_SYMBOL(do_gettimeofday);
-
-/*
- * settimeofday() first undoes the correction that gettimeofday would do
- * on the time, and then saves it. This is ugly, but has been like this for
- * ages already.
- */
-
-int do_settimeofday(struct timespec *tv)
-{
- time_t wtm_sec, sec = tv->tv_sec;
- long wtm_nsec, nsec = tv->tv_nsec;
-
- if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
- return -EINVAL;
-
- write_seqlock_irq(&xtime_lock);
-
- nsec -= do_gettimeoffset() * NSEC_PER_USEC +
- (jiffies - wall_jiffies) * NSEC_PER_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;
-}
-
-EXPORT_SYMBOL(do_settimeofday);
-
unsigned long profile_pc(struct pt_regs *regs)
{
unsigned long pc = instruction_pointer(regs);
@@ -278,85 +171,9 @@ static void set_rtc_mmss(unsigned long n
}
-/* monotonic_clock(): returns # of nanoseconds passed since time_init()
- * Note: This function is required to return accurate
- * time even in the absence of multiple timer ticks.
- */
-unsigned long long monotonic_clock(void)
-{
- unsigned long seq;
- u32 last_offset, this_offset, offset;
- unsigned long long base;
-
- if (vxtime.mode == VXTIME_HPET) {
- do {
- seq = read_seqbegin(&xtime_lock);
-
- last_offset = vxtime.last;
- base = monotonic_base;
- this_offset = hpet_readl(HPET_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);
-
- last_offset = vxtime.last_tsc;
- base = monotonic_base;
- } while (read_seqretry(&xtime_lock, seq));
- this_offset = get_cycles_sync();
- /* FIXME: 1000 or 1000000? */
- offset = (this_offset - last_offset)*1000 / cpu_khz;
- }
- return base + offset;
-}
-EXPORT_SYMBOL(monotonic_clock);
-
-static noinline void handle_lost_ticks(int lost, struct pt_regs *regs)
-{
- static long lost_count;
- static int warned;
- if (report_lost_ticks) {
- printk(KERN_WARNING "time.c: Lost %d timer tick(s)! ", lost);
- print_symbol("rip %s)\n", regs->rip);
- }
-
- if (lost_count == 1000 && !warned) {
- printk(KERN_WARNING "warning: many lost ticks.\n"
- KERN_WARNING "Your time source seems to be instable or "
- "some driver is hogging interupts\n");
- print_symbol("rip %s\n", regs->rip);
- if (vxtime.mode == VXTIME_TSC && 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;
- vxtime.hpet_address = hpet_address;
- do_gettimeoffset = do_gettimeoffset_hpet;
- }
- /* else should fall back to PIT, but code missing. */
- warned = 1;
- } else
- lost_count++;
-
-#ifdef CONFIG_CPU_FREQ
- /* In some cases the CPU can change frequency without us noticing
- Give cpufreq a change to catch up. */
- if ((lost_count+1) % 25 == 0)
- cpufreq_delayed_get();
-#endif
-}
-
void main_timer_handler(struct pt_regs *regs)
{
static unsigned long rtc_update = 0;
- unsigned long tsc;
- int delay = 0, offset = 0, lost = 0;
-
/*
* Here we are in the timer irq handler. We have irqs locally disabled (so we
* don't need spin_lock_irqsave()) but we don't know if the timer_bh is running
@@ -366,68 +183,6 @@ void main_timer_handler(struct pt_regs *
write_seqlock(&xtime_lock);
- if (hpet_address)
- offset = hpet_readl(HPET_COUNTER);
-
- if (hpet_use_timer) {
- /* if we're using the hpet timer functionality,
- * we can more accurately know the counter value
- * when the timer interrupt occured.
- */
- offset = hpet_readl(HPET_T0_CMP) - hpet_tick;
- delay = hpet_readl(HPET_COUNTER) - offset;
- } else if (!pmtmr_ioport) {
- spin_lock(&i8253_lock);
- outb_p(0x00, 0x43);
- delay = inb_p(0x40);
- delay |= inb(0x40) << 8;
- spin_unlock(&i8253_lock);
- delay = LATCH - 1 - delay;
- }
-
- 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;
-#ifdef CONFIG_X86_PM_TIMER
- } else if (vxtime.mode == VXTIME_PMTMR) {
- lost = pmtimer_mark_offset();
-#endif
- } else {
- offset = (((tsc - vxtime.last_tsc) *
- vxtime.tsc_quot) >> US_SCALE) - USEC_PER_TICK;
-
- if (offset < 0)
- offset = 0;
-
- if (offset > USEC_PER_TICK) {
- lost = offset / USEC_PER_TICK;
- offset %= USEC_PER_TICK;
- }
-
- /* FIXME: 1000 or 1000000? */
- monotonic_base += (tsc - vxtime.last_tsc) * 1000000 / cpu_khz;
-
- vxtime.last_tsc = tsc - vxtime.quot * delay / vxtime.tsc_quot;
-
- if ((((tsc - vxtime.last_tsc) *
- vxtime.tsc_quot) >> US_SCALE) < offset)
- vxtime.last_tsc = tsc -
- (((long) offset << US_SCALE) / vxtime.tsc_quot) - 1;
- }
-
- if (lost > 0) {
- handle_lost_ticks(lost, regs);
- jiffies += lost;
- }
-
/*
* Do the timer stuff.
*/
@@ -493,15 +248,6 @@ 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
@@ -511,6 +257,19 @@ unsigned long long sched_clock(void)
return cycles_2_ns(a);
}
+static int tsc_unstable;
+
+static inline int check_tsc_unstable(void)
+{
+ return tsc_unstable;
+}
+
+void mark_tsc_unstable(void)
+{
+ tsc_unstable = 1;
+}
+EXPORT_SYMBOL_GPL(mark_tsc_unstable);
+
static unsigned long get_cmos_time(void)
{
unsigned int year, mon, day, hour, min, sec;
@@ -589,24 +348,6 @@ static void handle_cpufreq_delayed_get(v
cpufreq_delayed_issched = 0;
}
-/* if we notice lost ticks, schedule a call to cpufreq_get() as it tries
- * to verify the CPU frequency the timing core thinks the CPU is running
- * at is still correct.
- */
-static void cpufreq_delayed_get(void)
-{
- static int warned;
- if (cpufreq_init && !cpufreq_delayed_issched) {
- cpufreq_delayed_issched = 1;
- if (!warned) {
- warned = 1;
- printk(KERN_DEBUG
- "Losing some ticks... checking if CPU frequency changed.\n");
- }
- schedule_work(&cpufreq_delayed_get_work);
- }
-}
-
static unsigned int ref_freq = 0;
static unsigned long loops_per_jiffy_ref = 0;
@@ -896,7 +637,6 @@ static struct irqaction irq0 = {
void __init time_init(void)
{
char *timename;
- char *gtod;
if (nohpet)
hpet_address = 0;
@@ -906,9 +646,7 @@ void __init time_init(void)
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
- if (!hpet_init())
- vxtime_hz = (FSEC_PER_SEC + hpet_period / 2) / hpet_period;
- else
+ if (hpet_init())
hpet_address = 0;
if (hpet_use_timer) {
@@ -916,29 +654,14 @@ void __init time_init(void)
tick_nsec = TICK_NSEC_HPET;
cpu_khz = hpet_calibrate_tsc();
timename = "HPET";
-#ifdef CONFIG_X86_PM_TIMER
- } else if (pmtmr_ioport && !hpet_address) {
- vxtime_hz = PM_TIMER_FREQUENCY;
- timename = "PM";
- pit_init();
- cpu_khz = pit_calibrate_tsc();
-#endif
} else {
pit_init();
cpu_khz = pit_calibrate_tsc();
timename = "PIT";
}
- vxtime.mode = VXTIME_TSC;
- gtod = time_init_gtod();
-
- printk(KERN_INFO "time.c: Using %ld.%06ld MHz WALL %s GTOD %s timer.\n",
- vxtime_hz / 1000000, vxtime_hz % 1000000, timename, gtod);
printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n",
cpu_khz / 1000, cpu_khz % 1000);
- vxtime.quot = (USEC_PER_SEC << US_SCALE) / vxtime_hz;
- vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz;
- vxtime.last_tsc = get_cycles_sync();
setup_irq(0, &irq0);
set_cyc2ns_scale(cpu_khz);
@@ -969,41 +692,6 @@ __cpuinit int unsynchronized_tsc(void)
return num_present_cpus() > 1;
}
-/*
- * Decide what mode gettimeofday should use.
- */
-__init static char *time_init_gtod(void)
-{
- char *timetype;
-
- if (unsynchronized_tsc())
- notsc = 1;
- if (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;
- vxtime.hpet_address = hpet_address;
- do_gettimeoffset = do_gettimeoffset_hpet;
-#ifdef CONFIG_X86_PM_TIMER
- /* Using PM for gettimeofday is quite slow, but we have no other
- choice because the TSC is too unreliable on some systems. */
- } else if (pmtmr_ioport && !hpet_address && notsc) {
- timetype = "PM";
- do_gettimeoffset = do_gettimeoffset_pm;
- vxtime.mode = VXTIME_PMTMR;
- sysctl_vsyscall = 0;
- printk(KERN_INFO "Disabling vsyscall due to use of PM timer\n");
-#endif
- } else {
- timetype = hpet_use_timer ? "HPET/TSC" : "PIT/TSC";
- vxtime.mode = VXTIME_TSC;
- }
- return timetype;
-}
-
__setup("report_lost_ticks", time_setup);
static long clock_cmos_diff;
@@ -1042,21 +730,9 @@ 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);
-#ifdef CONFIG_X86_PM_TIMER
- } else if (vxtime.mode == VXTIME_PMTMR) {
- pmtimer_resume();
-#endif
- } else
- vxtime.last_tsc = get_cycles_sync();
- write_sequnlock_irqrestore(&xtime_lock,flags);
jiffies += sleep_length;
wall_jiffies += sleep_length;
- monotonic_base += sleep_length * (NSEC_PER_SEC/HZ);
+ write_sequnlock_irqrestore(&xtime_lock,flags);
touch_softlockup_watchdog();
return 0;
}
diff --git a/include/asm-x86_64/proto.h b/include/asm-x86_64/proto.h
index 038fe1f..716ac55 100644
--- a/include/asm-x86_64/proto.h
+++ b/include/asm-x86_64/proto.h
@@ -47,7 +47,6 @@ extern u32 pmtmr_ioport;
#else
#define pmtmr_ioport 0
#endif
-extern unsigned long long monotonic_base;
extern int sysctl_vsyscall;
extern int nohpet;
extern unsigned long vxtime_hz;
^ permalink raw reply related [flat|nested] 18+ messages in thread* [RFC][PATCH 5/6] x86_64: Clocksources for x86-64
2006-08-09 2:17 [RFC][PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
` (3 preceding siblings ...)
2006-08-09 2:17 ` [RFC][PATCH 4/6] x86_64: Enable CONFIG_GENERIC_TIME john stultz
@ 2006-08-09 2:17 ` john stultz
2006-08-09 2:41 ` Andi Kleen
2006-08-09 2:17 ` [RFC][PATCH 6/6] x86_64: GENERIC_TIME based vsyscall code john stultz
2006-08-09 2:41 ` [RFC][PATCH 0/6] x86_64: Generic timekeeping for x86_64 Andi Kleen
6 siblings, 1 reply; 18+ messages in thread
From: john stultz @ 2006-08-09 2:17 UTC (permalink / raw)
To: ak; +Cc: john stultz, linux-kernel
Re-add TSC and HPET support to x86_64 via clocksource infrastructure.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
arch/x86_64/kernel/time.c | 133 +++++++++++++++++++++++++++++++++++++++++++--
include/asm-x86_64/timex.h | 3 +
2 files changed, 133 insertions(+), 3 deletions(-)
linux-2.6.18-rc4_timeofday-arch-x86-64-part4_C5.patch
============================================
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index d18230a..546abc7 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -39,6 +39,7 @@
#include <asm/sections.h>
#include <linux/cpufreq.h>
#include <linux/hpet.h>
+#include <linux/clocksource.h>
#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/apic.h>
#endif
@@ -60,8 +61,9 @@ static int notsc __initdata = 0;
#define NS_SCALE 10 /* 2^10, carefully chosen */
#define US_SCALE 32 /* 2^32, arbitralrily chosen */
-unsigned int cpu_khz; /* TSC clocks / usec, not used here */
+unsigned int cpu_khz; /* CPU clocks / usec, not used here */
EXPORT_SYMBOL(cpu_khz);
+unsigned int tsc_khz; /* TSC clocks / usec, not used here */
unsigned long hpet_address;
static unsigned long hpet_period; /* fsecs / HPET clock */
unsigned long hpet_tick; /* HPET clocks / interrupt */
@@ -382,8 +384,9 @@ static int time_cpufreq_notifier(struct
cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new);
cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new);
- if (!(freq->flags & CPUFREQ_CONST_LOOPS))
- vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz;
+ if (!(freq->flags & CPUFREQ_CONST_LOOPS)) {
+ tsc_khz = cpu_khz;
+ }
}
set_cyc2ns_scale(cpu_khz_ref);
@@ -659,6 +662,10 @@ void __init time_init(void)
cpu_khz = pit_calibrate_tsc();
timename = "PIT";
}
+ tsc_khz = cpu_khz;
+
+ if (unsynchronized_tsc())
+ mark_tsc_unstable();
printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n",
cpu_khz / 1000, cpu_khz % 1000);
@@ -999,3 +1006,123 @@ int __init notsc_setup(char *s)
}
__setup("notsc", notsc_setup);
+
+
+/* clock source code: */
+
+static unsigned long current_tsc_khz = 0;
+
+static int tsc_update_callback(void);
+
+static cycle_t read_tsc(void)
+{
+ cycle_t ret;
+ rdtscll(ret);
+ return ret;
+}
+
+static struct clocksource clocksource_tsc = {
+ .name = "tsc",
+ .rating = 300,
+ .read = read_tsc,
+ .mask = (cycle_t)-1,
+ .mult = 0, /* to be set */
+ .shift = 22,
+ .update_callback = tsc_update_callback,
+ .is_continuous = 1,
+};
+
+static int tsc_update_callback(void)
+{
+ int change = 0;
+
+ /* check to see if we should switch to the safe clocksource: */
+ if (clocksource_tsc.rating != 50 && check_tsc_unstable()) {
+ clocksource_tsc.rating = 50;
+ clocksource_reselect();
+ change = 1;
+ }
+
+ /* only update if tsc_khz has changed: */
+ if (current_tsc_khz != tsc_khz){
+ current_tsc_khz = tsc_khz;
+ clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
+ clocksource_tsc.shift);
+ change = 1;
+ }
+ return change;
+}
+
+static int __init init_tsc_clocksource(void)
+{
+ if (!notsc && tsc_khz) {
+ current_tsc_khz = tsc_khz;
+ clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
+ clocksource_tsc.shift);
+ return clocksource_register(&clocksource_tsc);
+ }
+ return 0;
+}
+
+module_init(init_tsc_clocksource);
+
+
+#define HPET_MASK 0xFFFFFFFF
+#define HPET_SHIFT 22
+
+/* FSEC = 10^-15 NSEC = 10^-9 */
+#define FSEC_PER_NSEC 1000000
+
+static void *hpet_ptr;
+
+static cycle_t read_hpet(void)
+{
+ return (cycle_t)readl(hpet_ptr);
+}
+
+struct clocksource clocksource_hpet = {
+ .name = "hpet",
+ .rating = 250,
+ .read = read_hpet,
+ .mask = (cycle_t)HPET_MASK,
+ .mult = 0, /* set below */
+ .shift = HPET_SHIFT,
+ .is_continuous = 1,
+};
+
+static int __init init_hpet_clocksource(void)
+{
+ unsigned long hpet_period;
+ void __iomem *hpet_base;
+ u64 tmp;
+
+ if (!hpet_address)
+ return -ENODEV;
+
+ /* calculate the hpet address: */
+ hpet_base =
+ (void __iomem*)ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
+ hpet_ptr = hpet_base + HPET_COUNTER;
+
+ /* calculate the frequency: */
+ hpet_period = readl(hpet_base + HPET_PERIOD);
+
+ /*
+ * hpet period is in femto seconds per cycle
+ * so we need to convert this to ns/cyc units
+ * aproximated by mult/2^shift
+ *
+ * fsec/cyc * 1nsec/1000000fsec = nsec/cyc = mult/2^shift
+ * fsec/cyc * 1ns/1000000fsec * 2^shift = mult
+ * fsec/cyc * 2^shift * 1nsec/1000000fsec = mult
+ * (fsec/cyc << shift)/1000000 = mult
+ * (hpet_period << shift)/FSEC_PER_NSEC = mult
+ */
+ tmp = (u64)hpet_period << HPET_SHIFT;
+ do_div(tmp, FSEC_PER_NSEC);
+ clocksource_hpet.mult = (u32)tmp;
+
+ return clocksource_register(&clocksource_hpet);
+}
+
+module_init(init_hpet_clocksource);
diff --git a/include/asm-x86_64/timex.h b/include/asm-x86_64/timex.h
index b9e5320..11c6820 100644
--- a/include/asm-x86_64/timex.h
+++ b/include/asm-x86_64/timex.h
@@ -40,6 +40,9 @@ static __always_inline cycles_t get_cycl
}
extern unsigned int cpu_khz;
+extern unsigned int tsc_khz;
+
+extern void mark_tsc_unstable(void);
extern int read_current_timer(unsigned long *timer_value);
#define ARCH_HAS_READ_CURRENT_TIMER 1
^ permalink raw reply related [flat|nested] 18+ messages in thread* Re: [RFC][PATCH 5/6] x86_64: Clocksources for x86-64
2006-08-09 2:17 ` [RFC][PATCH 5/6] x86_64: Clocksources for x86-64 john stultz
@ 2006-08-09 2:41 ` Andi Kleen
2006-08-09 3:41 ` john stultz
0 siblings, 1 reply; 18+ messages in thread
From: Andi Kleen @ 2006-08-09 2:41 UTC (permalink / raw)
To: john stultz; +Cc: linux-kernel
On Wednesday 09 August 2006 04:17, john stultz wrote:
> Re-add TSC and HPET support to x86_64 via clocksource infrastructure.
The actual review needed is in the existing clock source drivers
I guess.
I definitely don't want the "read three times" pmtimer code that
is in the generic clock source on 64bit. You would need at least an ifdef
there or better detect the case where it is needed at runtime.
> -unsigned int cpu_khz; /* TSC clocks / usec, not used here */
> +unsigned int cpu_khz; /* CPU clocks / usec, not used here */
The previous comment was more correct. It is really TSC clocks.
> EXPORT_SYMBOL(cpu_khz);
> +unsigned int tsc_khz; /* TSC clocks / usec, not used here */
And that comment can't have the same unit as the earlier one?
> +/* clock source code: */
> +
> +static unsigned long current_tsc_khz = 0;
Another one? Don't we have already too many of these variables?
> +
> +static int tsc_update_callback(void);
> +
> +static cycle_t read_tsc(void)
> +{
> + cycle_t ret;
> + rdtscll(ret);
It would need to be _sync
> +
> + /* only update if tsc_khz has changed: */
> + if (current_tsc_khz != tsc_khz){
> + current_tsc_khz = tsc_khz;
> + clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
> + clocksource_tsc.shift);
> + change = 1;
> + }
Are you sure this handles p-state invariant TSC correctly?
And I hope there is a printk somewhere when this happens?
> + return change;
> +}
> +
> +static int __init init_tsc_clocksource(void)
> +{
> + if (!notsc && tsc_khz) {
How can tsc_khz be 0 ?
> + current_tsc_khz = tsc_khz;
> + clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
> + clocksource_tsc.shift);
> + return clocksource_register(&clocksource_tsc);
> + }
> + return 0;
> +}
> +
> +module_init(init_tsc_clocksource);
So what clocksource does it use before?
BTW I guess i would be ok with putting tsc and hpet into their own files.
And is there a reason HPET can't be generic in drivers/clocksource now?
> +
> +
> +#define HPET_MASK 0xFFFFFFFF
> +#define HPET_SHIFT 22
> +
> +/* FSEC = 10^-15 NSEC = 10^-9 */
> +#define FSEC_PER_NSEC 1000000
> +
> +static void *hpet_ptr;
> +
> +static cycle_t read_hpet(void)
> +{
> + return (cycle_t)readl(hpet_ptr);
No 64bit HPET support?
> +}
> +
> +struct clocksource clocksource_hpet = {
> + .name = "hpet",
> + .rating = 250,
> + .read = read_hpet,
> + .mask = (cycle_t)HPET_MASK,
> + .mult = 0, /* set below */
> + .shift = HPET_SHIFT,
> + .is_continuous = 1,
> +};
How is priority of the different time sources established in this?
e.g. is the old fallback selection logic still fully functional?
-Andi
^ permalink raw reply [flat|nested] 18+ messages in thread* Re: [RFC][PATCH 5/6] x86_64: Clocksources for x86-64
2006-08-09 2:41 ` Andi Kleen
@ 2006-08-09 3:41 ` john stultz
0 siblings, 0 replies; 18+ messages in thread
From: john stultz @ 2006-08-09 3:41 UTC (permalink / raw)
To: Andi Kleen; +Cc: linux-kernel
On Wed, 2006-08-09 at 04:41 +0200, Andi Kleen wrote:
> On Wednesday 09 August 2006 04:17, john stultz wrote:
> > Re-add TSC and HPET support to x86_64 via clocksource infrastructure.
>
> The actual review needed is in the existing clock source drivers
> I guess.
Well, the acpi_pm is the only x86-64/i386 generic clocksource, so yes,
please look that one over if you have a chance.
> I definitely don't want the "read three times" pmtimer code that
> is in the generic clock source on 64bit. You would need at least an ifdef
> there or better detect the case where it is needed at runtime.
We do have blacklist detection enabled, and by default it does only a
single read.
>
> > -unsigned int cpu_khz; /* TSC clocks / usec, not used here */
> > +unsigned int cpu_khz; /* CPU clocks / usec, not used here */
>
> The previous comment was more correct. It is really TSC clocks.
Well, I'm trying to clean up the cpu_khz to be a cpufreq rating so the
scheduler can make better decisions, while still having a constant
tsc_khz on systems that do not change freq. This change can be thrown
out, or atleast delayed if its an issue.
>
> > EXPORT_SYMBOL(cpu_khz);
> > +unsigned int tsc_khz; /* TSC clocks / usec, not used here */
>
> And that comment can't have the same unit as the earlier one?
> > +/* clock source code: */
> > +
> > +static unsigned long current_tsc_khz = 0;
>
> Another one? Don't we have already too many of these variables?
Heh. :) That one is specific to the TSC clocksource, which can only
change state during an update_callback(). But yes, its unclear and could
use a name-change and/or just be static to tsc_update_callback()
> > +
> > +static int tsc_update_callback(void);
> > +
> > +static cycle_t read_tsc(void)
> > +{
> > + cycle_t ret;
> > + rdtscll(ret);
>
> It would need to be _sync
Good point.
> > +
> > + /* only update if tsc_khz has changed: */
> > + if (current_tsc_khz != tsc_khz){
> > + current_tsc_khz = tsc_khz;
> > + clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
> > + clocksource_tsc.shift);
> > + change = 1;
> > + }
>
> Are you sure this handles p-state invariant TSC correctly?
It should, as the tsc_khz won't be changed on those systems.
> And I hope there is a printk somewhere when this happens?
Maybe a BUGON would be the right thing if the TSC is p-state invariant?
> > + return change;
> > +}
> > +
> > +static int __init init_tsc_clocksource(void)
> > +{
> > + if (!notsc && tsc_khz) {
>
> How can tsc_khz be 0 ?
In the case that cpu_khz is zero. Hmmm, that be an i386-ism that slipped
in. I'll look into it.
> > + current_tsc_khz = tsc_khz;
> > + clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
> > + clocksource_tsc.shift);
> > + return clocksource_register(&clocksource_tsc);
> > + }
> > + return 0;
> > +}
> > +
> > +module_init(init_tsc_clocksource);
>
> So what clocksource does it use before?
In early boot, the jiffies clocksource is used until the clocksource
drivers are registered.
> BTW I guess i would be ok with putting tsc and hpet into their own files.
Great, I actually prefer that, but I didn't want to change too much
right off.
> And is there a reason HPET can't be generic in drivers/clocksource now?
Nope. Thomas and Ingo suggested the clocksource drivers should be arch
specific, but hpet has been generic before.
We'll still likely need an arch/x86_64/hpet.c for the differences in the
HPET interrupt bits between i386/x86_64, but those could be combined at
some point (also ia64 will be interested in the same bits).
> > +#define HPET_MASK 0xFFFFFFFF
> > +#define HPET_SHIFT 22
> > +
> > +/* FSEC = 10^-15 NSEC = 10^-9 */
> > +#define FSEC_PER_NSEC 1000000
> > +
> > +static void *hpet_ptr;
> > +
> > +static cycle_t read_hpet(void)
> > +{
> > + return (cycle_t)readl(hpet_ptr);
>
> No 64bit HPET support?
For no reason I can recall. Its probably a leftover from the i386/x86_64
shared hpet driver.
> > +}
> > +
> > +struct clocksource clocksource_hpet = {
> > + .name = "hpet",
> > + .rating = 250,
> > + .read = read_hpet,
> > + .mask = (cycle_t)HPET_MASK,
> > + .mult = 0, /* set below */
> > + .shift = HPET_SHIFT,
> > + .is_continuous = 1,
> > +};
>
> How is priority of the different time sources established in this?
Via the rating value above.
> e.g. is the old fallback selection logic still fully functional?
Yep, the only complication is when the TSC is marked unstable (using the
same logic as before) and we fall back to the next best clocksource
(HPET, then ACPI PM).
Once again, I really appreciate your time reviewing this!
I'll fix up the issues you pointed for the next release.
thanks
-john
^ permalink raw reply [flat|nested] 18+ messages in thread
* [RFC][PATCH 6/6] x86_64: GENERIC_TIME based vsyscall code
2006-08-09 2:17 [RFC][PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
` (4 preceding siblings ...)
2006-08-09 2:17 ` [RFC][PATCH 5/6] x86_64: Clocksources for x86-64 john stultz
@ 2006-08-09 2:17 ` john stultz
2006-08-09 2:45 ` Andi Kleen
2006-08-09 2:41 ` [RFC][PATCH 0/6] x86_64: Generic timekeeping for x86_64 Andi Kleen
6 siblings, 1 reply; 18+ messages in thread
From: john stultz @ 2006-08-09 2:17 UTC (permalink / raw)
To: ak; +Cc: john stultz, linux-kernel
Re-enable vsyscall gettimeofday using the generic clocksource
infrastructure.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
arch/x86_64/Kconfig | 4 +
arch/x86_64/kernel/time.c | 23 +++++--
arch/x86_64/kernel/vmlinux.lds.S | 24 +-------
arch/x86_64/kernel/vsyscall.c | 116 ++++++++++++++++++++++++++-------------
include/asm-x86_64/proto.h | 2
include/asm-x86_64/timex.h | 2
include/asm-x86_64/vsyscall.h | 38 +-----------
7 files changed, 105 insertions(+), 104 deletions(-)
linux-2.6.18-rc4_timeofday-arch-x86-64-part5_C5.patch
============================================
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index fabb174..6167ce2 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -28,6 +28,10 @@ config GENERIC_TIME
bool
default y
+config GENERIC_TIME_VSYSCALL
+ bool
+ default y
+
config LOCKDEP_SUPPORT
bool
default y
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index 546abc7..3501871 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -68,16 +68,9 @@ unsigned long hpet_address;
static unsigned long hpet_period; /* fsecs / HPET clock */
unsigned long hpet_tick; /* HPET clocks / interrupt */
int hpet_use_timer; /* Use counter of hpet for time keeping, otherwise PIT */
-unsigned long vxtime_hz = PIT_TICK_RATE;
int report_lost_ticks; /* command line option */
-unsigned long long monotonic_base;
-struct vxtime_data __vxtime __section_vxtime; /* for vsyscalls */
-
-volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES;
-unsigned long __wall_jiffies __section_wall_jiffies = INITIAL_JIFFIES;
-struct timespec __xtime __section_xtime;
-struct timezone __sys_tz __section_sys_tz;
+volatile unsigned long jiffies = INITIAL_JIFFIES;
unsigned long profile_pc(struct pt_regs *regs)
{
@@ -1021,6 +1014,13 @@ static cycle_t read_tsc(void)
return ret;
}
+static cycle_t __vsyscall_fn vread_tsc(void)
+{
+ cycle_t ret;
+ rdtscll(ret);
+ return ret;
+}
+
static struct clocksource clocksource_tsc = {
.name = "tsc",
.rating = 300,
@@ -1030,6 +1030,7 @@ static struct clocksource clocksource_ts
.shift = 22,
.update_callback = tsc_update_callback,
.is_continuous = 1,
+ .vread = vread_tsc,
};
static int tsc_update_callback(void)
@@ -1080,6 +1081,11 @@ static cycle_t read_hpet(void)
return (cycle_t)readl(hpet_ptr);
}
+static cycle_t __vsyscall_fn vread_hpet(void)
+{
+ return (cycle_t)readl((void *)fix_to_virt(VSYSCALL_HPET) + 0xf0);
+}
+
struct clocksource clocksource_hpet = {
.name = "hpet",
.rating = 250,
@@ -1088,6 +1094,7 @@ struct clocksource clocksource_hpet = {
.mult = 0, /* set below */
.shift = HPET_SHIFT,
.is_continuous = 1,
+ .vread = vread_hpet,
};
static int __init init_hpet_clocksource(void)
diff --git a/arch/x86_64/kernel/vmlinux.lds.S b/arch/x86_64/kernel/vmlinux.lds.S
index 7c4de31..9e7c048 100644
--- a/arch/x86_64/kernel/vmlinux.lds.S
+++ b/arch/x86_64/kernel/vmlinux.lds.S
@@ -93,27 +93,11 @@ SECTIONS
__vsyscall_0 = VSYSCALL_VIRT_ADDR;
. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
- .xtime_lock : AT(VLOAD(.xtime_lock)) { *(.xtime_lock) }
- xtime_lock = VVIRT(.xtime_lock);
-
- .vxtime : AT(VLOAD(.vxtime)) { *(.vxtime) }
- vxtime = VVIRT(.vxtime);
-
- .wall_jiffies : AT(VLOAD(.wall_jiffies)) { *(.wall_jiffies) }
- wall_jiffies = VVIRT(.wall_jiffies);
-
- .sys_tz : AT(VLOAD(.sys_tz)) { *(.sys_tz) }
- sys_tz = VVIRT(.sys_tz);
-
- .sysctl_vsyscall : AT(VLOAD(.sysctl_vsyscall)) { *(.sysctl_vsyscall) }
- sysctl_vsyscall = VVIRT(.sysctl_vsyscall);
-
- .xtime : AT(VLOAD(.xtime)) { *(.xtime) }
- xtime = VVIRT(.xtime);
-
+ .vsyscall_fn : AT(VLOAD(.vsyscall_fn)) { *(.vsyscall_fn) }
. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
- .jiffies : AT(VLOAD(.jiffies)) { *(.jiffies) }
- jiffies = VVIRT(.jiffies);
+ .vsyscall_gtod_data : AT(VLOAD(.vsyscall_gtod_data)) { *(.vsyscall_gtod_data) }
+ vsyscall_gtod_data = VVIRT(.vsyscall_gtod_data);
+
.vsyscall_1 ADDR(.vsyscall_0) + 1024: AT(VLOAD(.vsyscall_1)) { *(.vsyscall_1) }
.vsyscall_2 ADDR(.vsyscall_0) + 2048: AT(VLOAD(.vsyscall_2)) { *(.vsyscall_2) }
diff --git a/arch/x86_64/kernel/vsyscall.c b/arch/x86_64/kernel/vsyscall.c
index f603037..cdd8448 100644
--- a/arch/x86_64/kernel/vsyscall.c
+++ b/arch/x86_64/kernel/vsyscall.c
@@ -26,65 +26,105 @@
#include <linux/seqlock.h>
#include <linux/jiffies.h>
#include <linux/sysctl.h>
+#include <linux/clocksource.h>
#include <asm/vsyscall.h>
#include <asm/pgtable.h>
#include <asm/page.h>
+#include <asm/unistd.h>
#include <asm/fixmap.h>
#include <asm/errno.h>
#include <asm/io.h>
#define __vsyscall(nr) __attribute__ ((unused,__section__(".vsyscall_" #nr)))
-int __sysctl_vsyscall __section_sysctl_vsyscall = 1;
-seqlock_t __xtime_lock __section_xtime_lock = SEQLOCK_UNLOCKED;
+struct vsyscall_gtod_data_t {
+ seqlock_t lock;
+ int sysctl_enabled;
+ struct timeval wall_time_tv;
+ struct timezone sys_tz;
+ cycle_t offset_base;
+ struct clocksource clock;
+};
+
+struct vsyscall_gtod_data_t __vsyscall_gtod_data __section_vsyscall_gtod_data = {
+ .lock = SEQLOCK_UNLOCKED,
+ .sysctl_enabled = 1,
+};
+extern struct vsyscall_gtod_data_t vsyscall_gtod_data;
-#include <asm/unistd.h>
-static __always_inline void timeval_normalize(struct timeval * tv)
+void update_vsyscall(struct timespec* wall_time, struct clocksource* clock)
{
- time_t __sec;
+ unsigned long flags;
- __sec = tv->tv_usec / 1000000;
- if (__sec) {
- tv->tv_usec %= 1000000;
- tv->tv_sec += __sec;
- }
+ write_seqlock_irqsave(&vsyscall_gtod_data.lock, flags);
+ /* copy vsyscall data */
+ vsyscall_gtod_data.clock = *clock;
+ vsyscall_gtod_data.wall_time_tv.tv_sec = wall_time->tv_sec;
+ vsyscall_gtod_data.wall_time_tv.tv_usec = wall_time->tv_nsec/1000;
+ vsyscall_gtod_data.sys_tz = sys_tz;
+
+ write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags);
+}
+
+/*
+ * XXX - this is ugly. gettimeofday() has a label in it so we can't
+ * call it twice.
+ */
+static __always_inline int syscall_gtod(struct timeval *tv, struct timezone *tz)
+{
+ int ret;
+
+ asm volatile("syscall"
+ : "=a" (ret)
+ : "0" (__NR_gettimeofday),"D" (tv),"S" (tz)
+ : __syscall_clobber);
+
+ return ret;
}
+
static __always_inline void do_vgettimeofday(struct timeval * tv)
{
- long sequence, t;
- unsigned long sec, usec;
+ cycle_t now, base, mask, cycle_delta;
+ unsigned long seq, mult, shift, nsec_delta;
do {
- sequence = read_seqbegin(&__xtime_lock);
-
- sec = __xtime.tv_sec;
- usec = (__xtime.tv_nsec / 1000) +
- (__jiffies - __wall_jiffies) * (1000000 / HZ);
-
- if (__vxtime.mode != VXTIME_HPET) {
- 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 *)fix_to_virt(VSYSCALL_HPET) + 0xf0) -
- __vxtime.last) * __vxtime.quot) >> 32;
+ seq = read_seqbegin(&__vsyscall_gtod_data.lock);
+ if (!__vsyscall_gtod_data.clock.vread) {
+ syscall_gtod(tv, NULL);
+ return;
}
- } while (read_seqretry(&__xtime_lock, sequence));
- tv->tv_sec = sec + usec / 1000000;
- tv->tv_usec = usec % 1000000;
+ now = __vsyscall_gtod_data.clock.vread();
+
+ base = __vsyscall_gtod_data.clock.cycle_last;
+ mask = __vsyscall_gtod_data.clock.mask;
+ mult = __vsyscall_gtod_data.clock.mult;
+ shift = __vsyscall_gtod_data.clock.shift;
+
+ *tv = __vsyscall_gtod_data.wall_time_tv;
+
+ } while (read_seqretry(&__vsyscall_gtod_data.lock, seq));
+
+ /* calculate interval: */
+ cycle_delta = (now - base) & mask;
+ /* convert to nsecs: */
+ nsec_delta = (cycle_delta * mult) >> shift;
+
+ /* convert to usecs and add to timespec: */
+ tv->tv_usec += nsec_delta / NSEC_PER_USEC;
+ while (tv->tv_usec > USEC_PER_SEC) {
+ tv->tv_sec += 1;
+ tv->tv_usec -= USEC_PER_SEC;
+ }
}
/* RED-PEN may want to readd seq locking, but then the variable should be write-once. */
static __always_inline void do_get_tz(struct timezone * tz)
{
- *tz = __sys_tz;
+ *tz = __vsyscall_gtod_data.sys_tz;
}
static __always_inline int gettimeofday(struct timeval *tv, struct timezone *tz)
@@ -107,7 +147,7 @@ static __always_inline long time_syscall
int __vsyscall(0) vgettimeofday(struct timeval * tv, struct timezone * tz)
{
- if (!__sysctl_vsyscall)
+ if (unlikely(!__vsyscall_gtod_data.sysctl_enabled))
return gettimeofday(tv,tz);
if (tv)
do_vgettimeofday(tv);
@@ -120,11 +160,11 @@ int __vsyscall(0) vgettimeofday(struct t
* unlikely */
time_t __vsyscall(1) vtime(time_t *t)
{
- if (!__sysctl_vsyscall)
+ if (unlikely(!__vsyscall_gtod_data.sysctl_enabled))
return time_syscall(t);
else if (t)
- *t = __xtime.tv_sec;
- return __xtime.tv_sec;
+ *t = __vsyscall_gtod_data.wall_time_tv.tv_sec;
+ return __vsyscall_gtod_data.wall_time_tv.tv_sec;
}
long __vsyscall(2) venosys_0(void)
@@ -163,7 +203,7 @@ static int vsyscall_sysctl_change(ctl_ta
ret = -ENOMEM;
goto out;
}
- if (!sysctl_vsyscall) {
+ if (!vsyscall_gtod_data.sysctl_enabled) {
*map1 = SYSCALL;
*map2 = SYSCALL;
} else {
@@ -186,7 +226,7 @@ static int vsyscall_sysctl_nostrat(ctl_t
static ctl_table kernel_table2[] = {
{ .ctl_name = 99, .procname = "vsyscall64",
- .data = &sysctl_vsyscall, .maxlen = sizeof(int), .mode = 0644,
+ .data = &vsyscall_gtod_data.sysctl_enabled, .maxlen = sizeof(int), .mode = 0644,
.strategy = vsyscall_sysctl_nostrat,
.proc_handler = vsyscall_sysctl_change },
{ 0, }
diff --git a/include/asm-x86_64/proto.h b/include/asm-x86_64/proto.h
index 716ac55..33d1a19 100644
--- a/include/asm-x86_64/proto.h
+++ b/include/asm-x86_64/proto.h
@@ -47,9 +47,7 @@ extern u32 pmtmr_ioport;
#else
#define pmtmr_ioport 0
#endif
-extern int sysctl_vsyscall;
extern int nohpet;
-extern unsigned long vxtime_hz;
extern int numa_setup(char *opt);
diff --git a/include/asm-x86_64/timex.h b/include/asm-x86_64/timex.h
index 11c6820..043a774 100644
--- a/include/asm-x86_64/timex.h
+++ b/include/asm-x86_64/timex.h
@@ -47,6 +47,4 @@ extern void mark_tsc_unstable(void);
extern int read_current_timer(unsigned long *timer_value);
#define ARCH_HAS_READ_CURRENT_TIMER 1
-extern struct vxtime_data vxtime;
-
#endif
diff --git a/include/asm-x86_64/vsyscall.h b/include/asm-x86_64/vsyscall.h
index a85e16f..0b5a499 100644
--- a/include/asm-x86_64/vsyscall.h
+++ b/include/asm-x86_64/vsyscall.h
@@ -15,49 +15,19 @@ enum vsyscall_num {
#ifdef __KERNEL__
-#define __section_vxtime __attribute__ ((unused, __section__ (".vxtime"), aligned(16)))
-#define __section_wall_jiffies __attribute__ ((unused, __section__ (".wall_jiffies"), aligned(16)))
-#define __section_jiffies __attribute__ ((unused, __section__ (".jiffies"), aligned(16)))
-#define __section_sys_tz __attribute__ ((unused, __section__ (".sys_tz"), aligned(16)))
-#define __section_sysctl_vsyscall __attribute__ ((unused, __section__ (".sysctl_vsyscall"), aligned(16)))
-#define __section_xtime __attribute__ ((unused, __section__ (".xtime"), aligned(16)))
-#define __section_xtime_lock __attribute__ ((unused, __section__ (".xtime_lock"), aligned(16)))
-
-#define VXTIME_TSC 1
-#define VXTIME_HPET 2
-#define VXTIME_PMTMR 3
-
-struct vxtime_data {
- long hpet_address; /* HPET base address */
- int last;
- unsigned long last_tsc;
- long quot;
- long tsc_quot;
- int mode;
-};
+/* Definitions for CONFIG_GENERIC_TIME definitions */
+#define __section_vsyscall_gtod_data __attribute__ ((unused, __section__ (".vsyscall_gtod_data"),aligned(16)))
+#define __vsyscall_fn __attribute__ ((unused,__section__(".vsyscall_fn")))
+
#define hpet_readl(a) readl((const void __iomem *)fix_to_virt(FIX_HPET_BASE) + a)
#define hpet_writel(d,a) writel(d, (void __iomem *)fix_to_virt(FIX_HPET_BASE) + a)
-/* vsyscall space (readonly) */
-extern struct vxtime_data __vxtime;
-extern struct timespec __xtime;
-extern volatile unsigned long __jiffies;
-extern unsigned long __wall_jiffies;
-extern struct timezone __sys_tz;
-extern seqlock_t __xtime_lock;
-
/* kernel space (writeable) */
-extern struct vxtime_data vxtime;
extern unsigned long wall_jiffies;
extern struct timezone sys_tz;
-extern int sysctl_vsyscall;
extern seqlock_t xtime_lock;
-extern int sysctl_vsyscall;
-
-#define ARCH_HAVE_XTIME_LOCK 1
-
#endif /* __KERNEL__ */
#endif /* _ASM_X86_64_VSYSCALL_H_ */
^ permalink raw reply related [flat|nested] 18+ messages in thread* Re: [RFC][PATCH 6/6] x86_64: GENERIC_TIME based vsyscall code
2006-08-09 2:17 ` [RFC][PATCH 6/6] x86_64: GENERIC_TIME based vsyscall code john stultz
@ 2006-08-09 2:45 ` Andi Kleen
0 siblings, 0 replies; 18+ messages in thread
From: Andi Kleen @ 2006-08-09 2:45 UTC (permalink / raw)
To: john stultz; +Cc: linux-kernel
On Wednesday 09 August 2006 04:17, john stultz wrote:
> + cycle_t ret;
> + rdtscll(ret);
_sync
> +static cycle_t __vsyscall_fn vread_hpet(void)
> +{
> + return (cycle_t)readl((void *)fix_to_virt(VSYSCALL_HPET) + 0xf0);
> +}
64bit HPET?
> +extern struct vsyscall_gtod_data_t vsyscall_gtod_data;
No extern in .c please
> +static __always_inline int syscall_gtod(struct timeval *tv, struct timezone *tz)
> +{
> + int ret;
> +
> + asm volatile("syscall"
You eliminated the patching away of the syscall opcode? Please retain that.
> - tv->tv_sec = sec + usec / 1000000;
> - tv->tv_usec = usec % 1000000;
> + now = __vsyscall_gtod_data.clock.vread();
> +
> + base = __vsyscall_gtod_data.clock.cycle_last;
> + mask = __vsyscall_gtod_data.clock.mask;
> + mult = __vsyscall_gtod_data.clock.mult;
> + shift = __vsyscall_gtod_data.clock.shift;
> +
> + *tv = __vsyscall_gtod_data.wall_time_tv;
> +
> + } while (read_seqretry(&__vsyscall_gtod_data.lock, seq));
Do you have benchmarks on performance compared to the old code?
-Andi
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [RFC][PATCH 0/6] x86_64: Generic timekeeping for x86_64
2006-08-09 2:17 [RFC][PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
` (5 preceding siblings ...)
2006-08-09 2:17 ` [RFC][PATCH 6/6] x86_64: GENERIC_TIME based vsyscall code john stultz
@ 2006-08-09 2:41 ` Andi Kleen
2006-08-09 2:48 ` john stultz
6 siblings, 1 reply; 18+ messages in thread
From: Andi Kleen @ 2006-08-09 2:41 UTC (permalink / raw)
To: john stultz; +Cc: linux-kernel
On Wednesday 09 August 2006 04:17, john stultz wrote:
> Hey Andi,
> Just wanted to send this by as a first pass on the x86_64
> generic timekeeping conversion. If you have the time, a quick review
> and comments would be greatly appreciated.
Ok, but it's more 2.6.20 material
-Andi
^ permalink raw reply [flat|nested] 18+ messages in thread