From: john stultz <johnstul@us.ibm.com>
On Fri, 2003-11-21 at 11:53, Andrew Morton wrote:
> > Also, I was going to sync up w/ you today and send you my latest version
> > to reduce the number of little fix patches you have to manage, but if
> > you'd prefer I can do that after I track down the issue you're seeing.
>
> OK, I'll do mm5 this afternoon. I'll be out of town this weekend, then out
> of the country from Nov27->Dec14 so I'm likely to be even less than usually
> useful for some time.
Here it is then.
This patch depends on Dominik Brodowski's "acpi-pm-timer" patch found in
mm4. It fixes a compile bug, cleans up the math, adds lost-tick
compensation and monotonic_clock, fixes a bug in the ACPI table mapping
and moves the config option under the ACPI menu. Additionally the patch
includes additional fixes found during testing in -mm3 and -mm4.
This patch replaces the following broken out patches from -mm4:
acpi-pm-timer-fixes.patch
acpi-pm_timer-init-cpu_khz.patch
timer_pm-fix-fix-fix.patch
Many thanks to Dominik for the great work, and Thomas Schlichter for the
excellent bug hunting!
Documentation/kernel-parameters.txt | 2
arch/i386/Kconfig | 18 -----
arch/i386/kernel/acpi/boot.c | 10 ++-
arch/i386/kernel/timers/common.c | 20 ++++++
arch/i386/kernel/timers/timer_cyclone.c | 21 ------
arch/i386/kernel/timers/timer_pm.c | 105 +++++++++++++++++++++++++-------
drivers/acpi/Kconfig | 18 +++++
include/asm-i386/timer.h | 1
8 files changed, 132 insertions(+), 63 deletions(-)
diff -puN arch/i386/Kconfig~acpi-pm-timer-fixes-2 arch/i386/Kconfig
--- 25/arch/i386/Kconfig~acpi-pm-timer-fixes-2 2003-11-21 13:04:40.000000000 -0800
+++ 25-akpm/arch/i386/Kconfig 2003-11-21 13:04:40.000000000 -0800
@@ -411,24 +411,6 @@ config HPET_TIMER
config HPET_EMULATE_RTC
def_bool HPET_TIMER && RTC=y
-config X86_PM_TIMER
- bool "Power Management Timer Support"
- depends on (!X86_VISWS && !X86_VISWS) && EXPERIMENTAL
- default n
- help
- The Power Management Timer is available on all ACPI-capable,
- in most cases even if ACPI is unusable or blacklisted.
-
- This timing source is not affected by powermanagement features
- like aggressive processor idling, throttling, frequency and/or
- voltage scaling, unlike the commonly used Time Stamp Counter
- (TSC) timing source.
-
- So, if you see messages like 'Losing too many ticks!' in the
- kernel logs, and/or you are using a this on a notebook which
- does not yet have an HPET (see above), you should say "Y"
- here. Otherwise, say "N".
-
config SMP
bool "Symmetric multi-processing support"
---help---
diff -puN arch/i386/kernel/acpi/boot.c~acpi-pm-timer-fixes-2 arch/i386/kernel/acpi/boot.c
--- 25/arch/i386/kernel/acpi/boot.c~acpi-pm-timer-fixes-2 2003-11-21 13:04:40.000000000 -0800
+++ 25-akpm/arch/i386/kernel/acpi/boot.c 2003-11-21 13:04:40.000000000 -0800
@@ -327,15 +327,19 @@ static int __init acpi_parse_hpet(unsign
}
#endif
-/* detect the location of the ACPI PM Timer
+/* detect the location of the ACPI PM Timer */
#ifdef CONFIG_X86_PM_TIMER
extern u32 pmtmr_ioport;
static int __init acpi_parse_fadt(unsigned long phys, unsigned long size)
{
- struct fadt_descriptor_rev2 *fadt;
+ struct fadt_descriptor_rev2 *fadt =0;
- fadt = __va(phys);
+ fadt = (struct fadt_descriptor_rev2*) __acpi_map_table(phys,size);
+ if(!fadt) {
+ printk(KERN_WARNING PREFIX "Unable to map FADT\n");
+ return 0;
+ }
if (fadt->revision >= FADT2_REVISION_ID) {
/* FADT rev. 2 */
diff -puN arch/i386/kernel/timers/common.c~acpi-pm-timer-fixes-2 arch/i386/kernel/timers/common.c
--- 25/arch/i386/kernel/timers/common.c~acpi-pm-timer-fixes-2 2003-11-21 13:04:40.000000000 -0800
+++ 25-akpm/arch/i386/kernel/timers/common.c 2003-11-21 13:04:40.000000000 -0800
@@ -137,3 +137,23 @@ bad_calibration:
}
#endif
+/* calculate cpu_khz */
+void __init init_cpu_khz(void)
+{
+ if (cpu_has_tsc) {
+ unsigned long tsc_quotient = calibrate_tsc();
+ if (tsc_quotient) {
+ /* report CPU clock rate in Hz.
+ * The formula is (10^6 * 2^32) / (2^32 * 1 / (clocks/us)) =
+ * clock/second. Our precision is about 100 ppm.
+ */
+ { unsigned long eax=0, edx=1000;
+ __asm__("divl %2"
+ :"=a" (cpu_khz), "=d" (edx)
+ :"r" (tsc_quotient),
+ "0" (eax), "1" (edx));
+ printk("Detected %lu.%03lu MHz processor.\n", cpu_khz / 1000, cpu_khz % 1000);
+ }
+ }
+ }
+}
diff -puN arch/i386/kernel/timers/timer_cyclone.c~acpi-pm-timer-fixes-2 arch/i386/kernel/timers/timer_cyclone.c
--- 25/arch/i386/kernel/timers/timer_cyclone.c~acpi-pm-timer-fixes-2 2003-11-21 13:04:40.000000000 -0800
+++ 25-akpm/arch/i386/kernel/timers/timer_cyclone.c 2003-11-21 13:04:40.000000000 -0800
@@ -212,26 +212,7 @@ static int __init init_cyclone(char* ove
}
}
- /* init cpu_khz.
- * XXX - This should really be done elsewhere,
- * and in a more generic fashion. -johnstul@us.ibm.com
- */
- if (cpu_has_tsc) {
- unsigned long tsc_quotient = calibrate_tsc();
- if (tsc_quotient) {
- /* report CPU clock rate in Hz.
- * The formula is (10^6 * 2^32) / (2^32 * 1 / (clocks/us)) =
- * clock/second. Our precision is about 100 ppm.
- */
- { unsigned long eax=0, edx=1000;
- __asm__("divl %2"
- :"=a" (cpu_khz), "=d" (edx)
- :"r" (tsc_quotient),
- "0" (eax), "1" (edx));
- printk("Detected %lu.%03lu MHz processor.\n", cpu_khz / 1000, cpu_khz % 1000);
- }
- }
- }
+ init_cpu_khz();
/* Everything looks good! */
return 0;
diff -puN arch/i386/kernel/timers/timer_pm.c~acpi-pm-timer-fixes-2 arch/i386/kernel/timers/timer_pm.c
--- 25/arch/i386/kernel/timers/timer_pm.c~acpi-pm-timer-fixes-2 2003-11-21 13:04:40.000000000 -0800
+++ 25-akpm/arch/i386/kernel/timers/timer_pm.c 2003-11-21 13:04:40.000000000 -0800
@@ -30,7 +30,12 @@ u32 pmtmr_ioport = 0;
/* value of the Power timer at last timer interrupt */
static u32 offset_tick;
+static u32 offset_delay;
+static unsigned long long monotonic_base;
+static seqlock_t monotonic_lock = SEQLOCK_UNLOCKED;
+
+#define ACPI_PM_MASK 0xFFFFFF /* limit it to 24 bits */
static int init_pmtmr(char* override)
{
@@ -45,41 +50,109 @@ static int init_pmtmr(char* override)
/* "verify" this timing source */
value1 = inl(pmtmr_ioport);
- value1 &= 0xFFFFFF;
+ value1 &= ACPI_PM_MASK;
for (i=0; i < 10000; i++) {
value2 = inl(pmtmr_ioport);
- value2 &= 0xFFFFFF;
+ value2 &= ACPI_PM_MASK;
if (value2 == value1)
continue;
if (value2 > value1)
- return 0;
+ goto pm_good;
if ((value2 < value1) && ((value2) < 0xFFF))
- return 0;
+ goto pm_good;
printk(KERN_INFO "PM-Timer had inconsistent results: 0x%#x, 0x%#x - aborting.\n", value1, value2);
return -EINVAL;
}
printk(KERN_INFO "PM-Timer had no reasonable result: 0x%#x - aborting.\n", value1);
return -ENODEV;
+
+pm_good:
+ init_cpu_khz();
+ return 0;
}
+static inline u32 cyc2us(u32 cycles)
+{
+ /* The Power Management Timer ticks at 3.579545 ticks per microsecond.
+ * 1 / PM_TIMER_FREQUENCY == 0.27936511 =~ 286/1024 [error: 0.024%]
+ *
+ * Even with HZ = 100, delta is at maximum 35796 ticks, so it can
+ * easily be multiplied with 286 (=0x11E) without having to fear
+ * u32 overflows.
+ */
+ cycles *= 286;
+ return (cycles >> 10);
+}
/*
* this gets called during each timer interrupt
+ * - Called while holding the writer xtime_lock
*/
static void mark_offset_pmtmr(void)
{
+ u32 lost, delta, last_offset;
+ static int first_run = 1;
+ last_offset = offset_tick;
+
+ write_seqlock(&monotonic_lock);
+
offset_tick = inl(pmtmr_ioport);
- offset_tick &= 0xFFFFFF; /* limit it to 24 bits */
+ offset_tick &= ACPI_PM_MASK; /* limit it to 24 bits */
+
+ /* calculate tick interval */
+ delta = (offset_tick - last_offset) & ACPI_PM_MASK;
+
+ /* convert to usecs */
+ delta = cyc2us(delta);
+
+ /* update the monotonic base value */
+ monotonic_base += delta*NSEC_PER_USEC;
+ write_sequnlock(&monotonic_lock);
+
+ /* convert to ticks */
+ delta += offset_delay;
+ lost = delta/(USEC_PER_SEC/HZ);
+ offset_delay = delta%(USEC_PER_SEC/HZ);
+
+
+ /* compensate for lost ticks */
+ if (lost >= 2)
+ jiffies += lost - 1;
+
+ /* don't calculate delay for first run,
+ or if we've got less then a tick */
+ if (first_run || (lost < 1)) {
+ first_run = 0;
+ offset_delay = 0;
+ }
+
return;
}
static unsigned long long monotonic_clock_pmtmr(void)
{
- return 0;
+ u32 last_offset, this_offset;
+ unsigned long long base, ret;
+ unsigned seq;
+
+
+ /* atomically read monotonic base & last_offset */
+ do {
+ seq = read_seqbegin(&monotonic_lock);
+ last_offset = offset_tick;
+ base = monotonic_base;
+ } while (read_seqretry(&monotonic_lock, seq));
+
+ /* Read the pmtmr */
+ this_offset = inl(pmtmr_ioport) & ACPI_PM_MASK;
+
+ /* convert to nanoseconds */
+ ret = (this_offset - last_offset) & ACPI_PM_MASK;
+ ret = base + (cyc2us(ret)*NSEC_PER_USEC);
+ return ret;
}
-
/*
* copied from delay_pit
*/
@@ -99,6 +172,7 @@ static void delay_pmtmr(unsigned long lo
/*
* get the offset (in microseconds) from the last call to mark_offset()
+ * - Called holding a reader xtime_lock
*/
static unsigned long get_offset_pmtmr(void)
{
@@ -106,21 +180,10 @@ static unsigned long get_offset_pmtmr(vo
offset = offset_tick;
now = inl(pmtmr_ioport);
- now &= 0xFFFFFF;
- if (likely(offset < now))
- delta = now - offset;
- else if (offset > now)
- delta = (0xFFFFFF - offset) + now;
+ now &= ACPI_PM_MASK;
+ delta = (now - offset)&ACPI_PM_MASK;
- /* The Power Management Timer ticks at 3.579545 ticks per microsecond.
- * 1 / PM_TIMER_FREQUENCY == 0.27936511 =~ 286/1024 [error: 0.024%]
- *
- * Even with HZ = 100, delta is at maximum 35796 ticks, so it can
- * easily be multiplied with 286 (=0x11E) without having to fear
- * u32 overflows.
- */
- delta *= 286;
- return (unsigned long) (delta >> 10);
+ return (unsigned long) offset_delay + cyc2us(delta);
}
diff -puN Documentation/kernel-parameters.txt~acpi-pm-timer-fixes-2 Documentation/kernel-parameters.txt
--- 25/Documentation/kernel-parameters.txt~acpi-pm-timer-fixes-2 2003-11-21 13:04:40.000000000 -0800
+++ 25-akpm/Documentation/kernel-parameters.txt 2003-11-21 13:04:40.000000000 -0800
@@ -214,7 +214,7 @@ running once the system is up.
Forces specified timesource (if avaliable) to be used
when calculating gettimeofday(). If specicified timesource
is not avalible, it defaults to PIT.
- Format: { pit | tsc | cyclone | ... }
+ Format: { pit | tsc | cyclone | pmtmr }
hpet= [IA-32,HPET] option to disable HPET and use PIT.
Format: disable
diff -puN drivers/acpi/Kconfig~acpi-pm-timer-fixes-2 drivers/acpi/Kconfig
--- 25/drivers/acpi/Kconfig~acpi-pm-timer-fixes-2 2003-11-21 13:04:40.000000000 -0800
+++ 25-akpm/drivers/acpi/Kconfig 2003-11-21 13:04:40.000000000 -0800
@@ -263,5 +263,23 @@ config ACPI_RELAXED_AML
particular, many Toshiba laptops require this for correct operation
of the AC module.
+config X86_PM_TIMER
+ bool "Power Management Timer Support"
+ depends on X86 && ACPI
+ depends on ACPI_BOOT && EXPERIMENTAL
+ default n
+ help
+ The Power Management Timer is available on all ACPI-capable,
+ in most cases even if ACPI is unusable or blacklisted.
+
+ This timing source is not affected by powermanagement features
+ like aggressive processor idling, throttling, frequency and/or
+ voltage scaling, unlike the commonly used Time Stamp Counter
+ (TSC) timing source.
+
+ So, if you see messages like 'Losing too many ticks!' in the
+ kernel logs, and/or you are using a this on a notebook which
+ does not yet have an HPET, you should say "Y" here.
+
endmenu
diff -puN include/asm-i386/timer.h~acpi-pm-timer-fixes-2 include/asm-i386/timer.h
--- 25/include/asm-i386/timer.h~acpi-pm-timer-fixes-2 2003-11-21 13:04:40.000000000 -0800
+++ 25-akpm/include/asm-i386/timer.h 2003-11-21 13:04:40.000000000 -0800
@@ -40,6 +40,7 @@ extern struct timer_opts timer_cyclone;
#endif
extern unsigned long calibrate_tsc(void);
+extern void init_cpu_khz(void);
#ifdef CONFIG_HPET_TIMER
extern struct timer_opts timer_hpet;
extern unsigned long calibrate_tsc_hpet(unsigned long *tsc_hpet_quotient_ptr);
_