From db954b5898dd3ef3ef93f4144158ea8f97deb058 Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Mon, 6 Apr 2009 18:51:29 -0700 Subject: x86 ACPI: Add support for Always Running APIC timer Add support for Always Running APIC timer, CPUID_0x6_EAX_Bit2. This bit means the APIC timer continues to run even when CPU is in deep C-states. The advantage is that we can use LAPIC timer on these CPUs always, and there is no need for "slow to read and program" external timers (HPET/PIT) and the timer broadcast logic and related code in C-state entry and exit. Signed-off-by: Venkatesh Pallipadi Acked-by: H. Peter Anvin Signed-off-by: Len Brown --- drivers/acpi/processor_idle.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/acpi/processor_idle.c') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 4e6e758bd39..6fe121434ff 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -145,6 +145,9 @@ static void acpi_timer_check_state(int state, struct acpi_processor *pr, struct acpi_processor_power *pwr = &pr->power; u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2; + if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT)) + return; + /* * Check, if one of the previous states already marked the lapic * unstable -- cgit v1.2.3-70-g09d2 From a71e4917dc0ebbcb5a0ecb7ca3486643c1c9a6e2 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Tue, 21 Apr 2009 00:50:11 -0400 Subject: ACPI: idle: mark_tsc_unstable() at init-time, not run-time The c2 and c3 idle handlers check tsc_halts_in_c() after every time they return from idle. Um, when?:-) Move this check to init-time to remove the unnecessary run-time overhead, and also to have the check complete before the first entry into the idle handler. ff69f2bba67bd45514923aaedbf40fe351787c59 (acpi: fix of pmtimer overflow that make Cx states time incorrect) replaced the hard-coded use of the PM-timer inside idle, with ktime_get_readl(), which possibly uses the TSC -- so it is now especially prudent to detect a broken TSC before entering idle. http://bugzilla.kernel.org/show_bug.cgi?id=13087 Signed-off-by: Len Brown --- drivers/acpi/processor_idle.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) (limited to 'drivers/acpi/processor_idle.c') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 6fe121434ff..9d1f01ee65d 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -581,6 +581,11 @@ static int acpi_processor_power_verify(struct acpi_processor *pr) for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { struct acpi_processor_cx *cx = &pr->power.states[i]; +#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) + /* TSC could halt in idle, so notify users */ + if (tsc_halts_in_c(cx->type)) + mark_tsc_unstable("TSC halts in idle");; +#endif switch (cx->type) { case ACPI_STATE_C1: cx->valid = 1; @@ -871,11 +876,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, kt2 = ktime_get_real(); idle_time = ktime_to_us(ktime_sub(kt2, kt1)); -#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) - /* TSC could halt in idle, so notify users */ - if (tsc_halts_in_c(cx->type)) - mark_tsc_unstable("TSC halts in idle");; -#endif sleep_ticks = us_to_pm_timer_ticks(idle_time); /* Tell the scheduler how much we idled: */ @@ -989,11 +989,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, spin_unlock(&c3_lock); } -#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) - /* TSC could halt in idle, so notify users */ - if (tsc_halts_in_c(ACPI_STATE_C3)) - mark_tsc_unstable("TSC halts in idle"); -#endif sleep_ticks = us_to_pm_timer_ticks(idle_time); /* Tell the scheduler how much we idled: */ sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS); -- cgit v1.2.3-70-g09d2 From 92614610774072ea68131f16e024ee8fc15be9be Mon Sep 17 00:00:00 2001 From: Len Brown Date: Wed, 22 Apr 2009 19:28:15 -0400 Subject: ACPI: delete obsolete "bus master activity" proc field Linux-2.6.29 deleted the legacy ACPI idle handler, leaving the CPU_IDLE handler, which does not track bus master activity. So delete the unused bm_activity field -- it is confusing to print an always zero value. This patch could break programs that parse /proc/acpi/processor/*/power, since it deletes this line from that file: bus master activity: 00000000 http://bugzilla.kernel.org/show_bug.cgi?id=13145 is not fixed by this patch, but provoked this patch. Signed-off-by: Len Brown --- drivers/acpi/processor_idle.c | 4 +--- include/acpi/processor.h | 1 - 2 files changed, 1 insertion(+), 4 deletions(-) (limited to 'drivers/acpi/processor_idle.c') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 9d1f01ee65d..eed3b458eba 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -662,11 +662,9 @@ static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset) seq_printf(seq, "active state: C%zd\n" "max_cstate: C%d\n" - "bus master activity: %08x\n" "maximum allowed latency: %d usec\n", pr->power.state ? pr->power.state - pr->power.states : 0, - max_cstate, (unsigned)pr->power.bm_activity, - pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)); + max_cstate, pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)); seq_puts(seq, "states:\n"); diff --git a/include/acpi/processor.h b/include/acpi/processor.h index b09c4fde972..4927c063347 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -84,7 +84,6 @@ struct acpi_processor_power { struct acpi_processor_cx *state; unsigned long bm_check_timestamp; u32 default_state; - u32 bm_activity; int count; struct acpi_processor_cx states[ACPI_PROCESSOR_MAX_POWER]; int timer_broadcast_on_state; -- cgit v1.2.3-70-g09d2 From f461ddea0af8b98e2b7940eba9c693b0ee44d64a Mon Sep 17 00:00:00 2001 From: Len Brown Date: Thu, 23 Apr 2009 18:59:43 -0400 Subject: ACPI/hpet: prevent boot hang when hpet=force used on ICH-4M Linux tells ICH4 users that they can (manually) invoke "hpet=force" to enable the undocumented ICH-4M HPET. The HPET becomes available for both clocksource and clockevents. But as of ff69f2bba67bd45514923aaedbf40fe351787c59 (acpi: fix of pmtimer overflow that make Cx states time incorrect) the HPET may be used via clocksource for idle accounting, and hpet=force on an ICH4 box hangs boot. It turns out that touching the MMIO HPET withing the ARB_DIS part of C3 will hang the hardware. The fix is to simply move the timer access outside the ARB_DIS region. This is a no-op on modern hardware because ARB_DIS is no longer used. http://bugzilla.kernel.org/show_bug.cgi?id=13087 Acked-by: Venkatesh Pallipadi Signed-off-by: Len Brown --- drivers/acpi/processor_idle.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/acpi/processor_idle.c') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 6fe121434ff..ea23c64bd76 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -955,6 +955,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, */ acpi_state_timer_broadcast(pr, cx, 1); + kt1 = ktime_get_real(); /* * disable bus master * bm_check implies we need ARB_DIS @@ -976,10 +977,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, ACPI_FLUSH_CPU_CACHE(); } - kt1 = ktime_get_real(); acpi_idle_do_entry(cx); - kt2 = ktime_get_real(); - idle_time = ktime_to_us(ktime_sub(kt2, kt1)); /* Re-enable bus master arbitration */ if (pr->flags.bm_check && pr->flags.bm_control) { @@ -988,6 +986,8 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, c3_cpu_count--; spin_unlock(&c3_lock); } + kt2 = ktime_get_real(); + idle_time = ktime_to_us(ktime_sub(kt2, kt1)); #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) /* TSC could halt in idle, so notify users */ -- cgit v1.2.3-70-g09d2 From 615dfd93e2346b604232b559e7ea0835d24abe26 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Thu, 23 Apr 2009 23:21:29 -0400 Subject: ACPI: prevent processor.max_cstate=0 boot crash As processor.max_cstate is an init-time-only modparam, sanity checking it at init-time is sufficient. http://bugzilla.kernel.org/show_bug.cgi?id=13142 Signed-off-by: Len Brown --- drivers/acpi/processor_idle.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/acpi/processor_idle.c') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 6fe121434ff..436127e0eec 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -1037,6 +1037,9 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) dev->states[i].desc[0] = '\0'; } + if (max_cstate == 0) + max_cstate = 1; + for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { cx = &pr->power.states[i]; state = &dev->states[count]; -- cgit v1.2.3-70-g09d2