From d3ec5cae0921611ceae06464ef6291012dd9849f Mon Sep 17 00:00:00 2001 From: Ivan Vecera Date: Tue, 11 Nov 2008 14:33:44 +0100 Subject: x86: call machine_shutdown and stop all CPUs in native_machine_halt Impact: really halt all CPUs on halt Function machine_halt (resp. native_machine_halt) is empty for x86 architectures. When command 'halt -f' is invoked, the message "System halted." is displayed but this is not really true because all CPUs are still running. There are also similar inconsistencies for other arches (some uses power-off for halt or forever-loop with IRQs enabled/disabled). IMO there should be used the same approach for all architectures OR what does the message "System halted" really mean? This patch fixes it for x86. Signed-off-by: Ivan Vecera Signed-off-by: Ingo Molnar --- arch/x86/kernel/process.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'arch/x86/kernel/process.c') diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index c622772744d8..a4da7c4b3129 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -8,6 +8,7 @@ #include #include #include +#include unsigned long idle_halt; EXPORT_SYMBOL(idle_halt); @@ -122,6 +123,21 @@ void default_idle(void) EXPORT_SYMBOL(default_idle); #endif +void stop_this_cpu(void *dummy) +{ + local_irq_disable(); + /* + * Remove this CPU: + */ + cpu_clear(smp_processor_id(), cpu_online_map); + disable_local_APIC(); + + for (;;) { + if (hlt_works(smp_processor_id())) + halt(); + } +} + static void do_nothing(void *unused) { } -- cgit v1.2.3 From 40fb17152c50a69dc304dd632131c2f41281ce44 Mon Sep 17 00:00:00 2001 From: Venki Pallipadi Date: Mon, 17 Nov 2008 16:11:37 -0800 Subject: x86: support always running TSC on Intel CPUs Impact: reward non-stop TSCs with good TSC-based clocksources, etc. Add support for CPUID_0x80000007_Bit8 on Intel CPUs as well. This bit means that the TSC is invariant with C/P/T states and always runs at constant frequency. With Intel CPUs, we have 3 classes * CPUs where TSC runs at constant rate and does not stop n C-states * CPUs where TSC runs at constant rate, but will stop in deep C-states * CPUs where TSC rate will vary based on P/T-states and TSC will stop in deep C-states. To cover these 3, one feature bit (CONSTANT_TSC) is not enough. So, add a second bit (NONSTOP_TSC). CONSTANT_TSC indicates that the TSC runs at constant frequency irrespective of P/T-states, and NONSTOP_TSC indicates that TSC does not stop in deep C-states. CPUID_0x8000000_Bit8 indicates both these feature bit can be set. We still have CONSTANT_TSC _set_ and NONSTOP_TSC _not_set_ on some older Intel CPUs, based on model checks. We can use TSC on such CPUs for time, as long as those CPUs do not support/enter deep C-states. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/amd.c | 9 +++++++-- arch/x86/kernel/cpu/intel.c | 10 ++++++++++ arch/x86/kernel/process.c | 2 +- drivers/acpi/processor_idle.c | 6 +++--- 4 files changed, 21 insertions(+), 6 deletions(-) (limited to 'arch/x86/kernel/process.c') diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 8f1e31db2ad5..7c878f6aa919 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -283,9 +283,14 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c) { early_init_amd_mc(c); - /* c->x86_power is 8000_0007 edx. Bit 8 is constant TSC */ - if (c->x86_power & (1<<8)) + /* + * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate + * with P/T states and does not stop in deep C-states + */ + if (c->x86_power & (1 << 8)) { set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); + set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC); + } #ifdef CONFIG_X86_64 set_cpu_cap(c, X86_FEATURE_SYSCALL32); diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index cce0b6118d55..caec59437a22 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -41,6 +41,16 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c) if (c->x86 == 15 && c->x86_cache_alignment == 64) c->x86_cache_alignment = 128; #endif + + /* + * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate + * with P/T states and does not stop in deep C-states + */ + if (c->x86_power & (1 << 8)) { + set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); + set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC); + } + } #ifdef CONFIG_X86_32 diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index c622772744d8..18c70fedba32 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -270,7 +270,7 @@ static void c1e_idle(void) rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi); if (lo & K8_INTP_C1E_ACTIVE_MASK) { c1e_detected = 1; - if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) + if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) mark_tsc_unstable("TSC halt in AMD C1E"); printk(KERN_INFO "System has AMD C1E enabled\n"); set_cpu_cap(&boot_cpu_data, X86_FEATURE_AMDC1E); diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 5f8d746a9b81..38aca048e951 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -374,15 +374,15 @@ static int tsc_halts_in_c(int state) { switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_AMD: + case X86_VENDOR_INTEL: /* * AMD Fam10h TSC will tick in all * C/P/S0/S1 states when this bit is set. */ - if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) + if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) return 0; + /*FALL THROUGH*/ - case X86_VENDOR_INTEL: - /* Several cases known where TSC halts in C2 too */ default: return state > ACPI_STATE_C1; } -- cgit v1.2.3 From f0bc2202e0373eb8e9b1ddbec930e2e681357db8 Mon Sep 17 00:00:00 2001 From: Jaswinder Singh Date: Wed, 17 Dec 2008 23:20:05 +0530 Subject: x86: process.c declare c1e_remove_cpu before they get used Impact: cleanup, avoid sparse warning Included asm/idle.h for c1e_remove_cpu() declaration. Fixes this sparse warning: CHECK arch/x86/kernel/process.c arch/x86/kernel/process.c:284:6: warning: symbol 'c1e_remove_cpu' was not declared. Should it be static? Signed-off-by: Jaswinder Singh Signed-off-by: Ingo Molnar --- arch/x86/kernel/process.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/x86/kernel/process.c') diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index c622772744d8..b06100f1d612 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -1,6 +1,7 @@ #include #include #include +#include #include #include #include -- cgit v1.2.3