From 39b3a7910556005a7a0d042ecb7ff98bfa84ea57 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 11 Jan 2006 22:42:45 +0100 Subject: [PATCH] [PATCH] i386/x86-64: Generalize X86_FEATURE_CONSTANT_TSC flag Define it for i386 too. This is a synthetic flag that signifies that the CPU's TSC runs at a constant P state invariant frequency. Fix up the logic on x86-64/i386 to set it on all known CPUs. Use the AMD defined bit to set it on future AMD CPUs. Cc: venkatesh.pallipadi@intel.com Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/i386/kernel/cpu/amd.c | 6 ++++++ arch/i386/kernel/cpu/intel.c | 5 ++++- arch/i386/kernel/cpu/proc.c | 2 +- arch/x86_64/kernel/setup.c | 5 +++-- include/asm-i386/cpufeature.h | 1 + 5 files changed, 15 insertions(+), 4 deletions(-) diff --git a/arch/i386/kernel/cpu/amd.c b/arch/i386/kernel/cpu/amd.c index e7697e077f6b..4397f61705e2 100644 --- a/arch/i386/kernel/cpu/amd.c +++ b/arch/i386/kernel/cpu/amd.c @@ -216,6 +216,11 @@ static void __init init_amd(struct cpuinfo_x86 *c) c->x86_max_cores = 1; } + if (cpuid_eax(0x80000000) >= 0x80000007) { + if (cpuid_edx(0x80000007) & (1<<8)) + set_bit(X86_FEATURE_CONSTANT_TSC, &c->x86_capability); + } + #ifdef CONFIG_X86_HT /* * On a AMD dual core setup the lower bits of the APIC id @@ -233,6 +238,7 @@ static void __init init_amd(struct cpuinfo_x86 *c) cpu, c->x86_max_cores, cpu_core_id[cpu]); } #endif + } static unsigned int amd_size_cache(struct cpuinfo_x86 * c, unsigned int size) diff --git a/arch/i386/kernel/cpu/intel.c b/arch/i386/kernel/cpu/intel.c index 5e2da704f0fa..8c0120186b9f 100644 --- a/arch/i386/kernel/cpu/intel.c +++ b/arch/i386/kernel/cpu/intel.c @@ -183,10 +183,13 @@ static void __devinit init_intel(struct cpuinfo_x86 *c) } #endif - if (c->x86 == 15) + if (c->x86 == 15) set_bit(X86_FEATURE_P4, c->x86_capability); if (c->x86 == 6) set_bit(X86_FEATURE_P3, c->x86_capability); + if ((c->x86 == 0xf && c->x86_model >= 0x03) || + (c->x86 == 0x6 && c->x86_model >= 0x0e)) + set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability); } diff --git a/arch/i386/kernel/cpu/proc.c b/arch/i386/kernel/cpu/proc.c index 6d91b274589c..66592fad2bfe 100644 --- a/arch/i386/kernel/cpu/proc.c +++ b/arch/i386/kernel/cpu/proc.c @@ -40,7 +40,7 @@ static int show_cpuinfo(struct seq_file *m, void *v) /* Other (Linux-defined) */ "cxmmx", "k6_mtrr", "cyrix_arr", "centaur_mcr", NULL, NULL, NULL, NULL, - NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, + "constant_tsc", NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c index 754a05f9b4db..d9c1c3bd6150 100644 --- a/arch/x86_64/kernel/setup.c +++ b/arch/x86_64/kernel/setup.c @@ -1032,7 +1032,8 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c) if (c->x86 == 15) c->x86_cache_alignment = c->x86_clflush_size * 2; - if (c->x86 >= 15) + if ((c->x86 == 0xf && c->x86_model >= 0x03) || + (c->x86 == 0x6 && c->x86_model >= 0x0e)) set_bit(X86_FEATURE_CONSTANT_TSC, &c->x86_capability); c->x86_max_cores = intel_num_cpu_cores(c); @@ -1273,7 +1274,7 @@ static int show_cpuinfo(struct seq_file *m, void *v) "tm", "stc" "?", - "constant_tsc", + /* nothing */ /* constant_tsc - moved to flags */ }; diff --git a/include/asm-i386/cpufeature.h b/include/asm-i386/cpufeature.h index ff1187e80c32..c4ec2a4d8fdf 100644 --- a/include/asm-i386/cpufeature.h +++ b/include/asm-i386/cpufeature.h @@ -69,6 +69,7 @@ #define X86_FEATURE_K7 (3*32+ 5) /* Athlon */ #define X86_FEATURE_P3 (3*32+ 6) /* P3 */ #define X86_FEATURE_P4 (3*32+ 7) /* P4 */ +#define X86_FEATURE_CONSTANT_TSC (3*32+ 8) /* TSC ticks at a constant rate */ /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */ #define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */ -- 2.20.1