From 7d851c8d3db0f79b92c8b14361779ede8acd2488 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 30 Jan 2008 13:33:20 +0100 Subject: [PATCH] x86: add framework to disable CPUID bits on the command line There are already various options to disable specific cpuid bits on the command line. They all use their own variable. Add a generic mask to make this easier in the future. Signed-off-by: Andi Kleen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/cpu/common.c | 6 ++++++ arch/x86/kernel/setup_64.c | 6 ++++++ include/asm-x86/cpufeature.h | 4 ++++ include/asm-x86/processor.h | 1 + 4 files changed, 17 insertions(+) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 4bd326d0322c..f0f29ddf33a2 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -57,6 +57,8 @@ DEFINE_PER_CPU(struct gdt_page, gdt_page) = { .gdt = { } }; EXPORT_PER_CPU_SYMBOL_GPL(gdt_page); +__u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata; + static int cachesize_override __cpuinitdata = -1; static int disable_x86_fxsr __cpuinitdata; static int disable_x86_serial_nr __cpuinitdata = 1; @@ -497,6 +499,10 @@ void __cpuinit identify_cpu(struct cpuinfo_x86 *c) boot_cpu_data.x86_capability[i] &= c->x86_capability[i]; } + /* Clear all flags overriden by options */ + for (i = 0; i < NCAPINTS; i++) + c->x86_capability[i] ^= cleared_cpu_caps[i]; + /* Init Machine Check Exception if available. */ mcheck_init(c); diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c index 7edb43f0b279..df159520bbd2 100644 --- a/arch/x86/kernel/setup_64.c +++ b/arch/x86/kernel/setup_64.c @@ -80,6 +80,8 @@ struct cpuinfo_x86 boot_cpu_data __read_mostly; EXPORT_SYMBOL(boot_cpu_data); +__u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata; + unsigned long mmu_cr4_features; /* Boot loader ID as an integer, for the benefit of proc_dointvec */ @@ -1013,6 +1015,10 @@ void __cpuinit identify_cpu(struct cpuinfo_x86 *c) boot_cpu_data.x86_capability[i] &= c->x86_capability[i]; } + /* Clear all flags overriden by options */ + for (i = 0; i < NCAPINTS; i++) + c->x86_capability[i] ^= cleared_cpu_caps[i]; + #ifdef CONFIG_X86_MCE mcheck_init(c); #endif diff --git a/include/asm-x86/cpufeature.h b/include/asm-x86/cpufeature.h index 29727bf0e177..b8f53f869e1f 100644 --- a/include/asm-x86/cpufeature.h +++ b/include/asm-x86/cpufeature.h @@ -131,6 +131,10 @@ #define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability)) #define clear_cpu_cap(c, bit) clear_bit(bit, (unsigned long *)((c)->x86_capability)) +#define setup_clear_cpu_cap(bit) do { \ + clear_cpu_cap(&boot_cpu_data, bit); \ + set_bit(bit, cleared_cpu_caps); \ +} while (0) #define cpu_has_fpu boot_cpu_has(X86_FEATURE_FPU) #define cpu_has_vme boot_cpu_has(X86_FEATURE_VME) diff --git a/include/asm-x86/processor.h b/include/asm-x86/processor.h index 81ecfed83e47..ab4d0c2a3f8f 100644 --- a/include/asm-x86/processor.h +++ b/include/asm-x86/processor.h @@ -118,6 +118,7 @@ struct cpuinfo_x86 { extern struct cpuinfo_x86 boot_cpu_data; extern struct cpuinfo_x86 new_cpu_data; extern struct tss_struct doublefault_tss; +extern __u32 cleared_cpu_caps[NCAPINTS]; #ifdef CONFIG_SMP DECLARE_PER_CPU(struct cpuinfo_x86, cpu_info); -- 2.30.2