diff options
| -rw-r--r-- | arch/x86/kernel/cpu/addon_cpuid_features.c | 21 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 27 | ||||
| -rw-r--r-- | arch/x86/kernel/setup_64.c | 9 | ||||
| -rw-r--r-- | arch/x86/mm/pat.c | 50 | ||||
| -rw-r--r-- | include/asm-x86/pat.h | 8 |
5 files changed, 55 insertions, 60 deletions
diff --git a/arch/x86/kernel/cpu/addon_cpuid_features.c b/arch/x86/kernel/cpu/addon_cpuid_features.c index 238468ae1993..c2e1ce33c7cb 100644 --- a/arch/x86/kernel/cpu/addon_cpuid_features.c +++ b/arch/x86/kernel/cpu/addon_cpuid_features.c @@ -6,6 +6,7 @@ #include <linux/cpu.h> +#include <asm/pat.h> #include <asm/processor.h> struct cpuid_bit { @@ -48,3 +49,23 @@ void __cpuinit init_scattered_cpuid_features(struct cpuinfo_x86 *c) set_cpu_cap(c, cb->feature); } } + +#ifdef CONFIG_X86_PAT +void __cpuinit validate_pat_support(struct cpuinfo_x86 *c) +{ + switch (c->x86_vendor) { + case X86_VENDOR_AMD: + if (c->x86 >= 0xf && c->x86 <= 0x11) + return; + break; + case X86_VENDOR_INTEL: + if (c->x86 == 0xF || (c->x86 == 6 && c->x86_model >= 15)) + return; + break; + } + + pat_disable(cpu_has_pat ? + "PAT disabled. Not yet verified on this CPU type." : + "PAT not supported by CPU."); +} +#endif diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 35b4f6a9c8ef..d0463a946247 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -12,6 +12,7 @@ #include <asm/mmu_context.h> #include <asm/mtrr.h> #include <asm/mce.h> +#include <asm/pat.h> #ifdef CONFIG_X86_LOCAL_APIC #include <asm/mpspec.h> #include <asm/apic.h> @@ -308,19 +309,6 @@ static void __cpuinit early_get_cap(struct cpuinfo_x86 *c) } - clear_cpu_cap(c, X86_FEATURE_PAT); - - switch (c->x86_vendor) { - case X86_VENDOR_AMD: - if (c->x86 >= 0xf && c->x86 <= 0x11) - set_cpu_cap(c, X86_FEATURE_PAT); - break; - case X86_VENDOR_INTEL: - if (c->x86 == 0xF || (c->x86 == 6 && c->x86_model >= 15)) - set_cpu_cap(c, X86_FEATURE_PAT); - break; - } - } /* @@ -409,18 +397,6 @@ static void __cpuinit generic_identify(struct cpuinfo_x86 *c) init_scattered_cpuid_features(c); } - clear_cpu_cap(c, X86_FEATURE_PAT); - - switch (c->x86_vendor) { - case X86_VENDOR_AMD: - if (c->x86 >= 0xf && c->x86 <= 0x11) - set_cpu_cap(c, X86_FEATURE_PAT); - break; - case X86_VENDOR_INTEL: - if (c->x86 == 0xF || (c->x86 == 6 && c->x86_model >= 15)) - set_cpu_cap(c, X86_FEATURE_PAT); - break; - } } static void __cpuinit squash_the_stupid_serial_number(struct cpuinfo_x86 *c) @@ -651,6 +627,7 @@ void __init early_cpu_init(void) cpu_devs[cvdev->vendor] = cvdev->cpu_dev; early_cpu_detect(); + validate_pat_support(&boot_cpu_data); } /* Make sure %fs is initialized properly in idle threads */ diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c index 22c14e21c97c..80d80fab7006 100644 --- a/arch/x86/kernel/setup_64.c +++ b/arch/x86/kernel/setup_64.c @@ -70,6 +70,7 @@ #include <asm/ds.h> #include <asm/topology.h> #include <asm/trampoline.h> +#include <asm/pat.h> #include <mach_apic.h> #ifdef CONFIG_PARAVIRT @@ -1063,25 +1064,19 @@ static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c) if (c->extended_cpuid_level >= 0x80000007) c->x86_power = cpuid_edx(0x80000007); - - clear_cpu_cap(c, X86_FEATURE_PAT); - switch (c->x86_vendor) { case X86_VENDOR_AMD: early_init_amd(c); - if (c->x86 >= 0xf && c->x86 <= 0x11) - set_cpu_cap(c, X86_FEATURE_PAT); break; case X86_VENDOR_INTEL: early_init_intel(c); - if (c->x86 == 0xF || (c->x86 == 6 && c->x86_model >= 15)) - set_cpu_cap(c, X86_FEATURE_PAT); break; case X86_VENDOR_CENTAUR: early_init_centaur(c); break; } + validate_pat_support(c); } /* diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 277446cd30b6..60adbe22efa0 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -25,31 +25,24 @@ #include <asm/mtrr.h> #include <asm/io.h> -int pat_wc_enabled = 1; +#ifdef CONFIG_X86_PAT +int __read_mostly pat_wc_enabled = 1; -static u64 __read_mostly boot_pat_state; - -static int nopat(char *str) +void __init pat_disable(char *reason) { pat_wc_enabled = 0; - printk(KERN_INFO "x86: PAT support disabled.\n"); - - return 0; + printk(KERN_INFO "%s\n", reason); } -early_param("nopat", nopat); -static int pat_known_cpu(void) +static int nopat(char *str) { - if (!pat_wc_enabled) - return 0; - - if (cpu_has_pat) - return 1; - - pat_wc_enabled = 0; - printk(KERN_INFO "CPU and/or kernel does not support PAT.\n"); + pat_disable("PAT support disabled."); return 0; } +early_param("nopat", nopat); +#endif + +static u64 __read_mostly boot_pat_state; enum { PAT_UC = 0, /* uncached */ @@ -66,17 +59,19 @@ void pat_init(void) { u64 pat; -#ifndef CONFIG_X86_PAT - nopat(NULL); -#endif - - /* Boot CPU enables PAT based on CPU feature */ - if (!smp_processor_id() && !pat_known_cpu()) + if (!pat_wc_enabled) return; - /* APs enable PAT iff boot CPU has enabled it before */ - if (smp_processor_id() && !pat_wc_enabled) - return; + /* Paranoia check. */ + if (!cpu_has_pat) { + printk(KERN_ERR "PAT enabled, but CPU feature cleared\n"); + /* + * Panic if this happens on the secondary CPU, and we + * switched to PAT on the boot CPU. We have no way to + * undo PAT. + */ + BUG_ON(boot_pat_state); + } /* Set PWT to Write-Combining. All other bits stay the same */ /* @@ -95,9 +90,8 @@ void pat_init(void) PAT(4,WB) | PAT(5,WC) | PAT(6,UC_MINUS) | PAT(7,UC); /* Boot CPU check */ - if (!smp_processor_id()) { + if (!boot_pat_state) rdmsrl(MSR_IA32_CR_PAT, boot_pat_state); - } wrmsrl(MSR_IA32_CR_PAT, pat); printk(KERN_INFO "x86 PAT enabled: cpu %d, old 0x%Lx, new 0x%Lx\n", diff --git a/include/asm-x86/pat.h b/include/asm-x86/pat.h index 8b822b5a1786..88f60cc6a227 100644 --- a/include/asm-x86/pat.h +++ b/include/asm-x86/pat.h @@ -4,7 +4,13 @@ #include <linux/types.h> +#ifdef CONFIG_X86_PAT extern int pat_wc_enabled; +extern void validate_pat_support(struct cpuinfo_x86 *c); +#else +static const int pat_wc_enabled = 0; +static inline void validate_pat_support(struct cpuinfo_x86 *c) { } +#endif extern void pat_init(void); @@ -12,5 +18,7 @@ extern int reserve_memtype(u64 start, u64 end, unsigned long req_type, unsigned long *ret_type); extern int free_memtype(u64 start, u64 end); +extern void pat_disable(char *reason); + #endif |