diff options
Diffstat (limited to 'arch/x86/mm/pat.c')
| -rw-r--r-- | arch/x86/mm/pat.c | 50 |
1 files changed, 48 insertions, 2 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index ef75f3f89810..4c601276a556 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -31,6 +31,7 @@ #include <asm/io.h> #include "pat_internal.h" +#include "mm_internal.h" #ifdef CONFIG_X86_PAT int __read_mostly pat_enabled = 1; @@ -75,6 +76,52 @@ enum { PAT_UC_MINUS = 7, /* UC, but can be overriden by MTRR */ }; +#define CM(c) (_PAGE_CACHE_MODE_ ## c) + +static enum page_cache_mode pat_get_cache_mode(unsigned pat_val, char *msg) +{ + enum page_cache_mode cache; + char *cache_mode; + + switch (pat_val) { + case PAT_UC: cache = CM(UC); cache_mode = "UC "; break; + case PAT_WC: cache = CM(WC); cache_mode = "WC "; break; + case PAT_WT: cache = CM(WT); cache_mode = "WT "; break; + case PAT_WP: cache = CM(WP); cache_mode = "WP "; break; + case PAT_WB: cache = CM(WB); cache_mode = "WB "; break; + case PAT_UC_MINUS: cache = CM(UC_MINUS); cache_mode = "UC- "; break; + default: cache = CM(WB); cache_mode = "WB "; break; + } + + memcpy(msg, cache_mode, 4); + + return cache; +} + +#undef CM + +/* + * Update the cache mode to pgprot translation tables according to PAT + * configuration. + * Using lower indices is preferred, so we start with highest index. + */ +void pat_init_cache_modes(void) +{ + int i; + enum page_cache_mode cache; + char pat_msg[33]; + u64 pat; + + rdmsrl(MSR_IA32_CR_PAT, pat); + pat_msg[32] = 0; + for (i = 7; i >= 0; i--) { + cache = pat_get_cache_mode((pat >> (i * 8)) & 7, + pat_msg + 4 * i); + update_cache_mode_entry(i, cache); + } + pr_info("PAT configuration [0-7]: %s\n", pat_msg); +} + #define PAT(x, y) ((u64)PAT_ ## y << ((x)*8)) void pat_init(void) @@ -124,8 +171,7 @@ void pat_init(void) wrmsrl(MSR_IA32_CR_PAT, pat); if (boot_cpu) - printk(KERN_INFO "x86 PAT enabled: cpu %d, old 0x%Lx, new 0x%Lx\n", - smp_processor_id(), boot_pat_state, pat); + pat_init_cache_modes(); } #undef PAT |