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-rw-r--r--arch/x86/include/asm/pat.h1
-rw-r--r--arch/x86/include/asm/pgtable_types.h4
-rw-r--r--arch/x86/mm/init.c8
-rw-r--r--arch/x86/mm/mm_internal.h2
-rw-r--r--arch/x86/mm/pat.c50
5 files changed, 63 insertions, 2 deletions
diff --git a/arch/x86/include/asm/pat.h b/arch/x86/include/asm/pat.h
index 150407a7234d..91bc4ba95f91 100644
--- a/arch/x86/include/asm/pat.h
+++ b/arch/x86/include/asm/pat.h
@@ -11,6 +11,7 @@ static const int pat_enabled;
#endif
extern void pat_init(void);
+void pat_init_cache_modes(void);
extern int reserve_memtype(u64 start, u64 end,
enum page_cache_mode req_pcm, enum page_cache_mode *ret_pcm);
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index 6d5f6d154215..af447f95e3be 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -351,6 +351,10 @@ extern uint8_t __pte2cachemode_tbl[8];
((((cb) >> (_PAGE_BIT_PAT - 2)) & 4) | \
(((cb) >> (_PAGE_BIT_PCD - 1)) & 2) | \
(((cb) >> _PAGE_BIT_PWT) & 1))
+#define __cm_idx2pte(i) \
+ ((((i) & 4) << (_PAGE_BIT_PAT - 2)) | \
+ (((i) & 2) << (_PAGE_BIT_PCD - 1)) | \
+ (((i) & 1) << _PAGE_BIT_PWT))
static inline unsigned long cachemode2protval(enum page_cache_mode pcm)
{
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index a9776ba475d4..82b41d56bb98 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -716,3 +716,11 @@ void __init zone_sizes_init(void)
free_area_init_nodes(max_zone_pfns);
}
+void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache)
+{
+ /* entry 0 MUST be WB (hardwired to speed up translations) */
+ BUG_ON(!entry && cache != _PAGE_CACHE_MODE_WB);
+
+ __cachemode2pte_tbl[cache] = __cm_idx2pte(entry);
+ __pte2cachemode_tbl[entry] = cache;
+}
diff --git a/arch/x86/mm/mm_internal.h b/arch/x86/mm/mm_internal.h
index 6b563a118891..62474ba66c8e 100644
--- a/arch/x86/mm/mm_internal.h
+++ b/arch/x86/mm/mm_internal.h
@@ -16,4 +16,6 @@ void zone_sizes_init(void);
extern int after_bootmem;
+void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache);
+
#endif /* __X86_MM_INTERNAL_H */
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