[PATCH v9 02/38] x86/mm/pat: Set write-protect cache mode for full PAT support
From: Tom Lendacky
Date: Fri Jul 07 2017 - 09:39:01 EST
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For processors that support PAT, set the write-protect cache mode
(_PAGE_CACHE_MODE_WP) entry to the actual write-protect value (x05).
Acked-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
arch/x86/mm/pat.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 4597950..88990ab 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -293,7 +293,7 @@ void init_cache_modes(void)
* pat_init - Initialize PAT MSR and PAT table
*
* This function initializes PAT MSR and PAT table with an OS-defined value
- * to enable additional cache attributes, WC and WT.
+ * to enable additional cache attributes, WC, WT and WP.
*
* This function must be called on all CPUs using the specific sequence of
* operations defined in Intel SDM. mtrr_rendezvous_handler() provides this
@@ -352,7 +352,7 @@ void pat_init(void)
* 010 2 UC-: _PAGE_CACHE_MODE_UC_MINUS
* 011 3 UC : _PAGE_CACHE_MODE_UC
* 100 4 WB : Reserved
- * 101 5 WC : Reserved
+ * 101 5 WP : _PAGE_CACHE_MODE_WP
* 110 6 UC-: Reserved
* 111 7 WT : _PAGE_CACHE_MODE_WT
*
@@ -360,7 +360,7 @@ void pat_init(void)
* corresponding types in the presence of PAT errata.
*/
pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, UC) |
- PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, WT);
+ PAT(4, WB) | PAT(5, WP) | PAT(6, UC_MINUS) | PAT(7, WT);
}
if (!boot_cpu_done) {
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