The patch titled
Subject: mtrr, x86: fix MTRR state checks in mtrr_type_lookup()
has been added to the -mm tree. Its filename is
mtrr-x86-fix-mtrr-state-checks-in-mtrr_type_lookup.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mtrr-x86-fix-mtrr-state-checks-in-mtrr_type_lookup.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mtrr-x86-fix-mtrr-state-checks-in-mtrr_type_lookup.patch
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------------------------------------------------------
From: Toshi Kani <toshi.kani@xxxxxx>
Subject: mtrr, x86: fix MTRR state checks in mtrr_type_lookup()
'mtrr_state.enabled' contains the FE (fixed MTRRs enabled)
and E (MTRRs enabled) flags in MSR_MTRRdefType. Intel SDM,
section 11.11.2.1, defines these flags as follows:
- All MTRRs are disabled when the E flag is clear.
The FE flag has no affect when the E flag is clear.
- The default type is enabled when the E flag is set.
- MTRR variable ranges are enabled when the E flag is set.
- MTRR fixed ranges are enabled when both E and FE flags
are set.
MTRR state checks in __mtrr_type_lookup() do not match with
SDM. Hence, this patch makes the following changes:
- The current code detects MTRRs disabled when both E and
FE flags are clear in mtrr_state.enabled. Fix to detect
MTRRs disabled when the E flag is clear.
- The current code does not check if the FE bit is set in
mtrr_state.enabled when looking into the fixed entries.
Fix to check the FE flag.
- The current code returns the default type when the E flag
is clear in mtrr_state.enabled. However, the default type
is also disabled when the E flag is clear. Fix to remove
the code as this case is handled as MTRR disabled with
the 1st change.
In addition, this patch defines the E and FE flags in
mtrr_state.enabled as follows.
- FE flag: MTRR_STATE_MTRR_FIXED_ENABLED
- E flag: MTRR_STATE_MTRR_ENABLED
print_mtrr_state() is also updated accordingly.
Signed-off-by: Toshi Kani <toshi.kani@xxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Robert Elliott <Elliott@xxxxxx>
Cc: Paul Bolle <pebolle@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/uapi/asm/mtrr.h | 4 ++++
arch/x86/kernel/cpu/mtrr/generic.c | 15 ++++++++-------
2 files changed, 12 insertions(+), 7 deletions(-)
diff -puN arch/x86/include/uapi/asm/mtrr.h~mtrr-x86-fix-mtrr-state-checks-in-mtrr_type_lookup arch/x86/include/uapi/asm/mtrr.h
--- a/arch/x86/include/uapi/asm/mtrr.h~mtrr-x86-fix-mtrr-state-checks-in-mtrr_type_lookup
+++ a/arch/x86/include/uapi/asm/mtrr.h
@@ -88,6 +88,10 @@ struct mtrr_state_type {
mtrr_type def_type;
};
+/* Bit fields for enabled in struct mtrr_state_type */
+#define MTRR_STATE_MTRR_FIXED_ENABLED 0x01
+#define MTRR_STATE_MTRR_ENABLED 0x02
+
#define MTRRphysBase_MSR(reg) (0x200 + 2 * (reg))
#define MTRRphysMask_MSR(reg) (0x200 + 2 * (reg) + 1)
diff -puN arch/x86/kernel/cpu/mtrr/generic.c~mtrr-x86-fix-mtrr-state-checks-in-mtrr_type_lookup arch/x86/kernel/cpu/mtrr/generic.c
--- a/arch/x86/kernel/cpu/mtrr/generic.c~mtrr-x86-fix-mtrr-state-checks-in-mtrr_type_lookup
+++ a/arch/x86/kernel/cpu/mtrr/generic.c
@@ -119,14 +119,16 @@ static u8 __mtrr_type_lookup(u64 start,
if (!mtrr_state_set)
return 0xFF;
- if (!mtrr_state.enabled)
+ if (!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED))
return 0xFF;
/* Make end inclusive end, instead of exclusive */
end--;
/* Look in fixed ranges. Just return the type as per start */
- if (mtrr_state.have_fixed && (start < 0x100000)) {
+ if ((start < 0x100000) &&
+ (mtrr_state.have_fixed) &&
+ (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) {
int idx;
if (start < 0x80000) {
@@ -149,9 +151,6 @@ static u8 __mtrr_type_lookup(u64 start,
* Look of multiple ranges matching this address and pick type
* as per MTRR precedence
*/
- if (!(mtrr_state.enabled & 2))
- return mtrr_state.def_type;
-
prev_match = 0xFF;
for (i = 0; i < num_var_ranges; ++i) {
unsigned short start_state, end_state, inclusive;
@@ -348,7 +347,9 @@ static void __init print_mtrr_state(void
mtrr_attrib_to_str(mtrr_state.def_type));
if (mtrr_state.have_fixed) {
pr_debug("MTRR fixed ranges %sabled:\n",
- mtrr_state.enabled & 1 ? "en" : "dis");
+ ((mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED) &&
+ (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) ?
+ "en" : "dis");
print_fixed(0x00000, 0x10000, mtrr_state.fixed_ranges + 0);
for (i = 0; i < 2; ++i)
print_fixed(0x80000 + i * 0x20000, 0x04000,
@@ -361,7 +362,7 @@ static void __init print_mtrr_state(void
print_fixed_last();
}
pr_debug("MTRR variable ranges %sabled:\n",
- mtrr_state.enabled & 2 ? "en" : "dis");
+ mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED ? "en" : "dis");
high_width = (__ffs64(size_or_mask) - (32 - PAGE_SHIFT) + 3) / 4;
for (i = 0; i < num_var_ranges; ++i) {
_
Patches currently in -mm which might be from toshi.kani@xxxxxx are
mm-change-__get_vm_area_node-to-use-fls_long.patch
lib-add-huge-i-o-map-capability-interfaces.patch
lib-add-huge-i-o-map-capability-interfaces-fix.patch
mm-change-ioremap-to-set-up-huge-i-o-mappings.patch
mm-change-ioremap-to-set-up-huge-i-o-mappings-fix.patch
mm-change-vunmap-to-tear-down-huge-kva-mappings.patch
mm-change-vunmap-to-tear-down-huge-kva-mappings-fix.patch
x86-mm-support-huge-i-o-mapping-capability-i-f.patch
x86-mm-support-huge-kva-mappings-on-x86.patch
x86-mm-support-huge-kva-mappings-on-x86-fix.patch
linux-next.patch
mm-x86-document-return-values-of-mapping-funcs.patch
mtrr-x86-fix-mtrr-lookup-to-handle-inclusive-entry.patch
mtrr-x86-remove-a-wrong-address-check-in-__mtrr_type_lookup.patch
mtrr-x86-fix-mtrr-state-checks-in-mtrr_type_lookup.patch
mtrr-x86-define-mtrr_type_invalid-for-mtrr_type_lookup.patch
mtrr-x86-clean-up-mtrr_type_lookup.patch
mtrr-mm-x86-enhance-mtrr-checks-for-kva-huge-page-mapping.patch
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