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author | Toshi Kani <toshi.kani@hp.com> | 2015-03-25 13:27:04 +1100 |
---|---|---|
committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2015-03-27 19:01:21 +1100 |
commit | af5bfc39b296cac4aefdc3ef3709d6308cc02e05 (patch) | |
tree | 3e8fb8a6d65873b600964e81c2ead538088e82f1 | |
parent | 65d372c24324a361e6dd0d9cf70d82f8a35f08ce (diff) | |
download | linux-af5bfc39b296cac4aefdc3ef3709d6308cc02e05.tar.gz linux-af5bfc39b296cac4aefdc3ef3709d6308cc02e05.tar.xz |
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@hp.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Robert Elliott <Elliott@hp.com>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r-- | arch/x86/include/uapi/asm/mtrr.h | 4 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/mtrr/generic.c | 15 |
2 files changed, 12 insertions, 7 deletions
diff --git a/arch/x86/include/uapi/asm/mtrr.h b/arch/x86/include/uapi/asm/mtrr.h index d0acb658c8f4..66ba88dee38e 100644 --- a/arch/x86/include/uapi/asm/mtrr.h +++ b/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 --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index c5be32701077..4bff6db04fe8 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -119,14 +119,16 @@ static u8 __mtrr_type_lookup(u64 start, u64 end, u64 *partial_end, int *repeat) 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, u64 end, u64 *partial_end, int *repeat) * 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) { |