diff options
author | Toshi Kani <toshi.kani@hp.com> | 2015-05-01 09:35:27 +1000 |
---|---|---|
committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2015-05-01 09:35:27 +1000 |
commit | 897a6c9879f577d8febbec34700a56a9a5a558b5 (patch) | |
tree | 9b820f66c40be7dc1b17976ec3f0da5ab929dc50 /arch | |
parent | fcf3465f7845f9601043bd3c11a0b4df6a621a6a (diff) |
mtrr, x86: define MTRR_TYPE_INVALID for mtrr_type_lookup()
mtrr_type_lookup() returns 0xFF when it cannot return a valid MTRR memory
type since MTRRs are disabled. This patch defines MTRR_TYPE_INVALID to
clarify the meaning of this value, and documents its usage.
There is no functional change in this patch.
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>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/include/asm/mtrr.h | 2 | ||||
-rw-r--r-- | arch/x86/include/uapi/asm/mtrr.h | 8 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/mtrr/generic.c | 14 | ||||
-rw-r--r-- | arch/x86/mm/pgtable.c | 8 |
4 files changed, 19 insertions, 13 deletions
diff --git a/arch/x86/include/asm/mtrr.h b/arch/x86/include/asm/mtrr.h index f768f6298419..a174af612578 100644 --- a/arch/x86/include/asm/mtrr.h +++ b/arch/x86/include/asm/mtrr.h @@ -55,7 +55,7 @@ static inline u8 mtrr_type_lookup(u64 addr, u64 end) /* * Return no-MTRRs: */ - return 0xff; + return MTRR_TYPE_INVALID; } #define mtrr_save_fixed_ranges(arg) do {} while (0) #define mtrr_save_state() do {} while (0) diff --git a/arch/x86/include/uapi/asm/mtrr.h b/arch/x86/include/uapi/asm/mtrr.h index 66ba88dee38e..0bc86c6fcae0 100644 --- a/arch/x86/include/uapi/asm/mtrr.h +++ b/arch/x86/include/uapi/asm/mtrr.h @@ -107,7 +107,7 @@ struct mtrr_state_type { #define MTRRIOC_GET_PAGE_ENTRY _IOWR(MTRR_IOCTL_BASE, 8, struct mtrr_gentry) #define MTRRIOC_KILL_PAGE_ENTRY _IOW(MTRR_IOCTL_BASE, 9, struct mtrr_sentry) -/* These are the region types */ +/* MTRR memory types, which are defined in SDM */ #define MTRR_TYPE_UNCACHABLE 0 #define MTRR_TYPE_WRCOMB 1 /*#define MTRR_TYPE_ 2*/ @@ -117,5 +117,11 @@ struct mtrr_state_type { #define MTRR_TYPE_WRBACK 6 #define MTRR_NUM_TYPES 7 +/* + * Invalid MTRR memory type. mtrr_type_lookup() returns this value when + * MTRRs are disabled. Note, this value is allocated from the reserved + * values (0x7-0xff) of the MTRR memory types. + */ +#define MTRR_TYPE_INVALID 0xff #endif /* _UAPI_ASM_X86_MTRR_H */ diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index 4bff6db04fe8..8bd129845977 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -104,7 +104,7 @@ static int check_type_overlap(u8 *prev, u8 *curr) /* * Error/Semi-error returns: - * 0xFF - when MTRR is not enabled + * MTRR_TYPE_INVALID - when MTRR is not enabled * *repeat == 1 implies [start:end] spanned across MTRR range and type returned * corresponds only to [start:*partial_end]. * Caller has to lookup again for [*partial_end:end]. @@ -117,10 +117,10 @@ static u8 __mtrr_type_lookup(u64 start, u64 end, u64 *partial_end, int *repeat) *repeat = 0; if (!mtrr_state_set) - return 0xFF; + return MTRR_TYPE_INVALID; if (!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED)) - return 0xFF; + return MTRR_TYPE_INVALID; /* Make end inclusive end, instead of exclusive */ end--; @@ -151,7 +151,7 @@ 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 */ - prev_match = 0xFF; + prev_match = MTRR_TYPE_INVALID; for (i = 0; i < num_var_ranges; ++i) { unsigned short start_state, end_state, inclusive; @@ -199,7 +199,7 @@ static u8 __mtrr_type_lookup(u64 start, u64 end, u64 *partial_end, int *repeat) continue; curr_match = mtrr_state.var_ranges[i].base_lo & 0xff; - if (prev_match == 0xFF) { + if (prev_match == MTRR_TYPE_INVALID) { prev_match = curr_match; continue; } @@ -213,7 +213,7 @@ static u8 __mtrr_type_lookup(u64 start, u64 end, u64 *partial_end, int *repeat) return MTRR_TYPE_WRBACK; } - if (prev_match != 0xFF) + if (prev_match != MTRR_TYPE_INVALID) return prev_match; return mtrr_state.def_type; @@ -222,7 +222,7 @@ static u8 __mtrr_type_lookup(u64 start, u64 end, u64 *partial_end, int *repeat) /* * Returns the effective MTRR type for the region * Error return: - * 0xFF - when MTRR is not enabled + * MTRR_TYPE_INVALID - when MTRR is not enabled */ u8 mtrr_type_lookup(u64 start, u64 end) { diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 4891fa10e616..cfca4cff7eba 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -568,7 +568,7 @@ void native_set_fixmap(enum fixed_addresses idx, phys_addr_t phys, * * MTRR can override PAT memory types with 4KB granularity. Therefore, * it does not set up a huge page when the range is covered by a non-WB - * type of MTRR. 0xFF indicates that MTRR are disabled. + * type of MTRR. MTRR_TYPE_INVALID indicates that MTRR are disabled. * * Return 1 on success, and 0 when no PUD was set. */ @@ -577,7 +577,7 @@ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot) u8 mtrr; mtrr = mtrr_type_lookup(addr, addr + PUD_SIZE); - if ((mtrr != MTRR_TYPE_WRBACK) && (mtrr != 0xFF)) + if ((mtrr != MTRR_TYPE_WRBACK) && (mtrr != MTRR_TYPE_INVALID)) return 0; prot = pgprot_4k_2_large(prot); @@ -594,7 +594,7 @@ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot) * * MTRR can override PAT memory types with 4KB granularity. Therefore, * it does not set up a huge page when the range is covered by a non-WB - * type of MTRR. 0xFF indicates that MTRR are disabled. + * type of MTRR. MTRR_TYPE_INVALID indicates that MTRR are disabled. * * Return 1 on success, and 0 when no PMD was set. */ @@ -603,7 +603,7 @@ int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot) u8 mtrr; mtrr = mtrr_type_lookup(addr, addr + PMD_SIZE); - if ((mtrr != MTRR_TYPE_WRBACK) && (mtrr != 0xFF)) + if ((mtrr != MTRR_TYPE_WRBACK) && (mtrr != MTRR_TYPE_INVALID)) return 0; prot = pgprot_4k_2_large(prot); |