diff options
| author | Toshi Kani <toshi.kani@hp.com> | 2015-05-26 10:28:07 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-05-27 14:40:57 +0200 |
| commit | 3d3ca416d9b0784cfcf244eeeba1bcaf421bc64d (patch) | |
| tree | 2e7720065caaa8f92aa5d21b2e548f15b114ad21 /arch/x86/kernel/cpu/mtrr/generic.c | |
| parent | 9b3aca620883fc06636737c82a4d024b22182281 (diff) | |
x86/mm/mtrr: Use symbolic define as a retval for disabled MTRRs
mtrr_type_lookup() returns verbatim 0xFF when MTRRs are
disabled. This patch defines MTRR_TYPE_INVALID to clarify the
meaning of this value, and documents its usage.
Document the return values of the kernel virtual address mapping
helpers pud_set_huge(), pmd_set_huge, pud_clear_huge() and
pmd_clear_huge().
There is no functional change in this patch.
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Elliott@hp.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave.hansen@intel.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: pebolle@tiscali.nl
Link: http://lkml.kernel.org/r/1431714237-880-5-git-send-email-toshi.kani@hp.com
Link: http://lkml.kernel.org/r/1432628901-18044-5-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/cpu/mtrr/generic.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/generic.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index b0599dbb899a..7b1491c6232d 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; @@ -206,7 +206,7 @@ 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; } @@ -220,7 +220,7 @@ 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; @@ -229,7 +229,7 @@ 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) { |