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| author | Emese Revfy <re.emese@gmail.com> | 2010-01-31 20:16:34 +0100 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2010-02-01 11:20:43 -0800 |
| commit | 3b9cfc0a99f88c0db7c72363620584a9b40b4543 (patch) | |
| tree | f34b481d28eae0c04521a36c45bb50c1511cf5e6 /arch/x86/kernel/cpu/mtrr/mtrr.h | |
| parent | ab658321f32770b903a4426e2a6fae0392757755 (diff) | |
| download | blackbird-obmc-linux-3b9cfc0a99f88c0db7c72363620584a9b40b4543.tar.gz blackbird-obmc-linux-3b9cfc0a99f88c0db7c72363620584a9b40b4543.zip | |
x86, mtrr: Constify struct mtrr_ops
This is part of the ops structure constification
effort started by Arjan van de Ven et al.
Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime
* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime
* potentially better optimized code as the compiler
can assume that the const data cannot be changed
* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing
Signed-off-by: Emese Revfy <re.emese@gmail.com>
LKML-Reference: <4B65D712.3080804@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/kernel/cpu/mtrr/mtrr.h')
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/mtrr.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.h b/arch/x86/kernel/cpu/mtrr/mtrr.h index a501dee9a87a..df5e41f31a27 100644 --- a/arch/x86/kernel/cpu/mtrr/mtrr.h +++ b/arch/x86/kernel/cpu/mtrr/mtrr.h @@ -32,7 +32,7 @@ extern int generic_get_free_region(unsigned long base, unsigned long size, extern int generic_validate_add_page(unsigned long base, unsigned long size, unsigned int type); -extern struct mtrr_ops generic_mtrr_ops; +extern const struct mtrr_ops generic_mtrr_ops; extern int positive_have_wrcomb(void); @@ -53,10 +53,10 @@ void fill_mtrr_var_range(unsigned int index, u32 base_lo, u32 base_hi, u32 mask_lo, u32 mask_hi); void get_mtrr_state(void); -extern void set_mtrr_ops(struct mtrr_ops *ops); +extern void set_mtrr_ops(const struct mtrr_ops *ops); extern u64 size_or_mask, size_and_mask; -extern struct mtrr_ops *mtrr_if; +extern const struct mtrr_ops *mtrr_if; #define is_cpu(vnd) (mtrr_if && mtrr_if->vendor == X86_VENDOR_##vnd) #define use_intel() (mtrr_if && mtrr_if->use_intel_if == 1) |
