diff options
author | Emese Revfy <re.emese@gmail.com> | 2010-01-31 14:16:34 -0500 |
---|---|---|
committer | H. Peter Anvin <hpa@zytor.com> | 2010-02-01 14:20:43 -0500 |
commit | 3b9cfc0a99f88c0db7c72363620584a9b40b4543 (patch) | |
tree | f34b481d28eae0c04521a36c45bb50c1511cf5e6 /arch/x86/kernel/cpu/mtrr/main.c | |
parent | ab658321f32770b903a4426e2a6fae0392757755 (diff) |
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/main.c')
-rw-r--r-- | arch/x86/kernel/cpu/mtrr/main.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c index 84e83de54575..fe4622e8c837 100644 --- a/arch/x86/kernel/cpu/mtrr/main.c +++ b/arch/x86/kernel/cpu/mtrr/main.c | |||
@@ -60,14 +60,14 @@ static DEFINE_MUTEX(mtrr_mutex); | |||
60 | u64 size_or_mask, size_and_mask; | 60 | u64 size_or_mask, size_and_mask; |
61 | static bool mtrr_aps_delayed_init; | 61 | static bool mtrr_aps_delayed_init; |
62 | 62 | ||
63 | static struct mtrr_ops *mtrr_ops[X86_VENDOR_NUM]; | 63 | static const struct mtrr_ops *mtrr_ops[X86_VENDOR_NUM]; |
64 | 64 | ||
65 | struct mtrr_ops *mtrr_if; | 65 | const struct mtrr_ops *mtrr_if; |
66 | 66 | ||
67 | static void set_mtrr(unsigned int reg, unsigned long base, | 67 | static void set_mtrr(unsigned int reg, unsigned long base, |
68 | unsigned long size, mtrr_type type); | 68 | unsigned long size, mtrr_type type); |
69 | 69 | ||
70 | void set_mtrr_ops(struct mtrr_ops *ops) | 70 | void set_mtrr_ops(const struct mtrr_ops *ops) |
71 | { | 71 | { |
72 | if (ops->vendor && ops->vendor < X86_VENDOR_NUM) | 72 | if (ops->vendor && ops->vendor < X86_VENDOR_NUM) |
73 | mtrr_ops[ops->vendor] = ops; | 73 | mtrr_ops[ops->vendor] = ops; |