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linux-next/arch/x86/kernel/cpu/mtrr/mtrr.h
Emese Revfy 3b9cfc0a99 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>
2010-02-01 11:20:43 -08:00

79 lines
2.2 KiB
C

/*
* local MTRR defines.
*/
#include <linux/types.h>
#include <linux/stddef.h>
#define MTRR_CHANGE_MASK_FIXED 0x01
#define MTRR_CHANGE_MASK_VARIABLE 0x02
#define MTRR_CHANGE_MASK_DEFTYPE 0x04
extern unsigned int mtrr_usage_table[MTRR_MAX_VAR_RANGES];
struct mtrr_ops {
u32 vendor;
u32 use_intel_if;
void (*set)(unsigned int reg, unsigned long base,
unsigned long size, mtrr_type type);
void (*set_all)(void);
void (*get)(unsigned int reg, unsigned long *base,
unsigned long *size, mtrr_type *type);
int (*get_free_region)(unsigned long base, unsigned long size,
int replace_reg);
int (*validate_add_page)(unsigned long base, unsigned long size,
unsigned int type);
int (*have_wrcomb)(void);
};
extern int generic_get_free_region(unsigned long base, unsigned long size,
int replace_reg);
extern int generic_validate_add_page(unsigned long base, unsigned long size,
unsigned int type);
extern const struct mtrr_ops generic_mtrr_ops;
extern int positive_have_wrcomb(void);
/* library functions for processor-specific routines */
struct set_mtrr_context {
unsigned long flags;
unsigned long cr4val;
u32 deftype_lo;
u32 deftype_hi;
u32 ccr3;
};
void set_mtrr_done(struct set_mtrr_context *ctxt);
void set_mtrr_cache_disable(struct set_mtrr_context *ctxt);
void set_mtrr_prepare_save(struct set_mtrr_context *ctxt);
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(const struct mtrr_ops *ops);
extern u64 size_or_mask, size_and_mask;
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)
extern unsigned int num_var_ranges;
extern u64 mtrr_tom2;
extern struct mtrr_state_type mtrr_state;
void mtrr_state_warn(void);
const char *mtrr_attrib_to_str(int x);
void mtrr_wrmsr(unsigned, unsigned, unsigned);
/* CPU specific mtrr init functions */
int amd_init_mtrr(void);
int cyrix_init_mtrr(void);
int centaur_init_mtrr(void);
extern int changed_by_mtrr_cleanup;
extern int mtrr_cleanup(unsigned address_bits);