diff options
Diffstat (limited to 'include/asm-x86/fixmap.h')
| -rw-r--r-- | include/asm-x86/fixmap.h | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/include/asm-x86/fixmap.h b/include/asm-x86/fixmap.h index 5bd206973dc..01b0f98f992 100644 --- a/include/asm-x86/fixmap.h +++ b/include/asm-x86/fixmap.h @@ -7,7 +7,50 @@ # include "fixmap_64.h" #endif +extern void __set_fixmap(enum fixed_addresses idx, + unsigned long phys, pgprot_t flags); +#define set_fixmap(idx, phys) \ + __set_fixmap(idx, phys, PAGE_KERNEL) + +/* + * Some hardware wants to get fixmapped without caching. + */ +#define set_fixmap_nocache(idx, phys) \ + __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) + #define clear_fixmap(idx) \ __set_fixmap(idx, 0, __pgprot(0)) +#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) +#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) + +extern void __this_fixmap_does_not_exist(void); + +/* + * 'index to address' translation. If anyone tries to use the idx + * directly without translation, we catch the bug with a NULL-deference + * kernel oops. Illegal ranges of incoming indices are caught too. + */ +static __always_inline unsigned long fix_to_virt(const unsigned int idx) +{ + /* + * this branch gets completely eliminated after inlining, + * except when someone tries to use fixaddr indices in an + * illegal way. (such as mixing up address types or using + * out-of-range indices). + * + * If it doesn't get removed, the linker will complain + * loudly with a reasonably clear error message.. + */ + if (idx >= __end_of_fixed_addresses) + __this_fixmap_does_not_exist(); + + return __fix_to_virt(idx); +} + +static inline unsigned long virt_to_fix(const unsigned long vaddr) +{ + BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); + return __virt_to_fix(vaddr); +} #endif |