diff options
Diffstat (limited to 'src/include/cpu/x86/mtrr.h')
| -rw-r--r-- | src/include/cpu/x86/mtrr.h | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/src/include/cpu/x86/mtrr.h b/src/include/cpu/x86/mtrr.h index f32bececfd..79f98905b3 100644 --- a/src/include/cpu/x86/mtrr.h +++ b/src/include/cpu/x86/mtrr.h @@ -84,6 +84,33 @@ void set_var_mtrr(unsigned reg, unsigned base, unsigned size, unsigned type); int get_free_var_mtrr(void); #endif +#if !defined(__ASSEMBLER__) && !defined(__ROMCC__) + +/* fms: find most significant bit set, stolen from Linux Kernel Source. */ +static inline unsigned int fms(unsigned int x) +{ + int r; + + __asm__("bsrl %1,%0\n\t" + "jnz 1f\n\t" + "movl $0,%0\n" + "1:" : "=r" (r) : "g" (x)); + return r; +} + +/* fls: find least significant bit set */ +static inline unsigned int fls(unsigned int x) +{ + int r; + + __asm__("bsfl %1,%0\n\t" + "jnz 1f\n\t" + "movl $32,%0\n" + "1:" : "=r" (r) : "g" (x)); + return r; +} +#endif + /* Align up to next power of 2, suitable for ROMCC and assembler too. * Range of result 256kB to 128MB is good enough here. */ |