diff options
| author | Rizwan Qureshi <rizwan.qureshi@intel.com> | 2016-09-07 20:11:11 +0530 |
|---|---|---|
| committer | Martin Roth <martinroth@google.com> | 2016-09-12 19:51:36 +0200 |
| commit | 8453c4f2fba7ae95ed14137a14575226b24218af (patch) | |
| tree | 6b1a684c422910bef540077c03b972b4f843810b /src/include/cpu/x86 | |
| parent | b1b44d34e39e52edfe5521d0671d685962529885 (diff) | |
cpu/x86: Move fls() and fms() to mtrr.h
Move the funtion to find most significant bit set(fms)
and function to find least significant bit set(fls) to a common
place. And remove the duplicates.
Change-Id: Ia821038b622d93e7f719c18e5ee3e8112de66a53
Signed-off-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Reviewed-on: https://review.coreboot.org/16525
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Diffstat (limited to 'src/include/cpu/x86')
| -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. */ |