diff options
| author | Aaron Durbin <adurbin@chromium.org> | 2013-03-26 13:09:39 -0500 |
|---|---|---|
| committer | Stefan Reinauer <stefan.reinauer@coreboot.org> | 2013-03-29 20:09:36 +0100 |
| commit | bc07f5d93552640793254ce003937ec646120a21 (patch) | |
| tree | 091f2189c38629d64579c5864220f8b2f2039db0 /src/include/cpu/x86/mtrr.h | |
| parent | f567f16af4c3cbfcadc3bc5c44b569a592829262 (diff) | |
| download | coreboot-bc07f5d93552640793254ce003937ec646120a21.tar.xz | |
x86: add rom cache variable MTRR index to tables
Downstream payloads may need to take advantage of caching the
ROM for performance reasons. Add the ability to communicate the
variable range MTRR index to use to perform the caching enablement.
An example usage implementation would be to obtain the variable MTRR
index that covers the ROM from the coreboot tables. Then one would
disable caching and change the MTRR type from uncacheable to
write-protect and enable caching. The opposite sequence is required
to tearn down the caching.
Change-Id: I4d486cfb986629247ab2da7818486973c6720ef5
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2919
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/include/cpu/x86/mtrr.h')
| -rw-r--r-- | src/include/cpu/x86/mtrr.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/include/cpu/x86/mtrr.h b/src/include/cpu/x86/mtrr.h index bff736d296..15a5cad090 100644 --- a/src/include/cpu/x86/mtrr.h +++ b/src/include/cpu/x86/mtrr.h @@ -78,9 +78,12 @@ int x86_mtrr_check(void); #if CONFIG_CACHE_ROM void x86_mtrr_enable_rom_caching(void); void x86_mtrr_disable_rom_caching(void); +/* Return the variable range MTRR index of the ROM cache. */ +long x86_mtrr_rom_cache_var_index(void); #else static inline void x86_mtrr_enable_rom_caching(void) {} static inline void x86_mtrr_disable_rom_caching(void) {} +static inline long x86_mtrr_rom_cache_var_index(void) { return -1; } #endif /* CONFIG_CACHE_ROM */ #endif |