Aaron Durbin (adurbin@google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/2919
-gerrit
commit 77fa0ca9bad1029545290b9ce45c39b0159de086 Author: Aaron Durbin adurbin@chromium.org Date: Tue Mar 26 13:09:39 2013 -0500
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 --- src/cpu/x86/mtrr/mtrr.c | 5 +++++ src/include/boot/coreboot_tables.h | 8 ++++++++ src/include/cpu/x86/mtrr.h | 3 +++ src/lib/coreboot_table.c | 23 +++++++++++++++++++++++ 4 files changed, 39 insertions(+)
diff --git a/src/cpu/x86/mtrr/mtrr.c b/src/cpu/x86/mtrr/mtrr.c index dad1029..9c8f8c7 100644 --- a/src/cpu/x86/mtrr/mtrr.c +++ b/src/cpu/x86/mtrr/mtrr.c @@ -349,6 +349,11 @@ void x86_setup_fixed_mtrrs(void) #if CONFIG_CACHE_ROM static long rom_cache_mtrr = -1;
+long x86_mtrr_rom_cache_var_index(void) +{ + return rom_cache_mtrr; +} + void x86_mtrr_enable_rom_caching(void) { msr_t msr_val; diff --git a/src/include/boot/coreboot_tables.h b/src/include/boot/coreboot_tables.h index f624ac1..a7e4ab0 100644 --- a/src/include/boot/coreboot_tables.h +++ b/src/include/boot/coreboot_tables.h @@ -250,6 +250,14 @@ struct lb_vboot_handoff { uint32_t vboot_handoff_size; };
+#define LB_TAG_X86_ROM_MTRR 0x0021 +struct lb_x86_rom_mtrr { + uint32_t tag; + uint32_t size; + /* The variable range MTRR index covering the ROM. */ + uint32_t index; +}; + /* The following structures are for the cmos definitions table */ #define LB_TAG_CMOS_OPTION_TABLE 200 /* cmos header record */ diff --git a/src/include/cpu/x86/mtrr.h b/src/include/cpu/x86/mtrr.h index bff736d..15a5cad 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 diff --git a/src/lib/coreboot_table.c b/src/lib/coreboot_table.c index b9a82a8..765c510 100644 --- a/src/lib/coreboot_table.c +++ b/src/lib/coreboot_table.c @@ -40,6 +40,9 @@ #include <vendorcode/google/chromeos/chromeos.h> #include <vendorcode/google/chromeos/gnvs.h> #endif +#if CONFIG_ARCH_X86 +#include <cpu/x86/mtrr.h> +#endif
static struct lb_header *lb_table_init(unsigned long addr) { @@ -237,6 +240,24 @@ static inline void lb_vboot_handoff(struct lb_header *header) {} #endif /* CONFIG_VBOOT_VERIFY_FIRMWARE */ #endif /* CONFIG_CHROMEOS */
+static void lb_x86_rom_cache(struct lb_header *header) +{ +#if CONFIG_ARCH_X86 + long mtrr_index; + struct lb_x86_rom_mtrr *lb_x86_rom_mtrr; + + mtrr_index = x86_mtrr_rom_cache_var_index(); + + if (mtrr_index < 0) + return; + + lb_x86_rom_mtrr = (struct lb_x86_rom_mtrr *)lb_new_record(header); + lb_x86_rom_mtrr->tag = LB_TAG_X86_ROM_MTRR; + lb_x86_rom_mtrr->size = sizeof(struct lb_x86_rom_mtrr); + lb_x86_rom_mtrr->index = mtrr_index; +#endif +} + static void add_cbmem_pointers(struct lb_header *header) { /* @@ -539,6 +560,8 @@ unsigned long write_coreboot_table( lb_strings(head); /* Record our framebuffer */ lb_framebuffer(head); + /* Communicate x86 variable MTRR ROM cache information. */ + lb_x86_rom_cache(head);
#if CONFIG_CHROMEOS /* Record our GPIO settings (ChromeOS specific) */