diff options
Diffstat (limited to 'src/cpu')
| -rw-r--r-- | src/cpu/intel/haswell/romstage.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/src/cpu/intel/haswell/romstage.c b/src/cpu/intel/haswell/romstage.c index ac0e848c7d..b26cbde605 100644 --- a/src/cpu/intel/haswell/romstage.c +++ b/src/cpu/intel/haswell/romstage.c @@ -82,6 +82,7 @@ static void *setup_romstage_stack_after_car(void) int num_mtrrs; u32 *slot; u32 mtrr_mask_upper; + u32 top_of_ram; /* Top of stack needs to be aligned to a 4-byte boundary. */ top_of_stack = choose_top_of_stack() & ~3; @@ -120,6 +121,7 @@ static void *setup_romstage_stack_after_car(void) slot = stack_push(slot, 0 | MTRR_TYPE_WRBACK); num_mtrrs++; + top_of_ram = get_top_of_ram(); /* Cache 8MiB below the top of ram. On haswell systems the top of * ram under 4GiB is the start of the TSEG region. It is required to * be 8MiB aligned. Set this area as cacheable so it can be used later @@ -127,8 +129,18 @@ static void *setup_romstage_stack_after_car(void) slot = stack_push(slot, mtrr_mask_upper); /* upper mask */ slot = stack_push(slot, ~((8 << 20) - 1) | MTRRphysMaskValid); slot = stack_push(slot, 0); /* upper base */ - slot = stack_push(slot, - (get_top_of_ram() - (8 << 20)) | MTRR_TYPE_WRBACK); + slot = stack_push(slot, (top_of_ram - (8 << 20)) | MTRR_TYPE_WRBACK); + num_mtrrs++; + + /* Cache 8MiB at the top of ram. Top of ram on haswell systems + * is where the TSEG region resides. However, it is not restricted + * to SMM mode until SMM has been relocated. By setting the region + * to cacheable it provides faster access when relocating the SMM + * handler as well as using the TSEG region for other purposes. */ + slot = stack_push(slot, mtrr_mask_upper); /* upper mask */ + slot = stack_push(slot, ~((8 << 20) - 1) | MTRRphysMaskValid); + slot = stack_push(slot, 0); /* upper base */ + slot = stack_push(slot, top_of_ram | MTRR_TYPE_WRBACK); num_mtrrs++; /* Save the number of MTTRs to setup. Return the stack location |