From ceb52711d7120b4c53af2d2f2e3350727f93804c Mon Sep 17 00:00:00 2001 From: Nico Huber Date: Fri, 6 Oct 2017 19:08:51 +0200 Subject: cpu/x86/mtrr: Remove var-MTRR alignment optimization The code used to split up ranges >64MiB into 64MiB-aligned and unaligned parts. However in its current state the next step, calc_var_mtrr_range(), results in the same allocation, no mat- ter if we split the range up before. So just drop the split-up. Change-Id: I5481fbf3168cdf789879064077b63bbfcaf122c9 Signed-off-by: Nico Huber Reviewed-on: https://review.coreboot.org/21914 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin Reviewed-by: Paul Menzel --- src/cpu/x86/mtrr/mtrr.c | 48 ++++++++++-------------------------------------- 1 file changed, 10 insertions(+), 38 deletions(-) diff --git a/src/cpu/x86/mtrr/mtrr.c b/src/cpu/x86/mtrr/mtrr.c index ef1bb31317..c2c629cbe4 100644 --- a/src/cpu/x86/mtrr/mtrr.c +++ b/src/cpu/x86/mtrr/mtrr.c @@ -552,60 +552,32 @@ static void calc_var_mtrrs_with_hole(struct var_mtrr_state *var_state, static void calc_var_mtrrs_without_hole(struct var_mtrr_state *var_state, struct range_entry *r) { - uint32_t a1, a2, b1, b2, c1, c2; - int mtrr_type; + const int mtrr_type = range_entry_mtrr_type(r); - /* - * For each range that meets the non-default type process it in the - * following manner: - * +------------------+ c2 = end - * | 0 or more bytes | - * +------------------+ b2 = c1 = ALIGN_DOWN(end) - * | | - * +------------------+ b1 = a2 = ALIGN_UP(begin) - * | 0 or more bytes | - * +------------------+ a1 = begin - * - * Thus, there are 3 sub-ranges to configure variable MTRRs for. - */ - mtrr_type = range_entry_mtrr_type(r); - - a1 = range_entry_base_mtrr_addr(r); - c2 = range_entry_end_mtrr_addr(r); + uint32_t base = range_entry_base_mtrr_addr(r); + uint32_t end = range_entry_end_mtrr_addr(r); /* The end address is within the first 1MiB. The fixed MTRRs take * precedence over the variable ones. Therefore this range * can be ignored. */ - if (c2 <= RANGE_1MB) + if (end <= RANGE_1MB) return; /* Again, the fixed MTRRs take precedence so the beginning * of the range can be set to 0 if it starts at or below 1MiB. */ - if (a1 <= RANGE_1MB) - a1 = 0; + if (base <= RANGE_1MB) + base = 0; /* If the range starts above 4GiB the processing is done. */ - if (!var_state->above4gb && a1 >= RANGE_4GB) + if (!var_state->above4gb && base >= RANGE_4GB) return; /* Clip the upper address to 4GiB if addresses above 4GiB * are not being processed. */ - if (!var_state->above4gb && c2 > RANGE_4GB) - c2 = RANGE_4GB; - - /* Don't align up or down on the range if it is smaller - * than the minimum granularity. */ - if ((c2 - a1) < MTRR_MIN_ALIGN) { - calc_var_mtrr_range(var_state, a1, c2 - a1, mtrr_type); - return; - } - - b1 = a2 = ALIGN_UP(a1, MTRR_MIN_ALIGN); - b2 = c1 = ALIGN_DOWN(c2, MTRR_MIN_ALIGN); + if (!var_state->above4gb && end > RANGE_4GB) + end = RANGE_4GB; - calc_var_mtrr_range(var_state, a1, a2 - a1, mtrr_type); - calc_var_mtrr_range(var_state, b1, b2 - b1, mtrr_type); - calc_var_mtrr_range(var_state, c1, c2 - c1, mtrr_type); + calc_var_mtrr_range(var_state, base, end - base, mtrr_type); } static void __calc_var_mtrrs(struct memranges *addr_space, -- cgit v1.2.3