diff options
| -rw-r--r-- | src/cpu/x86/mtrr/mtrr.c | 184 |
1 files changed, 55 insertions, 129 deletions
diff --git a/src/cpu/x86/mtrr/mtrr.c b/src/cpu/x86/mtrr/mtrr.c index 7b1b659097..13fe85f5a6 100644 --- a/src/cpu/x86/mtrr/mtrr.c +++ b/src/cpu/x86/mtrr/mtrr.c @@ -133,20 +133,8 @@ static void enable_var_mtrr(unsigned char deftype) #define RANGE_1MB PHYS_TO_RANGE_ADDR(1 << 20) #define RANGE_4GB (1 << (ADDR_SHIFT_TO_RANGE_SHIFT(32))) -/* - * The default MTRR type selection uses 3 approaches for selecting the - * optimal number of variable MTRRs. For each range do 3 calculations: - * 1. UC as default type with no holes at top of range. - * 2. UC as default using holes at top of range. - * 3. WB as default. - * If using holes is optimal for a range when UC is the default type the - * tag is updated to direct the commit routine to use a hole at the top - * of a range. - */ #define MTRR_ALGO_SHIFT (8) #define MTRR_TAG_MASK ((1 << MTRR_ALGO_SHIFT) - 1) -/* If the default type is UC use the hole carving algorithm for a range. */ -#define MTRR_RANGE_UC_USE_HOLE (1 << MTRR_ALGO_SHIFT) static inline uint32_t range_entry_base_mtrr_addr(struct range_entry *r) { @@ -557,9 +545,7 @@ static void calc_var_mtrrs_with_hole(struct var_mtrr_state *var_state, struct range_entry *r) { uint32_t a1, a2, b1, b2; - uint64_t b2_limit; int mtrr_type, carve_hole; - struct range_entry *next; /* * Determine MTRRs based on the following algorithm for the given entry: @@ -597,42 +583,50 @@ static void calc_var_mtrrs_with_hole(struct var_mtrr_state *var_state, a2 = RANGE_4GB; b1 = a2; - - /* - * Depending on the type of the next range, there are three - * different situations to handle: - * - * 1. WB range is last in address space: - * Aligning up, up to the next power of 2, may gain us - * something. - * - * 2. The next range is of type UC: - * We may align up, up to the _end_ of the next range. If - * there is a gap between the current and the next range, - * it would have been covered by the default type UC anyway. - * - * 3. The next range is not of type UC: - * We may align up, up to the _base_ of the next range. This - * may either be the end of the current range (if the next - * range follows immediately) or the end of the gap between - * the ranges. - */ - next = memranges_next_entry(var_state->addr_space, r); - if (next == NULL) { - b2_limit = ALIGN_UP((uint64_t)b1, 1 << fms(b1)); - /* If it's the last range above 4GiB, we won't carve - the hole out. If an OS wanted to move MMIO there, - it would have to override the MTRR setting using - PAT just like it would with WB as default type. */ - carve_hole = a1 < RANGE_4GB; - } else if (range_entry_mtrr_type(next) == MTRR_TYPE_UNCACHEABLE) { - b2_limit = range_entry_end_mtrr_addr(next); - carve_hole = 1; - } else { - b2_limit = range_entry_base_mtrr_addr(next); - carve_hole = 1; + b2 = a2; + carve_hole = 0; + + /* We only consider WB type ranges for hole-carving. */ + if (mtrr_type == MTRR_TYPE_WRBACK) { + struct range_entry *next; + uint64_t b2_limit; + /* + * Depending on the type of the next range, there are three + * different situations to handle: + * + * 1. WB range is last in address space: + * Aligning up, up to the next power of 2, may gain us + * something. + * + * 2. The next range is of type UC: + * We may align up, up to the _end_ of the next range. If + * there is a gap between the current and the next range, + * it would have been covered by the default type UC anyway. + * + * 3. The next range is not of type UC: + * We may align up, up to the _base_ of the next range. This + * may either be the end of the current range (if the next + * range follows immediately) or the end of the gap between + * the ranges. + */ + next = memranges_next_entry(var_state->addr_space, r); + if (next == NULL) { + b2_limit = ALIGN_UP((uint64_t)b1, 1 << fms(b1)); + /* If it's the last range above 4GiB, we won't carve + the hole out. If an OS wanted to move MMIO there, + it would have to override the MTRR setting using + PAT just like it would with WB as default type. */ + carve_hole = a1 < RANGE_4GB; + } else if (range_entry_mtrr_type(next) + == MTRR_TYPE_UNCACHEABLE) { + b2_limit = range_entry_end_mtrr_addr(next); + carve_hole = 1; + } else { + b2_limit = range_entry_base_mtrr_addr(next); + carve_hole = 1; + } + b2 = optimize_var_mtrr_hole(a1, b1, b2_limit, carve_hole); } - b2 = optimize_var_mtrr_hole(a1, b1, b2_limit, carve_hole); calc_var_mtrr_range(var_state, a1, b2 - a1, mtrr_type); if (carve_hole && b2 != b1) { @@ -641,37 +635,6 @@ 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) -{ - const int mtrr_type = range_entry_mtrr_type(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 (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 (base <= RANGE_1MB) - base = 0; - - /* If the range starts above 4GiB the processing is done. */ - 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 && end > RANGE_4GB) - end = RANGE_4GB; - - calc_var_mtrr_range(var_state, base, end - base, mtrr_type); -} - static void __calc_var_mtrrs(struct memranges *addr_space, int above4gb, int address_bits, int *num_def_wb_mtrrs, int *num_def_uc_mtrrs) @@ -693,16 +656,14 @@ static void __calc_var_mtrrs(struct memranges *addr_space, uc_deftype_count = 0; /* - * For each range do 3 calculations: - * 1. UC as default type with no holes at top of range. - * 2. UC as default using holes at top of range. - * 3. WB as default. + * For each range do 2 calculations: + * 1. UC as default type with possible holes at top of range. + * 2. WB as default. * The lowest count is then used as default after totaling all - * MTRRs. Note that the optimal algorithm for UC default is marked in - * the tag of each range regardless of final decision. UC takes - * precedence in the MTRR architecture. Therefore, only holes can be - * used when the type of the region is MTRR_TYPE_WRBACK with - * MTRR_TYPE_UNCACHEABLE as the default type. + * MTRRs. UC takes precedence in the MTRR architecture. There- + * fore, only holes can be used when the type of the region is + * MTRR_TYPE_WRBACK with MTRR_TYPE_UNCACHEABLE as the default + * type. */ memranges_each_entry(r, var_state.addr_space) { int mtrr_type; @@ -710,43 +671,16 @@ static void __calc_var_mtrrs(struct memranges *addr_space, mtrr_type = range_entry_mtrr_type(r); if (mtrr_type != MTRR_TYPE_UNCACHEABLE) { - int uc_hole_count; - int uc_no_hole_count; - - var_state.def_mtrr_type = MTRR_TYPE_UNCACHEABLE; var_state.mtrr_index = 0; - - /* No hole calculation. */ - calc_var_mtrrs_without_hole(&var_state, r); - uc_no_hole_count = var_state.mtrr_index; - - /* Hole calculation only if type is WB. The 64 number - * is a count that is unachievable, thus making it - * a default large number in the case of not doing - * the hole calculation. */ - uc_hole_count = 64; - if (mtrr_type == MTRR_TYPE_WRBACK) { - var_state.mtrr_index = 0; - calc_var_mtrrs_with_hole(&var_state, r); - uc_hole_count = var_state.mtrr_index; - } - - /* Mark the entry with the optimal algorithm. */ - if (uc_no_hole_count < uc_hole_count) { - uc_deftype_count += uc_no_hole_count; - } else { - unsigned long new_tag; - - new_tag = mtrr_type | MTRR_RANGE_UC_USE_HOLE; - range_entry_update_tag(r, new_tag); - uc_deftype_count += uc_hole_count; - } + var_state.def_mtrr_type = MTRR_TYPE_UNCACHEABLE; + calc_var_mtrrs_with_hole(&var_state, r); + uc_deftype_count += var_state.mtrr_index; } if (mtrr_type != MTRR_TYPE_WRBACK) { var_state.mtrr_index = 0; var_state.def_mtrr_type = MTRR_TYPE_WRBACK; - calc_var_mtrrs_without_hole(&var_state, r); + calc_var_mtrrs_with_hole(&var_state, r); wb_deftype_count += var_state.mtrr_index; } } @@ -803,12 +737,7 @@ static void prepare_var_mtrrs(struct memranges *addr_space, int def_type, memranges_each_entry(r, var_state.addr_space) { if (range_entry_mtrr_type(r) == def_type) continue; - - if (def_type == MTRR_TYPE_UNCACHEABLE && - (range_entry_tag(r) & MTRR_RANGE_UC_USE_HOLE)) - calc_var_mtrrs_with_hole(&var_state, r); - else - calc_var_mtrrs_without_hole(&var_state, r); + calc_var_mtrrs_with_hole(&var_state, r); } /* Update the solution. */ @@ -919,9 +848,6 @@ void mtrr_use_temp_range(uintptr_t begin, size_t size, int type) memranges_each_entry(r, orig) { unsigned long tag = range_entry_tag(r); - /* Remove any special tags from original solution. */ - tag &= ~MTRR_RANGE_UC_USE_HOLE; - /* Remove any write combining MTRRs from the temporary * solution as it just fragments the address space. */ if (tag == MTRR_TYPE_WRCOMB) |