| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Yinghai Lu | 4248 | 96.00% | 5 | 20.83% |
| Jaswinder Singh Rajput | 114 | 2.58% | 3 | 12.50% |
| Chen Yucong | 23 | 0.52% | 1 | 4.17% |
| Ingo Molnar | 10 | 0.23% | 6 | 25.00% |
| Toshi Kani | 9 | 0.20% | 1 | 4.17% |
| Pu Wen | 6 | 0.14% | 1 | 4.17% |
| Jan Beulich | 5 | 0.11% | 1 | 4.17% |
| Joe Perches | 3 | 0.07% | 1 | 4.17% |
| Zheng Yongjun | 2 | 0.05% | 1 | 4.17% |
| Rasmus Villemoes | 2 | 0.05% | 1 | 4.17% |
| Dave Jones | 1 | 0.02% | 1 | 4.17% |
| Brijesh Singh | 1 | 0.02% | 1 | 4.17% |
| Duan Zhenzhong | 1 | 0.02% | 1 | 4.17% |
| Total | 4425 | 24 |
/* * MTRR (Memory Type Range Register) cleanup * * Copyright (C) 2009 Yinghai Lu * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <linux/init.h> #include <linux/pci.h> #include <linux/smp.h> #include <linux/cpu.h> #include <linux/mutex.h> #include <linux/uaccess.h> #include <linux/kvm_para.h> #include <linux/range.h> #include <asm/processor.h> #include <asm/e820/api.h> #include <asm/mtrr.h> #include <asm/msr.h> #include "mtrr.h" struct var_mtrr_range_state { unsigned long base_pfn; unsigned long size_pfn; mtrr_type type; }; struct var_mtrr_state { unsigned long range_startk; unsigned long range_sizek; unsigned long chunk_sizek; unsigned long gran_sizek; unsigned int reg; }; /* Should be related to MTRR_VAR_RANGES nums */ #define RANGE_NUM 256 static struct range __initdata range[RANGE_NUM]; static int __initdata nr_range; static struct var_mtrr_range_state __initdata range_state[RANGE_NUM]; static int __initdata debug_print; #define Dprintk(x...) do { if (debug_print) pr_debug(x); } while (0) #define BIOS_BUG_MSG \ "WARNING: BIOS bug: VAR MTRR %d contains strange UC entry under 1M, check with your system vendor!\n" static int __init x86_get_mtrr_mem_range(struct range *range, int nr_range, unsigned long extra_remove_base, unsigned long extra_remove_size) { unsigned long base, size; mtrr_type type; int i; for (i = 0; i < num_var_ranges; i++) { type = range_state[i].type; if (type != MTRR_TYPE_WRBACK) continue; base = range_state[i].base_pfn; size = range_state[i].size_pfn; nr_range = add_range_with_merge(range, RANGE_NUM, nr_range, base, base + size); } if (debug_print) { pr_debug("After WB checking\n"); for (i = 0; i < nr_range; i++) pr_debug("MTRR MAP PFN: %016llx - %016llx\n", range[i].start, range[i].end); } /* Take out UC ranges: */ for (i = 0; i < num_var_ranges; i++) { type = range_state[i].type; if (type != MTRR_TYPE_UNCACHABLE && type != MTRR_TYPE_WRPROT) continue; size = range_state[i].size_pfn; if (!size) continue; base = range_state[i].base_pfn; if (base < (1<<(20-PAGE_SHIFT)) && mtrr_state.have_fixed && (mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED) && (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) { /* Var MTRR contains UC entry below 1M? Skip it: */ pr_warn(BIOS_BUG_MSG, i); if (base + size <= (1<<(20-PAGE_SHIFT))) continue; size -= (1<<(20-PAGE_SHIFT)) - base; base = 1<<(20-PAGE_SHIFT); } subtract_range(range, RANGE_NUM, base, base + size); } if (extra_remove_size) subtract_range(range, RANGE_NUM, extra_remove_base, extra_remove_base + extra_remove_size); if (debug_print) { pr_debug("After UC checking\n"); for (i = 0; i < RANGE_NUM; i++) { if (!range[i].end) continue; pr_debug("MTRR MAP PFN: %016llx - %016llx\n", range[i].start, range[i].end); } } /* sort the ranges */ nr_range = clean_sort_range(range, RANGE_NUM); if (debug_print) { pr_debug("After sorting\n"); for (i = 0; i < nr_range; i++) pr_debug("MTRR MAP PFN: %016llx - %016llx\n", range[i].start, range[i].end); } return nr_range; } #ifdef CONFIG_MTRR_SANITIZER static unsigned long __init sum_ranges(struct range *range, int nr_range) { unsigned long sum = 0; int i; for (i = 0; i < nr_range; i++) sum += range[i].end - range[i].start; return sum; } static int enable_mtrr_cleanup __initdata = CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT; static int __init disable_mtrr_cleanup_setup(char *str) { enable_mtrr_cleanup = 0; return 0; } early_param("disable_mtrr_cleanup", disable_mtrr_cleanup_setup); static int __init enable_mtrr_cleanup_setup(char *str) { enable_mtrr_cleanup = 1; return 0; } early_param("enable_mtrr_cleanup", enable_mtrr_cleanup_setup); static int __init mtrr_cleanup_debug_setup(char *str) { debug_print = 1; return 0; } early_param("mtrr_cleanup_debug", mtrr_cleanup_debug_setup); static void __init set_var_mtrr(unsigned int reg, unsigned long basek, unsigned long sizek, unsigned char type, unsigned int address_bits) { u32 base_lo, base_hi, mask_lo, mask_hi; u64 base, mask; if (!sizek) { fill_mtrr_var_range(reg, 0, 0, 0, 0); return; } mask = (1ULL << address_bits) - 1; mask &= ~((((u64)sizek) << 10) - 1); base = ((u64)basek) << 10; base |= type; mask |= 0x800; base_lo = base & ((1ULL<<32) - 1); base_hi = base >> 32; mask_lo = mask & ((1ULL<<32) - 1); mask_hi = mask >> 32; fill_mtrr_var_range(reg, base_lo, base_hi, mask_lo, mask_hi); } static void __init save_var_mtrr(unsigned int reg, unsigned long basek, unsigned long sizek, unsigned char type) { range_state[reg].base_pfn = basek >> (PAGE_SHIFT - 10); range_state[reg].size_pfn = sizek >> (PAGE_SHIFT - 10); range_state[reg].type = type; } static void __init set_var_mtrr_all(unsigned int address_bits) { unsigned long basek, sizek; unsigned char type; unsigned int reg; for (reg = 0; reg < num_var_ranges; reg++) { basek = range_state[reg].base_pfn << (PAGE_SHIFT - 10); sizek = range_state[reg].size_pfn << (PAGE_SHIFT - 10); type = range_state[reg].type; set_var_mtrr(reg, basek, sizek, type, address_bits); } } static unsigned long to_size_factor(unsigned long sizek, char *factorp) { unsigned long base = sizek; char factor; if (base & ((1<<10) - 1)) { /* Not MB-aligned: */ factor = 'K'; } else if (base & ((1<<20) - 1)) { factor = 'M'; base >>= 10; } else { factor = 'G'; base >>= 20; } *factorp = factor; return base; } static unsigned int __init range_to_mtrr(unsigned int reg, unsigned long range_startk, unsigned long range_sizek, unsigned char type) { if (!range_sizek || (reg >= num_var_ranges)) return reg; while (range_sizek) { unsigned long max_align, align; unsigned long sizek; /* Compute the maximum size with which we can make a range: */ if (range_startk) max_align = __ffs(range_startk); else max_align = BITS_PER_LONG - 1; align = __fls(range_sizek); if (align > max_align) align = max_align; sizek = 1UL << align; if (debug_print) { char start_factor = 'K', size_factor = 'K'; unsigned long start_base, size_base; start_base = to_size_factor(range_startk, &start_factor); size_base = to_size_factor(sizek, &size_factor); Dprintk("Setting variable MTRR %d, " "base: %ld%cB, range: %ld%cB, type %s\n", reg, start_base, start_factor, size_base, size_factor, (type == MTRR_TYPE_UNCACHABLE) ? "UC" : ((type == MTRR_TYPE_WRBACK) ? "WB" : "Other") ); } save_var_mtrr(reg++, range_startk, sizek, type); range_startk += sizek; range_sizek -= sizek; if (reg >= num_var_ranges) break; } return reg; } static unsigned __init range_to_mtrr_with_hole(struct var_mtrr_state *state, unsigned long basek, unsigned long sizek) { unsigned long hole_basek, hole_sizek; unsigned long second_sizek; unsigned long range0_basek, range0_sizek; unsigned long range_basek, range_sizek; unsigned long chunk_sizek; unsigned long gran_sizek; hole_basek = 0; hole_sizek = 0; second_sizek = 0; chunk_sizek = state->chunk_sizek; gran_sizek = state->gran_sizek; /* Align with gran size, prevent small block used up MTRRs: */ range_basek = ALIGN(state->range_startk, gran_sizek); if ((range_basek > basek) && basek) return second_sizek; state->range_sizek -= (range_basek - state->range_startk); range_sizek = ALIGN(state->range_sizek, gran_sizek); while (range_sizek > state->range_sizek) { range_sizek -= gran_sizek; if (!range_sizek) return 0; } state->range_sizek = range_sizek; /* Try to append some small hole: */ range0_basek = state->range_startk; range0_sizek = ALIGN(state->range_sizek, chunk_sizek); /* No increase: */ if (range0_sizek == state->range_sizek) { Dprintk("rangeX: %016lx - %016lx\n", range0_basek<<10, (range0_basek + state->range_sizek)<<10); state->reg = range_to_mtrr(state->reg, range0_basek, state->range_sizek, MTRR_TYPE_WRBACK); return 0; } /* Only cut back when it is not the last: */ if (sizek) { while (range0_basek + range0_sizek > (basek + sizek)) { if (range0_sizek >= chunk_sizek) range0_sizek -= chunk_sizek; else range0_sizek = 0; if (!range0_sizek) break; } } second_try: range_basek = range0_basek + range0_sizek; /* One hole in the middle: */ if (range_basek > basek && range_basek <= (basek + sizek)) second_sizek = range_basek - basek; if (range0_sizek > state->range_sizek) { /* One hole in middle or at the end: */ hole_sizek = range0_sizek - state->range_sizek - second_sizek; /* Hole size should be less than half of range0 size: */ if (hole_sizek >= (range0_sizek >> 1) && range0_sizek >= chunk_sizek) { range0_sizek -= chunk_sizek; second_sizek = 0; hole_sizek = 0; goto second_try; } } if (range0_sizek) { Dprintk("range0: %016lx - %016lx\n", range0_basek<<10, (range0_basek + range0_sizek)<<10); state->reg = range_to_mtrr(state->reg, range0_basek, range0_sizek, MTRR_TYPE_WRBACK); } if (range0_sizek < state->range_sizek) { /* Need to handle left over range: */ range_sizek = state->range_sizek - range0_sizek; Dprintk("range: %016lx - %016lx\n", range_basek<<10, (range_basek + range_sizek)<<10); state->reg = range_to_mtrr(state->reg, range_basek, range_sizek, MTRR_TYPE_WRBACK); } if (hole_sizek) { hole_basek = range_basek - hole_sizek - second_sizek; Dprintk("hole: %016lx - %016lx\n", hole_basek<<10, (hole_basek + hole_sizek)<<10); state->reg = range_to_mtrr(state->reg, hole_basek, hole_sizek, MTRR_TYPE_UNCACHABLE); } return second_sizek; } static void __init set_var_mtrr_range(struct var_mtrr_state *state, unsigned long base_pfn, unsigned long size_pfn) { unsigned long basek, sizek; unsigned long second_sizek = 0; if (state->reg >= num_var_ranges) return; basek = base_pfn << (PAGE_SHIFT - 10); sizek = size_pfn << (PAGE_SHIFT - 10); /* See if I can merge with the last range: */ if ((basek <= 1024) || (state->range_startk + state->range_sizek == basek)) { unsigned long endk = basek + sizek; state->range_sizek = endk - state->range_startk; return; } /* Write the range mtrrs: */ if (state->range_sizek != 0) second_sizek = range_to_mtrr_with_hole(state, basek, sizek); /* Allocate an msr: */ state->range_startk = basek + second_sizek; state->range_sizek = sizek - second_sizek; } /* Minimum size of mtrr block that can take hole: */ static u64 mtrr_chunk_size __initdata = (256ULL<<20); static int __init parse_mtrr_chunk_size_opt(char *p) { if (!p) return -EINVAL; mtrr_chunk_size = memparse(p, &p); return 0; } early_param("mtrr_chunk_size", parse_mtrr_chunk_size_opt); /* Granularity of mtrr of block: */ static u64 mtrr_gran_size __initdata; static int __init parse_mtrr_gran_size_opt(char *p) { if (!p) return -EINVAL; mtrr_gran_size = memparse(p, &p); return 0; } early_param("mtrr_gran_size", parse_mtrr_gran_size_opt); static unsigned long nr_mtrr_spare_reg __initdata = CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT; static int __init parse_mtrr_spare_reg(char *arg) { if (arg) nr_mtrr_spare_reg = simple_strtoul(arg, NULL, 0); return 0; } early_param("mtrr_spare_reg_nr", parse_mtrr_spare_reg); static int __init x86_setup_var_mtrrs(struct range *range, int nr_range, u64 chunk_size, u64 gran_size) { struct var_mtrr_state var_state; int num_reg; int i; var_state.range_startk = 0; var_state.range_sizek = 0; var_state.reg = 0; var_state.chunk_sizek = chunk_size >> 10; var_state.gran_sizek = gran_size >> 10; memset(range_state, 0, sizeof(range_state)); /* Write the range: */ for (i = 0; i < nr_range; i++) { set_var_mtrr_range(&var_state, range[i].start, range[i].end - range[i].start); } /* Write the last range: */ if (var_state.range_sizek != 0) range_to_mtrr_with_hole(&var_state, 0, 0); num_reg = var_state.reg; /* Clear out the extra MTRR's: */ while (var_state.reg < num_var_ranges) { save_var_mtrr(var_state.reg, 0, 0, 0); var_state.reg++; } return num_reg; } struct mtrr_cleanup_result { unsigned long gran_sizek; unsigned long chunk_sizek; unsigned long lose_cover_sizek; unsigned int num_reg; int bad; }; /* * gran_size: 64K, 128K, 256K, 512K, 1M, 2M, ..., 2G * chunk size: gran_size, ..., 2G * so we need (1+16)*8 */ #define NUM_RESULT 136 #define PSHIFT (PAGE_SHIFT - 10) static struct mtrr_cleanup_result __initdata result[NUM_RESULT]; static unsigned long __initdata min_loss_pfn[RANGE_NUM]; static void __init print_out_mtrr_range_state(void) { char start_factor = 'K', size_factor = 'K'; unsigned long start_base, size_base; mtrr_type type; int i; for (i = 0; i < num_var_ranges; i++) { size_base = range_state[i].size_pfn << (PAGE_SHIFT - 10); if (!size_base) continue; size_base = to_size_factor(size_base, &size_factor); start_base = range_state[i].base_pfn << (PAGE_SHIFT - 10); start_base = to_size_factor(start_base, &start_factor); type = range_state[i].type; pr_debug("reg %d, base: %ld%cB, range: %ld%cB, type %s\n", i, start_base, start_factor, size_base, size_factor, (type == MTRR_TYPE_UNCACHABLE) ? "UC" : ((type == MTRR_TYPE_WRPROT) ? "WP" : ((type == MTRR_TYPE_WRBACK) ? "WB" : "Other")) ); } } static int __init mtrr_need_cleanup(void) { int i; mtrr_type type; unsigned long size; /* Extra one for all 0: */ int num[MTRR_NUM_TYPES + 1]; /* Check entries number: */ memset(num, 0, sizeof(num)); for (i = 0; i < num_var_ranges; i++) { type = range_state[i].type; size = range_state[i].size_pfn; if (type >= MTRR_NUM_TYPES) continue; if (!size) type = MTRR_NUM_TYPES; num[type]++; } /* Check if we got UC entries: */ if (!num[MTRR_TYPE_UNCACHABLE]) return 0; /* Check if we only had WB and UC */ if (num[MTRR_TYPE_WRBACK] + num[MTRR_TYPE_UNCACHABLE] != num_var_ranges - num[MTRR_NUM_TYPES]) return 0; return 1; } static unsigned long __initdata range_sums; static void __init mtrr_calc_range_state(u64 chunk_size, u64 gran_size, unsigned long x_remove_base, unsigned long x_remove_size, int i) { /* * range_new should really be an automatic variable, but * putting 4096 bytes on the stack is frowned upon, to put it * mildly. It is safe to make it a static __initdata variable, * since mtrr_calc_range_state is only called during init and * there's no way it will call itself recursively. */ static struct range range_new[RANGE_NUM] __initdata; unsigned long range_sums_new; int nr_range_new; int num_reg; /* Convert ranges to var ranges state: */ num_reg = x86_setup_var_mtrrs(range, nr_range, chunk_size, gran_size); /* We got new setting in range_state, check it: */ memset(range_new, 0, sizeof(range_new)); nr_range_new = x86_get_mtrr_mem_range(range_new, 0, x_remove_base, x_remove_size); range_sums_new = sum_ranges(range_new, nr_range_new); result[i].chunk_sizek = chunk_size >> 10; result[i].gran_sizek = gran_size >> 10; result[i].num_reg = num_reg; if (range_sums < range_sums_new) { result[i].lose_cover_sizek = (range_sums_new - range_sums) << PSHIFT; result[i].bad = 1; } else { result[i].lose_cover_sizek = (range_sums - range_sums_new) << PSHIFT; } /* Double check it: */ if (!result[i].bad && !result[i].lose_cover_sizek) { if (nr_range_new != nr_range || memcmp(range, range_new, sizeof(range))) result[i].bad = 1; } if (!result[i].bad && (range_sums - range_sums_new < min_loss_pfn[num_reg])) min_loss_pfn[num_reg] = range_sums - range_sums_new; } static void __init mtrr_print_out_one_result(int i) { unsigned long gran_base, chunk_base, lose_base; char gran_factor, chunk_factor, lose_factor; gran_base = to_size_factor(result[i].gran_sizek, &gran_factor); chunk_base = to_size_factor(result[i].chunk_sizek, &chunk_factor); lose_base = to_size_factor(result[i].lose_cover_sizek, &lose_factor); pr_info("%sgran_size: %ld%c \tchunk_size: %ld%c \t", result[i].bad ? "*BAD*" : " ", gran_base, gran_factor, chunk_base, chunk_factor); pr_cont("num_reg: %d \tlose cover RAM: %s%ld%c\n", result[i].num_reg, result[i].bad ? "-" : "", lose_base, lose_factor); } static int __init mtrr_search_optimal_index(void) { int num_reg_good; int index_good; int i; if (nr_mtrr_spare_reg >= num_var_ranges) nr_mtrr_spare_reg = num_var_ranges - 1; num_reg_good = -1; for (i = num_var_ranges - nr_mtrr_spare_reg; i > 0; i--) { if (!min_loss_pfn[i]) num_reg_good = i; } index_good = -1; if (num_reg_good != -1) { for (i = 0; i < NUM_RESULT; i++) { if (!result[i].bad && result[i].num_reg == num_reg_good && !result[i].lose_cover_sizek) { index_good = i; break; } } } return index_good; } int __init mtrr_cleanup(unsigned address_bits) { unsigned long x_remove_base, x_remove_size; unsigned long base, size, def, dummy; u64 chunk_size, gran_size; mtrr_type type; int index_good; int i; if (!is_cpu(INTEL) || enable_mtrr_cleanup < 1) return 0; rdmsr(MSR_MTRRdefType, def, dummy); def &= 0xff; if (def != MTRR_TYPE_UNCACHABLE) return 0; /* Get it and store it aside: */ memset(range_state, 0, sizeof(range_state)); for (i = 0; i < num_var_ranges; i++) { mtrr_if->get(i, &base, &size, &type); range_state[i].base_pfn = base; range_state[i].size_pfn = size; range_state[i].type = type; } /* Check if we need handle it and can handle it: */ if (!mtrr_need_cleanup()) return 0; /* Print original var MTRRs at first, for debugging: */ pr_debug("original variable MTRRs\n"); print_out_mtrr_range_state(); memset(range, 0, sizeof(range)); x_remove_size = 0; x_remove_base = 1 << (32 - PAGE_SHIFT); if (mtrr_tom2) x_remove_size = (mtrr_tom2 >> PAGE_SHIFT) - x_remove_base; /* * [0, 1M) should always be covered by var mtrr with WB * and fixed mtrrs should take effect before var mtrr for it: */ nr_range = add_range_with_merge(range, RANGE_NUM, 0, 0, 1ULL<<(20 - PAGE_SHIFT)); /* add from var mtrr at last */ nr_range = x86_get_mtrr_mem_range(range, nr_range, x_remove_base, x_remove_size); range_sums = sum_ranges(range, nr_range); pr_info("total RAM covered: %ldM\n", range_sums >> (20 - PAGE_SHIFT)); if (mtrr_chunk_size && mtrr_gran_size) { i = 0; mtrr_calc_range_state(mtrr_chunk_size, mtrr_gran_size, x_remove_base, x_remove_size, i); mtrr_print_out_one_result(i); if (!result[i].bad) { set_var_mtrr_all(address_bits); pr_debug("New variable MTRRs\n"); print_out_mtrr_range_state(); return 1; } pr_info("invalid mtrr_gran_size or mtrr_chunk_size, will find optimal one\n"); } i = 0; memset(min_loss_pfn, 0xff, sizeof(min_loss_pfn)); memset(result, 0, sizeof(result)); for (gran_size = (1ULL<<16); gran_size < (1ULL<<32); gran_size <<= 1) { for (chunk_size = gran_size; chunk_size < (1ULL<<32); chunk_size <<= 1) { if (i >= NUM_RESULT) continue; mtrr_calc_range_state(chunk_size, gran_size, x_remove_base, x_remove_size, i); if (debug_print) { mtrr_print_out_one_result(i); pr_info("\n"); } i++; } } /* Try to find the optimal index: */ index_good = mtrr_search_optimal_index(); if (index_good != -1) { pr_info("Found optimal setting for mtrr clean up\n"); i = index_good; mtrr_print_out_one_result(i); /* Convert ranges to var ranges state: */ chunk_size = result[i].chunk_sizek; chunk_size <<= 10; gran_size = result[i].gran_sizek; gran_size <<= 10; x86_setup_var_mtrrs(range, nr_range, chunk_size, gran_size); set_var_mtrr_all(address_bits); pr_debug("New variable MTRRs\n"); print_out_mtrr_range_state(); return 1; } else { /* print out all */ for (i = 0; i < NUM_RESULT; i++) mtrr_print_out_one_result(i); } pr_info("mtrr_cleanup: can not find optimal value\n"); pr_info("please specify mtrr_gran_size/mtrr_chunk_size\n"); return 0; } #else int __init mtrr_cleanup(unsigned address_bits) { return 0; } #endif static int disable_mtrr_trim; static int __init disable_mtrr_trim_setup(char *str) { disable_mtrr_trim = 1; return 0; } early_param("disable_mtrr_trim", disable_mtrr_trim_setup); /* * Newer AMD K8s and later CPUs have a special magic MSR way to force WB * for memory >4GB. Check for that here. * Note this won't check if the MTRRs < 4GB where the magic bit doesn't * apply to are wrong, but so far we don't know of any such case in the wild. */ #define Tom2Enabled (1U << 21) #define Tom2ForceMemTypeWB (1U << 22) int __init amd_special_default_mtrr(void) { u32 l, h; if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD && boot_cpu_data.x86_vendor != X86_VENDOR_HYGON) return 0; if (boot_cpu_data.x86 < 0xf) return 0; /* In case some hypervisor doesn't pass SYSCFG through: */ if (rdmsr_safe(MSR_AMD64_SYSCFG, &l, &h) < 0) return 0; /* * Memory between 4GB and top of mem is forced WB by this magic bit. * Reserved before K8RevF, but should be zero there. */ if ((l & (Tom2Enabled | Tom2ForceMemTypeWB)) == (Tom2Enabled | Tom2ForceMemTypeWB)) return 1; return 0; } static u64 __init real_trim_memory(unsigned long start_pfn, unsigned long limit_pfn) { u64 trim_start, trim_size; trim_start = start_pfn; trim_start <<= PAGE_SHIFT; trim_size = limit_pfn; trim_size <<= PAGE_SHIFT; trim_size -= trim_start; return e820__range_update(trim_start, trim_size, E820_TYPE_RAM, E820_TYPE_RESERVED); } /** * mtrr_trim_uncached_memory - trim RAM not covered by MTRRs * @end_pfn: ending page frame number * * Some buggy BIOSes don't setup the MTRRs properly for systems with certain * memory configurations. This routine checks that the highest MTRR matches * the end of memory, to make sure the MTRRs having a write back type cover * all of the memory the kernel is intending to use. If not, it'll trim any * memory off the end by adjusting end_pfn, removing it from the kernel's * allocation pools, warning the user with an obnoxious message. */ int __init mtrr_trim_uncached_memory(unsigned long end_pfn) { unsigned long i, base, size, highest_pfn = 0, def, dummy; mtrr_type type; u64 total_trim_size; /* extra one for all 0 */ int num[MTRR_NUM_TYPES + 1]; /* * Make sure we only trim uncachable memory on machines that * support the Intel MTRR architecture: */ if (!is_cpu(INTEL) || disable_mtrr_trim) return 0; rdmsr(MSR_MTRRdefType, def, dummy); def &= 0xff; if (def != MTRR_TYPE_UNCACHABLE) return 0; /* Get it and store it aside: */ memset(range_state, 0, sizeof(range_state)); for (i = 0; i < num_var_ranges; i++) { mtrr_if->get(i, &base, &size, &type); range_state[i].base_pfn = base; range_state[i].size_pfn = size; range_state[i].type = type; } /* Find highest cached pfn: */ for (i = 0; i < num_var_ranges; i++) { type = range_state[i].type; if (type != MTRR_TYPE_WRBACK) continue; base = range_state[i].base_pfn; size = range_state[i].size_pfn; if (highest_pfn < base + size) highest_pfn = base + size; } /* kvm/qemu doesn't have mtrr set right, don't trim them all: */ if (!highest_pfn) { pr_info("CPU MTRRs all blank - virtualized system.\n"); return 0; } /* Check entries number: */ memset(num, 0, sizeof(num)); for (i = 0; i < num_var_ranges; i++) { type = range_state[i].type; if (type >= MTRR_NUM_TYPES) continue; size = range_state[i].size_pfn; if (!size) type = MTRR_NUM_TYPES; num[type]++; } /* No entry for WB? */ if (!num[MTRR_TYPE_WRBACK]) return 0; /* Check if we only had WB and UC: */ if (num[MTRR_TYPE_WRBACK] + num[MTRR_TYPE_UNCACHABLE] != num_var_ranges - num[MTRR_NUM_TYPES]) return 0; memset(range, 0, sizeof(range)); nr_range = 0; if (mtrr_tom2) { range[nr_range].start = (1ULL<<(32 - PAGE_SHIFT)); range[nr_range].end = mtrr_tom2 >> PAGE_SHIFT; if (highest_pfn < range[nr_range].end) highest_pfn = range[nr_range].end; nr_range++; } nr_range = x86_get_mtrr_mem_range(range, nr_range, 0, 0); /* Check the head: */ total_trim_size = 0; if (range[0].start) total_trim_size += real_trim_memory(0, range[0].start); /* Check the holes: */ for (i = 0; i < nr_range - 1; i++) { if (range[i].end < range[i+1].start) total_trim_size += real_trim_memory(range[i].end, range[i+1].start); } /* Check the top: */ i = nr_range - 1; if (range[i].end < end_pfn) total_trim_size += real_trim_memory(range[i].end, end_pfn); if (total_trim_size) { pr_warn("WARNING: BIOS bug: CPU MTRRs don't cover all of memory, losing %lluMB of RAM.\n", total_trim_size >> 20); if (!changed_by_mtrr_cleanup) WARN_ON(1); pr_info("update e820 for mtrr\n"); e820__update_table_print(); return 1; } return 0; }
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