// SPDX-License-Identifier: GPL-2.0-only /* * This only handles 32bit MTRR on 32bit hosts. This is strictly wrong * because MTRRs can span up to 40 bits (36bits on most modern x86) */ #define DEBUG #include #include #include #include #include #include #include #include #include #include #include "mtrr.h" struct fixed_range_block { int base_msr; /* start address of an MTRR block */ int ranges; /* number of MTRRs in this block */ }; static struct fixed_range_block fixed_range_blocks[] = { { MSR_MTRRfix64K_00000, 1 }, /* one 64k MTRR */ { MSR_MTRRfix16K_80000, 2 }, /* two 16k MTRRs */ { MSR_MTRRfix4K_C0000, 8 }, /* eight 4k MTRRs */ {} }; static unsigned long smp_changes_mask; static int mtrr_state_set; u64 mtrr_tom2; struct mtrr_state_type mtrr_state; EXPORT_SYMBOL_GPL(mtrr_state); /* * BIOS is expected to clear MtrrFixDramModEn bit, see for example * "BIOS and Kernel Developer's Guide for the AMD Athlon 64 and AMD * Opteron Processors" (26094 Rev. 3.30 February 2006), section * "13.2.1.2 SYSCFG Register": "The MtrrFixDramModEn bit should be set * to 1 during BIOS initialization of the fixed MTRRs, then cleared to * 0 for operation." */ static inline void k8_check_syscfg_dram_mod_en(void) { u32 lo, hi; if (!((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && (boot_cpu_data.x86 >= 0x0f))) return; rdmsr(MSR_K8_SYSCFG, lo, hi); if (lo & K8_MTRRFIXRANGE_DRAM_MODIFY) { pr_err(FW_WARN "MTRR: CPU %u: SYSCFG[MtrrFixDramModEn]" " not cleared by BIOS, clearing this bit\n", smp_processor_id()); lo &= ~K8_MTRRFIXRANGE_DRAM_MODIFY; mtrr_wrmsr(MSR_K8_SYSCFG, lo, hi); } } /* Get the size of contiguous MTRR range */ static u64 get_mtrr_size(u64 mask) { u64 size; mask >>= PAGE_SHIFT; mask |= size_or_mask; size = -mask; size <<= PAGE_SHIFT; return size; } /* * Check and return the effective type for MTRR-MTRR type overlap. * Returns 1 if the effective type is UNCACHEABLE, else returns 0 */ static int check_type_overlap(u8 *prev, u8 *curr) { if (*prev == MTRR_TYPE_UNCACHABLE || *curr == MTRR_TYPE_UNCACHABLE) { *prev = MTRR_TYPE_UNCACHABLE; *curr = MTRR_TYPE_UNCACHABLE; return 1; } if ((*prev == MTRR_TYPE_WRBACK && *curr == MTRR_TYPE_WRTHROUGH) || (*prev == MTRR_TYPE_WRTHROUGH && *curr == MTRR_TYPE_WRBACK)) { *prev = MTRR_TYPE_WRTHROUGH; *curr = MTRR_TYPE_WRTHROUGH; } if (*prev != *curr) { *prev = MTRR_TYPE_UNCACHABLE; *curr = MTRR_TYPE_UNCACHABLE; return 1; } return 0; } /** * mtrr_type_lookup_fixed - look up memory type in MTRR fixed entries * * Return the MTRR fixed memory type of 'start'. * * MTRR fixed entries are divided into the following ways: * 0x00000 - 0x7FFFF : This range is divided into eight 64KB sub-ranges * 0x80000 - 0xBFFFF : This range is divided into sixteen 16KB sub-ranges * 0xC0000 - 0xFFFFF : This range is divided into sixty-four 4KB sub-ranges * * Return Values: * MTRR_TYPE_(type) - Matched memory type * MTRR_TYPE_INVALID - Unmatched */ static u8 mtrr_type_lookup_fixed(u64 start, u64 end) { int idx; if (start >= 0x100000) return MTRR_TYPE_INVALID; /* 0x0 - 0x7FFFF */ if (start < 0x80000) { idx = 0; idx += (start >> 16); return mtrr_state.fixed_ranges[idx]; /* 0x80000 - 0xBFFFF */ } else if (start < 0xC0000) { idx = 1 * 8; idx += ((start - 0x80000) >> 14); return mtrr_state.fixed_ranges[idx]; } /* 0xC0000 - 0xFFFFF */ idx = 3 * 8; idx += ((start - 0xC0000) >> 12); return mtrr_state.fixed_ranges[idx]; } /** * mtrr_type_lookup_variable - look up memory type in MTRR variable entries * * Return Value: * MTRR_TYPE_(type) - Matched memory type or default memory type (unmatched) * * Output Arguments: * repeat - Set to 1 when [start:end] spanned across MTRR range and type * returned corresponds only to [start:*partial_end]. Caller has * to lookup again for [*partial_end:end]. * * uniform - Set to 1 when an MTRR covers the region uniformly, i.e. the * region is fully covered by a single MTRR entry or the default * type. */ static u8 mtrr_type_lookup_variable(u64 start, u64 end, u64 *partial_end, int *repeat, u8 *uniform) { int i; u64 base, mask; u8 prev_match, curr_match; *repeat = 0; *uniform = 1; prev_match = MTRR_TYPE_INVALID; for (i = 0; i < num_var_ranges; ++i) { unsigned short start_state, end_state, inclusive; if (!(mtrr_state.var_ranges[i].mask_lo & (1 << 11))) continue; base = (((u64)mtrr_state.var_ranges[i].base_hi) << 32) + (mtrr_state.var_ranges[i].base_lo & PAGE_MASK); mask = (((u64)mtrr_state.var_ranges[i].mask_hi) << 32) + (mtrr_state.var_ranges[i].mask_lo & PAGE_MASK); start_state = ((start & mask) == (base & mask)); end_state = ((end & mask) == (base & mask)); inclusive = ((start < base) && (end > base)); if ((start_state != end_state) || inclusive) { /* * We have start:end spanning across an MTRR. * We split the region into either * * - start_state:1 * (start:mtrr_end)(mtrr_end:end) * - end_state:1 * (start:mtrr_start)(mtrr_start:end) * - inclusive:1 * (start:mtrr_start)(mtrr_start:mtrr_end)(mtrr_end:end) * * depending on kind of overlap. * * Return the type of the first region and a pointer * to the start of next region so that caller will be * advised to lookup again after having adjusted start * and end. * * Note: This way we handle overlaps with multiple * entries and the default type properly. */ if (start_state) *partial_end = base + get_mtrr_size(mask); else *partial_end = base; if (unlikely(*partial_end <= start)) { WARN_ON(1); *partial_end = start + PAGE_SIZE; } end = *partial_end - 1; /* end is inclusive */ *repeat = 1; *uniform = 0; } if ((start & mask) != (base & mask)) continue; curr_match = mtrr_state.var_ranges[i].base_lo & 0xff; if (prev_match == MTRR_TYPE_INVALID) { prev_match = curr_match; continue; } *uniform = 0; if (check_type_overlap(&prev_match, &curr_match)) return curr_match; } if (prev_match != MTRR_TYPE_INVALID) return prev_match; return mtrr_state.def_type; } /** * mtrr_type_lookup - look up memory type in MTRR * * Return Values: * MTRR_TYPE_(type) - The effective MTRR type for the region * MTRR_TYPE_INVALID - MTRR is disabled * * Output Argument: * uniform - Set to 1 when an MTRR covers the region uniformly, i.e. the * region is fully covered by a single MTRR entry or the default * type. */ u8 mtrr_type_lookup(u64 start, u64 end, u8 *uniform) { u8 type, prev_type, is_uniform = 1, dummy; int repeat; u64 partial_end; /* Make end inclusive instead of exclusive */ end--; if (!mtrr_state_set) return MTRR_TYPE_INVALID; if (!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED)) return MTRR_TYPE_INVALID; /* * Look up the fixed ranges first, which take priority over * the variable ranges. */ if ((start < 0x100000) && (mtrr_state.have_fixed) && (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) { is_uniform = 0; type = mtrr_type_lookup_fixed(start, end); goto out; } /* * Look up the variable ranges. Look of multiple ranges matching * this address and pick type as per MTRR precedence. */ type = mtrr_type_lookup_variable(start, end, &partial_end, &repeat, &is_uniform); /* * Common path is with repeat = 0. * However, we can have cases where [start:end] spans across some * MTRR ranges and/or the default type. Do repeated lookups for * that case here. */ while (repeat) { prev_type = type; start = partial_end; is_uniform = 0; type = mtrr_type_lookup_variable(start, end, &partial_end, &repeat, &dummy); if (check_type_overlap(&prev_type, &type)) goto out; } if (mtrr_tom2 && (start >= (1ULL<<32)) && (end < mtrr_tom2)) type = MTRR_TYPE_WRBACK; out: *uniform = is_uniform; return type; } /* Get the MSR pair relating to a var range */ static void get_mtrr_var_range(unsigned int index, struct mtrr_var_range *vr) { rdmsr(MTRRphysBase_MSR(index), vr->base_lo, vr->base_hi); rdmsr(MTRRphysMask_MSR(index), vr->mask_lo, vr->mask_hi); } /* Fill the MSR pair relating to a var range */ void fill_mtrr_var_range(unsigned int index, u32 base_lo, u32 base_hi, u32 mask_lo, u32 mask_hi) { struct mtrr_var_range *vr; vr = mtrr_state.var_ranges; vr[index].base_lo = base_lo; vr[index].base_hi = base_hi; vr[index].mask_lo = mask_lo; vr[index].mask_hi = mask_hi; } static void get_fixed_ranges(mtrr_type *frs) { unsigned int *p = (unsigned int *)frs; int i; k8_check_syscfg_dram_mod_en(); rdmsr(MSR_MTRRfix64K_00000, p[0], p[1]); for (i = 0; i < 2; i++) rdmsr(MSR_MTRRfix16K_80000 + i, p[2 + i * 2], p[3 + i * 2]); for (i = 0; i < 8; i++) rdmsr(MSR_MTRRfix4K_C0000 + i, p[6 + i * 2], p[7 + i * 2]); } void mtrr_save_fixed_ranges(void *info) { if (boot_cpu_has(X86_FEATURE_MTRR)) get_fixed_ranges(mtrr_state.fixed_ranges); } static unsigned __initdata last_fixed_start; static unsigned __initdata last_fixed_end; static mtrr_type __initdata last_fixed_type; static void __init print_fixed_last(void) { if (!last_fixed_end) return; pr_debug(" %05X-%05X %s\n", last_fixed_start, last_fixed_end - 1, mtrr_attrib_to_str(last_fixed_type)); last_fixed_end = 0; } static void __init update_fixed_last(unsigned base, unsigned end, mtrr_type type) { last_fixed_start = base; last_fixed_end = end; last_fixed_type = type; } static void __init print_fixed(unsigned base, unsigned step, const mtrr_type *types) { unsigned i; for (i = 0; i < 8; ++i, ++types, base += step) { if (last_fixed_end == 0) { update_fixed_last(base, base + step, *types); continue; } if (last_fixed_end == base && last_fixed_type == *types) { last_fixed_end = base + step; continue; } /* new segments: gap or different type */ print_fixed_last(); update_fixed_last(base, base + step, *types); } } static void prepare_set(void); static void post_set(void); static void __init print_mtrr_state(void) { unsigned int i; int high_width; pr_debug("MTRR default type: %s\n", mtrr_attrib_to_str(mtrr_state.def_type)); if (mtrr_state.have_fixed) { pr_debug("MTRR fixed ranges %sabled:\n", ((mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED) && (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) ? "en" : "dis"); print_fixed(0x00000, 0x10000, mtrr_state.fixed_ranges + 0); for (i = 0; i < 2; ++i) print_fixed(0x80000 + i * 0x20000, 0x04000, mtrr_state.fixed_ranges + (i + 1) * 8); for (i = 0; i < 8; ++i) print_fixed(0xC0000 + i * 0x08000, 0x01000, mtrr_state.fixed_ranges + (i + 3) * 8); /* tail */ print_fixed_last(); } pr_debug("MTRR variable ranges %sabled:\n", mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED ? "en" : "dis"); high_width = (__ffs64(size_or_mask) - (32 - PAGE_SHIFT) + 3) / 4; for (i = 0; i < num_var_ranges; ++i) { if (mtrr_state.var_ranges[i].mask_lo & (1 << 11)) pr_debug(" %u base %0*X%05X000 mask %0*X%05X000 %s\n", i, high_width, mtrr_state.var_ranges[i].base_hi, mtrr_state.var_ranges[i].base_lo >> 12, high_width, mtrr_state.var_ranges[i].mask_hi, mtrr_state.var_ranges[i].mask_lo >> 12, mtrr_attrib_to_str(mtrr_state.var_ranges[i].base_lo & 0xff)); else pr_debug(" %u disabled\n", i); } if (mtrr_tom2) pr_debug("TOM2: %016llx aka %lldM\n", mtrr_tom2, mtrr_tom2>>20); } /* PAT setup for BP. We need to go through sync steps here */ void __init mtrr_bp_pat_init(void) { unsigned long flags; local_irq_save(flags); prepare_set(); pat_init(); post_set(); local_irq_restore(flags); } /* Grab all of the MTRR state for this CPU into *state */ bool __init get_mtrr_state(void) { struct mtrr_var_range *vrs; unsigned lo, dummy; unsigned int i; vrs = mtrr_state.var_ranges; rdmsr(MSR_MTRRcap, lo, dummy); mtrr_state.have_fixed = (lo >> 8) & 1; for (i = 0; i < num_var_ranges; i++) get_mtrr_var_range(i, &vrs[i]); if (mtrr_state.have_fixed) get_fixed_ranges(mtrr_state.fixed_ranges); rdmsr(MSR_MTRRdefType, lo, dummy); mtrr_state.def_type = (lo & 0xff); mtrr_state.enabled = (lo & 0xc00) >> 10; if (amd_special_default_mtrr()) { unsigned low, high; /* TOP_MEM2 */ rdmsr(MSR_K8_TOP_MEM2, low, high); mtrr_tom2 = high; mtrr_tom2 <<= 32; mtrr_tom2 |= low; mtrr_tom2 &= 0xffffff800000ULL; } print_mtrr_state(); mtrr_state_set = 1; return !!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED); } /* Some BIOS's are messed up and don't set all MTRRs the same! */ void __init mtrr_state_warn(void) { unsigned long mask = smp_changes_mask; if (!mask) return; if (mask & MTRR_CHANGE_MASK_FIXED) pr_warn("mtrr: your CPUs had inconsistent fixed MTRR settings\n"); if (mask & MTRR_CHANGE_MASK_VARIABLE) pr_warn("mtrr: your CPUs had inconsistent variable MTRR settings\n"); if (mask & MTRR_CHANGE_MASK_DEFTYPE) pr_warn("mtrr: your CPUs had inconsistent MTRRdefType settings\n"); pr_info("mtrr: probably your BIOS does not setup all CPUs.\n"); pr_info("mtrr: corrected configuration.\n"); } /* * Doesn't attempt to pass an error out to MTRR users * because it's quite complicated in some cases and probably not * worth it because the best error handling is to ignore it. */ void mtrr_wrmsr(unsigned msr, unsigned a, unsigned b) { if (wrmsr_safe(msr, a, b) < 0) { pr_err("MTRR: CPU %u: Writing MSR %x to %x:%x failed\n", smp_processor_id(), msr, a, b); } } /** * set_fixed_range - checks & updates a fixed-range MTRR if it * differs from the value it should have * @msr: MSR address of the MTTR which should be checked and updated * @changed: pointer which indicates whether the MTRR needed to be changed * @msrwords: pointer to the MSR values which the MSR should have */ static void set_fixed_range(int msr, bool *changed, unsigned int *msrwords) { unsigned lo, hi; rdmsr(msr, lo, hi); if (lo != msrwords[0] || hi != msrwords[1]) { mtrr_wrmsr(msr, msrwords[0], msrwords[1]); *changed = true; } } /** * generic_get_free_region - Get a free MTRR. * @base: The starting (base) address of the region. * @size: The size (in bytes) of the region. * @replace_reg: mtrr index to be replaced; set to invalid value if none. * * Returns: The index of the region on success, else negative on error. */ int generic_get_free_region(unsigned long base, unsigned long size, int replace_reg) { unsigned long lbase, lsize; mtrr_type ltype; int i, max; max = num_var_ranges; if (replace_reg >= 0 && replace_reg < max) return replace_reg; for (i = 0; i < max; ++i) { mtrr_if->get(i, &lbase, &lsize, <ype); if (lsize == 0) return i; } return -ENOSPC; } static void generic_get_mtrr(unsigned int reg, unsigned long *base, unsigned long *size, mtrr_type *type) { u32 mask_lo, mask_hi, base_lo, base_hi; unsigned int hi; u64 tmp, mask; /* * get_mtrr doesn't need to update mtrr_state, also it could be called * from any cpu, so try to print it out directly. */ get_cpu(); rdmsr(MTRRphysMask_MSR(reg), mask_lo, mask_hi); if ((mask_lo & 0x800) == 0) { /* Invalid (i.e. free) range */ *base = 0; *size = 0; *type = 0; goto out_put_cpu; } rdmsr(MTRRphysBase_MSR(reg), base_lo, base_hi); /* Work out the shifted address mask: */ tmp = (u64)mask_hi << (32 - PAGE_SHIFT) | mask_lo >> PAGE_SHIFT; mask = size_or_mask | tmp; /* Expand tmp with high bits to all 1s: */ hi = fls64(tmp); if (hi > 0) { tmp |= ~((1ULL<<(hi - 1)) - 1); if (tmp != mask) { pr_warn("mtrr: your BIOS has configured an incorrect mask, fixing it.\n"); add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK); mask = tmp; } } /* * This works correctly if size is a power of two, i.e. a * contiguous range: */ *size = -mask; *base = (u64)base_hi << (32 - PAGE_SHIFT) | base_lo >> PAGE_SHIFT; *type = base_lo & 0xff; out_put_cpu: put_cpu(); } /** * set_fixed_ranges - checks & updates the fixed-range MTRRs if they * differ from the saved set * @frs: pointer to fixed-range MTRR values, saved by get_fixed_ranges() */ static int set_fixed_ranges(mtrr_type *frs) { unsigned long long *saved = (unsigned long long *)frs; bool changed = false; int block = -1, range; k8_check_syscfg_dram_mod_en(); while (fixed_range_blocks[++block].ranges) { for (range = 0; range < fixed_range_blocks[block].ranges; range++) set_fixed_range(fixed_range_blocks[block].base_msr + range, &changed, (unsigned int *)saved++); } return changed; } /* * Set the MSR pair relating to a var range. * Returns true if changes are made. */ static bool set_mtrr_var_ranges(unsigned int index, struct mtrr_var_range *vr) { unsigned int lo, hi; bool changed = false; rdmsr(MTRRphysBase_MSR(index), lo, hi); if ((vr->base_lo & 0xfffff0ffUL) != (lo & 0xfffff0ffUL) || (vr->base_hi & (size_and_mask >> (32 - PAGE_SHIFT))) != (hi & (size_and_mask >> (32 - PAGE_SHIFT)))) { mtrr_wrmsr(MTRRphysBase_MSR(index), vr->base_lo, vr->base_hi); changed = true; } rdmsr(MTRRphysMask_MSR(index), lo, hi); if ((vr->mask_lo & 0xfffff800UL) != (lo & 0xfffff800UL) || (vr->mask_hi & (size_and_mask >> (32 - PAGE_SHIFT))) != (hi & (size_and_mask >> (32 - PAGE_SHIFT)))) { mtrr_wrmsr(MTRRphysMask_MSR(index), vr->mask_lo, vr->mask_hi); changed = true; } return changed; } static u32 deftype_lo, deftype_hi; /** * set_mtrr_state - Set the MTRR state for this CPU. * * NOTE: The CPU must already be in a safe state for MTRR changes. * RETURNS: 0 if no changes made, else a mask indicating what was changed. */ static unsigned long set_mtrr_state(void) { unsigned long change_mask = 0; unsigned int i; for (i = 0; i < num_var_ranges; i++) { if (set_mtrr_var_ranges(i, &mtrr_state.var_ranges[i])) change_mask |= MTRR_CHANGE_MASK_VARIABLE; } if (mtrr_state.have_fixed && set_fixed_ranges(mtrr_state.fixed_ranges)) change_mask |= MTRR_CHANGE_MASK_FIXED; /* * Set_mtrr_restore restores the old value of MTRRdefType, * so to set it we fiddle with the saved value: */ if ((deftype_lo & 0xff) != mtrr_state.def_type || ((deftype_lo & 0xc00) >> 10) != mtrr_state.enabled) { deftype_lo = (deftype_lo & ~0xcff) | mtrr_state.def_type | (mtrr_state.enabled << 10); change_mask |= MTRR_CHANGE_MASK_DEFTYPE; } return change_mask; } static unsigned long cr4; static DEFINE_RAW_SPINLOCK(set_atomicity_lock); /* * Since we are disabling the cache don't allow any interrupts, * they would run extremely slow and would only increase the pain. * * The caller must ensure that local interrupts are disabled and * are reenabled after post_set() has been called. */ static void prepare_set(void) __acquires(set_atomicity_lock) { unsigned long cr0; /* * Note that this is not ideal * since the cache is only flushed/disabled for this CPU while the * MTRRs are changed, but changing this requires more invasive * changes to the way the kernel boots */ raw_spin_lock(&set_atomicity_lock); /* Enter the no-fill (CD=1, NW=0) cache mode and flush caches. */ cr0 = read_cr0() | X86_CR0_CD; write_cr0(cr0); /* * Cache flushing is the most time-consuming step when programming * the MTRRs. Fortunately, as per the Intel Software Development * Manual, we can skip it if the processor supports cache self- * snooping. */ if (!static_cpu_has(X86_FEATURE_SELFSNOOP)) wbinvd(); /* Save value of CR4 and clear Page Global Enable (bit 7) */ if (boot_cpu_has(X86_FEATURE_PGE)) { cr4 = __read_cr4(); __write_cr4(cr4 & ~X86_CR4_PGE); } /* Flush all TLBs via a mov %cr3, %reg; mov %reg, %cr3 */ count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL); flush_tlb_local(); /* Save MTRR state */ rdmsr(MSR_MTRRdefType, deftype_lo, deftype_hi); /* Disable MTRRs, and set the default type to uncached */ mtrr_wrmsr(MSR_MTRRdefType, deftype_lo & ~0xcff, deftype_hi); /* Again, only flush caches if we have to. */ if (!static_cpu_has(X86_FEATURE_SELFSNOOP)) wbinvd(); } static void post_set(void) __releases(set_atomicity_lock) { /* Flush TLBs (no need to flush caches - they are disabled) */ count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL); flush_tlb_local(); /* Intel (P6) standard MTRRs */ mtrr_wrmsr(MSR_MTRRdefType, deftype_lo, deftype_hi); /* Enable caches */ write_cr0(read_cr0() & ~X86_CR0_CD); /* Restore value of CR4 */ if (boot_cpu_has(X86_FEATURE_PGE)) __write_cr4(cr4); raw_spin_unlock(&set_atomicity_lock); } static void generic_set_all(void) { unsigned long mask, count; unsigned long flags; local_irq_save(flags); prepare_set(); /* Actually set the state */ mask = set_mtrr_state(); /* also set PAT */ pat_init(); post_set(); local_irq_restore(flags); /* Use the atomic bitops to update the global mask */ for (count = 0; count < sizeof(mask) * 8; ++count) { if (mask & 0x01) set_bit(count, &smp_changes_mask); mask >>= 1; } } /** * generic_set_mtrr - set variable MTRR register on the local CPU. * * @reg: The register to set. * @base: The base address of the region. * @size: The size of the region. If this is 0 the region is disabled. * @type: The type of the region. * * Returns nothing. */ static void generic_set_mtrr(unsigned int reg, unsigned long base, unsigned long size, mtrr_type type) { unsigned long flags; struct mtrr_var_range *vr; vr = &mtrr_state.var_ranges[reg]; local_irq_save(flags); prepare_set(); if (size == 0) { /* * The invalid bit is kept in the mask, so we simply * clear the relevant mask register to disable a range. */ mtrr_wrmsr(MTRRphysMask_MSR(reg), 0, 0); memset(vr, 0, sizeof(struct mtrr_var_range)); } else { vr->base_lo = base << PAGE_SHIFT | type; vr->base_hi = (base & size_and_mask) >> (32 - PAGE_SHIFT); vr->mask_lo = -size << PAGE_SHIFT | 0x800; vr->mask_hi = (-size & size_and_mask) >> (32 - PAGE_SHIFT); mtrr_wrmsr(MTRRphysBase_MSR(reg), vr->base_lo, vr->base_hi); mtrr_wrmsr(MTRRphysMask_MSR(reg), vr->mask_lo, vr->mask_hi); } post_set(); local_irq_restore(flags); } int generic_validate_add_page(unsigned long base, unsigned long size, unsigned int type) { unsigned long lbase, last; /* * For Intel PPro stepping <= 7 * must be 4 MiB aligned and not touch 0x70000000 -> 0x7003FFFF */ if (is_cpu(INTEL) && boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model == 1 && boot_cpu_data.x86_stepping <= 7) { if (base & ((1 << (22 - PAGE_SHIFT)) - 1)) { pr_warn("mtrr: base(0x%lx000) is not 4 MiB aligned\n", base); return -EINVAL; } if (!(base + size < 0x70000 || base > 0x7003F) && (type == MTRR_TYPE_WRCOMB || type == MTRR_TYPE_WRBACK)) { pr_warn("mtrr: writable mtrr between 0x70000000 and 0x7003FFFF may hang the CPU.\n"); return -EINVAL; } } /* * Check upper bits of base and last are equal and lower bits are 0 * for base and 1 for last */ last = base + size - 1; for (lbase = base; !(lbase & 1) && (last & 1); lbase = lbase >> 1, last = last >> 1) ; if (lbase != last) { pr_warn("mtrr: base(0x%lx000) is not aligned on a size(0x%lx000) boundary\n", base, size); return -EINVAL; } return 0; } static int generic_have_wrcomb(void) { unsigned long config, dummy; rdmsr(MSR_MTRRcap, config, dummy); return config & (1 << 10); } int positive_have_wrcomb(void) { return 1; } /* * Generic structure... */ const struct mtrr_ops generic_mtrr_ops = { .use_intel_if = 1, .set_all = generic_set_all, .get = generic_get_mtrr, .get_free_region = generic_get_free_region, .set = generic_set_mtrr, .validate_add_page = generic_validate_add_page, .have_wrcomb = generic_have_wrcomb, };