/* This only handles 32bit MTRR on 32bit hosts. This is strictly wrong because MTRRs can span upto 40 bits (36bits on most modern x86) */ #include #include #include #include #include #include #include #include #include #include #include #include #include "mtrr.h" struct mtrr_state { struct mtrr_var_range var_ranges[MAX_VAR_RANGES]; mtrr_type fixed_ranges[NUM_FIXED_RANGES]; unsigned char enabled; unsigned char have_fixed; mtrr_type def_type; }; 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[] = { { MTRRfix64K_00000_MSR, 1 }, /* one 64k MTRR */ { MTRRfix16K_80000_MSR, 2 }, /* two 16k MTRRs */ { MTRRfix4K_C0000_MSR, 8 }, /* eight 4k MTRRs */ {} }; static unsigned long smp_changes_mask; static struct mtrr_state mtrr_state = {}; static int mtrr_state_set; u64 mtrr_tom2; #undef MODULE_PARAM_PREFIX #define MODULE_PARAM_PREFIX "mtrr." static int mtrr_show; module_param_named(show, mtrr_show, bool, 0); /* * Returns the effective MTRR type for the region * Error returns: * - 0xFE - when the range is "not entirely covered" by _any_ var range MTRR * - 0xFF - when MTRR is not enabled */ u8 mtrr_type_lookup(u64 start, u64 end) { int i; u64 base, mask; u8 prev_match, curr_match; if (!mtrr_state_set) return 0xFF; if (!mtrr_state.enabled) return 0xFF; /* Make end inclusive end, instead of exclusive */ end--; /* Look in fixed ranges. Just return the type as per start */ if (mtrr_state.have_fixed && (start < 0x100000)) { int idx; if (start < 0x80000) { idx = 0; idx += (start >> 16); return mtrr_state.fixed_ranges[idx]; } else if (start < 0xC0000) { idx = 1 * 8; idx += ((start - 0x80000) >> 14); return mtrr_state.fixed_ranges[idx]; } else if (start < 0x1000000) { idx = 3 * 8; idx += ((start - 0xC0000) >> 12); return mtrr_state.fixed_ranges[idx]; } } /* * Look in variable ranges * Look of multiple ranges matching this address and pick type * as per MTRR precedence */ if (!(mtrr_state.enabled & 2)) { return mtrr_state.def_type; } prev_match = 0xFF; for (i = 0; i < num_var_ranges; ++i) { unsigned short start_state, end_state; 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)); if (start_state != end_state) return 0xFE; if ((start & mask) != (base & mask)) { continue; } curr_match = mtrr_state.var_ranges[i].base_lo & 0xff; if (prev_match == 0xFF) { prev_match = curr_match; continue; } if (prev_match == MTRR_TYPE_UNCACHABLE || curr_match == MTRR_TYPE_UNCACHABLE) { return MTRR_TYPE_UNCACHABLE; } if ((prev_match == MTRR_TYPE_WRBACK && curr_match == MTRR_TYPE_WRTHROUGH) || (prev_match == MTRR_TYPE_WRTHROUGH && curr_match == MTRR_TYPE_WRBACK)) { prev_match = MTRR_TYPE_WRTHROUGH; curr_match = MTRR_TYPE_WRTHROUGH; } if (prev_match != curr_match) { return MTRR_TYPE_UNCACHABLE; } } if (mtrr_tom2) { if (start >= (1ULL<<32) && (end < mtrr_tom2)) return MTRR_TYPE_WRBACK; } if (prev_match != 0xFF) return prev_match; return mtrr_state.def_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; rdmsr(MTRRfix64K_00000_MSR, p[0], p[1]); for (i = 0; i < 2; i++) rdmsr(MTRRfix16K_80000_MSR + i, p[2 + i * 2], p[3 + i * 2]); for (i = 0; i < 8; i++) rdmsr(MTRRfix4K_C0000_MSR + i, p[6 + i * 2], p[7 + i * 2]); } void mtrr_save_fixed_ranges(void *info) { if (cpu_has_mtrr) get_fixed_ranges(mtrr_state.fixed_ranges); } static void print_fixed(unsigned base, unsigned step, const mtrr_type*types) { unsigned i; for (i = 0; i < 8; ++i, ++types, base += step) printk(KERN_INFO "MTRR %05X-%05X %s\n", base, base + step - 1, mtrr_attrib_to_str(*types)); } static void prepare_set(void); static void post_set(void); /* Grab all of the MTRR state for this CPU into *state */ void __init get_mtrr_state(void) { unsigned int i; struct mtrr_var_range *vrs; unsigned lo, dummy; unsigned long flags; vrs = mtrr_state.var_ranges; rdmsr(MTRRcap_MSR, 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(MTRRdefType_MSR, 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; } if (mtrr_show) { int high_width; printk(KERN_INFO "MTRR default type: %s\n", mtrr_attrib_to_str(mtrr_state.def_type)); if (mtrr_state.have_fixed) { printk(KERN_INFO "MTRR fixed ranges %sabled:\n", mtrr_state.enabled & 1 ? "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); } printk(KERN_INFO "MTRR variable ranges %sabled:\n", mtrr_state.enabled & 2 ? "en" : "dis"); high_width = ((size_or_mask ? ffs(size_or_mask) - 1 : 32) - (32 - PAGE_SHIFT) + 3) / 4; for (i = 0; i < num_var_ranges; ++i) { if (mtrr_state.var_ranges[i].mask_lo & (1 << 11)) printk(KERN_INFO "MTRR %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 printk(KERN_INFO "MTRR %u disabled\n", i); } if (mtrr_tom2) { printk(KERN_INFO "TOM2: %016llx aka %lldM\n", mtrr_tom2, mtrr_tom2>>20); } } mtrr_state_set = 1; /* PAT setup for BP. We need to go through sync steps here */ local_irq_save(flags); prepare_set(); pat_init(); post_set(); local_irq_restore(flags); } /* Some BIOS's are fucked 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) printk(KERN_WARNING "mtrr: your CPUs had inconsistent fixed MTRR settings\n"); if (mask & MTRR_CHANGE_MASK_VARIABLE) printk(KERN_WARNING "mtrr: your CPUs had inconsistent variable MTRR settings\n"); if (mask & MTRR_CHANGE_MASK_DEFTYPE) printk(KERN_WARNING "mtrr: your CPUs had inconsistent MTRRdefType settings\n"); printk(KERN_INFO "mtrr: probably your BIOS does not setup all CPUs.\n"); printk(KERN_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) printk(KERN_ERR "MTRR: CPU %u: Writing MSR %x to %x:%x failed\n", smp_processor_id(), msr, a, b); } /** * Enable and allow read/write of extended fixed-range MTRR bits on K8 CPUs * see AMD publication no. 24593, chapter 3.2.1 for more information */ static inline void k8_enable_fixed_iorrs(void) { unsigned lo, hi; rdmsr(MSR_K8_SYSCFG, lo, hi); mtrr_wrmsr(MSR_K8_SYSCFG, lo | K8_MTRRFIXRANGE_DRAM_ENABLE | K8_MTRRFIXRANGE_DRAM_MODIFY, hi); } /** * 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 * * If K8 extentions are wanted, update the K8 SYSCFG MSR also. * See AMD publication no. 24593, chapter 7.8.1, page 233 for more information. */ 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]) { if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD && (boot_cpu_data.x86 >= 0x0f && boot_cpu_data.x86 <= 0x11) && ((msrwords[0] | msrwords[1]) & K8_MTRR_RDMEM_WRMEM_MASK)) k8_enable_fixed_iorrs(); 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) { int i, max; mtrr_type ltype; unsigned long lbase, lsize; 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) { unsigned int mask_lo, mask_hi, base_lo, base_hi; rdmsr(MTRRphysMask_MSR(reg), mask_lo, mask_hi); if ((mask_lo & 0x800) == 0) { /* Invalid (i.e. free) range */ *base = 0; *size = 0; *type = 0; return; } rdmsr(MTRRphysBase_MSR(reg), base_lo, base_hi); /* Work out the shifted address mask. */ mask_lo = size_or_mask | mask_hi << (32 - PAGE_SHIFT) | mask_lo >> PAGE_SHIFT; /* This works correctly if size is a power of two, i.e. a contiguous range. */ *size = -mask_lo; *base = base_hi << (32 - PAGE_SHIFT) | base_lo >> PAGE_SHIFT; *type = base_lo & 0xff; } /** * 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; 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 int i; unsigned long change_mask = 0; 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 = 0; static DEFINE_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 */ 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); wbinvd(); /* Save value of CR4 and clear Page Global Enable (bit 7) */ if ( cpu_has_pge ) { cr4 = read_cr4(); write_cr4(cr4 & ~X86_CR4_PGE); } /* Flush all TLBs via a mov %cr3, %reg; mov %reg, %cr3 */ __flush_tlb(); /* Save MTRR state */ rdmsr(MTRRdefType_MSR, deftype_lo, deftype_hi); /* Disable MTRRs, and set the default type to uncached */ mtrr_wrmsr(MTRRdefType_MSR, deftype_lo & ~0xcff, deftype_hi); } static void post_set(void) __releases(set_atomicity_lock) { /* Flush TLBs (no need to flush caches - they are disabled) */ __flush_tlb(); /* Intel (P6) standard MTRRs */ mtrr_wrmsr(MTRRdefType_MSR, deftype_lo, deftype_hi); /* Enable caches */ write_cr0(read_cr0() & 0xbfffffff); /* Restore value of CR4 */ if ( cpu_has_pge ) write_cr4(cr4); 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; } } static void generic_set_mtrr(unsigned int reg, unsigned long base, unsigned long size, mtrr_type type) /* [SUMMARY] Set variable MTRR register on the local CPU. The register to set. The base address of the region. The size of the region. If this is 0 the region is disabled. The type of the region. [RETURNS] Nothing. */ { 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_mask <= 7) { if (base & ((1 << (22 - PAGE_SHIFT)) - 1)) { printk(KERN_WARNING "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)) { printk(KERN_WARNING "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) { printk(KERN_WARNING "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(MTRRcap_MSR, config, dummy); return (config & (1 << 10)); } int positive_have_wrcomb(void) { return 1; } /* generic structure... */ 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, };