diff options
Diffstat (limited to 'arch/x86/kernel/cpu/mtrr/generic.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/generic.c | 924 |
1 files changed, 924 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c new file mode 100644 index 000000000..558108296 --- /dev/null +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -0,0 +1,924 @@ +// 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) + */ + +#include <linux/export.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/mm.h> + +#include <asm/processor-flags.h> +#include <asm/cpufeature.h> +#include <asm/tlbflush.h> +#include <asm/mtrr.h> +#include <asm/msr.h> +#include <asm/memtype.h> + +#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_AMD64_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_AMD64_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, +}; |