diff options
Diffstat (limited to 'arch/x86/kernel/cpu/mtrr/generic.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/generic.c | 509 |
1 files changed, 509 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 000000000000..56f64e34829f --- /dev/null +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -0,0 +1,509 @@ +/* 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 <linux/init.h> +#include <linux/slab.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <asm/io.h> +#include <asm/mtrr.h> +#include <asm/msr.h> +#include <asm/system.h> +#include <asm/cpufeature.h> +#include <asm/tlbflush.h> +#include "mtrr.h" + +struct mtrr_state { + struct mtrr_var_range *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 = {}; + +#undef MODULE_PARAM_PREFIX +#define MODULE_PARAM_PREFIX "mtrr." + +static int mtrr_show; +module_param_named(show, mtrr_show, bool, 0); + +/* 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); +} + +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)); +} + +/* 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; + + if (!mtrr_state.var_ranges) { + mtrr_state.var_ranges = kmalloc(num_var_ranges * sizeof (struct mtrr_var_range), + GFP_KERNEL); + if (!mtrr_state.var_ranges) + return; + } + 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 (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); + } + } +} + +/* 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); +} + +/** + * Checks and updates an fixed-range MTRR if it differs from the value it + * should have. If K8 extenstions are wanted, update the K8 SYSCFG MSR also. + * see AMD publication no. 24593, chapter 7.8.1, page 233 for more information + * \param msr MSR address of the MTTR which should be checked and updated + * \param changed pointer which indicates whether the MTRR needed to be changed + * \param msrwords pointer to the MSR values which the MSR should have + */ +static void set_fixed_range(int msr, int * 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 == 15 && + ((msrwords[0] | msrwords[1]) & K8_MTRR_RDMEM_WRMEM_MASK)) + k8_enable_fixed_iorrs(); + mtrr_wrmsr(msr, msrwords[0], msrwords[1]); + *changed = TRUE; + } +} + +int generic_get_free_region(unsigned long base, unsigned long size, int replace_reg) +/* [SUMMARY] Get a free MTRR. + <base> The starting (base) address of the region. + <size> The size (in bytes) of the region. + [RETURNS] The index of the region on success, else -1 on error. +*/ +{ + 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; +} + +/** + * Checks and updates the fixed-range MTRRs if they differ from the saved set + * \param 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; + int 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 int set_mtrr_var_ranges(unsigned int index, struct mtrr_var_range *vr) +{ + unsigned int lo, hi; + int 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; + +static unsigned long set_mtrr_state(void) +/* [SUMMARY] Set the MTRR state for this CPU. + <state> The MTRR state information to read. + <ctxt> Some relevant CPU context. + [NOTE] The CPU must already be in a safe state for MTRR changes. + [RETURNS] 0 if no changes made, else a mask indication what was changed. +*/ +{ + 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() | 0x40000000; /* set CD flag */ + 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(); + + 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. + <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. + <do_safe> If TRUE, do the change safely. If FALSE, safety measures should + be done externally. + [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, +}; |