diff options
Diffstat (limited to 'arch/x86/kernel/cpu/mtrr')
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/generic.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index 3e18db4cefe..011e07e99cd 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -11,6 +11,7 @@ #include <asm/cpufeature.h> #include <asm/processor-flags.h> #include <asm/tlbflush.h> +#include <asm/pat.h> #include "mtrr.h" struct mtrr_state { @@ -35,6 +36,7 @@ static struct fixed_range_block fixed_range_blocks[] = { static unsigned long smp_changes_mask; static struct mtrr_state mtrr_state = {}; +static int mtrr_state_set; #undef MODULE_PARAM_PREFIX #define MODULE_PARAM_PREFIX "mtrr." @@ -42,6 +44,106 @@ static struct mtrr_state mtrr_state = {}; 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 (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) @@ -79,12 +181,16 @@ static void print_fixed(unsigned base, unsigned step, const mtrr_type*types) 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; @@ -131,6 +237,17 @@ void __init get_mtrr_state(void) printk(KERN_INFO "MTRR %u disabled\n", i); } } + 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! */ @@ -397,6 +514,9 @@ static void generic_set_all(void) /* Actually set the state */ mask = set_mtrr_state(); + /* also set PAT */ + pat_init(); + post_set(); local_irq_restore(flags); |