--- zzzz-none-000/linux-3.10.107/arch/x86/kernel/cpu/mtrr/main.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/arch/x86/kernel/cpu/mtrr/main.c 2021-02-04 17:41:59.000000000 +0000 @@ -51,10 +51,20 @@ #include #include #include +#include #include "mtrr.h" +/* arch_phys_wc_add returns an MTRR register index plus this offset. */ +#define MTRR_TO_PHYS_WC_OFFSET 1000 + u32 num_var_ranges; +static bool __mtrr_enabled; + +static bool mtrr_enabled(void) +{ + return __mtrr_enabled; +} unsigned int mtrr_usage_table[MTRR_MAX_VAR_RANGES]; static DEFINE_MUTEX(mtrr_mutex); @@ -282,7 +292,7 @@ int i, replace, error; mtrr_type ltype; - if (!mtrr_if) + if (!mtrr_enabled()) return -ENXIO; error = mtrr_if->validate_add_page(base, size, type); @@ -431,12 +441,13 @@ int mtrr_add(unsigned long base, unsigned long size, unsigned int type, bool increment) { + if (!mtrr_enabled()) + return -ENODEV; if (mtrr_check(base, size)) return -EINVAL; return mtrr_add_page(base >> PAGE_SHIFT, size >> PAGE_SHIFT, type, increment); } -EXPORT_SYMBOL(mtrr_add); /** * mtrr_del_page - delete a memory type region @@ -459,8 +470,8 @@ unsigned long lbase, lsize; int error = -EINVAL; - if (!mtrr_if) - return -ENXIO; + if (!mtrr_enabled()) + return -ENODEV; max = num_var_ranges; /* No CPU hotplug when we change MTRR entries */ @@ -519,11 +530,82 @@ */ int mtrr_del(int reg, unsigned long base, unsigned long size) { + if (!mtrr_enabled()) + return -ENODEV; if (mtrr_check(base, size)) return -EINVAL; return mtrr_del_page(reg, base >> PAGE_SHIFT, size >> PAGE_SHIFT); } -EXPORT_SYMBOL(mtrr_del); + +/** + * arch_phys_wc_add - add a WC MTRR and handle errors if PAT is unavailable + * @base: Physical base address + * @size: Size of region + * + * If PAT is available, this does nothing. If PAT is unavailable, it + * attempts to add a WC MTRR covering size bytes starting at base and + * logs an error if this fails. + * + * The called should provide a power of two size on an equivalent + * power of two boundary. + * + * Drivers must store the return value to pass to mtrr_del_wc_if_needed, + * but drivers should not try to interpret that return value. + */ +int arch_phys_wc_add(unsigned long base, unsigned long size) +{ + int ret; + + if (pat_enabled() || !mtrr_enabled()) + return 0; /* Success! (We don't need to do anything.) */ + + ret = mtrr_add(base, size, MTRR_TYPE_WRCOMB, true); + if (ret < 0) { + pr_warn("Failed to add WC MTRR for [%p-%p]; performance may suffer.", + (void *)base, (void *)(base + size - 1)); + return ret; + } + return ret + MTRR_TO_PHYS_WC_OFFSET; +} +EXPORT_SYMBOL(arch_phys_wc_add); + +/* + * arch_phys_wc_del - undoes arch_phys_wc_add + * @handle: Return value from arch_phys_wc_add + * + * This cleans up after mtrr_add_wc_if_needed. + * + * The API guarantees that mtrr_del_wc_if_needed(error code) and + * mtrr_del_wc_if_needed(0) do nothing. + */ +void arch_phys_wc_del(int handle) +{ + if (handle >= 1) { + WARN_ON(handle < MTRR_TO_PHYS_WC_OFFSET); + mtrr_del(handle - MTRR_TO_PHYS_WC_OFFSET, 0, 0); + } +} +EXPORT_SYMBOL(arch_phys_wc_del); + +/* + * arch_phys_wc_index - translates arch_phys_wc_add's return value + * @handle: Return value from arch_phys_wc_add + * + * This will turn the return value from arch_phys_wc_add into an mtrr + * index suitable for debugging. + * + * Note: There is no legitimate use for this function, except possibly + * in printk line. Alas there is an illegitimate use in some ancient + * drm ioctls. + */ +int arch_phys_wc_index(int handle) +{ + if (handle < MTRR_TO_PHYS_WC_OFFSET) + return -1; + else + return handle - MTRR_TO_PHYS_WC_OFFSET; +} +EXPORT_SYMBOL_GPL(arch_phys_wc_index); /* * HACK ALERT! @@ -636,7 +718,7 @@ } else { switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_AMD: - if (cpu_has_k6_mtrr) { + if (cpu_feature_enabled(X86_FEATURE_K6_MTRR)) { /* Pre-Athlon (K6) AMD CPU MTRRs */ mtrr_if = mtrr_ops[X86_VENDOR_AMD]; size_or_mask = SIZE_OR_MASK_BITS(32); @@ -644,14 +726,14 @@ } break; case X86_VENDOR_CENTAUR: - if (cpu_has_centaur_mcr) { + if (cpu_feature_enabled(X86_FEATURE_CENTAUR_MCR)) { mtrr_if = mtrr_ops[X86_VENDOR_CENTAUR]; size_or_mask = SIZE_OR_MASK_BITS(32); size_and_mask = 0; } break; case X86_VENDOR_CYRIX: - if (cpu_has_cyrix_arr) { + if (cpu_feature_enabled(X86_FEATURE_CYRIX_ARR)) { mtrr_if = mtrr_ops[X86_VENDOR_CYRIX]; size_or_mask = SIZE_OR_MASK_BITS(32); size_and_mask = 0; @@ -663,10 +745,15 @@ } if (mtrr_if) { + __mtrr_enabled = true; set_num_var_ranges(); init_table(); if (use_intel()) { - get_mtrr_state(); + /* BIOS may override */ + __mtrr_enabled = get_mtrr_state(); + + if (mtrr_enabled()) + mtrr_bp_pat_init(); if (mtrr_cleanup(phys_addr)) { changed_by_mtrr_cleanup = 1; @@ -674,10 +761,24 @@ } } } + + if (!mtrr_enabled()) { + pr_info("MTRR: Disabled\n"); + + /* + * PAT initialization relies on MTRR's rendezvous handler. + * Skip PAT init until the handler can initialize both + * features independently. + */ + pat_disable("MTRRs disabled, skipping PAT initialization too."); + } } void mtrr_ap_init(void) { + if (!mtrr_enabled()) + return; + if (!use_intel() || mtrr_aps_delayed_init) return; /* @@ -703,6 +804,9 @@ { int first_cpu; + if (!mtrr_enabled()) + return; + get_online_cpus(); first_cpu = cpumask_first(cpu_online_mask); smp_call_function_single(first_cpu, mtrr_save_fixed_ranges, NULL, 1); @@ -711,6 +815,8 @@ void set_mtrr_aps_delayed_init(void) { + if (!mtrr_enabled()) + return; if (!use_intel()) return; @@ -722,7 +828,7 @@ */ void mtrr_aps_init(void) { - if (!use_intel()) + if (!use_intel() || !mtrr_enabled()) return; /* @@ -739,7 +845,7 @@ void mtrr_bp_restore(void) { - if (!use_intel()) + if (!use_intel() || !mtrr_enabled()) return; mtrr_if->set_all(); @@ -747,7 +853,7 @@ static int __init mtrr_init_finialize(void) { - if (!mtrr_if) + if (!mtrr_enabled()) return 0; if (use_intel()) {