The following commit has been merged into the x86/cpu branch of tip: Commit-ID: 45fa71f19a2d73f157d6892a8d677a738a0414fd Gitweb: https://git.kernel.org/tip/45fa71f19a2d73f157d6892a8d677a738a0414fd Author: Juergen Gross <jgross@xxxxxxxx> AuthorDate: Wed, 02 Nov 2022 08:47:00 +01:00 Committer: Borislav Petkov <bp@xxxxxxx> CommitterDate: Thu, 10 Nov 2022 13:12:44 +01:00 x86/mtrr: Replace use_intel() with a local flag In MTRR code use_intel() is only used in one source file, and the relevant use_intel_if member of struct mtrr_ops is set only in generic_mtrr_ops. Replace use_intel() with a single flag in cacheinfo.c which can be set when assigning generic_mtrr_ops to mtrr_if. This allows to drop use_intel_if from mtrr_ops, while preparing to decouple PAT from MTRR. As another preparation for the PAT/MTRR decoupling use a bit for MTRR control and one for PAT control. For now set both bits together, this can be changed later. As the new flag will be set only if mtrr_enabled is set, the test for mtrr_enabled can be dropped at some places. [ bp: Massage commit message. ] Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Link: https://lore.kernel.org/r/20221102074713.21493-4-jgross@xxxxxxxx Signed-off-by: Borislav Petkov <bp@xxxxxxx> --- arch/x86/include/asm/cacheinfo.h | 5 +++++ arch/x86/kernel/cpu/cacheinfo.c | 3 +++ arch/x86/kernel/cpu/mtrr/generic.c | 1 - arch/x86/kernel/cpu/mtrr/mtrr.c | 28 +++++++++++++--------------- arch/x86/kernel/cpu/mtrr/mtrr.h | 2 -- 5 files changed, 21 insertions(+), 18 deletions(-) diff --git a/arch/x86/include/asm/cacheinfo.h b/arch/x86/include/asm/cacheinfo.h index 86b2e0d..c387396 100644 --- a/arch/x86/include/asm/cacheinfo.h +++ b/arch/x86/include/asm/cacheinfo.h @@ -2,6 +2,11 @@ #ifndef _ASM_X86_CACHEINFO_H #define _ASM_X86_CACHEINFO_H +/* Kernel controls MTRR and/or PAT MSRs. */ +extern unsigned int memory_caching_control; +#define CACHE_MTRR 0x01 +#define CACHE_PAT 0x02 + void cacheinfo_amd_init_llc_id(struct cpuinfo_x86 *c, int cpu); void cacheinfo_hygon_init_llc_id(struct cpuinfo_x86 *c, int cpu); diff --git a/arch/x86/kernel/cpu/cacheinfo.c b/arch/x86/kernel/cpu/cacheinfo.c index 6655683..32fb049 100644 --- a/arch/x86/kernel/cpu/cacheinfo.c +++ b/arch/x86/kernel/cpu/cacheinfo.c @@ -35,6 +35,9 @@ DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_llc_shared_map); /* Shared L2 cache maps */ DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_l2c_shared_map); +/* Kernel controls MTRR and/or PAT MSRs. */ +unsigned int memory_caching_control __ro_after_init; + struct _cache_table { unsigned char descriptor; char cache_type; diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index c8f8951..7bbaba4 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -917,7 +917,6 @@ int positive_have_wrcomb(void) * 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, diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.c b/arch/x86/kernel/cpu/mtrr/mtrr.c index 2746cac..4209945 100644 --- a/arch/x86/kernel/cpu/mtrr/mtrr.c +++ b/arch/x86/kernel/cpu/mtrr/mtrr.c @@ -46,6 +46,7 @@ #include <linux/syscore_ops.h> #include <linux/rcupdate.h> +#include <asm/cacheinfo.h> #include <asm/cpufeature.h> #include <asm/e820/api.h> #include <asm/mtrr.h> @@ -119,11 +120,11 @@ static int have_wrcomb(void) } /* This function returns the number of variable MTRRs */ -static void __init set_num_var_ranges(void) +static void __init set_num_var_ranges(bool use_generic) { unsigned long config = 0, dummy; - if (use_intel()) + if (use_generic) rdmsr(MSR_MTRRcap, config, dummy); else if (is_cpu(AMD) || is_cpu(HYGON)) config = 2; @@ -756,14 +757,16 @@ void __init mtrr_bp_init(void) if (mtrr_if) { __mtrr_enabled = true; - set_num_var_ranges(); + set_num_var_ranges(mtrr_if == &generic_mtrr_ops); init_table(); - if (use_intel()) { + if (mtrr_if == &generic_mtrr_ops) { /* BIOS may override */ __mtrr_enabled = get_mtrr_state(); - if (mtrr_enabled()) + if (mtrr_enabled()) { mtrr_bp_pat_init(); + memory_caching_control |= CACHE_MTRR | CACHE_PAT; + } if (mtrr_cleanup(phys_addr)) { changed_by_mtrr_cleanup = 1; @@ -786,10 +789,7 @@ void __init mtrr_bp_init(void) void mtrr_ap_init(void) { - if (!mtrr_enabled()) - return; - - if (!use_intel() || mtrr_aps_delayed_init) + if (!memory_caching_control || mtrr_aps_delayed_init) return; /* @@ -825,9 +825,7 @@ void mtrr_save_state(void) void set_mtrr_aps_delayed_init(void) { - if (!mtrr_enabled()) - return; - if (!use_intel()) + if (!memory_caching_control) return; mtrr_aps_delayed_init = true; @@ -838,7 +836,7 @@ void set_mtrr_aps_delayed_init(void) */ void mtrr_aps_init(void) { - if (!use_intel() || !mtrr_enabled()) + if (!memory_caching_control) return; /* @@ -855,7 +853,7 @@ void mtrr_aps_init(void) void mtrr_bp_restore(void) { - if (!use_intel() || !mtrr_enabled()) + if (!memory_caching_control) return; mtrr_if->set_all(); @@ -866,7 +864,7 @@ static int __init mtrr_init_finialize(void) if (!mtrr_enabled()) return 0; - if (use_intel()) { + if (memory_caching_control & CACHE_MTRR) { if (!changed_by_mtrr_cleanup) mtrr_state_warn(); return 0; diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.h b/arch/x86/kernel/cpu/mtrr/mtrr.h index 2ac99e5..88b1c4b 100644 --- a/arch/x86/kernel/cpu/mtrr/mtrr.h +++ b/arch/x86/kernel/cpu/mtrr/mtrr.h @@ -14,7 +14,6 @@ extern unsigned int mtrr_usage_table[MTRR_MAX_VAR_RANGES]; struct mtrr_ops { u32 vendor; - u32 use_intel_if; void (*set)(unsigned int reg, unsigned long base, unsigned long size, mtrr_type type); void (*set_all)(void); @@ -61,7 +60,6 @@ extern u64 size_or_mask, size_and_mask; extern const struct mtrr_ops *mtrr_if; #define is_cpu(vnd) (mtrr_if && mtrr_if->vendor == X86_VENDOR_##vnd) -#define use_intel() (mtrr_if && mtrr_if->use_intel_if == 1) extern unsigned int num_var_ranges; extern u64 mtrr_tom2;
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