From 23a63e369098a8503550d1df80f4b4801af32c19 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Wed, 2 Nov 2022 08:47:03 +0100 Subject: x86/mtrr: Move cache control code to cacheinfo.c Prepare making PAT and MTRR support independent from each other by moving some code needed by both out of the MTRR-specific sources. [ bp: Massage commit message. ] Signed-off-by: Juergen Gross Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/20221102074713.21493-7-jgross@suse.com Signed-off-by: Borislav Petkov --- arch/x86/kernel/cpu/cacheinfo.c | 77 ++++++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/mtrr/generic.c | 74 ------------------------------------ 2 files changed, 77 insertions(+), 74 deletions(-) diff --git a/arch/x86/kernel/cpu/cacheinfo.c b/arch/x86/kernel/cpu/cacheinfo.c index 32fb04920171..0cbacece87db 100644 --- a/arch/x86/kernel/cpu/cacheinfo.c +++ b/arch/x86/kernel/cpu/cacheinfo.c @@ -20,6 +20,8 @@ #include #include #include +#include +#include #include "cpu.h" @@ -1043,3 +1045,78 @@ int populate_cache_leaves(unsigned int cpu) return 0; } + +/* + * Disable and enable caches. Needed for changing MTRRs and the PAT MSR. + * + * 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 cache_enable() has been called. + */ +static unsigned long saved_cr4; +static DEFINE_RAW_SPINLOCK(cache_disable_lock); + +void cache_disable(void) __acquires(cache_disable_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(&cache_disable_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 (cpu_feature_enabled(X86_FEATURE_PGE)) { + saved_cr4 = __read_cr4(); + __write_cr4(saved_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(); + + if (cpu_feature_enabled(X86_FEATURE_MTRR)) + mtrr_disable(); + + /* Again, only flush caches if we have to. */ + if (!static_cpu_has(X86_FEATURE_SELFSNOOP)) + wbinvd(); +} + +void cache_enable(void) __releases(cache_disable_lock) +{ + /* Flush TLBs (no need to flush caches - they are disabled) */ + count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL); + flush_tlb_local(); + + if (cpu_feature_enabled(X86_FEATURE_MTRR)) + mtrr_enable(); + + /* Enable caches */ + write_cr0(read_cr0() & ~X86_CR0_CD); + + /* Restore value of CR4 */ + if (cpu_feature_enabled(X86_FEATURE_PGE)) + __write_cr4(saved_cr4); + + raw_spin_unlock(&cache_disable_lock); +} diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index 0db0770e75f6..396cb1eb1171 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -731,80 +731,6 @@ void mtrr_enable(void) mtrr_wrmsr(MSR_MTRRdefType, deftype_lo, deftype_hi); } -/* - * Disable and enable caches. Needed for changing MTRRs and the PAT MSR. - * - * 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 cache_enable() has been called. - */ -static unsigned long saved_cr4; -static DEFINE_RAW_SPINLOCK(cache_disable_lock); - -void cache_disable(void) __acquires(cache_disable_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(&cache_disable_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)) { - saved_cr4 = __read_cr4(); - __write_cr4(saved_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(); - - if (cpu_feature_enabled(X86_FEATURE_MTRR)) - mtrr_disable(); - - /* Again, only flush caches if we have to. */ - if (!static_cpu_has(X86_FEATURE_SELFSNOOP)) - wbinvd(); -} - -void cache_enable(void) __releases(cache_disable_lock) -{ - /* Flush TLBs (no need to flush caches - they are disabled) */ - count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL); - flush_tlb_local(); - - if (cpu_feature_enabled(X86_FEATURE_MTRR)) - mtrr_enable(); - - /* Enable caches */ - write_cr0(read_cr0() & ~X86_CR0_CD); - - /* Restore value of CR4 */ - if (boot_cpu_has(X86_FEATURE_PGE)) - __write_cr4(saved_cr4); - raw_spin_unlock(&cache_disable_lock); -} - static void generic_set_all(void) { unsigned long mask, count; -- cgit v1.2.3