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linux/debian/patches/patchset-zen/invlpgb-v9/0004-x86-mm-get-INVLPGB-count-max-from-CPUID.patch
2025-02-09 19:40:34 +03:00

91 lines
2.9 KiB
Diff

From e772b2eb66e5c3cf668feadab678f2a88d896189 Mon Sep 17 00:00:00 2001
From: Rik van Riel <riel@surriel.com>
Date: Wed, 5 Feb 2025 23:43:23 -0500
Subject: x86/mm: get INVLPGB count max from CPUID
The CPU advertises the maximum number of pages that can be shot down
with one INVLPGB instruction in the CPUID data.
Save that information for later use.
Signed-off-by: Rik van Riel <riel@surriel.com>
Tested-by: Manali Shukla <Manali.Shukla@amd.com>
---
arch/x86/Kconfig.cpu | 5 +++++
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/include/asm/tlbflush.h | 7 +++++++
arch/x86/kernel/cpu/amd.c | 8 ++++++++
4 files changed, 21 insertions(+)
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -726,6 +726,10 @@ config X86_VMX_FEATURE_NAMES
def_bool y
depends on IA32_FEAT_CTL
+config X86_BROADCAST_TLB_FLUSH
+ def_bool y
+ depends on CPU_SUP_AMD && 64BIT
+
menuconfig PROCESSOR_SELECT
bool "Supported processor vendors" if EXPERT
help
@@ -762,6 +766,7 @@ config CPU_SUP_CYRIX_32
config CPU_SUP_AMD
default y
bool "Support AMD processors" if PROCESSOR_SELECT
+ select X86_BROADCAST_TLB_FLUSH
help
This enables detection, tunings and quirks for AMD processors
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -335,6 +335,7 @@
#define X86_FEATURE_CLZERO (13*32+ 0) /* "clzero" CLZERO instruction */
#define X86_FEATURE_IRPERF (13*32+ 1) /* "irperf" Instructions Retired Count */
#define X86_FEATURE_XSAVEERPTR (13*32+ 2) /* "xsaveerptr" Always save/restore FP error pointers */
+#define X86_FEATURE_INVLPGB (13*32+ 3) /* INVLPGB and TLBSYNC instruction supported. */
#define X86_FEATURE_RDPRU (13*32+ 4) /* "rdpru" Read processor register at user level */
#define X86_FEATURE_WBNOINVD (13*32+ 9) /* "wbnoinvd" WBNOINVD instruction */
#define X86_FEATURE_AMD_IBPB (13*32+12) /* Indirect Branch Prediction Barrier */
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -183,6 +183,13 @@ static inline void cr4_init_shadow(void)
extern unsigned long mmu_cr4_features;
extern u32 *trampoline_cr4_features;
+/* How many pages can we invalidate with one INVLPGB. */
+#ifdef CONFIG_X86_BROADCAST_TLB_FLUSH
+extern u16 invlpgb_count_max;
+#else
+#define invlpgb_count_max 1
+#endif
+
extern void initialize_tlbstate_and_flush(void);
/*
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -29,6 +29,8 @@
#include "cpu.h"
+u16 invlpgb_count_max __ro_after_init;
+
static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
{
u32 gprs[8] = { 0 };
@@ -1135,6 +1137,12 @@ static void cpu_detect_tlb_amd(struct cp
tlb_lli_2m[ENTRIES] = eax & mask;
tlb_lli_4m[ENTRIES] = tlb_lli_2m[ENTRIES] >> 1;
+
+ /* Max number of pages INVLPGB can invalidate in one shot */
+ if (boot_cpu_has(X86_FEATURE_INVLPGB)) {
+ cpuid(0x80000008, &eax, &ebx, &ecx, &edx);
+ invlpgb_count_max = (edx & 0xffff) + 1;
+ }
}
static const struct cpu_dev amd_cpu_dev = {