[PATCH] x86/CPU/AMD: Add X86_FEATURE_ZEN5

From: Borislav Petkov
Date: Thu Jan 04 2024 - 15:12:05 EST


From: "Borislav Petkov (AMD)" <bp@xxxxxxxxx>

Add a synthetic feature flag for Zen5.

Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
---
arch/x86/include/asm/cpufeatures.h | 4 +---
arch/x86/kernel/cpu/amd.c | 25 +++++++++++++++++++++----
2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 29cb275a219d..fdf723b6f6d0 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -81,10 +81,8 @@
#define X86_FEATURE_K6_MTRR ( 3*32+ 1) /* AMD K6 nonstandard MTRRs */
#define X86_FEATURE_CYRIX_ARR ( 3*32+ 2) /* Cyrix ARRs (= MTRRs) */
#define X86_FEATURE_CENTAUR_MCR ( 3*32+ 3) /* Centaur MCRs (= MTRRs) */
-
-/* CPU types for specific tunings: */
#define X86_FEATURE_K8 ( 3*32+ 4) /* "" Opteron, Athlon64 */
-/* FREE, was #define X86_FEATURE_K7 ( 3*32+ 5) "" Athlon */
+#define X86_FEATURE_ZEN5 ( 3*32+ 5) /* "" CPU based on Zen5 microarchitecture */
#define X86_FEATURE_P3 ( 3*32+ 6) /* "" P3 */
#define X86_FEATURE_P4 ( 3*32+ 7) /* "" P4 */
#define X86_FEATURE_CONSTANT_TSC ( 3*32+ 8) /* TSC ticks at a constant rate */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 9f42d1c59e09..bc49e3b3aae0 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -538,7 +538,7 @@ static void bsp_init_amd(struct cpuinfo_x86 *c)

/* Figure out Zen generations: */
switch (c->x86) {
- case 0x17: {
+ case 0x17:
switch (c->x86_model) {
case 0x00 ... 0x2f:
case 0x50 ... 0x5f:
@@ -554,8 +554,8 @@ static void bsp_init_amd(struct cpuinfo_x86 *c)
goto warn;
}
break;
- }
- case 0x19: {
+
+ case 0x19:
switch (c->x86_model) {
case 0x00 ... 0x0f:
case 0x20 ... 0x5f:
@@ -569,7 +569,17 @@ static void bsp_init_amd(struct cpuinfo_x86 *c)
goto warn;
}
break;
- }
+
+ case 0x1a:
+ switch (c->x86_model) {
+ case 0x00 ... 0x0f:
+ setup_force_cpu_cap(X86_FEATURE_ZEN5);
+ break;
+ default:
+ goto warn;
+ }
+ break;
+
default:
break;
}
@@ -1039,6 +1049,11 @@ static void init_amd_zen4(struct cpuinfo_x86 *c)
msr_set_bit(MSR_ZEN4_BP_CFG, MSR_ZEN4_BP_CFG_SHARED_BTB_FIX_BIT);
}

+static void init_amd_zen5(struct cpuinfo_x86 *c)
+{
+ init_amd_zen_common();
+}
+
static void init_amd(struct cpuinfo_x86 *c)
{
u64 vm_cr;
@@ -1084,6 +1099,8 @@ static void init_amd(struct cpuinfo_x86 *c)
init_amd_zen3(c);
else if (boot_cpu_has(X86_FEATURE_ZEN4))
init_amd_zen4(c);
+ else if (boot_cpu_has(X86_FEATURE_ZEN5))
+ init_amd_zen5(c);

/*
* Enable workaround for FXSAVE leak on CPUs
--
2.42.0.rc0.25.ga82fb66fed25