x86/CPU/AMD: Add X86_FEATURE_ZEN5

Add a synthetic feature flag for Zen5.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240104201138.5072-1-bp@alien8.de

Author: bp3tk0v

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 */

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