[RFC,14/15] perf/x86: Simplify p6_pmu_init()

Commit Message

Sohil Mehta Dec. 20, 2024, 9:37 p.m. UTC

A switch case is unnecessary when only a single case matters. Also, the
gaps in the case numbers are due to no CPU with those model numbers
being released.

Avoid the switch case and combine the cases into simpler VFM checks.
Also, this gets rid of one last few Intel x86_model comparisons. No
functional change intended.

Signed-off-by: Sohil Mehta <[e-mail]>
---
 arch/x86/events/intel/p6.c | 28 +++++++---------------------
 1 file changed, 7 insertions(+), 21 deletions(-)

Patch

diff --git a/arch/x86/events/intel/p6.c b/arch/x86/events/intel/p6.c
index a6cffb4f4ef5..37e3beb6d633 100644
--- a/arch/x86/events/intel/p6.c
+++ b/arch/x86/events/intel/p6.c
@@ -2,6 +2,8 @@ 
 #include <linux/perf_event.h>
 #include <linux/types.h>
 
+#include <asm/cpu_device_id.h>
+
 #include "../perf_event.h"
 
 /*
@@ -244,35 +246,19 @@  static __init void p6_pmu_rdpmc_quirk(void)
 	}
 }
 
+/* Only called for Family 6 CPUs without X86_FEATURE_ARCH_PERFMON */
 __init int p6_pmu_init(void)
 {
 	x86_pmu = p6_pmu;
 
-	switch (boot_cpu_data.x86_model) {
-	case  1: /* Pentium Pro */
-		x86_add_quirk(p6_pmu_rdpmc_quirk);
-		break;
-
-	case  3: /* Pentium II - Klamath */
-	case  5: /* Pentium II - Deschutes */
-	case  6: /* Pentium II - Mendocino */
-		break;
-
-	case  7: /* Pentium III - Katmai */
-	case  8: /* Pentium III - Coppermine */
-	case 10: /* Pentium III Xeon */
-	case 11: /* Pentium III - Tualatin */
-		break;
-
-	case  9: /* Pentium M - Banias */
-	case 13: /* Pentium M - Dothan */
-		break;
-
-	default:
+	if (boot_cpu_data.x86_vfm >= INTEL_CORE_YONAH) {
 		pr_cont("unsupported p6 CPU model %d ", boot_cpu_data.x86_model);
 		return -ENODEV;
 	}
 
+	if (boot_cpu_data.x86_vfm == INTEL_PENTIUM_PRO)
+		x86_add_quirk(p6_pmu_rdpmc_quirk);
+
 	memcpy(hw_cache_event_ids, p6_hw_cache_event_ids,
 		sizeof(hw_cache_event_ids));