[PATCH v2 10/17] x86/cpu/intel: Replace early Family 6 checks with VFM ones

From: Sohil Mehta
Date: Tue Feb 11 2025 - 14:48:52 EST


Introduce names for some old pentium models and replace the x86_model
checks with VFM ones.

Signed-off-by: Sohil Mehta <sohil.mehta@xxxxxxxxx>

---

v2: No change

---
arch/x86/include/asm/intel-family.h | 4 ++++
arch/x86/kernel/cpu/intel.c | 13 ++++++-------
2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/intel-family.h b/arch/x86/include/asm/intel-family.h
index cccc932d761e..c1a081585fcb 100644
--- a/arch/x86/include/asm/intel-family.h
+++ b/arch/x86/include/asm/intel-family.h
@@ -45,8 +45,12 @@
/* Wildcard match so X86_MATCH_VFM(ANY) works */
#define INTEL_ANY IFM(X86_FAMILY_ANY, X86_MODEL_ANY)

+/* Family 6 */
#define INTEL_PENTIUM_PRO IFM(6, 0x01)
+#define INTEL_PENTIUM_II_KLAMATH IFM(6, 0x03)
#define INTEL_PENTIUM_III_DESCHUTES IFM(6, 0x05)
+#define INTEL_PENTIUM_III_TUALATIN IFM(6, 0x0B)
+#define INTEL_PENTIUM_M_DOTHAN IFM(6, 0x0D)

#define INTEL_CORE_YONAH IFM(6, 0x0E)

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 4f8b02cbe8c5..1b6e077a037a 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -195,7 +195,7 @@ void intel_unlock_cpuid_leafs(struct cpuinfo_x86 *c)
if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
return;

- if (c->x86 < 6 || (c->x86 == 6 && c->x86_model < 0xd))
+ if (c->x86_vfm < INTEL_PENTIUM_M_DOTHAN)
return;

/*
@@ -309,7 +309,7 @@ static void early_init_intel(struct cpuinfo_x86 *c)
* If fast string is not enabled in IA32_MISC_ENABLE for any reason,
* clear the fast string and enhanced fast string CPU capabilities.
*/
- if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
+ if (c->x86_vfm >= INTEL_PENTIUM_M_DOTHAN) {
rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
if (!(misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING)) {
pr_info("Disabled fast string operations\n");
@@ -358,9 +358,7 @@ static void bsp_init_intel(struct cpuinfo_x86 *c)
int ppro_with_ram_bug(void)
{
/* Uses data from early_cpu_detect now */
- if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
- boot_cpu_data.x86 == 6 &&
- boot_cpu_data.x86_model == 1 &&
+ if (boot_cpu_data.x86_vfm == INTEL_PENTIUM_PRO &&
boot_cpu_data.x86_stepping < 8) {
pr_info("Pentium Pro with Errata#50 detected. Taking evasive action.\n");
return 1;
@@ -421,7 +419,8 @@ static void intel_workarounds(struct cpuinfo_x86 *c)
* SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
* model 3 mask 3
*/
- if ((c->x86<<8 | c->x86_model<<4 | c->x86_stepping) < 0x633)
+ if ((c->x86_vfm == INTEL_PENTIUM_II_KLAMATH && c->x86_stepping < 3) ||
+ c->x86_vfm < INTEL_PENTIUM_II_KLAMATH)
clear_cpu_cap(c, X86_FEATURE_SEP);

/*
@@ -621,7 +620,7 @@ static unsigned int intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
* to determine which, so we use a boottime override
* for the 512kb model, and assume 256 otherwise.
*/
- if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
+ if (c->x86_vfm == INTEL_PENTIUM_III_TUALATIN && size == 0)
size = 256;

/*
--
2.43.0