[PATCH v2 3/6] x86/cpu: X86_FEATURE_INTEL_PPIN finally has a CPUID bit

From: Tony Luck
Date: Fri Jan 21 2022 - 12:48:03 EST


After nine generations of adding to model specific list of CPUs that
support PPIN (Protected Processor Inventory Number) Intel allocated
a CPUID bit to enumerate the MSRs.

CPUID(EAX=7, ECX=1).EBX bit 0 enumerates presence of MSR_PPIN_CTL and
MSR_PPIN. Add it to the "scattered" CPUID bits and add an entry to the
ppin_cpuids[] x86_match_cpu() array to catch Intel CPUs that implement
it.

Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
arch/x86/kernel/cpu/common.c | 1 +
arch/x86/kernel/cpu/scattered.c | 1 +
2 files changed, 2 insertions(+)

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index b7700a47eadd..8a039d1ea57f 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -106,6 +106,7 @@ static struct ppin_info {

static const struct x86_cpu_id ppin_cpuids[] = {
X86_MATCH_FEATURE(X86_FEATURE_AMD_PPIN, &ppin_info[X86_VENDOR_AMD]),
+ X86_MATCH_FEATURE(X86_FEATURE_INTEL_PPIN, &ppin_info[X86_VENDOR_INTEL]),

/* Legacy models without CPUID enumeration */
X86_MATCH_INTEL_FAM6_MODEL(IVYBRIDGE_X, &ppin_info[X86_VENDOR_INTEL]),
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index 21d1f062895a..4143b1e4c5c6 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -26,6 +26,7 @@ struct cpuid_bit {
static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_APERFMPERF, CPUID_ECX, 0, 0x00000006, 0 },
{ X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 },
+ { X86_FEATURE_INTEL_PPIN, CPUID_EBX, 0, 0x00000007, 1 },
{ X86_FEATURE_CQM_LLC, CPUID_EDX, 1, 0x0000000f, 0 },
{ X86_FEATURE_CQM_OCCUP_LLC, CPUID_EDX, 0, 0x0000000f, 1 },
{ X86_FEATURE_CQM_MBM_TOTAL, CPUID_EDX, 1, 0x0000000f, 1 },
--
2.31.1