[PATCH] x86/cpufeatures: Carve out CQM features retrieval

From: Borislav Petkov
Date: Wed Jun 19 2019 - 11:24:34 EST


... into a separate function for better readability. Split out from a
patch from Fenghua Yu <fenghua.yu@xxxxxxxxx> to keep the mechanical,
sole code movement separate for easy review.

No functional changes.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: x86@xxxxxxxxxx
---
arch/x86/kernel/cpu/common.c | 60 ++++++++++++++++++++----------------
1 file changed, 33 insertions(+), 27 deletions(-)

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 2c57fffebf9b..fe6ed9696467 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -801,6 +801,38 @@ static void init_speculation_control(struct cpuinfo_x86 *c)
}
}

+static void init_cqm(struct cpuinfo_x86 *c)
+{
+ u32 eax, ebx, ecx, edx;
+
+ /* Additional Intel-defined flags: level 0x0000000F */
+ if (c->cpuid_level >= 0x0000000F) {
+
+ /* QoS sub-leaf, EAX=0Fh, ECX=0 */
+ cpuid_count(0x0000000F, 0, &eax, &ebx, &ecx, &edx);
+ c->x86_capability[CPUID_F_0_EDX] = edx;
+
+ if (cpu_has(c, X86_FEATURE_CQM_LLC)) {
+ /* will be overridden if occupancy monitoring exists */
+ c->x86_cache_max_rmid = ebx;
+
+ /* QoS sub-leaf, EAX=0Fh, ECX=1 */
+ cpuid_count(0x0000000F, 1, &eax, &ebx, &ecx, &edx);
+ c->x86_capability[CPUID_F_1_EDX] = edx;
+
+ if ((cpu_has(c, X86_FEATURE_CQM_OCCUP_LLC)) ||
+ ((cpu_has(c, X86_FEATURE_CQM_MBM_TOTAL)) ||
+ (cpu_has(c, X86_FEATURE_CQM_MBM_LOCAL)))) {
+ c->x86_cache_max_rmid = ecx;
+ c->x86_cache_occ_scale = ebx;
+ }
+ } else {
+ c->x86_cache_max_rmid = -1;
+ c->x86_cache_occ_scale = -1;
+ }
+ }
+}
+
void get_cpu_cap(struct cpuinfo_x86 *c)
{
u32 eax, ebx, ecx, edx;
@@ -832,33 +864,6 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
c->x86_capability[CPUID_D_1_EAX] = eax;
}

- /* Additional Intel-defined flags: level 0x0000000F */
- if (c->cpuid_level >= 0x0000000F) {
-
- /* QoS sub-leaf, EAX=0Fh, ECX=0 */
- cpuid_count(0x0000000F, 0, &eax, &ebx, &ecx, &edx);
- c->x86_capability[CPUID_F_0_EDX] = edx;
-
- if (cpu_has(c, X86_FEATURE_CQM_LLC)) {
- /* will be overridden if occupancy monitoring exists */
- c->x86_cache_max_rmid = ebx;
-
- /* QoS sub-leaf, EAX=0Fh, ECX=1 */
- cpuid_count(0x0000000F, 1, &eax, &ebx, &ecx, &edx);
- c->x86_capability[CPUID_F_1_EDX] = edx;
-
- if ((cpu_has(c, X86_FEATURE_CQM_OCCUP_LLC)) ||
- ((cpu_has(c, X86_FEATURE_CQM_MBM_TOTAL)) ||
- (cpu_has(c, X86_FEATURE_CQM_MBM_LOCAL)))) {
- c->x86_cache_max_rmid = ecx;
- c->x86_cache_occ_scale = ebx;
- }
- } else {
- c->x86_cache_max_rmid = -1;
- c->x86_cache_occ_scale = -1;
- }
- }
-
/* AMD-defined flags: level 0x80000001 */
eax = cpuid_eax(0x80000000);
c->extended_cpuid_level = eax;
@@ -889,6 +894,7 @@ void get_cpu_cap(struct cpuinfo_x86 *c)

init_scattered_cpuid_features(c);
init_speculation_control(c);
+ init_cqm(c);

/*
* Clear/Set all flags overridden by options, after probe.
--
2.21.0

---

This way you have *pure* code movement only.

And then your second patch turns into this, which shows *exactly* what
has been changed in init_cqm().

Please have a look and send me only the now third patch with corrected
commit message.

Thx.

---