[PATCH V2 2/7] x86/cpu: Move resctrl CPUID code to resctrl

From: Reinette Chatre
Date: Tue May 05 2020 - 18:36:51 EST


The function determining a platform's support and properties of cache
occupancy and memory bandwidth monitoring (properties of
X86_FEATURE_CQM_LLC) can be found among the common CPU code. After
the feature's properties is populated in the per-CPU data the resctrl
subsystem is the only consumer (via boot_cpu_data).

Move the function that obtains the CPU information used by resctrl to
the resctrl subsystem and rename it from init_cqm() to
resctrl_cpu_detect(). The function continues to be called from the
common CPU code. This move is done in preparation of the addition of some
vendor specific code.

No functional change.

Suggested-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
---
arch/x86/include/asm/resctrl.h | 3 +++
arch/x86/kernel/cpu/common.c | 27 ++-------------------------
arch/x86/kernel/cpu/resctrl/core.c | 24 ++++++++++++++++++++++++
3 files changed, 29 insertions(+), 25 deletions(-)

diff --git a/arch/x86/include/asm/resctrl.h b/arch/x86/include/asm/resctrl.h
index 99b5728e441d..07603064df8f 100644
--- a/arch/x86/include/asm/resctrl.h
+++ b/arch/x86/include/asm/resctrl.h
@@ -84,9 +84,12 @@ static inline void resctrl_sched_in(void)
__resctrl_sched_in();
}

+void resctrl_cpu_detect(struct cpuinfo_x86 *c);
+
#else

static inline void resctrl_sched_in(void) {}
+static inline void resctrl_cpu_detect(struct cpuinfo_x86 *c) {}

#endif /* CONFIG_X86_CPU_RESCTRL */

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index bed0cb83fe24..a8f0f22ee5c1 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -56,6 +56,7 @@
#include <asm/intel-family.h>
#include <asm/cpu_device_id.h>
#include <asm/uv/uv.h>
+#include <asm/resctrl.h>

#include "cpu.h"

@@ -854,30 +855,6 @@ static void init_speculation_control(struct cpuinfo_x86 *c)
}
}

-static void init_cqm(struct cpuinfo_x86 *c)
-{
- if (!cpu_has(c, X86_FEATURE_CQM_LLC)) {
- c->x86_cache_max_rmid = -1;
- c->x86_cache_occ_scale = -1;
- return;
- }
-
- /* will be overridden if occupancy monitoring exists */
- c->x86_cache_max_rmid = cpuid_ebx(0xf);
-
- 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)) {
- u32 eax, ebx, ecx, edx;
-
- /* QoS sub-leaf, EAX=0Fh, ECX=1 */
- cpuid_count(0xf, 1, &eax, &ebx, &ecx, &edx);
-
- c->x86_cache_max_rmid = ecx;
- c->x86_cache_occ_scale = ebx;
- }
-}
-
void get_cpu_cap(struct cpuinfo_x86 *c)
{
u32 eax, ebx, ecx, edx;
@@ -945,7 +922,7 @@ void get_cpu_cap(struct cpuinfo_x86 *c)

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

/*
* Clear/Set all flags overridden by options, after probe.
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 6f38c88226af..861c6d1ba9ab 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -958,6 +958,30 @@ static __init void rdt_init_res_defs(void)

static enum cpuhp_state rdt_online;

+void resctrl_cpu_detect(struct cpuinfo_x86 *c)
+{
+ if (!cpu_has(c, X86_FEATURE_CQM_LLC)) {
+ c->x86_cache_max_rmid = -1;
+ c->x86_cache_occ_scale = -1;
+ return;
+ }
+
+ /* will be overridden if occupancy monitoring exists */
+ c->x86_cache_max_rmid = cpuid_ebx(0xf);
+
+ 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)) {
+ u32 eax, ebx, ecx, edx;
+
+ /* QoS sub-leaf, EAX=0Fh, ECX=1 */
+ cpuid_count(0xf, 1, &eax, &ebx, &ecx, &edx);
+
+ c->x86_cache_max_rmid = ecx;
+ c->x86_cache_occ_scale = ebx;
+ }
+}
+
static int __init resctrl_late_init(void)
{
struct rdt_resource *r;
--
2.21.0