[RFC PATCH 4/4] x86/resctrl: Delete resctrl_cpu_detect()
From: Tony Luck
Date: Wed Aug 19 2026 - 12:16:42 EST
cpuinfo_x86::x86_cache_{max_rmid,occ_scale,mbm_width_offset} are no
longer used.
Delete resctrl_cpu_detect() and the fields from struct cpuinfo_x86.
Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
arch/x86/include/asm/processor.h | 4 ---
arch/x86/include/asm/resctrl.h | 3 ---
arch/x86/kernel/cpu/amd.c | 3 ---
arch/x86/kernel/cpu/hygon.c | 3 ---
arch/x86/kernel/cpu/intel.c | 7 -----
arch/x86/kernel/cpu/resctrl/core.c | 42 ------------------------------
6 files changed, 62 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index ec9db0dfa0df..4deb88c61c94 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -185,10 +185,6 @@ struct cpuinfo_x86 {
/* in KB - valid for CPUS which support this call: */
unsigned int x86_cache_size;
int x86_cache_alignment; /* In bytes */
- /* Cache QoS architectural values, valid only on the BSP: */
- int x86_cache_max_rmid; /* max index */
- int x86_cache_occ_scale; /* scale to bytes */
- int x86_cache_mbm_width_offset;
int x86_power;
unsigned long loops_per_jiffy;
/* protected processor identification number */
diff --git a/arch/x86/include/asm/resctrl.h b/arch/x86/include/asm/resctrl.h
index 9bfa9b14002b..ab7f6ccd149e 100644
--- a/arch/x86/include/asm/resctrl.h
+++ b/arch/x86/include/asm/resctrl.h
@@ -193,12 +193,9 @@ static inline void resctrl_arch_mon_ctx_free(struct rdt_resource *r,
enum resctrl_event_id evtid,
void *ctx) { }
-void resctrl_cpu_detect(struct cpuinfo_x86 *c);
-
#else
static inline void resctrl_arch_sched_in(struct task_struct *tsk) {}
-static inline void resctrl_cpu_detect(struct cpuinfo_x86 *c) {}
#endif /* CONFIG_X86_CPU_RESCTRL */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 54e14ed276b5..dd82a11084f4 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -23,7 +23,6 @@
#include <asm/pci-direct.h>
#include <asm/delay.h>
#include <asm/debugreg.h>
-#include <asm/resctrl.h>
#include <asm/msr.h>
#include <asm/sev.h>
@@ -475,8 +474,6 @@ static void bsp_init_amd(struct cpuinfo_x86 *c)
}
}
- resctrl_cpu_detect(c);
-
/* Figure out Zen generations: */
switch (c->x86) {
case 0x17:
diff --git a/arch/x86/kernel/cpu/hygon.c b/arch/x86/kernel/cpu/hygon.c
index ec51c2b9a257..0f226335dd9a 100644
--- a/arch/x86/kernel/cpu/hygon.c
+++ b/arch/x86/kernel/cpu/hygon.c
@@ -17,7 +17,6 @@
#include <asm/spec-ctrl.h>
#include <asm/delay.h>
#include <asm/msr.h>
-#include <asm/resctrl.h>
#include "cpu.h"
@@ -119,8 +118,6 @@ static void bsp_init_hygon(struct cpuinfo_x86 *c)
x86_amd_ls_cfg_ssbd_mask = 1ULL << 10;
}
}
-
- resctrl_cpu_detect(c);
}
static void early_init_hygon(struct cpuinfo_x86 *c)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 4297ceb2cb24..2f09710e863c 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -22,7 +22,6 @@
#include <asm/microcode.h>
#include <asm/msr.h>
#include <asm/numa.h>
-#include <asm/resctrl.h>
#include <asm/thermal.h>
#include <asm/uaccess.h>
@@ -371,11 +370,6 @@ static void early_init_intel(struct cpuinfo_x86 *c)
detect_tme_early(c);
}
-static void bsp_init_intel(struct cpuinfo_x86 *c)
-{
- resctrl_cpu_detect(c);
-}
-
#ifdef CONFIG_X86_32
/*
* Early probe support logic for ppro memory erratum #50
@@ -804,7 +798,6 @@ static const struct cpu_dev intel_cpu_dev = {
#endif
.c_detect_tlb = intel_detect_tlb,
.c_early_init = early_init_intel,
- .c_bsp_init = bsp_init_intel,
.c_init = init_intel,
.c_x86_vendor = X86_VENDOR_INTEL,
};
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index da94a12f9256..1e36630c5da7 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -1078,48 +1078,6 @@ static __init void rdt_init_res_defs(void)
static enum cpuhp_state rdt_online;
-/* Runs once on the BSP during boot. */
-void resctrl_cpu_detect(struct cpuinfo_x86 *c)
-{
- if (!cpu_has(c, X86_FEATURE_CQM_LLC) && !cpu_has(c, X86_FEATURE_ABMC)) {
- c->x86_cache_max_rmid = -1;
- c->x86_cache_occ_scale = -1;
- c->x86_cache_mbm_width_offset = -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) ||
- cpu_has(c, X86_FEATURE_ABMC)) {
- 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;
- c->x86_cache_mbm_width_offset = eax & 0xff;
-
- if (!c->x86_cache_mbm_width_offset) {
- switch (c->x86_vendor) {
- case X86_VENDOR_AMD:
- c->x86_cache_mbm_width_offset = MBM_CNTR_WIDTH_OFFSET_AMD;
- break;
- case X86_VENDOR_HYGON:
- c->x86_cache_mbm_width_offset = MBM_CNTR_WIDTH_OFFSET_HYGON;
- break;
- default:
- /* Leave c->x86_cache_mbm_width_offset as 0 */
- break;
- }
- }
- }
-}
-
static int __init resctrl_arch_late_init(void)
{
struct rdt_resource *r;
--
2.55.0