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perf/x86/intel: Support the 4 new OMR MSRs introduced in DMR and NVL

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Diamond Rapids (DMR) and Nova Lake (NVL) introduce an enhanced
Off-Module Response (OMR) facility, replacing the Off-Core Response (OCR)
Performance Monitoring of previous processors.

Legacy microarchitectures used the OCR facility to evaluate off-core and
multi-core off-module transactions. The newly named OMR facility improves
OCR capabilities for scalable coverage of new memory systems in
multi-core module systems.

Similar to OCR, 4 additional off-module configuration MSRs
(OFFMODULE_RSP_0 to OFFMODULE_RSP_3) are introduced to specify attributes
of off-module transactions. When multiple identical OMR events are
created, they need to occupy the same OFFMODULE_RSP_x MSR. To ensure
these multiple identical OMR events can work simultaneously, the
intel_alt_er() and intel_fixup_er() helpers are enhanced to rotate these
OMR events across different OFFMODULE_RSP_* MSRs, similar to previous OCR
events.

For more details about OMR, please refer to section 16.1 "OFF-MODULE
 RESPONSE (OMR) FACILITY" in ISE documentation.

Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260114011750.350569-2-dapeng1.mi@linux.intel.com
This commit is contained in:
Dapeng Mi
2026-01-14 09:17:44 +08:00
committed by Peter Zijlstra
parent 4960626f95
commit 4e955c08d6
3 changed files with 52 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

59
arch/x86/events/intel/core.c
View File

@@ -3532,17 +3532,32 @@ static int intel_alt_er(struct cpu_hw_events *cpuc,
struct extra_reg *extra_regs = hybrid(cpuc->pmu, extra_regs);
int alt_idx = idx;
if (!(x86_pmu.flags & PMU_FL_HAS_RSP_1))
return idx;
switch (idx) {
case EXTRA_REG_RSP_0 ... EXTRA_REG_RSP_1:
if (!(x86_pmu.flags & PMU_FL_HAS_RSP_1))
return idx;
if (++alt_idx > EXTRA_REG_RSP_1)
alt_idx = EXTRA_REG_RSP_0;
if (config & ~extra_regs[alt_idx].valid_mask)
return idx;
break;
if (idx == EXTRA_REG_RSP_0)
alt_idx = EXTRA_REG_RSP_1;
case EXTRA_REG_OMR_0 ... EXTRA_REG_OMR_3:
if (!(x86_pmu.flags & PMU_FL_HAS_OMR))
return idx;
if (++alt_idx > EXTRA_REG_OMR_3)
alt_idx = EXTRA_REG_OMR_0;
/*
* Subtracting EXTRA_REG_OMR_0 ensures to get correct
* OMR extra_reg entries which start from 0.
*/
if (config & ~extra_regs[alt_idx - EXTRA_REG_OMR_0].valid_mask)
return idx;
break;
if (idx == EXTRA_REG_RSP_1)
alt_idx = EXTRA_REG_RSP_0;
if (config & ~extra_regs[alt_idx].valid_mask)
return idx;
default:
break;
}
return alt_idx;
}
@@ -3550,16 +3565,26 @@ static int intel_alt_er(struct cpu_hw_events *cpuc,
static void intel_fixup_er(struct perf_event *event, int idx)
{
struct extra_reg *extra_regs = hybrid(event->pmu, extra_regs);
event->hw.extra_reg.idx = idx;
int er_idx;
if (idx == EXTRA_REG_RSP_0) {
event->hw.extra_reg.idx = idx;
switch (idx) {
case EXTRA_REG_RSP_0 ... EXTRA_REG_RSP_1:
er_idx = idx - EXTRA_REG_RSP_0;
event->hw.config &= ~INTEL_ARCH_EVENT_MASK;
event->hw.config |= extra_regs[EXTRA_REG_RSP_0].event;
event->hw.extra_reg.reg = MSR_OFFCORE_RSP_0;
} else if (idx == EXTRA_REG_RSP_1) {
event->hw.config &= ~INTEL_ARCH_EVENT_MASK;
event->hw.config |= extra_regs[EXTRA_REG_RSP_1].event;
event->hw.extra_reg.reg = MSR_OFFCORE_RSP_1;
event->hw.config |= extra_regs[er_idx].event;
event->hw.extra_reg.reg = MSR_OFFCORE_RSP_0 + er_idx;
break;
case EXTRA_REG_OMR_0 ... EXTRA_REG_OMR_3:
er_idx = idx - EXTRA_REG_OMR_0;
event->hw.config &= ~ARCH_PERFMON_EVENTSEL_UMASK;
event->hw.config |= 1ULL << (8 + er_idx);
event->hw.extra_reg.reg = MSR_OMR_0 + er_idx;
break;
default:
pr_warn("The extra reg idx %d is not supported.\n", idx);
}
}

5
arch/x86/events/perf_event.h
View File

@@ -45,6 +45,10 @@ enum extra_reg_type {
EXTRA_REG_FE = 4, /* fe_* */
EXTRA_REG_SNOOP_0 = 5, /* snoop response 0 */
EXTRA_REG_SNOOP_1 = 6, /* snoop response 1 */
EXTRA_REG_OMR_0 = 7, /* OMR 0 */
EXTRA_REG_OMR_1 = 8, /* OMR 1 */
EXTRA_REG_OMR_2 = 9, /* OMR 2 */
EXTRA_REG_OMR_3 = 10, /* OMR 3 */
EXTRA_REG_MAX /* number of entries needed */
};
@@ -1099,6 +1103,7 @@ do { \
#define PMU_FL_RETIRE_LATENCY 0x200 /* Support Retire Latency in PEBS */
#define PMU_FL_BR_CNTR 0x400 /* Support branch counter logging */
#define PMU_FL_DYN_CONSTRAINT 0x800 /* Needs dynamic constraint */
#define PMU_FL_HAS_OMR 0x1000 /* has 4 equivalent OMR regs */
#define EVENT_VAR(_id) event_attr_##_id
#define EVENT_PTR(_id) &event_attr_##_id.attr.attr

5
arch/x86/include/asm/msr-index.h
View File

@@ -263,6 +263,11 @@
#define MSR_SNOOP_RSP_0 0x00001328
#define MSR_SNOOP_RSP_1 0x00001329
#define MSR_OMR_0 0x000003e0
#define MSR_OMR_1 0x000003e1
#define MSR_OMR_2 0x000003e2
#define MSR_OMR_3 0x000003e3
#define MSR_LBR_SELECT 0x000001c8
#define MSR_LBR_TOS 0x000001c9