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authorZide Chen <zide.chen@intel.com>2026-02-09 16:52:25 -0800
committerPeter Zijlstra <peterz@infradead.org>2026-02-23 11:19:25 +0100
commit6a8a48644c4b804123e59dbfc5d6cd29a0194046 (patch)
treed8d55cb51e0d730477fd9e1a4fa66b67976e91bd
parent486ff5ad49bc50315bcaf6d45f04a33ef0a45ced (diff)
perf/x86/intel/uncore: Add per-scheduler IMC CAS count events
IMC on SPR and EMR does not support sub-channels. In contrast, CPUs that use gnr_uncores[] (e.g. Granite Rapids and Sierra Forest) implement two command schedulers (SCH0/SCH1) per memory channel, providing logically independent command and data paths. Do not reuse the spr_uncore_imc[] configuration for these CPUs. Instead, introduce a dedicated gnr_uncore_imc[] with per-scheduler events, so userspace can monitor SCH0 and SCH1 independently. On these CPUs, replace cas_count_{read,write} with cas_count_{read,write}_sch{0,1}. This may break existing userspace that relies on cas_count_{read,write}, prompting it to switch to the per-scheduler events, as the legacy event reports only partial traffic (SCH0). Fixes: 632c4bf6d007 ("perf/x86/intel/uncore: Support Granite Rapids") Fixes: cb4a6ccf3583 ("perf/x86/intel/uncore: Support Sierra Forest and Grand Ridge") Reported-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Zide Chen <zide.chen@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260210005225.20311-1-zide.chen@intel.com
-rw-r--r--arch/x86/events/intel/uncore_snbep.c28
1 files changed, 27 insertions, 1 deletions
diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
index 5ed6e0b7e715..0a1d08136cc1 100644
--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -6497,6 +6497,32 @@ static struct intel_uncore_type gnr_uncore_ubox = {
.attr_update = uncore_alias_groups,
};
+static struct uncore_event_desc gnr_uncore_imc_events[] = {
+ INTEL_UNCORE_EVENT_DESC(clockticks, "event=0x01,umask=0x00"),
+ INTEL_UNCORE_EVENT_DESC(cas_count_read_sch0, "event=0x05,umask=0xcf"),
+ INTEL_UNCORE_EVENT_DESC(cas_count_read_sch0.scale, "6.103515625e-5"),
+ INTEL_UNCORE_EVENT_DESC(cas_count_read_sch0.unit, "MiB"),
+ INTEL_UNCORE_EVENT_DESC(cas_count_read_sch1, "event=0x06,umask=0xcf"),
+ INTEL_UNCORE_EVENT_DESC(cas_count_read_sch1.scale, "6.103515625e-5"),
+ INTEL_UNCORE_EVENT_DESC(cas_count_read_sch1.unit, "MiB"),
+ INTEL_UNCORE_EVENT_DESC(cas_count_write_sch0, "event=0x05,umask=0xf0"),
+ INTEL_UNCORE_EVENT_DESC(cas_count_write_sch0.scale, "6.103515625e-5"),
+ INTEL_UNCORE_EVENT_DESC(cas_count_write_sch0.unit, "MiB"),
+ INTEL_UNCORE_EVENT_DESC(cas_count_write_sch1, "event=0x06,umask=0xf0"),
+ INTEL_UNCORE_EVENT_DESC(cas_count_write_sch1.scale, "6.103515625e-5"),
+ INTEL_UNCORE_EVENT_DESC(cas_count_write_sch1.unit, "MiB"),
+ { /* end: all zeroes */ },
+};
+
+static struct intel_uncore_type gnr_uncore_imc = {
+ SPR_UNCORE_MMIO_COMMON_FORMAT(),
+ .name = "imc",
+ .fixed_ctr_bits = 48,
+ .fixed_ctr = SNR_IMC_MMIO_PMON_FIXED_CTR,
+ .fixed_ctl = SNR_IMC_MMIO_PMON_FIXED_CTL,
+ .event_descs = gnr_uncore_imc_events,
+};
+
static struct intel_uncore_type gnr_uncore_pciex8 = {
SPR_UNCORE_PCI_COMMON_FORMAT(),
.name = "pciex8",
@@ -6544,7 +6570,7 @@ static struct intel_uncore_type *gnr_uncores[UNCORE_GNR_NUM_UNCORE_TYPES] = {
NULL,
&spr_uncore_pcu,
&gnr_uncore_ubox,
- &spr_uncore_imc,
+ &gnr_uncore_imc,
NULL,
&gnr_uncore_upi,
NULL,