perf/x86/intel: Add PMU support for Clearwater Forest

JIRA: https://issues.redhat.com/browse/RHEL-45092

JIRA: https://issues.redhat.com/browse/RHEL-47453

upstream
========
commit 48d66c8
Author: Dapeng Mi <dapeng1.mi@linux.intel.com>
Date: Tue Apr 15 11:44:08 2025 +0000

description
===========
From the PMU's perspective, Clearwater Forest is similar to the previous
generation Sierra Forest.

The key differences are the ARCH PEBS feature and the new added 3 fixed
counters for topdown L1 metrics events.

The ARCH PEBS is supported in the following patches. This patch provides
support for basic perfmon features and 3 new added fixed counters.

    Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
    Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
    Signed-off-by: Ingo Molnar <mingo@kernel.org>
    Link: https://lkml.kernel.org/r/20250415114428.341182-3-dapeng1.mi@linux.intel.com

Signed-off-by: Michael Petlan <mpetlan@redhat.com>

Author: rfmvh

arch/x86/events/intel/core.c

@@ -2224,6 +2224,18 @@ static struct extra_reg intel_cmt_extra_regs[] __read_mostly = {
 	EVENT_EXTRA_END
 };
 
+EVENT_ATTR_STR(topdown-fe-bound,       td_fe_bound_skt,        "event=0x9c,umask=0x01");
+EVENT_ATTR_STR(topdown-retiring,       td_retiring_skt,        "event=0xc2,umask=0x02");
+EVENT_ATTR_STR(topdown-be-bound,       td_be_bound_skt,        "event=0xa4,umask=0x02");
+
+static struct attribute *skt_events_attrs[] = {
+	EVENT_PTR(td_fe_bound_skt),
+	EVENT_PTR(td_retiring_skt),
+	EVENT_PTR(td_bad_spec_cmt),
+	EVENT_PTR(td_be_bound_skt),
+	NULL,
+};
+
 #define KNL_OT_L2_HITE		BIT_ULL(19) /* Other Tile L2 Hit */
 #define KNL_OT_L2_HITF		BIT_ULL(20) /* Other Tile L2 Hit */
 #define KNL_MCDRAM_LOCAL	BIT_ULL(21)
@@ -6825,6 +6837,18 @@ __init int intel_pmu_init(void)
 		name = "crestmont";
 		break;
 
+	case INTEL_ATOM_DARKMONT_X:
+		intel_pmu_init_skt(NULL);
+		intel_pmu_pebs_data_source_cmt();
+		x86_pmu.pebs_latency_data = cmt_latency_data;
+		x86_pmu.get_event_constraints = cmt_get_event_constraints;
+		td_attr = skt_events_attrs;
+		mem_attr = grt_mem_attrs;
+		extra_attr = cmt_format_attr;
+		pr_cont("Darkmont events, ");
+		name = "darkmont";
+		break;
+
 	case INTEL_WESTMERE:
 	case INTEL_WESTMERE_EP:
 	case INTEL_WESTMERE_EX: