From: Zide Chen <zide.chen@intel.com>
Date: Tue, 2 Jun 2026 14:49:08 +0000 (-0700)
Subject: perf/x86/intel/uncore: Implement global init callback for GNR uncore
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=1a308a168c9286a335a05926204ef3ebb68fba1c;p=thirdparty%2Fkernel%2Flinux.git

perf/x86/intel/uncore: Implement global init callback for GNR uncore

On Sierra Forest and Clearwater Forest, the FRZ_ALL bit in the global
control register defaults to 0 at boot, but UBOX PMON units do not
work until the global control register is explicitly written with 0
to trigger hardware initialization properly.

Implement the generic uncore_msr_global_init() callback and add it to
gnr_uncore_init[], which is shared by GNR, GRR, SRF, and CWF.

Fixes: 632c4bf6d007 ("perf/x86/intel/uncore: Support Granite Rapids")
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>
Link: https://patch.msgid.link/20260602144908.263680-8-zide.chen@intel.com
---

diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index 4b3a1fa5b41b..7857959c6e82 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -1716,7 +1716,7 @@ err:
 	return ret;
 }
 
-static int uncore_mmio_global_init(u64 ctl)
+static int uncore_mmio_global_init(int die, u64 ctl)
 {
 	void __iomem *io_addr;
 
@@ -1731,6 +1731,16 @@ static int uncore_mmio_global_init(u64 ctl)
 	return 0;
 }
 
+static int uncore_msr_global_init(int die, u64 msr)
+{
+	int cpu = uncore_die_to_cpu(die);
+
+	if (cpu == -1)
+		return -ENODEV;
+
+	return wrmsrq_on_cpu(cpu, msr, 0);
+}
+
 static const struct uncore_plat_init nhm_uncore_init __initconst = {
 	.cpu_init = nhm_uncore_cpu_init,
 };
@@ -1871,6 +1881,7 @@ static const struct uncore_plat_init gnr_uncore_init __initconst = {
 	.domain[0].base_is_pci = true,
 	.domain[0].discovery_base = UNCORE_DISCOVERY_TABLE_DEVICE,
 	.domain[0].units_ignore = gnr_uncore_units_ignore,
+	.domain[0].global_init = uncore_msr_global_init,
 };
 
 static const struct uncore_plat_init dmr_uncore_init __initconst = {
diff --git a/arch/x86/events/intel/uncore.h b/arch/x86/events/intel/uncore.h
index 94c68e3417b6..c2e5ccb1d72c 100644
--- a/arch/x86/events/intel/uncore.h
+++ b/arch/x86/events/intel/uncore.h
@@ -53,7 +53,7 @@ struct uncore_discovery_domain {
 	/* MSR address or PCI device used as the discovery base */
 	u32	discovery_base;
 	bool	base_is_pci;
-	int	(*global_init)(u64 ctl);
+	int	(*global_init)(int die, u64 ctl);
 
 	/* The units in the discovery table should be ignored. */
 	int	*units_ignore;
diff --git a/arch/x86/events/intel/uncore_discovery.c b/arch/x86/events/intel/uncore_discovery.c
index af7e80fee81f..e50776222256 100644
--- a/arch/x86/events/intel/uncore_discovery.c
+++ b/arch/x86/events/intel/uncore_discovery.c
@@ -287,7 +287,7 @@ static int __parse_discovery_table(struct uncore_discovery_domain *domain,
 	if (!io_addr)
 		return -ENOMEM;
 
-	if (domain->global_init && domain->global_init(global.ctl)) {
+	if (domain->global_init && domain->global_init(die, global.ctl)) {
 		ret = -ENODEV;
 		goto out;
 	}
@@ -399,7 +399,6 @@ static bool uncore_discovery_msr(struct uncore_discovery_domain *domain)
 	if (!die_mask)
 		return false;
 
-	cpus_read_lock();
 	for_each_online_cpu(cpu) {
 		die = topology_logical_die_id(cpu);
 		if (__test_and_set_bit(die, die_mask))
@@ -414,8 +413,6 @@ static bool uncore_discovery_msr(struct uncore_discovery_domain *domain)
 		__parse_discovery_table(domain, base, die, &parsed);
 	}
 
-	cpus_read_unlock();
-
 	kfree(die_mask);
 	return parsed;
 }
@@ -429,10 +426,14 @@ bool uncore_discovery(struct uncore_plat_init *init)
 	for (i = 0; i < UNCORE_DISCOVERY_DOMAINS; i++) {
 		domain = &init->domain[i];
 		if (domain->discovery_base) {
+			cpus_read_lock();
+
 			if (!domain->base_is_pci)
 				ret |= uncore_discovery_msr(domain);
 			else
 				ret |= uncore_discovery_pci(domain);
+
+			cpus_read_unlock();
 		}
 	}