perf/x86/intel/uncore: Move die_to_cpu() to uncore.c

Move die_to_cpu() into uncore.c so it can be reused by the MSR
initialization path, preparing for the introduction of an MSR global
initialization callback.

Move the cpus_read_{lock,unlock}() out of the API, in order to make
it possible to be called when the lock is being held.

Add the uncore_ prefix for consistency with other uncore APIs.

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/20260602144908.263680-6-zide.chen@intel.com

3 files changed, 23 insertions, 20 deletions

diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index e9cc1ba921c5..22256ded2d67 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -83,6 +83,25 @@ int uncore_device_to_die(struct pci_dev *dev)
 	return -1;
 }
 
+/*
+ * Using cpus_read_lock() to ensure cpu is not going down between
+ * looking at cpu_online_mask.
+ *
+ * The lock must be held by the caller.
+ */
+int uncore_die_to_cpu(int die)
+{
+	int res = 0, cpu;
+
+	for_each_online_cpu(cpu) {
+		if (topology_logical_die_id(cpu) == die) {
+			res = cpu;
+			break;
+		}
+	}
+	return res;
+}
+
 static void uncore_free_pcibus_map(void)
 {
 	struct pci2phy_map *map, *tmp;
diff --git a/arch/x86/events/intel/uncore.h b/arch/x86/events/intel/uncore.h
index c35918c01afa..94c68e3417b6 100644
--- a/arch/x86/events/intel/uncore.h
+++ b/arch/x86/events/intel/uncore.h
@@ -235,6 +235,7 @@ struct pci2phy_map *__find_pci2phy_map(int segment);
 int uncore_pcibus_to_dieid(struct pci_bus *bus);
 int uncore_die_to_segment(int die);
 int uncore_device_to_die(struct pci_dev *dev);
+int uncore_die_to_cpu(int die);
 
 ssize_t uncore_event_show(struct device *dev,
 			  struct device_attribute *attr, char *buf);
diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
index c9ce206fcbb6..772b78237424 100644
--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -3704,25 +3704,6 @@ static int skx_msr_cpu_bus_read(int cpu, u64 *topology)
 	return 0;
 }
 
-static int die_to_cpu(int die)
-{
-	int res = 0, cpu, current_die;
-	/*
-	 * Using cpus_read_lock() to ensure cpu is not going down between
-	 * looking at cpu_online_mask.
-	 */
-	cpus_read_lock();
-	for_each_online_cpu(cpu) {
-		current_die = topology_logical_die_id(cpu);
-		if (current_die == die) {
-			res = cpu;
-			break;
-		}
-	}
-	cpus_read_unlock();
-	return res;
-}
-
 enum {
 	IIO_TOPOLOGY_TYPE,
 	UPI_TOPOLOGY_TYPE,
@@ -3794,8 +3775,9 @@ static int skx_pmu_get_topology(struct intel_uncore_type *type,
 	int die, ret = -EPERM;
 	u64 cpu_bus_msr;
 
+	cpus_read_lock();
 	for (die = 0; die < uncore_max_dies(); die++) {
-		ret = skx_msr_cpu_bus_read(die_to_cpu(die), &cpu_bus_msr);
+		ret = skx_msr_cpu_bus_read(uncore_die_to_cpu(die), &cpu_bus_msr);
 		if (ret)
 			break;
 
@@ -3807,6 +3789,7 @@ static int skx_pmu_get_topology(struct intel_uncore_type *type,
 		if (ret)
 			break;
 	}
+	cpus_read_unlock();
 
 	return ret;
 }