ARM: perf: allocate CPU PMU dynamically at probe time

Supporting multiple, heterogeneous CPU PMUs requires us to allocate the
arm_pmu structures dynamically as the devices are probed.

This patch removes the static structure definitions for each CPU PMU
type and instead passes pointers to the PMU-specific init functions.

Signed-off-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 30 insertions, 17 deletions

diff --git a/arch/arm/kernel/perf_event_cpu.c b/arch/arm/kernel/perf_event_cpu.c
index 8d7d8d4de9d..3863fd405fa 100644
--- a/arch/arm/kernel/perf_event_cpu.c
+++ b/arch/arm/kernel/perf_event_cpu.c
@@ -23,6 +23,7 @@
 #include <linux/kernel.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/slab.h>
 #include <linux/spinlock.h>
 
 #include <asm/cputype.h>
@@ -195,13 +196,13 @@ static struct platform_device_id __devinitdata cpu_pmu_plat_device_ids[] = {
 /*
  * CPU PMU identification and probing.
  */
-static struct arm_pmu *__devinit probe_current_pmu(void)
+static int __devinit probe_current_pmu(struct arm_pmu *pmu)
 {
-	struct arm_pmu *pmu = NULL;
 	int cpu = get_cpu();
 	unsigned long cpuid = read_cpuid_id();
 	unsigned long implementor = (cpuid & 0xFF000000) >> 24;
 	unsigned long part_number = (cpuid & 0xFFF0);
+	int ret = -ENODEV;
 
 	pr_info("probing PMU on CPU %d\n", cpu);
 
@@ -211,25 +212,25 @@ static struct arm_pmu *__devinit probe_current_pmu(void)
 		case 0xB360:	/* ARM1136 */
 		case 0xB560:	/* ARM1156 */
 		case 0xB760:	/* ARM1176 */
-			pmu = armv6pmu_init();
+			ret = armv6pmu_init(pmu);
 			break;
 		case 0xB020:	/* ARM11mpcore */
-			pmu = armv6mpcore_pmu_init();
+			ret = armv6mpcore_pmu_init(pmu);
 			break;
 		case 0xC080:	/* Cortex-A8 */
-			pmu = armv7_a8_pmu_init();
+			ret = armv7_a8_pmu_init(pmu);
 			break;
 		case 0xC090:	/* Cortex-A9 */
-			pmu = armv7_a9_pmu_init();
+			ret = armv7_a9_pmu_init(pmu);
 			break;
 		case 0xC050:	/* Cortex-A5 */
-			pmu = armv7_a5_pmu_init();
+			ret = armv7_a5_pmu_init(pmu);
 			break;
 		case 0xC0F0:	/* Cortex-A15 */
-			pmu = armv7_a15_pmu_init();
+			ret = armv7_a15_pmu_init(pmu);
 			break;
 		case 0xC070:	/* Cortex-A7 */
-			pmu = armv7_a7_pmu_init();
+			ret = armv7_a7_pmu_init(pmu);
 			break;
 		}
 	/* Intel CPUs [xscale]. */
@@ -237,39 +238,51 @@ static struct arm_pmu *__devinit probe_current_pmu(void)
 		part_number = (cpuid >> 13) & 0x7;
 		switch (part_number) {
 		case 1:
-			pmu = xscale1pmu_init();
+			ret = xscale1pmu_init(pmu);
 			break;
 		case 2:
-			pmu = xscale2pmu_init();
+			ret = xscale2pmu_init(pmu);
 			break;
 		}
 	}
 
 	put_cpu();
-	return pmu;
+	return ret;
 }
 
 static int __devinit cpu_pmu_device_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *of_id;
-	struct arm_pmu *(*init_fn)(void);
+	int (*init_fn)(struct arm_pmu *);
 	struct device_node *node = pdev->dev.of_node;
+	struct arm_pmu *pmu;
+	int ret = -ENODEV;
 
 	if (cpu_pmu) {
 		pr_info("attempt to register multiple PMU devices!");
 		return -ENOSPC;
 	}
 
+	pmu = kzalloc(sizeof(struct arm_pmu), GFP_KERNEL);
+	if (!pmu) {
+		pr_info("failed to allocate PMU device!");
+		return -ENOMEM;
+	}
+
 	if (node && (of_id = of_match_node(cpu_pmu_of_device_ids, pdev->dev.of_node))) {
 		init_fn = of_id->data;
-		cpu_pmu = init_fn();
+		ret = init_fn(pmu);
 	} else {
-		cpu_pmu = probe_current_pmu();
+		ret = probe_current_pmu(pmu);
 	}
 
-	if (!cpu_pmu)
-		return -ENODEV;
+	if (ret) {
+		pr_info("failed to register PMU devices!");
+		kfree(pmu);
+		return ret;
+	}
 
+	cpu_pmu = pmu;
 	cpu_pmu->plat_device = pdev;
 	cpu_pmu_init(cpu_pmu);
 	register_cpu_notifier(&cpu_pmu_hotplug_notifier);