[PATCH v7 1/9] arm64: pmu: add fallback probe table

[jeremy.linton@arm.com (Jeremy Linton)]

From: Mark Salter <msalter@redhat.com>

In preparation for ACPI support, add a pmu_probe_info table to
the arm_pmu_device_probe() call. This table gets used when
probing in the absence of a devicetree node for PMU.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
---
 arch/arm64/kernel/perf_event.c | 13 ++++++++++++-
 drivers/perf/arm_pmu.c         |  2 +-
 include/linux/perf/arm_pmu.h   |  3 +++
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index 838ccf1..3aac598 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -24,6 +24,7 @@
 #include <asm/sysreg.h>
 #include <asm/virt.h>
 
+#include <linux/acpi.h>
 #include <linux/of.h>
 #include <linux/perf/arm_pmu.h>
 #include <linux/platform_device.h>
@@ -1044,9 +1045,19 @@ static const struct of_device_id armv8_pmu_of_device_ids[] = {
 	{},
 };
 
+static const struct pmu_probe_info armv8_pmu_probe_table[] = {
+	PMU_PROBE(0, 0, armv8_pmuv3_init), /* if all else fails... */
+	{ /* sentinel value */ }
+};
+
 static int armv8_pmu_device_probe(struct platform_device *pdev)
 {
-	return arm_pmu_device_probe(pdev, armv8_pmu_of_device_ids, NULL);
+	if (acpi_disabled)
+		return arm_pmu_device_probe(pdev, armv8_pmu_of_device_ids,
+					    NULL);
+
+	return arm_pmu_device_probe(pdev, armv8_pmu_of_device_ids,
+				    armv8_pmu_probe_table);
 }
 
 static struct platform_driver armv8_pmu_driver = {
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index c494613..f1aee26 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -1028,7 +1028,7 @@ int arm_pmu_device_probe(struct platform_device *pdev,
 		ret = of_pmu_irq_cfg(pmu);
 		if (!ret)
 			ret = init_fn(pmu);
-	} else {
+	} else if (probe_table) {
 		cpumask_setall(&pmu->supported_cpus);
 		ret = probe_current_pmu(pmu, probe_table);
 	}
diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index e188438..65d8e27 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -147,6 +147,9 @@ struct pmu_probe_info {
 #define XSCALE_PMU_PROBE(_version, _fn) \
 	PMU_PROBE(ARM_CPU_IMP_INTEL << 24 | _version, ARM_PMU_XSCALE_MASK, _fn)
 
+#define ARMV8_PMU_PART_PROBE(_part, _fn) \
+	PMU_PROBE((_part) << MIDR_PARTNUM_SHIFT, MIDR_PARTNUM_MASK, _fn)
+
 int arm_pmu_device_probe(struct platform_device *pdev,
 			 const struct of_device_id *of_table,
 			 const struct pmu_probe_info *probe_table);
-- 
2.5.5