@@ -220,6 +220,26 @@ static int arm_pmu_acpi_cpu_starting(unsigned int cpu)
return 0;
}
+/*
+ * Check if the given child device of the CPU device matches a PMU variant
+ * device declared with ACPI_DECLARE_PMU_VARIANT, if so, pass the arm_pmu
+ * structure and the matching device for further initialization.
+ */
+static int arm_pmu_variant_init(struct device *dev, void *data)
+{
+ extern struct acpi_device_id ACPI_PROBE_TABLE(pmu);
+ unsigned int cpu = *((unsigned int *)data);
+ const struct acpi_device_id *id;
+
+ id = acpi_match_device(&ACPI_PROBE_TABLE(pmu), dev);
+ if (id) {
+ armpmu_acpi_init_fn fn = (armpmu_acpi_init_fn)id->driver_data;
+
+ return fn(per_cpu(probed_pmus, cpu), dev);
+ }
+ return 0;
+}
+
int arm_pmu_acpi_probe(armpmu_init_fn init_fn)
{
int pmu_idx = 0;
@@ -240,6 +260,7 @@ int arm_pmu_acpi_probe(armpmu_init_fn init_fn)
*/
for_each_possible_cpu(cpu) {
struct arm_pmu *pmu = per_cpu(probed_pmus, cpu);
+ struct device *dev = get_cpu_device(cpu);
char *base_name;
if (!pmu || pmu->name)
@@ -254,6 +275,10 @@ int arm_pmu_acpi_probe(armpmu_init_fn init_fn)
return ret;
}
+ ret = device_for_each_child(dev, &cpu, arm_pmu_variant_init);
+ if (ret == -ENODEV)
+ pr_warn("Failed PMU re-init, fallback to plain PMUv3");
+
base_name = pmu->name;
pmu->name = kasprintf(GFP_KERNEL, "%s_%d", base_name, pmu_idx++);
if (!pmu->name) {
@@ -290,3 +315,5 @@ static int arm_pmu_acpi_init(void)
return ret;
}
subsys_initcall(arm_pmu_acpi_init)
+
+ACPI_DECLARE_PMU_SENTINEL();
@@ -609,6 +609,7 @@
IRQCHIP_OF_MATCH_TABLE() \
ACPI_PROBE_TABLE(irqchip) \
ACPI_PROBE_TABLE(timer) \
+ ACPI_PROBE_TABLE(pmu) \
EARLYCON_TABLE()
#define INIT_TEXT \
@@ -1158,6 +1158,17 @@ struct acpi_probe_entry {
(&ACPI_PROBE_TABLE_END(t) - \
&ACPI_PROBE_TABLE(t))); \
})
+
+#define ACPI_DECLARE_PMU_VARIANT(name, hid, init_fn) \
+ static const struct acpi_device_id __acpi_probe_##name \
+ __used __section(__pmu_acpi_probe_table) \
+ = { .id = hid, .driver_data = (kernel_ulong_t)init_fn }
+
+#define ACPI_DECLARE_PMU_SENTINEL() \
+ static const struct acpi_device_id __acpi_probe_sentinel \
+ __used __section(__pmu_acpi_probe_table_end) \
+ = { .id = "", .driver_data = 0 }
+
#else
static inline int acpi_dev_get_property(struct acpi_device *adev,
const char *name, acpi_object_type type,
@@ -123,6 +123,7 @@ int armpmu_map_event(struct perf_event *event,
u32 raw_event_mask);
typedef int (*armpmu_init_fn)(struct arm_pmu *);
+typedef int (*armpmu_acpi_init_fn)(struct arm_pmu *, struct device *);
struct pmu_probe_info {
unsigned int cpuid;
DT allows CPU PMU variant detection via the PMU device compatible property. ACPI does not have an equivalent mechanism so we introduce a probe table to allow this via a device nested inside the CPU device in the DSDT: Device (CPU0) { Name (_HID, "ACPI0007" /* Processor Device */) ... Device (PMU0) { Name (_HID, "QCOM8150") /* Qualcomm Falkor PMU device */ /* * The device might also contain _DSD properties to indicate other * IMPLEMENTATION DEFINED PMU features. */ Name (_DSD, Package () { ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), Package () { ... } }) } } With this in place we can declare the variant: ACPI_DECLARE_PMU_VARIANT(qcom_falkor, "QCOM8150", falkor_pmu_init); The init function is called after the default PMU initialization and is passed a pointer to the arm_pmu structure and a pointer to the PMU device. The init function can then override arm_pmu callbacks and attributes and query more properties from the PMU device. Signed-off-by: Agustin Vega-Frias <agustinv@codeaurora.org> --- drivers/perf/arm_pmu_acpi.c | 27 +++++++++++++++++++++++++++ include/asm-generic/vmlinux.lds.h | 1 + include/linux/acpi.h | 11 +++++++++++ include/linux/perf/arm_pmu.h | 1 + 4 files changed, 40 insertions(+)