perf: arm_cspmu: Separate Arm and vendor module

Arm Coresight PMU driver consists of main standard code and
vendor backend code. Both are currently built as a single module.
This patch adds vendor registration API to separate the two to
keep things modular. The main driver requests each known backend
module during initialization and defer device binding process.
The backend module then registers an init callback to the main
driver and continue the device driver binding process.

Signed-off-by: Besar Wicaksono <bwicaksono@nvidia.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-and-tested-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Link: https://lore.kernel.org/r/20230821231608.50911-1-bwicaksono@nvidia.com
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 24 insertions, 1 deletions

diff --git a/drivers/perf/arm_cspmu/arm_cspmu.h b/drivers/perf/arm_cspmu/arm_cspmu.h
index 83df53d1c132..7936a90ded7f 100644
--- a/drivers/perf/arm_cspmu/arm_cspmu.h
+++ b/drivers/perf/arm_cspmu/arm_cspmu.h
@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0
  *
  * ARM CoreSight Architecture PMU driver.
- * Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+ * Copyright (c) 2022-2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
  *
  */
 
@@ -69,6 +69,9 @@
 #define ARM_CSPMU_PMIIDR_IMPLEMENTER	GENMASK(11, 0)
 #define ARM_CSPMU_PMIIDR_PRODUCTID	GENMASK(31, 20)
 
+/* JEDEC-assigned JEP106 identification code */
+#define ARM_CSPMU_IMPL_ID_NVIDIA	0x36B
+
 struct arm_cspmu;
 
 /* This tracks the events assigned to each counter in the PMU. */
@@ -106,9 +109,23 @@ struct arm_cspmu_impl_ops {
 					 struct attribute *attr, int unused);
 };
 
+/* Vendor/implementer registration parameter. */
+struct arm_cspmu_impl_match {
+	/* Backend module. */
+	struct module *module;
+	const char *module_name;
+	/* PMIIDR value/mask. */
+	u32 pmiidr_val;
+	u32 pmiidr_mask;
+	/* Callback to vendor backend to init arm_cspmu_impl::ops. */
+	int (*impl_init_ops)(struct arm_cspmu *cspmu);
+};
+
 /* Vendor/implementer descriptor. */
 struct arm_cspmu_impl {
 	u32 pmiidr;
+	struct module *module;
+	struct arm_cspmu_impl_match *match;
 	struct arm_cspmu_impl_ops ops;
 	void *ctx;
 };
@@ -147,4 +164,10 @@ ssize_t arm_cspmu_sysfs_format_show(struct device *dev,
 				    struct device_attribute *attr,
 				    char *buf);
 
+/* Register vendor backend. */
+int arm_cspmu_impl_register(const struct arm_cspmu_impl_match *impl_match);
+
+/* Unregister vendor backend. */
+void arm_cspmu_impl_unregister(const struct arm_cspmu_impl_match *impl_match);
+
 #endif /* __ARM_CSPMU_H__ */