drm/amd/pm: Add STB accessors interface

Add interface to collect STB logs.

Signed-off-by: Andrey Grodzovsky <[e-mail]>
Reviewed-by: Lijo Lazar <[e-mail]>
Reviewed-by: Luben Tuikov <[e-mail]>
Acked-by: Alex Deucher <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/pm/inc/amdgpu_smu.h

···
 	int	map_to;
 };
 
+struct stb_context {
+	uint32_t stb_buf_size;
+	bool enabled;
+	spinlock_t lock;
+};
+
 #define WORKLOAD_POLICY_MAX 7
 struct smu_context
 {
···
 	uint16_t cpu_core_num;
 
 	struct smu_user_dpm_profile user_dpm_profile;
+
+	struct stb_context stb_context;
 };
 
 struct i2c_adapter;
···
 	 * @get_ecc_table:  message SMU to get ECC INFO table.
 	 */
 	ssize_t (*get_ecc_info)(struct smu_context *smu, void *table);
+	
+	
+	/**
+	 * @stb_collect_info: Collects Smart Trace Buffers data.
+	 */
+	int (*stb_collect_info)(struct smu_context *smu, void *buf, uint32_t size);
 };
 
 typedef enum {
···
 int smu_wait_for_event(struct amdgpu_device *adev, enum smu_event_type event,
 		       uint64_t event_arg);
 int smu_get_ecc_info(struct smu_context *smu, void *umc_ecc);
+int smu_stb_collect_info(struct smu_context *smu, void *buff, uint32_t size);
 
 #endif
 #endif

drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c

···
 
 	return ret;
 }
+
+int smu_stb_collect_info(struct smu_context *smu, void *buf, uint32_t size)
+{
+
+	if (!smu->ppt_funcs->stb_collect_info || !smu->stb_context.enabled)
+		return -EOPNOTSUPP;
+
+	/* Confirm the buffer allocated is of correct size */
+	if (size != smu->stb_context.stb_buf_size)
+		return -EINVAL;
+
+	/*
+	 * No need to lock smu mutex as we access STB directly through MMIO
+	 * and not going through SMU messaging route (for now at least).
+	 * For registers access rely on implementation internal locking.
+	 */
+	return smu->ppt_funcs->stb_collect_info(smu, buf, size);
+}