drm/amdgpu: Reduce dequeue retry timeout for gfx9 family

Dequeue retry timeout controls the interval between checks for unmet
conditions. On MI series, reduce this from 0x40 to 0x1 (~ 1 uS). The
cost of additional bandwidth consumed by CP when polling memory
shouldn't be substantial.

Signed-off-by: Harish Kasiviswanathan <[e-mail]>
Reviewed-by: Jonathan Kim <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_aldebaran.c

···
 	.set_address_watch = kgd_gfx_aldebaran_set_address_watch,
 	.clear_address_watch = kgd_gfx_v9_clear_address_watch,
 	.get_iq_wait_times = kgd_gfx_v9_get_iq_wait_times,
-	.build_grace_period_packet_info = kgd_gfx_v9_build_grace_period_packet_info,
+	.build_dequeue_wait_counts_packet_info = kgd_gfx_v9_build_dequeue_wait_counts_packet_info,
 	.program_trap_handler_settings = kgd_gfx_v9_program_trap_handler_settings,
 	.hqd_get_pq_addr = kgd_gfx_v9_hqd_get_pq_addr,
 	.hqd_reset = kgd_gfx_v9_hqd_reset,

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c

···
 	.set_address_watch = kgd_gfx_v9_set_address_watch,
 	.clear_address_watch = kgd_gfx_v9_clear_address_watch,
 	.get_iq_wait_times = kgd_gfx_v9_get_iq_wait_times,
-	.build_grace_period_packet_info = kgd_gfx_v9_build_grace_period_packet_info,
+	.build_dequeue_wait_counts_packet_info = kgd_gfx_v9_build_dequeue_wait_counts_packet_info,
 	.get_cu_occupancy = kgd_gfx_v9_get_cu_occupancy,
 	.program_trap_handler_settings = kgd_gfx_v9_program_trap_handler_settings,
 	.hqd_get_pq_addr = kgd_gfx_v9_hqd_get_pq_addr,

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gc_9_4_3.c

···
 	.get_cu_occupancy = kgd_gfx_v9_get_cu_occupancy,
 	.program_trap_handler_settings =
 				kgd_gfx_v9_program_trap_handler_settings,
-	.build_grace_period_packet_info =
-				kgd_gfx_v9_build_grace_period_packet_info,
+	.build_dequeue_wait_counts_packet_info =
+				kgd_gfx_v9_build_dequeue_wait_counts_packet_info,
 	.get_iq_wait_times = kgd_gfx_v9_get_iq_wait_times,
 	.enable_debug_trap = kgd_aldebaran_enable_debug_trap,
 	.disable_debug_trap = kgd_gfx_v9_4_3_disable_debug_trap,

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c

···
 	*wait_times = RREG32(SOC15_REG_OFFSET(GC, 0, mmCP_IQ_WAIT_TIME2));
 }
 
-void kgd_gfx_v10_build_grace_period_packet_info(struct amdgpu_device *adev,
+void kgd_gfx_v10_build_dequeue_wait_counts_packet_info(struct amdgpu_device *adev,
 						uint32_t wait_times,
-						uint32_t grace_period,
+						uint32_t sch_wave,
+						uint32_t que_sleep,
 						uint32_t *reg_offset,
 						uint32_t *reg_data)
 {
 	*reg_data = wait_times;
 
-	/*
-	 * The CP cannont handle a 0 grace period input and will result in
-	 * an infinite grace period being set so set to 1 to prevent this.
-	 */
-	if (grace_period == 0)
-		grace_period = 1;
-
-	*reg_data = REG_SET_FIELD(*reg_data,
-			CP_IQ_WAIT_TIME2,
-			SCH_WAVE,
-			grace_period);
+	if (sch_wave)
+		*reg_data = REG_SET_FIELD(*reg_data,
+				CP_IQ_WAIT_TIME2,
+				SCH_WAVE,
+				sch_wave);
+	if (que_sleep)
+		*reg_data = REG_SET_FIELD(*reg_data,
+				CP_IQ_WAIT_TIME2,
+				QUE_SLEEP,
+				que_sleep);
 
 	*reg_offset = SOC15_REG_OFFSET(GC, 0, mmCP_IQ_WAIT_TIME2);
 }
···
 	.set_address_watch = kgd_gfx_v10_set_address_watch,
 	.clear_address_watch = kgd_gfx_v10_clear_address_watch,
 	.get_iq_wait_times = kgd_gfx_v10_get_iq_wait_times,
-	.build_grace_period_packet_info = kgd_gfx_v10_build_grace_period_packet_info,
+	.build_dequeue_wait_counts_packet_info = kgd_gfx_v10_build_dequeue_wait_counts_packet_info,
 	.program_trap_handler_settings = program_trap_handler_settings,
 	.hqd_get_pq_addr = kgd_gfx_v10_hqd_get_pq_addr,
 	.hqd_reset = kgd_gfx_v10_hqd_reset,

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.h

···
 void kgd_gfx_v10_get_iq_wait_times(struct amdgpu_device *adev,
 				uint32_t *wait_times,
 				uint32_t inst);
-void kgd_gfx_v10_build_grace_period_packet_info(struct amdgpu_device *adev,
+void kgd_gfx_v10_build_dequeue_wait_counts_packet_info(struct amdgpu_device *adev,
 					       uint32_t wait_times,
-					       uint32_t grace_period,
+					       uint32_t sch_wave,
+					       uint32_t que_sleep,
 					       uint32_t *reg_offset,
 					       uint32_t *reg_data);
 uint64_t kgd_gfx_v10_hqd_get_pq_addr(struct amdgpu_device *adev,

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10_3.c

···
 	.set_vm_context_page_table_base = set_vm_context_page_table_base_v10_3,
 	.program_trap_handler_settings = program_trap_handler_settings_v10_3,
 	.get_iq_wait_times = kgd_gfx_v10_get_iq_wait_times,
-	.build_grace_period_packet_info = kgd_gfx_v10_build_grace_period_packet_info,
+	.build_dequeue_wait_counts_packet_info = kgd_gfx_v10_build_dequeue_wait_counts_packet_info,
 	.enable_debug_trap = kgd_gfx_v10_enable_debug_trap,
 	.disable_debug_trap = kgd_gfx_v10_disable_debug_trap,
 	.validate_trap_override_request = kgd_gfx_v10_validate_trap_override_request,

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c

···
 				adev->gfx.cu_info.max_waves_per_simd;
 }
 
-void kgd_gfx_v9_build_grace_period_packet_info(struct amdgpu_device *adev,
+void kgd_gfx_v9_build_dequeue_wait_counts_packet_info(struct amdgpu_device *adev,
 		uint32_t wait_times,
-		uint32_t grace_period,
+		uint32_t sch_wave,
+		uint32_t que_sleep,
 		uint32_t *reg_offset,
 		uint32_t *reg_data)
 {
 	*reg_data = wait_times;
 
-	/*
-	 * The CP cannot handle a 0 grace period input and will result in
-	 * an infinite grace period being set so set to 1 to prevent this.
-	 */
-	if (grace_period == 0)
-		grace_period = 1;
-
-	*reg_data = REG_SET_FIELD(*reg_data,
-			CP_IQ_WAIT_TIME2,
-			SCH_WAVE,
-			grace_period);
+	if (sch_wave)
+		*reg_data = REG_SET_FIELD(*reg_data,
+				CP_IQ_WAIT_TIME2,
+				SCH_WAVE,
+				sch_wave);
+	if (que_sleep)
+		*reg_data = REG_SET_FIELD(*reg_data,
+				CP_IQ_WAIT_TIME2,
+				QUE_SLEEP,
+				que_sleep);
 
 	*reg_offset = SOC15_REG_OFFSET(GC, 0, mmCP_IQ_WAIT_TIME2);
 }
···
 	.set_address_watch = kgd_gfx_v9_set_address_watch,
 	.clear_address_watch = kgd_gfx_v9_clear_address_watch,
 	.get_iq_wait_times = kgd_gfx_v9_get_iq_wait_times,
-	.build_grace_period_packet_info = kgd_gfx_v9_build_grace_period_packet_info,
+	.build_dequeue_wait_counts_packet_info = kgd_gfx_v9_build_dequeue_wait_counts_packet_info,
 	.get_cu_occupancy = kgd_gfx_v9_get_cu_occupancy,
 	.program_trap_handler_settings = kgd_gfx_v9_program_trap_handler_settings,
 	.hqd_get_pq_addr = kgd_gfx_v9_hqd_get_pq_addr,

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.h

···
 void kgd_gfx_v9_get_iq_wait_times(struct amdgpu_device *adev,
 				uint32_t *wait_times,
 				uint32_t inst);
-void kgd_gfx_v9_build_grace_period_packet_info(struct amdgpu_device *adev,
+void kgd_gfx_v9_build_dequeue_wait_counts_packet_info(struct amdgpu_device *adev,
 					       uint32_t wait_times,
-					       uint32_t grace_period,
+					       uint32_t sch_wave,
+					       uint32_t que_sleep,
 					       uint32_t *reg_offset,
 					       uint32_t *reg_data);
 uint64_t kgd_gfx_v9_hqd_get_pq_addr(struct amdgpu_device *adev,

drivers/gpu/drm/amd/amdkfd/kfd_packet_manager_v9.c

···
 }
 
 static inline void pm_build_dequeue_wait_counts_packet_info(struct packet_manager *pm,
-			uint32_t sch_value, uint32_t *reg_offset,
+			uint32_t sch_value, uint32_t que_sleep, uint32_t *reg_offset,
 			uint32_t *reg_data)
 {
-	pm->dqm->dev->kfd2kgd->build_grace_period_packet_info(
+	pm->dqm->dev->kfd2kgd->build_dequeue_wait_counts_packet_info(
 		pm->dqm->dev->adev,
 		pm->dqm->wait_times,
 		sch_value,
+		que_sleep,
 		reg_offset,
 		reg_data);
 }
···
 	uint32_t reg_data = 0;
 
 	switch (cmd) {
-	case KFD_DEQUEUE_WAIT_INIT:
-		/* Set CWSR grace period to 1x1000 cycle for GFX9.4.3 APU */
-		if (amdgpu_emu_mode == 0 && pm->dqm->dev->adev->gmc.is_app_apu &&
-		   (KFD_GC_VERSION(pm->dqm->dev) == IP_VERSION(9, 4, 3)))
-			pm_build_dequeue_wait_counts_packet_info(pm, 1, &reg_offset, &reg_data);
-		else
+	case KFD_DEQUEUE_WAIT_INIT: {
+		uint32_t sch_wave = 0, que_sleep = 0;
+		/* Reduce CP_IQ_WAIT_TIME2.QUE_SLEEP to 0x1 from default 0x40.
+		 * On a 1GHz machine this is roughly 1 microsecond, which is
+		 * about how long it takes to load data out of memory during
+		 * queue connect
+		 * QUE_SLEEP: Wait Count for Dequeue Retry.
+		 */
+		if (KFD_GC_VERSION(pm->dqm->dev) >= IP_VERSION(9, 4, 1) &&
+		    KFD_GC_VERSION(pm->dqm->dev) < IP_VERSION(10, 0, 0)) {
+			que_sleep = 1;
+
+			/* Set CWSR grace period to 1x1000 cycle for GFX9.4.3 APU */
+			if (amdgpu_emu_mode == 0 && pm->dqm->dev->adev->gmc.is_app_apu &&
+			(KFD_GC_VERSION(pm->dqm->dev) == IP_VERSION(9, 4, 3)))
+				sch_wave = 1;
+		} else {
 			return 0;
+		}
+		pm_build_dequeue_wait_counts_packet_info(pm, sch_wave, que_sleep,
+			&reg_offset, &reg_data);
+
 		break;
+	}
 	case KFD_DEQUEUE_WAIT_RESET:
-		/* function called only to get reg_offset */
-		pm_build_dequeue_wait_counts_packet_info(pm, 0, &reg_offset, &reg_data);
-		reg_data = pm->dqm->wait_times;
+		/* reg_data would be set to dqm->wait_times */
+		pm_build_dequeue_wait_counts_packet_info(pm, 0, 0, &reg_offset, &reg_data);
 		break;
 
 	case KFD_DEQUEUE_WAIT_SET_SCH_WAVE:
 		/* The CP cannot handle value 0 and it will result in
-		 * an infinite grace period being set so set to 1 to prevent this.
+		 * an infinite grace period being set so set to 1 to prevent this. Also
+		 * avoid debugger API breakage as it sets 0 and expects a low value.
 		 */
 		if (!value)
 			value = 1;
-		pm_build_dequeue_wait_counts_packet_info(pm, value, &reg_offset, &reg_data);
+		pm_build_dequeue_wait_counts_packet_info(pm, value, 0, &reg_offset, &reg_data);
 		break;
 	default:
 		pr_err("Invalid dequeue wait cmd\n");

drivers/gpu/drm/amd/include/kgd_kfd_interface.h

···
 	void (*get_iq_wait_times)(struct amdgpu_device *adev,
 			uint32_t *wait_times,
 			uint32_t inst);
-	void (*build_grace_period_packet_info)(struct amdgpu_device *adev,
+	void (*build_dequeue_wait_counts_packet_info)(struct amdgpu_device *adev,
 			uint32_t wait_times,
-			uint32_t grace_period,
+			uint32_t sch_wave,
+			uint32_t que_sleep,
 			uint32_t *reg_offset,
 			uint32_t *reg_data);
 	void (*get_cu_occupancy)(struct amdgpu_device *adev,