drm/amdgpu: Add doorbell routing info to kgd2kfd_shared_resources

This is needed for Vega10 and later ASICs to let KFD know which
doorbells can be used for SDMA and CP queues respectively.
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

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

@@ -179,6 +179,28 @@ void amdgpu_amdkfd_device_init(struct amdgpu_device *adev)
 				&gpu_resources.doorbell_physical_address,
 				&gpu_resources.doorbell_aperture_size,
 				&gpu_resources.doorbell_start_offset);
+		if (adev->asic_type >= CHIP_VEGA10) {
+			/* On SOC15 the BIF is involved in routing
+			 * doorbells using the low 12 bits of the
+			 * address. Communicate the assignments to
+			 * KFD. KFD uses two doorbell pages per
+			 * process in case of 64-bit doorbells so we
+			 * can use each doorbell assignment twice.
+			 */
+			gpu_resources.sdma_doorbell[0][0] =
+				AMDGPU_DOORBELL64_sDMA_ENGINE0;
+			gpu_resources.sdma_doorbell[0][1] =
+				AMDGPU_DOORBELL64_sDMA_ENGINE0 + 0x200;
+			gpu_resources.sdma_doorbell[1][0] =
+				AMDGPU_DOORBELL64_sDMA_ENGINE1;
+			gpu_resources.sdma_doorbell[1][1] =
+				AMDGPU_DOORBELL64_sDMA_ENGINE1 + 0x200;
+			/* Doorbells 0x0f0-0ff and 0x2f0-2ff are reserved for
+			 * SDMA, IH and VCN. So don't use them for the CP.
+			 */
+			gpu_resources.reserved_doorbell_mask = 0x1f0;
+			gpu_resources.reserved_doorbell_val  = 0x0f0;
+		}
 
 		kgd2kfd->device_init(adev->kfd, &gpu_resources);
 	}

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

@@ -100,6 +100,21 @@ struct kgd2kfd_shared_resources {
 	/* Bit n == 1 means Queue n is available for KFD */
 	DECLARE_BITMAP(queue_bitmap, KGD_MAX_QUEUES);
 
+	/* Doorbell assignments (SOC15 and later chips only). Only
+	 * specific doorbells are routed to each SDMA engine. Others
+	 * are routed to IH and VCN. They are not usable by the CP.
+	 *
+	 * Any doorbell number D that satisfies the following condition
+	 * is reserved: (D & reserved_doorbell_mask) == reserved_doorbell_val
+	 *
+	 * KFD currently uses 1024 (= 0x3ff) doorbells per process. If
+	 * doorbells 0x0f0-0x0f7 and 0x2f-0x2f7 are reserved, that means
+	 * mask would be set to 0x1f8 and val set to 0x0f0.
+	 */
+	unsigned int sdma_doorbell[2][2];
+	unsigned int reserved_doorbell_mask;
+	unsigned int reserved_doorbell_val;
+
 	/* Base address of doorbell aperture. */
 	phys_addr_t doorbell_physical_address;