gpu: nvgpu: Add uapi support for NVGPU_GPU_IOCTL_GET_ENGINE_INFO

Implement NVGPU_GPU_IOCTL_GET_ENGINE_INFO for retrieving the
list of supported engines and their corresponding run list id:s.

JIRA DNVGPU-25

Change-Id: I8703388660190f7dcb509c0676f283ca4b820b6f
Signed-off-by: Lakshmanan M <lm@nvidia.com>
Reviewed-on: http://git-master/r/1160939
Reviewed-by: Sami Kiminki <skiminki@nvidia.com>
Reviewed-by: Konsta Holtta <kholtta@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c

@@ -674,6 +674,69 @@ clean_up:
 	return err;
 }
 
+static int nvgpu_gpu_get_engine_info(
+	struct gk20a *g,
+	struct nvgpu_gpu_get_engine_info_args *args)
+{
+	int err = 0;
+	u32 engine_enum = ENGINE_INVAL_GK20A;
+	u32 report_index = 0;
+	u32 engine_id_idx;
+	const u32 max_buffer_engines = args->engine_info_buf_size /
+		sizeof(struct nvgpu_gpu_get_engine_info_item);
+	struct nvgpu_gpu_get_engine_info_item __user *dst_item_list =
+		(void __user *)(uintptr_t)args->engine_info_buf_addr;
+
+	for (engine_id_idx = 0; engine_id_idx < g->fifo.num_engines;
+		++engine_id_idx) {
+		u32 active_engine_id = g->fifo.active_engines_list[engine_id_idx];
+		const struct fifo_engine_info_gk20a *src_info =
+			&g->fifo.engine_info[active_engine_id];
+		struct nvgpu_gpu_get_engine_info_item dst_info;
+
+		memset(&dst_info, 0, sizeof(dst_info));
+
+		engine_enum = src_info->engine_enum;
+
+		switch (engine_enum) {
+		case ENGINE_GR_GK20A:
+			dst_info.engine_id = NVGPU_GPU_ENGINE_ID_GR;
+			break;
+
+		case ENGINE_GRCE_GK20A:
+			dst_info.engine_id = NVGPU_GPU_ENGINE_ID_GR_COPY;
+			break;
+
+		case ENGINE_ASYNC_CE_GK20A:
+			dst_info.engine_id = NVGPU_GPU_ENGINE_ID_ASYNC_COPY;
+			break;
+
+		default:
+			gk20a_err(dev_from_gk20a(g), "Unmapped engine enum %u\n",
+				  engine_enum);
+			continue;
+		}
+
+		dst_info.engine_instance = src_info->inst_id;
+		dst_info.runlist_id = src_info->runlist_id;
+
+		if (report_index < max_buffer_engines) {
+			err = copy_to_user(&dst_item_list[report_index],
+					   &dst_info, sizeof(dst_info));
+			if (err)
+				goto clean_up;
+		}
+
+		++report_index;
+	}
+
+	args->engine_info_buf_size =
+		report_index * sizeof(struct nvgpu_gpu_get_engine_info_item);
+
+clean_up:
+	return err;
+}
+
 long gk20a_ctrl_dev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct device *dev = filp->private_data;
@@ -916,6 +979,11 @@ long gk20a_ctrl_dev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg
 			(struct nvgpu_gpu_get_gpu_time_args *)buf);
 		break;
 
+        case NVGPU_GPU_IOCTL_GET_ENGINE_INFO:
+		err = nvgpu_gpu_get_engine_info(g,
+			(struct nvgpu_gpu_get_engine_info_args *)buf);
+		break;
+
 	default:
 		dev_dbg(dev_from_gk20a(g), "unrecognized gpu ioctl cmd: 0x%x", cmd);
 		err = -ENOTTY;

include/uapi/linux/nvgpu.h

@@ -394,6 +394,33 @@ struct nvgpu_gpu_get_gpu_time_args {
 	__u64 reserved;
 };
 
+struct nvgpu_gpu_get_engine_info_item {
+
+#define NVGPU_GPU_ENGINE_ID_GR 0
+#define NVGPU_GPU_ENGINE_ID_GR_COPY 1
+#define NVGPU_GPU_ENGINE_ID_ASYNC_COPY 2
+	__u32 engine_id;
+
+	__u32 engine_instance;
+
+	/* runlist id for opening channels to the engine, or -1 if
+	 * channels are not supported */
+	__s32 runlist_id;
+
+	__u32 reserved;
+};
+
+struct nvgpu_gpu_get_engine_info_args {
+	/* [in]  Buffer size reserved by userspace.
+	 *
+	 * [out] Full kernel buffer size. Multiple of sizeof(struct
+	 *       nvgpu_gpu_get_engine_info_item)
+	*/
+	__u32 engine_info_buf_size;
+	__u32 reserved;
+	__u64 engine_info_buf_addr;
+};
+
 #define NVGPU_GPU_IOCTL_ZCULL_GET_CTX_SIZE \
 	_IOR(NVGPU_GPU_IOCTL_MAGIC, 1, struct nvgpu_gpu_zcull_get_ctx_size_args)
 #define NVGPU_GPU_IOCTL_ZCULL_GET_INFO \
@@ -446,8 +473,11 @@ struct nvgpu_gpu_get_gpu_time_args {
 #define NVGPU_GPU_IOCTL_GET_GPU_TIME \
 	_IOWR(NVGPU_GPU_IOCTL_MAGIC, 25, \
 			struct nvgpu_gpu_get_gpu_time_args)
+#define NVGPU_GPU_IOCTL_GET_ENGINE_INFO \
+	_IOWR(NVGPU_GPU_IOCTL_MAGIC, 26, \
+			struct nvgpu_gpu_get_engine_info_args)
 #define NVGPU_GPU_IOCTL_LAST		\
-	_IOC_NR(NVGPU_GPU_IOCTL_GET_GPU_TIME)
+	_IOC_NR(NVGPU_GPU_IOCTL_GET_ENGINE_INFO)
 #define NVGPU_GPU_IOCTL_MAX_ARG_SIZE	\
 	sizeof(struct nvgpu_gpu_get_cpu_time_correlation_info_args)