nvdla: kmd: handle {RELEASE,ALLOC}_QUEUE ioctls

[1] This commit separates the allocation and deallocation
    of mission critical resources away from open() and close()
[2] It is achieved through introduction of NVDLA_IOCTL_{ALLOC,RELEASE}
    IOCTLs.
[3] nvdla_buffer_* APIs introduced to facilitate easier split.

Bug 200628173

Change-Id: I3fb07ecaff69c62ec5eb9e5bea39b07ae1624240
Signed-off-by: Arvind M <am@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvidia/+/2403689
Reviewed-by: automaticguardword <automaticguardword@nvidia.com>
Reviewed-by: Anup Mahindre <amahindre@nvidia.com>
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
GVS: Gerrit_Virtual_Submit

drivers/video/tegra/host/nvdla/nvdla_buffer.c

@@ -1,7 +1,7 @@
 /*
  * NVHOST buffer management for T194
  *
- * Copyright (c) 2016-2018, NVIDIA Corporation.  All rights reserved.
+ * Copyright (c) 2016-2020, NVIDIA Corporation.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -236,6 +236,18 @@ nvdla_buffer_init_err:
 	return ERR_PTR(err);
 }
 
+bool nvdla_buffer_is_valid(struct nvdla_buffers *nvdla_buffers)
+{
+	/* Currently there is only one check */
+	return (nvdla_buffers->pdev != NULL);
+}
+
+void nvdla_buffer_set_platform_device(struct nvdla_buffers *nvdla_buffers,
+		struct platform_device *pdev)
+{
+	nvdla_buffers->pdev = pdev;
+}
+
 int nvdla_buffer_submit_pin(struct nvdla_buffers *nvdla_buffers,
 			     struct dma_buf **dmabufs, u32 count,
 			     dma_addr_t *paddr, size_t *psize,

drivers/video/tegra/host/nvdla/nvdla_buffer.h

@@ -1,7 +1,7 @@
 /*
  * NVDLA Buffer Management Header
  *
- * Copyright (c) 2019, NVIDIA Corporation.  All rights reserved.
+ * Copyright (c) 2019-2020, NVIDIA Corporation.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -59,6 +59,28 @@ struct nvdla_buffers {
  */
 struct nvdla_buffers *nvdla_buffer_init(struct platform_device *pdev);
 
+/**
+ * @brief	Checks for validity of nvdla_buffer
+ *
+ * This function checks the validity of buffer and is
+ * recommended to be called prior to any buffer operations
+ *
+ * @param nvdla_buffers Pointer to nvdla_buffers struct
+ * @return	            true on buffer being valid, and false otherwise
+ **/
+bool nvdla_buffer_is_valid(struct nvdla_buffers *nvdla_buffers);
+
+/**
+ * @brief	Sets host1x platform device corresponding to nvdla_buffer
+ *
+ * This function resets the platform_device pdev information of nvdla_buffer.
+ *
+ * @param nvdla_buffers	Pointer to nvdla_buffers struct
+ * @param pdev			Pointer to NvHost device
+ **/
+void nvdla_buffer_set_platform_device(struct nvdla_buffers *nvdla_buffers,
+		struct platform_device *pdev);
+
 /**
  * @brief			Pin the memhandle using dma_buf functions
  *

drivers/video/tegra/host/nvdla/nvdla_ioctl.c

@@ -178,6 +178,12 @@ static int nvdla_pin(struct nvdla_private *priv, void *arg)
 
 	nvdla_dbg_fn(pdev, "");
 
+	if (!nvdla_buffer_is_valid(priv->buffers)) {
+		nvdla_dbg_err(pdev, "Invalid buffer\n");
+		err = -EINVAL;
+		goto fail_to_get_val_arg;
+	}
+
 	if (!buf_list) {
 		nvdla_dbg_err(pdev, "Invalid argument ptr in pin\n");
 		err = -EINVAL;
@@ -234,6 +240,12 @@ static int nvdla_unpin(struct nvdla_private *priv, void *arg)
 
 	nvdla_dbg_fn(pdev, "");
 
+	if (!nvdla_buffer_is_valid(priv->buffers)) {
+		nvdla_dbg_err(pdev, "Invalid buffer\n");
+		err = -EINVAL;
+		goto fail_to_get_val_arg;
+	}
+
 	if (!buf_list) {
 		nvdla_dbg_err(pdev, "Invalid argument for pointer\n");
 		err = -EINVAL;
@@ -938,6 +950,70 @@ exit:
 	return 0;
 }
 
+static int nvdla_queue_alloc_handler(struct nvdla_private *priv, void *arg)
+{
+	int err = 0;
+	struct platform_device *pdev = priv->pdev;
+	struct nvhost_device_data *pdata = platform_get_drvdata(pdev);
+	struct nvdla_device *nvdla_dev = pdata->private_data;
+
+	/* Currently unused and kept to be consistent with other handlers. */
+	(void) arg;
+
+	/* If queue is already allocated, error out. */
+	if (unlikely(NULL != priv->queue)) {
+		nvdla_dbg_err(pdev, "Queue already allocated");
+		err = -EINVAL;
+		goto fail;
+	}
+
+	/* Allocate the queue */
+	priv->queue = nvdla_queue_alloc(nvdla_dev->pool, MAX_NVDLA_TASK_COUNT,
+					nvdla_dev->submit_mode == NVDLA_SUBMIT_MODE_CHANNEL);
+	if (IS_ERR(priv->queue)) {
+		err = PTR_ERR(priv->queue);
+		priv->queue = NULL;
+		goto fail;
+	}
+
+	/* Set nvdla_buffers platform device */
+	nvdla_buffer_set_platform_device(priv->buffers, priv->queue->vm_pdev);
+
+fail:
+	return err;
+}
+
+static int nvdla_queue_release_handler(struct nvdla_private *priv, void *arg)
+{
+	int err = 0;
+	struct platform_device *pdev = priv->pdev;
+
+	/**
+	 * Note: This functiona shall be reached directly either
+	 * [1] NVDLA_IOCTL_RELEASE_QUEUE ioctl call.
+	 * [2] when fd is closed before releasing the queue.
+	 **/
+
+	/* Currently unused and kept to be consistent with other handlers. */
+	(void) arg;
+
+	/* If no queue is allocated, error out. */
+	if (unlikely(NULL == priv->queue)) {
+		nvdla_dbg_err(pdev, "No queue to be released.");
+		err = -EINVAL;
+		goto fail;
+	}
+
+	/* Release the queue */
+	(void) nvdla_queue_abort(priv->queue);
+	nvdla_queue_put(priv->queue);
+
+	priv->queue = NULL;
+fail:
+	return err;
+}
+
+
 static int nvdla_submit(struct nvdla_private *priv, void *arg)
 {
 	struct nvdla_submit_args *args =
@@ -1105,6 +1181,12 @@ static long nvdla_ioctl(struct file *file, unsigned int cmd,
 	case NVDLA_IOCTL_EMU_TASK_SUBMIT:
 		err = nvdla_emu_task_submit(priv, (void *)buf);
 		break;
+	case NVDLA_IOCTL_ALLOC_QUEUE:
+		err = nvdla_queue_alloc_handler(priv, (void*)buf);
+		break;
+	case NVDLA_IOCTL_RELEASE_QUEUE:
+		err = nvdla_queue_release_handler(priv, (void*)buf);
+		break;
 	default:
 		nvdla_dbg_err(pdev, "invalid IOCTL CMD");
 		err = -ENOIOCTLCMD;
@@ -1123,7 +1205,6 @@ static int nvdla_open(struct inode *inode, struct file *file)
 	struct nvhost_device_data *pdata = container_of(inode->i_cdev,
 					struct nvhost_device_data, ctrl_cdev);
 	struct platform_device *pdev = pdata->pdev;
-	struct nvdla_device *nvdla_dev = pdata->private_data;
 	struct nvdla_private *priv;
 	int err = 0, index;
 
@@ -1154,20 +1235,19 @@ static int nvdla_open(struct inode *inode, struct file *file)
 			err = nvhost_module_set_rate(pdev, priv, UINT_MAX,
 				index, clock->request_type);
 			if (err < 0)
-				goto err_alloc_queue;
+				goto err_set_emc_rate;
 			break;
 		}
 	}
 
-	priv->queue = nvdla_queue_alloc(nvdla_dev->pool,
-		MAX_NVDLA_TASK_COUNT,
-		nvdla_dev->submit_mode == NVDLA_SUBMIT_MODE_CHANNEL);
-	if (IS_ERR(priv->queue)) {
-		err = PTR_ERR(priv->queue);
-		goto err_alloc_queue;
-	}
+	/* Zero out explicitly */
+	priv->queue = NULL;
 
-	priv->buffers = nvdla_buffer_init(priv->queue->vm_pdev);
+	/**
+	 * Platform device corresponding to buffers is deferred
+	 * to queue allocation.
+	 **/
+	priv->buffers = nvdla_buffer_init(NULL);
 	if (IS_ERR(priv->buffers)) {
 		err = PTR_ERR(priv->buffers);
 		goto err_alloc_buffer;
@@ -1177,7 +1257,7 @@ static int nvdla_open(struct inode *inode, struct file *file)
 
 err_alloc_buffer:
 	kfree(priv->buffers);
-err_alloc_queue:
+err_set_emc_rate:
 	nvhost_module_remove_client(pdev, priv);
 err_add_client:
 	kfree(priv);
@@ -1192,8 +1272,16 @@ static int nvdla_release(struct inode *inode, struct file *file)
 
 	nvdla_dbg_fn(pdev, "priv:%p", priv);
 
-	nvdla_queue_abort(priv->queue);
-	nvdla_queue_put(priv->queue);
+	/* If NVDLA_IOCTL_RELEASE_QUEUE is not called, free it explicitly. */
+	if (NULL != priv->queue) {
+		/**
+		 * Error value is intentionally ignored to continue freeing
+		 * other resources.
+		 * arg is set to NULL and should work since they are unused.
+		 **/
+		nvdla_queue_release_handler(priv, NULL);
+	}
+
 	nvdla_buffer_release(priv->buffers);
 	nvhost_module_remove_client(pdev, priv);
 

include/uapi/linux/nvhost_nvdla_ioctl.h

@@ -254,8 +254,12 @@ struct nvdla_status_notify {
 	_IOWR(NVHOST_NVDLA_IOCTL_MAGIC, 7, struct nvdla_get_q_status_args)
 #define NVDLA_IOCTL_EMU_TASK_SUBMIT \
 	_IOWR(NVHOST_NVDLA_IOCTL_MAGIC, 8, struct nvdla_submit_args)
+#define NVDLA_IOCTL_ALLOC_QUEUE \
+	_IO(NVHOST_NVDLA_IOCTL_MAGIC, 9)
+#define NVDLA_IOCTL_RELEASE_QUEUE \
+	_IO(NVHOST_NVDLA_IOCTL_MAGIC, 10)
 #define NVDLA_IOCTL_LAST		\
-		_IOC_NR(NVDLA_IOCTL_EMU_TASK_SUBMIT)
+		_IOC_NR(NVDLA_IOCTL_RELEASE_QUEUE)
 
 #define NVDLA_IOCTL_MAX_ARG_SIZE  \
 		sizeof(struct nvdla_pin_unpin_args)