diff mbox series

[v7,4/4] remoteproc: virtio: Create platform device for the remoteproc_virtio

Message ID 20220713113612.2117279-5-arnaud.pouliquen@foss.st.com (mailing list archive)
State Superseded
Headers show
Series remoteproc: restructure the remoteproc VirtIO device | expand

Commit Message

Arnaud POULIQUEN July 13, 2022, 11:36 a.m. UTC 
Define a platform driver to manage the remoteproc virtio device as
a platform devices.

The platform device allows to pass rproc_vdev_data platform data to
specify properties that are stored in the rproc_vdev structure.

Such approach will allow to preserve legacy remoteproc virtio device
creation but also to probe the device using device tree mechanism.

remoteproc_virtio.c update:
  - Add rproc_virtio_driver platform driver. The probe ops replaces
    the rproc_rvdev_add_device function.
  - All reference to the rvdev->dev has been updated to rvdev-pdev->dev.
  - rproc_rvdev_release is removed as associated to the rvdev device.
  - The use of rvdev->kref counter is replaced by get/put_device on the
    remoteproc virtio platform device.
  - The vdev device no longer increments rproc device counter.
    increment/decrement is done in rproc_virtio_probe/rproc_virtio_remove
    function in charge of the vrings allocation/free.

remoteproc_core.c update:
  Migrate from the rvdev device to the rvdev platform device.
  From this patch, when a vdev resource is found in the resource table
  the remoteproc core register a platform device.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>

---
Update vs previous revision:
 - update commit message to remove reference to rproc_rvdev_remove_device.

---
 drivers/remoteproc/remoteproc_core.c     |  12 +-
 drivers/remoteproc/remoteproc_internal.h |   2 -
 drivers/remoteproc/remoteproc_virtio.c   | 141 ++++++++++++-----------
 include/linux/remoteproc.h               |   6 +-
 4 files changed, 81 insertions(+), 80 deletions(-)

Comments

Mathieu Poirier July 26, 2022, 4:48 p.m. UTC | #1 
On Wed, Jul 13, 2022 at 01:36:12PM +0200, Arnaud Pouliquen wrote:
> Define a platform driver to manage the remoteproc virtio device as
> a platform devices.
> 
> The platform device allows to pass rproc_vdev_data platform data to
> specify properties that are stored in the rproc_vdev structure.
> 
> Such approach will allow to preserve legacy remoteproc virtio device
> creation but also to probe the device using device tree mechanism.
> 
> remoteproc_virtio.c update:
>   - Add rproc_virtio_driver platform driver. The probe ops replaces
>     the rproc_rvdev_add_device function.
>   - All reference to the rvdev->dev has been updated to rvdev-pdev->dev.
>   - rproc_rvdev_release is removed as associated to the rvdev device.
>   - The use of rvdev->kref counter is replaced by get/put_device on the
>     remoteproc virtio platform device.
>   - The vdev device no longer increments rproc device counter.
>     increment/decrement is done in rproc_virtio_probe/rproc_virtio_remove
>     function in charge of the vrings allocation/free.
> 
> remoteproc_core.c update:
>   Migrate from the rvdev device to the rvdev platform device.
>   From this patch, when a vdev resource is found in the resource table
>   the remoteproc core register a platform device.
> 
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
> 
> ---
> Update vs previous revision:
>  - update commit message to remove reference to rproc_rvdev_remove_device.
> 
> ---
>  drivers/remoteproc/remoteproc_core.c     |  12 +-
>  drivers/remoteproc/remoteproc_internal.h |   2 -
>  drivers/remoteproc/remoteproc_virtio.c   | 141 ++++++++++++-----------
>  include/linux/remoteproc.h               |   6 +-

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

>  4 files changed, 81 insertions(+), 80 deletions(-)
> 
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index d3eca1da8aa1..f5f2f500a50e 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -478,6 +478,7 @@ static int rproc_handle_vdev(struct rproc *rproc, void *ptr,
>  	struct device *dev = &rproc->dev;
>  	struct rproc_vdev *rvdev;
>  	struct rproc_vdev_data rvdev_data;
> +	struct platform_device *pdev;
>  
>  	/* make sure resource isn't truncated */
>  	if (struct_size(rsc, vring, rsc->num_of_vrings) + rsc->config_len >
> @@ -506,9 +507,12 @@ static int rproc_handle_vdev(struct rproc *rproc, void *ptr,
>  	rvdev_data.rsc_offset = offset;
>  	rvdev_data.rsc = rsc;
>  
> -	rvdev = rproc_rvdev_add_device(rproc, &rvdev_data);
> -	if (IS_ERR(rvdev))
> -		return PTR_ERR(rvdev);
> +	pdev = platform_device_register_data(dev, "rproc-virtio", rvdev_data.index, &rvdev_data,
> +					     sizeof(rvdev_data));
> +	if (IS_ERR(pdev)) {
> +		dev_err(dev, "failed to create rproc-virtio device\n");
> +		return PTR_ERR(pdev);
> +	}
>  
>  	return 0;
>  }
> @@ -1244,7 +1248,7 @@ void rproc_resource_cleanup(struct rproc *rproc)
>  
>  	/* clean up remote vdev entries */
>  	list_for_each_entry_safe(rvdev, rvtmp, &rproc->rvdevs, node)
> -		kref_put(&rvdev->refcount, rproc_vdev_release);
> +		platform_device_unregister(rvdev->pdev);
>  
>  	rproc_coredump_cleanup(rproc);
>  }
> diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
> index 711b0e1f2118..bf1fb7bba1a3 100644
> --- a/drivers/remoteproc/remoteproc_internal.h
> +++ b/drivers/remoteproc/remoteproc_internal.h
> @@ -45,9 +45,7 @@ int rproc_of_parse_firmware(struct device *dev, int index,
>  			    const char **fw_name);
>  
>  /* from remoteproc_virtio.c */
> -struct rproc_vdev *rproc_rvdev_add_device(struct rproc *rproc, struct rproc_vdev_data *rvdev_data);
>  irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id);
> -void rproc_vdev_release(struct kref *ref);
>  
>  /* from remoteproc_debugfs.c */
>  void rproc_remove_trace_file(struct dentry *tfile);
> diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
> index ccc95d4e42cf..06d2131dad11 100644
> --- a/drivers/remoteproc/remoteproc_virtio.c
> +++ b/drivers/remoteproc/remoteproc_virtio.c
> @@ -13,6 +13,7 @@
>  #include <linux/dma-map-ops.h>
>  #include <linux/dma-mapping.h>
>  #include <linux/export.h>
> +#include <linux/of_platform.h>
>  #include <linux/of_reserved_mem.h>
>  #include <linux/remoteproc.h>
>  #include <linux/virtio.h>
> @@ -46,7 +47,11 @@ static int copy_dma_range_map(struct device *to, struct device *from)
>  
>  static struct rproc_vdev *vdev_to_rvdev(struct virtio_device *vdev)
>  {
> -	return container_of(vdev->dev.parent, struct rproc_vdev, dev);
> +	struct platform_device *pdev;
> +
> +	pdev = container_of(vdev->dev.parent, struct platform_device, dev);
> +
> +	return platform_get_drvdata(pdev);
>  }
>  
>  static  struct rproc *vdev_to_rproc(struct virtio_device *vdev)
> @@ -341,13 +346,10 @@ static void rproc_virtio_dev_release(struct device *dev)
>  {
>  	struct virtio_device *vdev = dev_to_virtio(dev);
>  	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
> -	struct rproc *rproc = vdev_to_rproc(vdev);
>  
>  	kfree(vdev);
>  
> -	kref_put(&rvdev->refcount, rproc_vdev_release);
> -
> -	put_device(&rproc->dev);
> +	put_device(&rvdev->pdev->dev);
>  }
>  
>  /**
> @@ -363,7 +365,7 @@ static void rproc_virtio_dev_release(struct device *dev)
>  static int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
>  {
>  	struct rproc *rproc = rvdev->rproc;
> -	struct device *dev = &rvdev->dev;
> +	struct device *dev = &rvdev->pdev->dev;
>  	struct virtio_device *vdev;
>  	struct rproc_mem_entry *mem;
>  	int ret;
> @@ -433,18 +435,8 @@ static int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
>  	vdev->dev.parent = dev;
>  	vdev->dev.release = rproc_virtio_dev_release;
>  
> -	/*
> -	 * We're indirectly making a non-temporary copy of the rproc pointer
> -	 * here, because drivers probed with this vdev will indirectly
> -	 * access the wrapping rproc.
> -	 *
> -	 * Therefore we must increment the rproc refcount here, and decrement
> -	 * it _only_ when the vdev is released.
> -	 */
> -	get_device(&rproc->dev);
> -
>  	/* Reference the vdev and vring allocations */
> -	kref_get(&rvdev->refcount);
> +	get_device(dev);
>  
>  	ret = register_virtio_device(vdev);
>  	if (ret) {
> @@ -486,78 +478,57 @@ static int rproc_vdev_do_start(struct rproc_subdev *subdev)
>  static void rproc_vdev_do_stop(struct rproc_subdev *subdev, bool crashed)
>  {
>  	struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
> +	struct device *dev = &rvdev->pdev->dev;
>  	int ret;
>  
> -	ret = device_for_each_child(&rvdev->dev, NULL, rproc_remove_virtio_dev);
> +	ret = device_for_each_child(dev, NULL, rproc_remove_virtio_dev);
>  	if (ret)
> -		dev_warn(&rvdev->dev, "can't remove vdev child device: %d\n", ret);
> +		dev_warn(dev, "can't remove vdev child device: %d\n", ret);
>  }
>  
> -/**
> - * rproc_rvdev_release() - release the existence of a rvdev
> - *
> - * @dev: the subdevice's dev
> - */
> -static void rproc_rvdev_release(struct device *dev)
> -{
> -	struct rproc_vdev *rvdev = container_of(dev, struct rproc_vdev, dev);
> -
> -	of_reserved_mem_device_release(dev);
> -
> -	kfree(rvdev);
> -}
> -
> -struct rproc_vdev *
> -rproc_rvdev_add_device(struct rproc *rproc, struct rproc_vdev_data *rvdev_data)
> +static int rproc_virtio_probe(struct platform_device *pdev)
>  {
> +	struct device *dev = &pdev->dev;
> +	struct rproc_vdev_data *rvdev_data = dev->platform_data;
>  	struct rproc_vdev *rvdev;
> -	struct fw_rsc_vdev *rsc = rvdev_data->rsc;
> -	char name[16];
> +	struct rproc *rproc = container_of(dev->parent, struct rproc, dev);
> +	struct fw_rsc_vdev *rsc;
>  	int i, ret;
>  
> -	rvdev = kzalloc(sizeof(*rvdev), GFP_KERNEL);
> -	if (!rvdev)
> -		return ERR_PTR(-ENOMEM);
> +	if (!rvdev_data)
> +		return -EINVAL;
>  
> -	kref_init(&rvdev->refcount);
> +	rvdev = devm_kzalloc(dev, sizeof(*rvdev), GFP_KERNEL);
> +	if (!rvdev)
> +		return -ENOMEM;
>  
>  	rvdev->id = rvdev_data->id;
>  	rvdev->rproc = rproc;
>  	rvdev->index = rvdev_data->index;
>  
> -	/* Initialise vdev subdevice */
> -	snprintf(name, sizeof(name), "vdev%dbuffer", rvdev->index);
> -	rvdev->dev.parent = &rproc->dev;
> -	rvdev->dev.release = rproc_rvdev_release;
> -	dev_set_name(&rvdev->dev, "%s#%s", dev_name(rvdev->dev.parent), name);
> -	dev_set_drvdata(&rvdev->dev, rvdev);
> -
> -	ret = device_register(&rvdev->dev);
> -	if (ret) {
> -		put_device(&rvdev->dev);
> -		return ERR_PTR(ret);
> -	}
> -
> -	ret = copy_dma_range_map(&rvdev->dev, rproc->dev.parent);
> +	ret = copy_dma_range_map(dev, rproc->dev.parent);
>  	if (ret)
> -		goto free_rvdev;
> +		return ret;
>  
>  	/* Make device dma capable by inheriting from parent's capabilities */
> -	set_dma_ops(&rvdev->dev, get_dma_ops(rproc->dev.parent));
> +	set_dma_ops(dev, get_dma_ops(rproc->dev.parent));
>  
> -	ret = dma_coerce_mask_and_coherent(&rvdev->dev,
> -					   dma_get_mask(rproc->dev.parent));
> +	ret = dma_coerce_mask_and_coherent(dev, dma_get_mask(rproc->dev.parent));
>  	if (ret) {
> -		dev_warn(&rvdev->dev,
> -			 "Failed to set DMA mask %llx. Trying to continue... (%pe)\n",
> +		dev_warn(dev, "Failed to set DMA mask %llx. Trying to continue... (%pe)\n",
>  			 dma_get_mask(rproc->dev.parent), ERR_PTR(ret));
>  	}
>  
> +	platform_set_drvdata(pdev, rvdev);
> +	rvdev->pdev = pdev;
> +
> +	rsc = rvdev_data->rsc;
> +
>  	/* parse the vrings */
>  	for (i = 0; i < rsc->num_of_vrings; i++) {
>  		ret = rproc_parse_vring(rvdev, rsc, i);
>  		if (ret)
> -			goto free_rvdev;
> +			return ret;
>  	}
>  
>  	/* remember the resource offset*/
> @@ -577,21 +548,30 @@ rproc_rvdev_add_device(struct rproc *rproc, struct rproc_vdev_data *rvdev_data)
>  
>  	rproc_add_subdev(rproc, &rvdev->subdev);
>  
> -	return rvdev;
> +	/*
> +	 * We're indirectly making a non-temporary copy of the rproc pointer
> +	 * here, because the platform device or the vdev device will indirectly
> +	 * access the wrapping rproc.
> +	 *
> +	 * Therefore we must increment the rproc refcount here, and decrement
> +	 * it _only_ on platform remove.
> +	 */
> +	get_device(&rproc->dev);
> +
> +	return 0;
>  
>  unwind_vring_allocations:
>  	for (i--; i >= 0; i--)
>  		rproc_free_vring(&rvdev->vring[i]);
> -free_rvdev:
> -	device_unregister(&rvdev->dev);
> -	return ERR_PTR(ret);
> +
> +	return ret;
>  }
>  
> -void rproc_vdev_release(struct kref *ref)
> +static int rproc_virtio_remove(struct platform_device *pdev)
>  {
> -	struct rproc_vdev *rvdev = container_of(ref, struct rproc_vdev, refcount);
> -	struct rproc_vring *rvring;
> +	struct rproc_vdev *rvdev = dev_get_drvdata(&pdev->dev);
>  	struct rproc *rproc = rvdev->rproc;
> +	struct rproc_vring *rvring;
>  	int id;
>  
>  	for (id = 0; id < ARRAY_SIZE(rvdev->vring); id++) {
> @@ -601,5 +581,26 @@ void rproc_vdev_release(struct kref *ref)
>  
>  	rproc_remove_subdev(rproc, &rvdev->subdev);
>  	rproc_remove_rvdev(rvdev);
> -	device_unregister(&rvdev->dev);
> +
> +	of_reserved_mem_device_release(&pdev->dev);
> +
> +	put_device(&rproc->dev);
> +
> +	return 0;
>  }
> +
> +/* Platform driver */
> +static const struct of_device_id rproc_virtio_match[] = {
> +	{ .compatible = "virtio,rproc", },
> +	{},
> +};
> +
> +static struct platform_driver rproc_virtio_driver = {
> +	.probe		= rproc_virtio_probe,
> +	.remove		= rproc_virtio_remove,
> +	.driver		= {
> +		.name	= "rproc-virtio",
> +		.of_match_table	= rproc_virtio_match,
> +	},
> +};
> +builtin_platform_driver(rproc_virtio_driver);
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index 7c943f0a2fc4..64b9809d0ec1 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -616,9 +616,8 @@ struct rproc_vring {
>  
>  /**
>   * struct rproc_vdev - remoteproc state for a supported virtio device
> - * @refcount: reference counter for the vdev and vring allocations
>   * @subdev: handle for registering the vdev as a rproc subdevice
> - * @dev: device struct used for reference count semantics
> + * @pdev: remoteproc virtio platform device
>   * @id: virtio device id (as in virtio_ids.h)
>   * @node: list node
>   * @rproc: the rproc handle
> @@ -627,10 +626,9 @@ struct rproc_vring {
>   * @index: vdev position versus other vdev declared in resource table
>   */
>  struct rproc_vdev {
> -	struct kref refcount;
>  
>  	struct rproc_subdev subdev;
> -	struct device dev;
> +	struct platform_device *pdev;
>  
>  	unsigned int id;
>  	struct list_head node;
> -- 
> 2.24.3
>
diff mbox series

Patch

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index d3eca1da8aa1..f5f2f500a50e 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -478,6 +478,7 @@  static int rproc_handle_vdev(struct rproc *rproc, void *ptr,
 	struct device *dev = &rproc->dev;
 	struct rproc_vdev *rvdev;
 	struct rproc_vdev_data rvdev_data;
+	struct platform_device *pdev;
 
 	/* make sure resource isn't truncated */
 	if (struct_size(rsc, vring, rsc->num_of_vrings) + rsc->config_len >
@@ -506,9 +507,12 @@  static int rproc_handle_vdev(struct rproc *rproc, void *ptr,
 	rvdev_data.rsc_offset = offset;
 	rvdev_data.rsc = rsc;
 
-	rvdev = rproc_rvdev_add_device(rproc, &rvdev_data);
-	if (IS_ERR(rvdev))
-		return PTR_ERR(rvdev);
+	pdev = platform_device_register_data(dev, "rproc-virtio", rvdev_data.index, &rvdev_data,
+					     sizeof(rvdev_data));
+	if (IS_ERR(pdev)) {
+		dev_err(dev, "failed to create rproc-virtio device\n");
+		return PTR_ERR(pdev);
+	}
 
 	return 0;
 }
@@ -1244,7 +1248,7 @@  void rproc_resource_cleanup(struct rproc *rproc)
 
 	/* clean up remote vdev entries */
 	list_for_each_entry_safe(rvdev, rvtmp, &rproc->rvdevs, node)
-		kref_put(&rvdev->refcount, rproc_vdev_release);
+		platform_device_unregister(rvdev->pdev);
 
 	rproc_coredump_cleanup(rproc);
 }
diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
index 711b0e1f2118..bf1fb7bba1a3 100644
--- a/drivers/remoteproc/remoteproc_internal.h
+++ b/drivers/remoteproc/remoteproc_internal.h
@@ -45,9 +45,7 @@  int rproc_of_parse_firmware(struct device *dev, int index,
 			    const char **fw_name);
 
 /* from remoteproc_virtio.c */
-struct rproc_vdev *rproc_rvdev_add_device(struct rproc *rproc, struct rproc_vdev_data *rvdev_data);
 irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id);
-void rproc_vdev_release(struct kref *ref);
 
 /* from remoteproc_debugfs.c */
 void rproc_remove_trace_file(struct dentry *tfile);
diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
index ccc95d4e42cf..06d2131dad11 100644
--- a/drivers/remoteproc/remoteproc_virtio.c
+++ b/drivers/remoteproc/remoteproc_virtio.c
@@ -13,6 +13,7 @@ 
 #include <linux/dma-map-ops.h>
 #include <linux/dma-mapping.h>
 #include <linux/export.h>
+#include <linux/of_platform.h>
 #include <linux/of_reserved_mem.h>
 #include <linux/remoteproc.h>
 #include <linux/virtio.h>
@@ -46,7 +47,11 @@  static int copy_dma_range_map(struct device *to, struct device *from)
 
 static struct rproc_vdev *vdev_to_rvdev(struct virtio_device *vdev)
 {
-	return container_of(vdev->dev.parent, struct rproc_vdev, dev);
+	struct platform_device *pdev;
+
+	pdev = container_of(vdev->dev.parent, struct platform_device, dev);
+
+	return platform_get_drvdata(pdev);
 }
 
 static  struct rproc *vdev_to_rproc(struct virtio_device *vdev)
@@ -341,13 +346,10 @@  static void rproc_virtio_dev_release(struct device *dev)
 {
 	struct virtio_device *vdev = dev_to_virtio(dev);
 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
-	struct rproc *rproc = vdev_to_rproc(vdev);
 
 	kfree(vdev);
 
-	kref_put(&rvdev->refcount, rproc_vdev_release);
-
-	put_device(&rproc->dev);
+	put_device(&rvdev->pdev->dev);
 }
 
 /**
@@ -363,7 +365,7 @@  static void rproc_virtio_dev_release(struct device *dev)
 static int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
 {
 	struct rproc *rproc = rvdev->rproc;
-	struct device *dev = &rvdev->dev;
+	struct device *dev = &rvdev->pdev->dev;
 	struct virtio_device *vdev;
 	struct rproc_mem_entry *mem;
 	int ret;
@@ -433,18 +435,8 @@  static int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
 	vdev->dev.parent = dev;
 	vdev->dev.release = rproc_virtio_dev_release;
 
-	/*
-	 * We're indirectly making a non-temporary copy of the rproc pointer
-	 * here, because drivers probed with this vdev will indirectly
-	 * access the wrapping rproc.
-	 *
-	 * Therefore we must increment the rproc refcount here, and decrement
-	 * it _only_ when the vdev is released.
-	 */
-	get_device(&rproc->dev);
-
 	/* Reference the vdev and vring allocations */
-	kref_get(&rvdev->refcount);
+	get_device(dev);
 
 	ret = register_virtio_device(vdev);
 	if (ret) {
@@ -486,78 +478,57 @@  static int rproc_vdev_do_start(struct rproc_subdev *subdev)
 static void rproc_vdev_do_stop(struct rproc_subdev *subdev, bool crashed)
 {
 	struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
+	struct device *dev = &rvdev->pdev->dev;
 	int ret;
 
-	ret = device_for_each_child(&rvdev->dev, NULL, rproc_remove_virtio_dev);
+	ret = device_for_each_child(dev, NULL, rproc_remove_virtio_dev);
 	if (ret)
-		dev_warn(&rvdev->dev, "can't remove vdev child device: %d\n", ret);
+		dev_warn(dev, "can't remove vdev child device: %d\n", ret);
 }
 
-/**
- * rproc_rvdev_release() - release the existence of a rvdev
- *
- * @dev: the subdevice's dev
- */
-static void rproc_rvdev_release(struct device *dev)
-{
-	struct rproc_vdev *rvdev = container_of(dev, struct rproc_vdev, dev);
-
-	of_reserved_mem_device_release(dev);
-
-	kfree(rvdev);
-}
-
-struct rproc_vdev *
-rproc_rvdev_add_device(struct rproc *rproc, struct rproc_vdev_data *rvdev_data)
+static int rproc_virtio_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
+	struct rproc_vdev_data *rvdev_data = dev->platform_data;
 	struct rproc_vdev *rvdev;
-	struct fw_rsc_vdev *rsc = rvdev_data->rsc;
-	char name[16];
+	struct rproc *rproc = container_of(dev->parent, struct rproc, dev);
+	struct fw_rsc_vdev *rsc;
 	int i, ret;
 
-	rvdev = kzalloc(sizeof(*rvdev), GFP_KERNEL);
-	if (!rvdev)
-		return ERR_PTR(-ENOMEM);
+	if (!rvdev_data)
+		return -EINVAL;
 
-	kref_init(&rvdev->refcount);
+	rvdev = devm_kzalloc(dev, sizeof(*rvdev), GFP_KERNEL);
+	if (!rvdev)
+		return -ENOMEM;
 
 	rvdev->id = rvdev_data->id;
 	rvdev->rproc = rproc;
 	rvdev->index = rvdev_data->index;
 
-	/* Initialise vdev subdevice */
-	snprintf(name, sizeof(name), "vdev%dbuffer", rvdev->index);
-	rvdev->dev.parent = &rproc->dev;
-	rvdev->dev.release = rproc_rvdev_release;
-	dev_set_name(&rvdev->dev, "%s#%s", dev_name(rvdev->dev.parent), name);
-	dev_set_drvdata(&rvdev->dev, rvdev);
-
-	ret = device_register(&rvdev->dev);
-	if (ret) {
-		put_device(&rvdev->dev);
-		return ERR_PTR(ret);
-	}
-
-	ret = copy_dma_range_map(&rvdev->dev, rproc->dev.parent);
+	ret = copy_dma_range_map(dev, rproc->dev.parent);
 	if (ret)
-		goto free_rvdev;
+		return ret;
 
 	/* Make device dma capable by inheriting from parent's capabilities */
-	set_dma_ops(&rvdev->dev, get_dma_ops(rproc->dev.parent));
+	set_dma_ops(dev, get_dma_ops(rproc->dev.parent));
 
-	ret = dma_coerce_mask_and_coherent(&rvdev->dev,
-					   dma_get_mask(rproc->dev.parent));
+	ret = dma_coerce_mask_and_coherent(dev, dma_get_mask(rproc->dev.parent));
 	if (ret) {
-		dev_warn(&rvdev->dev,
-			 "Failed to set DMA mask %llx. Trying to continue... (%pe)\n",
+		dev_warn(dev, "Failed to set DMA mask %llx. Trying to continue... (%pe)\n",
 			 dma_get_mask(rproc->dev.parent), ERR_PTR(ret));
 	}
 
+	platform_set_drvdata(pdev, rvdev);
+	rvdev->pdev = pdev;
+
+	rsc = rvdev_data->rsc;
+
 	/* parse the vrings */
 	for (i = 0; i < rsc->num_of_vrings; i++) {
 		ret = rproc_parse_vring(rvdev, rsc, i);
 		if (ret)
-			goto free_rvdev;
+			return ret;
 	}
 
 	/* remember the resource offset*/
@@ -577,21 +548,30 @@  rproc_rvdev_add_device(struct rproc *rproc, struct rproc_vdev_data *rvdev_data)
 
 	rproc_add_subdev(rproc, &rvdev->subdev);
 
-	return rvdev;
+	/*
+	 * We're indirectly making a non-temporary copy of the rproc pointer
+	 * here, because the platform device or the vdev device will indirectly
+	 * access the wrapping rproc.
+	 *
+	 * Therefore we must increment the rproc refcount here, and decrement
+	 * it _only_ on platform remove.
+	 */
+	get_device(&rproc->dev);
+
+	return 0;
 
 unwind_vring_allocations:
 	for (i--; i >= 0; i--)
 		rproc_free_vring(&rvdev->vring[i]);
-free_rvdev:
-	device_unregister(&rvdev->dev);
-	return ERR_PTR(ret);
+
+	return ret;
 }
 
-void rproc_vdev_release(struct kref *ref)
+static int rproc_virtio_remove(struct platform_device *pdev)
 {
-	struct rproc_vdev *rvdev = container_of(ref, struct rproc_vdev, refcount);
-	struct rproc_vring *rvring;
+	struct rproc_vdev *rvdev = dev_get_drvdata(&pdev->dev);
 	struct rproc *rproc = rvdev->rproc;
+	struct rproc_vring *rvring;
 	int id;
 
 	for (id = 0; id < ARRAY_SIZE(rvdev->vring); id++) {
@@ -601,5 +581,26 @@  void rproc_vdev_release(struct kref *ref)
 
 	rproc_remove_subdev(rproc, &rvdev->subdev);
 	rproc_remove_rvdev(rvdev);
-	device_unregister(&rvdev->dev);
+
+	of_reserved_mem_device_release(&pdev->dev);
+
+	put_device(&rproc->dev);
+
+	return 0;
 }
+
+/* Platform driver */
+static const struct of_device_id rproc_virtio_match[] = {
+	{ .compatible = "virtio,rproc", },
+	{},
+};
+
+static struct platform_driver rproc_virtio_driver = {
+	.probe		= rproc_virtio_probe,
+	.remove		= rproc_virtio_remove,
+	.driver		= {
+		.name	= "rproc-virtio",
+		.of_match_table	= rproc_virtio_match,
+	},
+};
+builtin_platform_driver(rproc_virtio_driver);
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 7c943f0a2fc4..64b9809d0ec1 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -616,9 +616,8 @@  struct rproc_vring {
 
 /**
  * struct rproc_vdev - remoteproc state for a supported virtio device
- * @refcount: reference counter for the vdev and vring allocations
  * @subdev: handle for registering the vdev as a rproc subdevice
- * @dev: device struct used for reference count semantics
+ * @pdev: remoteproc virtio platform device
  * @id: virtio device id (as in virtio_ids.h)
  * @node: list node
  * @rproc: the rproc handle
@@ -627,10 +626,9 @@  struct rproc_vring {
  * @index: vdev position versus other vdev declared in resource table
  */
 struct rproc_vdev {
-	struct kref refcount;
 
 	struct rproc_subdev subdev;
-	struct device dev;
+	struct platform_device *pdev;
 
 	unsigned int id;
 	struct list_head node;