Merge tag 'rproc-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux

Pull remoteproc updates from Bjorn Andersson:
 "Support for remoteprocs that will perform recovery without help from
  Linux is introduced.

  The virtio integration is transitioned towards remoteproc_virtio.c and
  represented by a platform_device, in preparation for instantiating
  virtio instances from DeviceTree.

  The iMX remoteproc driver has a couple of sparse warnings corrected
  and a couple of error message printouts are cleaned up. The keystone
  driver is transitioned to use the gpiod API"

* tag 'rproc-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux:
  remoteproc: virtio: Fix warning on bindings by removing the of_match_table
  remoteproc: Support attach recovery after rproc crash
  remoteproc: Introduce rproc features
  remoteproc: virtio: Create platform device for the remoteproc_virtio
  remoteproc: Move rproc_vdev management to remoteproc_virtio.c
  remoteproc: core: Introduce rproc_add_rvdev function
  remoteproc: core: Introduce rproc_rvdev_add_device function
  remoteproc: Harden rproc_handle_vdev() against integer overflow
  remoteproc/keystone: Switch to using gpiod API
  drivers/remoteproc: Fix repeated words in comments
  remoteproc: imx_dsp_rproc: fix argument 2 of rproc_mem_entry_init
  remoteproc: imx_rproc: Simplify some error message

drivers/remoteproc/imx_dsp_rproc.c

@@ -599,7 +599,7 @@ static int imx_dsp_rproc_add_carveout(struct imx_dsp_rproc *priv)
 		}
 
 		/* Register memory region */
-		mem = rproc_mem_entry_init(dev, cpu_addr, (dma_addr_t)att->sa,
+		mem = rproc_mem_entry_init(dev, (void __force *)cpu_addr, (dma_addr_t)att->sa,
 					   att->size, da, NULL, NULL, "dsp_mem");
 
 		if (mem)
@@ -635,7 +635,7 @@ static int imx_dsp_rproc_add_carveout(struct imx_dsp_rproc *priv)
 		}
 
 		/* Register memory region */
-		mem = rproc_mem_entry_init(dev, cpu_addr, (dma_addr_t)rmem->base,
+		mem = rproc_mem_entry_init(dev, (void __force *)cpu_addr, (dma_addr_t)rmem->base,
 					   rmem->size, da, NULL, NULL, it.node->name);
 
 		if (mem)

drivers/remoteproc/imx_rproc.c

@@ -646,7 +646,6 @@ static int imx_rproc_xtr_mbox_init(struct rproc *rproc)
 	struct imx_rproc *priv = rproc->priv;
 	struct device *dev = priv->dev;
 	struct mbox_client *cl;
-	int ret;
 
 	if (!of_get_property(dev->of_node, "mbox-names", NULL))
 		return 0;
@@ -659,18 +658,15 @@ static int imx_rproc_xtr_mbox_init(struct rproc *rproc)
 	cl->rx_callback = imx_rproc_rx_callback;
 
 	priv->tx_ch = mbox_request_channel_byname(cl, "tx");
-	if (IS_ERR(priv->tx_ch)) {
-		ret = PTR_ERR(priv->tx_ch);
-		return dev_err_probe(cl->dev, ret,
-				     "failed to request tx mailbox channel: %d\n", ret);
-	}
+	if (IS_ERR(priv->tx_ch))
+		return dev_err_probe(cl->dev, PTR_ERR(priv->tx_ch),
+				     "failed to request tx mailbox channel\n");
 
 	priv->rx_ch = mbox_request_channel_byname(cl, "rx");
 	if (IS_ERR(priv->rx_ch)) {
 		mbox_free_channel(priv->tx_ch);
-		ret = PTR_ERR(priv->rx_ch);
-		return dev_err_probe(cl->dev, ret,
-				     "failed to request rx mailbox channel: %d\n", ret);
+		return dev_err_probe(cl->dev, PTR_ERR(priv->rx_ch),
+				     "failed to request rx mailbox channel\n");
 	}
 
 	return 0;

drivers/remoteproc/keystone_remoteproc.c

@@ -14,7 +14,7 @@
 #include <linux/workqueue.h>
 #include <linux/of_address.h>
 #include <linux/of_reserved_mem.h>
-#include <linux/of_gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/regmap.h>
 #include <linux/mfd/syscon.h>
 #include <linux/remoteproc.h>
@@ -59,10 +59,10 @@ struct keystone_rproc {
 	int num_mems;
 	struct regmap *dev_ctrl;
 	struct reset_control *reset;
+	struct gpio_desc *kick_gpio;
 	u32 boot_offset;
 	int irq_ring;
 	int irq_fault;
-	int kick_gpio;
 	struct work_struct workqueue;
 };
 
@@ -232,10 +232,10 @@ static void keystone_rproc_kick(struct rproc *rproc, int vqid)
 {
 	struct keystone_rproc *ksproc = rproc->priv;
 
-	if (WARN_ON(ksproc->kick_gpio < 0))
+	if (!ksproc->kick_gpio)
 		return;
 
-	gpio_set_value(ksproc->kick_gpio, 1);
+	gpiod_set_value(ksproc->kick_gpio, 1);
 }
 
 /*
@@ -432,9 +432,9 @@ static int keystone_rproc_probe(struct platform_device *pdev)
 		goto disable_clk;
 	}
 
-	ksproc->kick_gpio = of_get_named_gpio_flags(np, "kick-gpios", 0, NULL);
-	if (ksproc->kick_gpio < 0) {
-		ret = ksproc->kick_gpio;
+	ksproc->kick_gpio = gpiod_get(dev, "kick", GPIOD_ASIS);
+	ret = PTR_ERR_OR_ZERO(ksproc->kick_gpio);
+	if (ret) {
 		dev_err(dev, "failed to get gpio for virtio kicks, status = %d\n",
 			ret);
 		goto disable_clk;
@@ -466,6 +466,7 @@ static int keystone_rproc_probe(struct platform_device *pdev)
 
 release_mem:
 	of_reserved_mem_device_release(dev);
+	gpiod_put(ksproc->kick_gpio);
 disable_clk:
 	pm_runtime_put_sync(dev);
 disable_rpm:
@@ -480,6 +481,7 @@ static int keystone_rproc_remove(struct platform_device *pdev)
 	struct keystone_rproc *ksproc = platform_get_drvdata(pdev);
 
 	rproc_del(ksproc->rproc);
+	gpiod_put(ksproc->kick_gpio);
 	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	rproc_free(ksproc->rproc);

drivers/remoteproc/remoteproc_core.c

@@ -23,9 +23,7 @@
 #include <linux/panic_notifier.h>
 #include <linux/slab.h>
 #include <linux/mutex.h>
-#include <linux/dma-map-ops.h>
 #include <linux/dma-mapping.h>
-#include <linux/dma-direct.h> /* XXX: pokes into bus_dma_range */
 #include <linux/firmware.h>
 #include <linux/string.h>
 #include <linux/debugfs.h>
@@ -346,7 +344,7 @@ int rproc_alloc_vring(struct rproc_vdev *rvdev, int i)
 		if (rproc_check_carveout_da(rproc, mem, rsc->vring[i].da, size))
 			return -ENOMEM;
 	} else {
-		/* Register carveout in in list */
+		/* Register carveout in list */
 		mem = rproc_mem_entry_init(dev, NULL, 0,
 					   size, rsc->vring[i].da,
 					   rproc_alloc_carveout,
@@ -384,7 +382,7 @@ int rproc_alloc_vring(struct rproc_vdev *rvdev, int i)
 	return 0;
 }
 
-static int
+int
 rproc_parse_vring(struct rproc_vdev *rvdev, struct fw_rsc_vdev *rsc, int i)
 {
 	struct rproc *rproc = rvdev->rproc;
@@ -435,57 +433,17 @@ void rproc_free_vring(struct rproc_vring *rvring)
 	}
 }
 
-static int rproc_vdev_do_start(struct rproc_subdev *subdev)
+void rproc_add_rvdev(struct rproc *rproc, struct rproc_vdev *rvdev)
 {
-	struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
-
-	return rproc_add_virtio_dev(rvdev, rvdev->id);
-}
-
-static void rproc_vdev_do_stop(struct rproc_subdev *subdev, bool crashed)
-{
-	struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
-	int ret;
-
-	ret = device_for_each_child(&rvdev->dev, NULL, rproc_remove_virtio_dev);
-	if (ret)
-		dev_warn(&rvdev->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);
-	dma_release_coherent_memory(dev);
-
-	kfree(rvdev);
+	if (rvdev && rproc)
+		list_add_tail(&rvdev->node, &rproc->rvdevs);
 }
 
-static int copy_dma_range_map(struct device *to, struct device *from)
+void rproc_remove_rvdev(struct rproc_vdev *rvdev)
 {
-	const struct bus_dma_region *map = from->dma_range_map, *new_map, *r;
-	int num_ranges = 0;
-
-	if (!map)
-		return 0;
-
-	for (r = map; r->size; r++)
-		num_ranges++;
-
-	new_map = kmemdup(map, array_size(num_ranges + 1, sizeof(*map)),
-			  GFP_KERNEL);
-	if (!new_map)
-		return -ENOMEM;
-	to->dma_range_map = new_map;
-	return 0;
+	if (rvdev)
+		list_del(&rvdev->node);
 }
-
 /**
  * rproc_handle_vdev() - handle a vdev fw resource
  * @rproc: the remote processor
@@ -520,12 +478,13 @@ static int rproc_handle_vdev(struct rproc *rproc, void *ptr,
 	struct fw_rsc_vdev *rsc = ptr;
 	struct device *dev = &rproc->dev;
 	struct rproc_vdev *rvdev;
-	int i, ret;
-	char name[16];
+	size_t rsc_size;
+	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 >
-			avail) {
+	rsc_size = struct_size(rsc, vring, rsc->num_of_vrings);
+	if (size_add(rsc_size, rsc->config_len) > avail) {
 		dev_err(dev, "vdev rsc is truncated\n");
 		return -EINVAL;
 	}
@@ -545,93 +504,19 @@ static int rproc_handle_vdev(struct rproc *rproc, void *ptr,
 		return -EINVAL;
 	}
 
-	rvdev = kzalloc(sizeof(*rvdev), GFP_KERNEL);
-	if (!rvdev)
-		return -ENOMEM;
-
-	kref_init(&rvdev->refcount);
-
-	rvdev->id = rsc->id;
-	rvdev->rproc = rproc;
-	rvdev->index = rproc->nb_vdev++;
+	rvdev_data.id = rsc->id;
+	rvdev_data.index = rproc->nb_vdev++;
+	rvdev_data.rsc_offset = offset;
+	rvdev_data.rsc = rsc;
 
-	/* 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 ret;
+	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);
 	}
 
-	ret = copy_dma_range_map(&rvdev->dev, rproc->dev.parent);
-	if (ret)
-		goto free_rvdev;
-
-	/* Make device dma capable by inheriting from parent's capabilities */
-	set_dma_ops(&rvdev->dev, get_dma_ops(rproc->dev.parent));
-
-	ret = dma_coerce_mask_and_coherent(&rvdev->dev,
-					   dma_get_mask(rproc->dev.parent));
-	if (ret) {
-		dev_warn(dev,
-			 "Failed to set DMA mask %llx. Trying to continue... (%pe)\n",
-			 dma_get_mask(rproc->dev.parent), ERR_PTR(ret));
-	}
-
-	/* parse the vrings */
-	for (i = 0; i < rsc->num_of_vrings; i++) {
-		ret = rproc_parse_vring(rvdev, rsc, i);
-		if (ret)
-			goto free_rvdev;
-	}
-
-	/* remember the resource offset*/
-	rvdev->rsc_offset = offset;
-
-	/* allocate the vring resources */
-	for (i = 0; i < rsc->num_of_vrings; i++) {
-		ret = rproc_alloc_vring(rvdev, i);
-		if (ret)
-			goto unwind_vring_allocations;
-	}
-
-	list_add_tail(&rvdev->node, &rproc->rvdevs);
-
-	rvdev->subdev.start = rproc_vdev_do_start;
-	rvdev->subdev.stop = rproc_vdev_do_stop;
-
-	rproc_add_subdev(rproc, &rvdev->subdev);
-
 	return 0;
-
-unwind_vring_allocations:
-	for (i--; i >= 0; i--)
-		rproc_free_vring(&rvdev->vring[i]);
-free_rvdev:
-	device_unregister(&rvdev->dev);
-	return ret;
-}
-
-void rproc_vdev_release(struct kref *ref)
-{
-	struct rproc_vdev *rvdev = container_of(ref, struct rproc_vdev, refcount);
-	struct rproc_vring *rvring;
-	struct rproc *rproc = rvdev->rproc;
-	int id;
-
-	for (id = 0; id < ARRAY_SIZE(rvdev->vring); id++) {
-		rvring = &rvdev->vring[id];
-		rproc_free_vring(rvring);
-	}
-
-	rproc_remove_subdev(rproc, &rvdev->subdev);
-	list_del(&rvdev->node);
-	device_unregister(&rvdev->dev);
 }
 
 /**
@@ -1365,7 +1250,7 @@ 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);
 }
@@ -1885,6 +1770,45 @@ static int __rproc_detach(struct rproc *rproc)
 	return 0;
 }
 
+static int rproc_attach_recovery(struct rproc *rproc)
+{
+	int ret;
+
+	ret = __rproc_detach(rproc);
+	if (ret)
+		return ret;
+
+	return __rproc_attach(rproc);
+}
+
+static int rproc_boot_recovery(struct rproc *rproc)
+{
+	const struct firmware *firmware_p;
+	struct device *dev = &rproc->dev;
+	int ret;
+
+	ret = rproc_stop(rproc, true);
+	if (ret)
+		return ret;
+
+	/* generate coredump */
+	rproc->ops->coredump(rproc);
+
+	/* load firmware */
+	ret = request_firmware(&firmware_p, rproc->firmware, dev);
+	if (ret < 0) {
+		dev_err(dev, "request_firmware failed: %d\n", ret);
+		return ret;
+	}
+
+	/* boot the remote processor up again */
+	ret = rproc_start(rproc, firmware_p);
+
+	release_firmware(firmware_p);
+
+	return ret;
+}
+
 /**
  * rproc_trigger_recovery() - recover a remoteproc
  * @rproc: the remote processor
@@ -1899,7 +1823,6 @@ static int __rproc_detach(struct rproc *rproc)
  */
 int rproc_trigger_recovery(struct rproc *rproc)
 {
-	const struct firmware *firmware_p;
 	struct device *dev = &rproc->dev;
 	int ret;
 
@@ -1913,24 +1836,10 @@ int rproc_trigger_recovery(struct rproc *rproc)
 
 	dev_err(dev, "recovering %s\n", rproc->name);
 
-	ret = rproc_stop(rproc, true);
-	if (ret)
-		goto unlock_mutex;
-
-	/* generate coredump */
-	rproc->ops->coredump(rproc);
-
-	/* load firmware */
-	ret = request_firmware(&firmware_p, rproc->firmware, dev);
-	if (ret < 0) {
-		dev_err(dev, "request_firmware failed: %d\n", ret);
-		goto unlock_mutex;
-	}
-
-	/* boot the remote processor up again */
-	ret = rproc_start(rproc, firmware_p);
-
-	release_firmware(firmware_p);
+	if (rproc_has_feature(rproc, RPROC_FEAT_ATTACH_ON_RECOVERY))
+		ret = rproc_attach_recovery(rproc);
+	else
+		ret = rproc_boot_recovery(rproc);
 
 unlock_mutex:
 	mutex_unlock(&rproc->lock);

drivers/remoteproc/remoteproc_internal.h

@@ -24,16 +24,43 @@ struct rproc_debug_trace {
 	struct rproc_mem_entry trace_mem;
 };
 
+/**
+ * struct rproc_vdev_data - remoteproc virtio device data
+ * @rsc_offset: offset of the vdev's resource entry
+ * @id: virtio device id (as in virtio_ids.h)
+ * @index: vdev position versus other vdev declared in resource table
+ * @rsc: pointer to the vdev resource entry. Valid only during vdev init as
+ *       the resource can be cached by rproc.
+ */
+struct rproc_vdev_data {
+	u32 rsc_offset;
+	unsigned int id;
+	u32 index;
+	struct fw_rsc_vdev *rsc;
+};
+
+static inline bool rproc_has_feature(struct rproc *rproc, unsigned int feature)
+{
+	return test_bit(feature, rproc->features);
+}
+
+static inline int rproc_set_feature(struct rproc *rproc, unsigned int feature)
+{
+	if (feature >= RPROC_MAX_FEATURES)
+		return -EINVAL;
+
+	set_bit(feature, rproc->features);
+
+	return 0;
+}
+
 /* from remoteproc_core.c */
 void rproc_release(struct kref *kref);
-irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id);
-void rproc_vdev_release(struct kref *ref);
 int rproc_of_parse_firmware(struct device *dev, int index,
 			    const char **fw_name);
 
 /* from remoteproc_virtio.c */
-int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id);
-int rproc_remove_virtio_dev(struct device *dev, void *data);
+irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id);
 
 /* from remoteproc_debugfs.c */
 void rproc_remove_trace_file(struct dentry *tfile);
@@ -83,6 +110,7 @@ static inline void  rproc_char_device_remove(struct rproc *rproc)
 
 void rproc_free_vring(struct rproc_vring *rvring);
 int rproc_alloc_vring(struct rproc_vdev *rvdev, int i);
+int rproc_parse_vring(struct rproc_vdev *rvdev, struct fw_rsc_vdev *rsc, int i);
 
 phys_addr_t rproc_va_to_pa(void *cpu_addr);
 int rproc_trigger_recovery(struct rproc *rproc);
@@ -95,6 +123,8 @@ struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
 						       const struct firmware *fw);
 struct rproc_mem_entry *
 rproc_find_carveout_by_name(struct rproc *rproc, const char *name, ...);
+void rproc_add_rvdev(struct rproc *rproc, struct rproc_vdev *rvdev);
+void rproc_remove_rvdev(struct rproc_vdev *rvdev);
 
 static inline int rproc_prepare_device(struct rproc *rproc)
 {

drivers/remoteproc/remoteproc_virtio.c

@@ -9,9 +9,12 @@
  * Brian Swetland <swetland@google.com>
  */
 
+#include <linux/dma-direct.h>
 #include <linux/dma-map-ops.h>
+#include <linux/dma-mapping.h>
 #include <linux/export.h>
 #include <linux/of_reserved_mem.h>
+#include <linux/platform_device.h>
 #include <linux/remoteproc.h>
 #include <linux/virtio.h>
 #include <linux/virtio_config.h>
@@ -23,9 +26,32 @@
 
 #include "remoteproc_internal.h"
 
+static int copy_dma_range_map(struct device *to, struct device *from)
+{
+	const struct bus_dma_region *map = from->dma_range_map, *new_map, *r;
+	int num_ranges = 0;
+
+	if (!map)
+		return 0;
+
+	for (r = map; r->size; r++)
+		num_ranges++;
+
+	new_map = kmemdup(map, array_size(num_ranges + 1, sizeof(*map)),
+			  GFP_KERNEL);
+	if (!new_map)
+		return -ENOMEM;
+	to->dma_range_map = new_map;
+	return 0;
+}
+
 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)
@@ -322,13 +348,10 @@ 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);
 }
 
 /**
@@ -341,10 +364,10 @@ static void rproc_virtio_dev_release(struct device *dev)
  *
  * Return: 0 on success or an appropriate error value otherwise
  */
-int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
+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;
@@ -414,18 +437,8 @@ 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) {
@@ -449,10 +462,142 @@ int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
  *
  * Return: 0
  */
-int rproc_remove_virtio_dev(struct device *dev, void *data)
+static int rproc_remove_virtio_dev(struct device *dev, void *data)
 {
 	struct virtio_device *vdev = dev_to_virtio(dev);
 
 	unregister_virtio_device(vdev);
 	return 0;
 }
+
+static int rproc_vdev_do_start(struct rproc_subdev *subdev)
+{
+	struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
+
+	return rproc_add_virtio_dev(rvdev, rvdev->id);
+}
+
+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(dev, NULL, rproc_remove_virtio_dev);
+	if (ret)
+		dev_warn(dev, "can't remove vdev child device: %d\n", ret);
+}
+
+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 rproc *rproc = container_of(dev->parent, struct rproc, dev);
+	struct fw_rsc_vdev *rsc;
+	int i, ret;
+
+	if (!rvdev_data)
+		return -EINVAL;
+
+	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;
+
+	ret = copy_dma_range_map(dev, rproc->dev.parent);
+	if (ret)
+		return ret;
+
+	/* Make device dma capable by inheriting from parent's capabilities */
+	set_dma_ops(dev, get_dma_ops(rproc->dev.parent));
+
+	ret = dma_coerce_mask_and_coherent(dev, dma_get_mask(rproc->dev.parent));
+	if (ret) {
+		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)
+			return ret;
+	}
+
+	/* remember the resource offset*/
+	rvdev->rsc_offset = rvdev_data->rsc_offset;
+
+	/* allocate the vring resources */
+	for (i = 0; i < rsc->num_of_vrings; i++) {
+		ret = rproc_alloc_vring(rvdev, i);
+		if (ret)
+			goto unwind_vring_allocations;
+	}
+
+	rproc_add_rvdev(rproc, rvdev);
+
+	rvdev->subdev.start = rproc_vdev_do_start;
+	rvdev->subdev.stop = rproc_vdev_do_stop;
+
+	rproc_add_subdev(rproc, &rvdev->subdev);
+
+	/*
+	 * 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]);
+
+	return ret;
+}
+
+static int rproc_virtio_remove(struct platform_device *pdev)
+{
+	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++) {
+		rvring = &rvdev->vring[id];
+		rproc_free_vring(rvring);
+	}
+
+	rproc_remove_subdev(rproc, &rvdev->subdev);
+	rproc_remove_rvdev(rvdev);
+
+	of_reserved_mem_device_release(&pdev->dev);
+	dma_release_coherent_memory(&pdev->dev);
+
+	put_device(&rproc->dev);
+
+	return 0;
+}
+
+/* Platform driver */
+static struct platform_driver rproc_virtio_driver = {
+	.probe		= rproc_virtio_probe,
+	.remove		= rproc_virtio_remove,
+	.driver		= {
+		.name	= "rproc-virtio",
+	},
+};
+builtin_platform_driver(rproc_virtio_driver);

include/linux/remoteproc.h

@@ -489,6 +489,20 @@ struct rproc_dump_segment {
 	loff_t offset;
 };
 
+/**
+ * enum rproc_features - features supported
+ *
+ * @RPROC_FEAT_ATTACH_ON_RECOVERY: The remote processor does not need help
+ *				   from Linux to recover, such as firmware
+ *				   loading. Linux just needs to attach after
+ *				   recovery.
+ */
+
+enum rproc_features {
+	RPROC_FEAT_ATTACH_ON_RECOVERY,
+	RPROC_MAX_FEATURES,
+};
+
 /**
  * struct rproc - represents a physical remote processor device
  * @node: list node of this rproc object
@@ -530,6 +544,7 @@ struct rproc_dump_segment {
  * @elf_machine: firmware ELF machine
  * @cdev: character device of the rproc
  * @cdev_put_on_release: flag to indicate if remoteproc should be shutdown on @char_dev release
+ * @features: indicate remoteproc features
  */
 struct rproc {
 	struct list_head node;
@@ -570,6 +585,7 @@ struct rproc {
 	u16 elf_machine;
 	struct cdev cdev;
 	bool cdev_put_on_release;
+	DECLARE_BITMAP(features, RPROC_MAX_FEATURES);
 };
 
 /**
@@ -616,9 +632,8 @@ 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 +642,9 @@ 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;