drivers/remoteproc/remoteproc_virtio.c - kernel/quantenna - Git at Google

 /*
  * Remote processor messaging transport (OMAP platform-specific bits)
  *
  * Copyright (C) 2011 Texas Instruments, Inc.
  * Copyright (C) 2011 Google, Inc.
  *
  * Ohad Ben-Cohen <ohad@wizery.com>
  * Brian Swetland <swetland@google.com>
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #include <linux/export.h>
 #include <linux/remoteproc.h>
 #include <linux/virtio.h>
 #include <linux/virtio_config.h>
 #include <linux/virtio_ids.h>
 #include <linux/virtio_ring.h>
 #include <linux/err.h>
 #include <linux/kref.h>
 #include <linux/slab.h>

 #include "remoteproc_internal.h"

 /* kick the remote processor, and let it know which virtqueue to poke at */
 static bool rproc_virtio_notify(struct virtqueue *vq)
 {
 	struct rproc_vring *rvring = vq->priv;
 	struct rproc *rproc = rvring->rvdev->rproc;
 	int notifyid = rvring->notifyid;

 	dev_dbg(&rproc->dev, "kicking vq index: %d\n", notifyid);

 	rproc->ops->kick(rproc, notifyid);
 	return true;
 }

 /**
  * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted
  * @rproc: handle to the remote processor
  * @notifyid: index of the signalled virtqueue (unique per this @rproc)
  *
  * This function should be called by the platform-specific rproc driver,
  * when the remote processor signals that a specific virtqueue has pending
  * messages available.
  *
  * Returns IRQ_NONE if no message was found in the @notifyid virtqueue,
  * and otherwise returns IRQ_HANDLED.
  */
 irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid)
 {
 	struct rproc_vring *rvring;

 	dev_dbg(&rproc->dev, "vq index %d is interrupted\n", notifyid);

 	rvring = idr_find(&rproc->notifyids, notifyid);
 	if (!rvring || !rvring->vq)
 		return IRQ_NONE;

 	return vring_interrupt(0, rvring->vq);
 }
 EXPORT_SYMBOL(rproc_vq_interrupt);

 static struct virtqueue *rp_find_vq(struct virtio_device *vdev,
 				    unsigned id,
 				    void (*callback)(struct virtqueue *vq),
 				    const char *name)
 {
 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 	struct rproc *rproc = vdev_to_rproc(vdev);
 	struct device *dev = &rproc->dev;
 	struct rproc_vring *rvring;
 	struct virtqueue *vq;
 	void *addr;
 	int len, size, ret;

 	/* we're temporarily limited to two virtqueues per rvdev */
 	if (id >= ARRAY_SIZE(rvdev->vring))
 		return ERR_PTR(-EINVAL);

 	if (!name)
 		return NULL;

 	ret = rproc_alloc_vring(rvdev, id);
 	if (ret)
 		return ERR_PTR(ret);

 	rvring = &rvdev->vring[id];
 	addr = rvring->va;
 	len = rvring->len;

 	/* zero vring */
 	size = vring_size(len, rvring->align);
 	memset(addr, 0, size);

 	dev_dbg(dev, "vring%d: va %p qsz %d notifyid %d\n",
 					id, addr, len, rvring->notifyid);

 	/*
 	 * Create the new vq, and tell virtio we're not interested in
 	 * the 'weak' smp barriers, since we're talking with a real device.
 	 */
 	vq = vring_new_virtqueue(id, len, rvring->align, vdev, false, addr,
 					rproc_virtio_notify, callback, name);
 	if (!vq) {
 		dev_err(dev, "vring_new_virtqueue %s failed\n", name);
 		rproc_free_vring(rvring);
 		return ERR_PTR(-ENOMEM);
 	}

 	rvring->vq = vq;
 	vq->priv = rvring;

 	return vq;
 }

 static void __rproc_virtio_del_vqs(struct virtio_device *vdev)
 {
 	struct virtqueue *vq, *n;
 	struct rproc_vring *rvring;

 	list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
 		rvring = vq->priv;
 		rvring->vq = NULL;
 		vring_del_virtqueue(vq);
 		rproc_free_vring(rvring);
 	}
 }

 static void rproc_virtio_del_vqs(struct virtio_device *vdev)
 {
 	struct rproc *rproc = vdev_to_rproc(vdev);

 	/* power down the remote processor before deleting vqs */
 	rproc_shutdown(rproc);

 	__rproc_virtio_del_vqs(vdev);
 }

 static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 		       struct virtqueue *vqs[],
 		       vq_callback_t *callbacks[],
 		       const char * const names[])
 {
 	struct rproc *rproc = vdev_to_rproc(vdev);
 	int i, ret;

 	for (i = 0; i < nvqs; ++i) {
 		vqs[i] = rp_find_vq(vdev, i, callbacks[i], names[i]);
 		if (IS_ERR(vqs[i])) {
 			ret = PTR_ERR(vqs[i]);
 			goto error;
 		}
 	}

 	/* now that the vqs are all set, boot the remote processor */
 	ret = rproc_boot_nowait(rproc);
 	if (ret) {
 		dev_err(&rproc->dev, "rproc_boot() failed %d\n", ret);
 		goto error;
 	}

 	return 0;

 error:
 	__rproc_virtio_del_vqs(vdev);
 	return ret;
 }

 static u8 rproc_virtio_get_status(struct virtio_device *vdev)
 {
 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 	struct fw_rsc_vdev *rsc;

 	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

 	return rsc->status;
 }

 static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status)
 {
 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 	struct fw_rsc_vdev *rsc;

 	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

 	rsc->status = status;
 	dev_dbg(&vdev->dev, "status: %d\n", status);
 }

 static void rproc_virtio_reset(struct virtio_device *vdev)
 {
 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 	struct fw_rsc_vdev *rsc;

 	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

 	rsc->status = 0;
 	dev_dbg(&vdev->dev, "reset !\n");
 }

 /* provide the vdev features as retrieved from the firmware */
 static u64 rproc_virtio_get_features(struct virtio_device *vdev)
 {
 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 	struct fw_rsc_vdev *rsc;

 	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

 	return rsc->dfeatures;
 }

 static int rproc_virtio_finalize_features(struct virtio_device *vdev)
 {
 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 	struct fw_rsc_vdev *rsc;

 	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

 	/* Give virtio_ring a chance to accept features */
 	vring_transport_features(vdev);

 	/* Make sure we don't have any features > 32 bits! */
 	BUG_ON((u32)vdev->features != vdev->features);

 	/*
 	 * Remember the finalized features of our vdev, and provide it
 	 * to the remote processor once it is powered on.
 	 */
 	rsc->gfeatures = vdev->features;

 	return 0;
 }

 static void rproc_virtio_get(struct virtio_device *vdev, unsigned offset,
 							void *buf, unsigned len)
 {
 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 	struct fw_rsc_vdev *rsc;
 	void *cfg;

 	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 	cfg = &rsc->vring[rsc->num_of_vrings];

 	if (offset + len > rsc->config_len || offset + len < len) {
 		dev_err(&vdev->dev, "rproc_virtio_get: access out of bounds\n");
 		return;
 	}

 	memcpy(buf, cfg + offset, len);
 }

 static void rproc_virtio_set(struct virtio_device *vdev, unsigned offset,
 		      const void *buf, unsigned len)
 {
 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 	struct fw_rsc_vdev *rsc;
 	void *cfg;

 	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 	cfg = &rsc->vring[rsc->num_of_vrings];

 	if (offset + len > rsc->config_len || offset + len < len) {
 		dev_err(&vdev->dev, "rproc_virtio_set: access out of bounds\n");
 		return;
 	}

 	memcpy(cfg + offset, buf, len);
 }

 static const struct virtio_config_ops rproc_virtio_config_ops = {
 	.get_features	= rproc_virtio_get_features,
 	.finalize_features = rproc_virtio_finalize_features,
 	.find_vqs	= rproc_virtio_find_vqs,
 	.del_vqs	= rproc_virtio_del_vqs,
 	.reset		= rproc_virtio_reset,
 	.set_status	= rproc_virtio_set_status,
 	.get_status	= rproc_virtio_get_status,
 	.get		= rproc_virtio_get,
 	.set		= rproc_virtio_set,
 };

 /*
  * This function is called whenever vdev is released, and is responsible
  * to decrement the remote processor's refcount which was taken when vdev was
  * added.
  *
  * Never call this function directly; it will be called by the driver
  * core when needed.
  */
 static void rproc_vdev_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);

 	list_del(&rvdev->node);
 	kfree(rvdev);

 	put_device(&rproc->dev);
 }

 /**
  * rproc_add_virtio_dev() - register an rproc-induced virtio device
  * @rvdev: the remote vdev
  *
  * This function registers a virtio device. This vdev's partent is
  * the rproc device.
  *
  * Returns 0 on success or an appropriate error value otherwise.
  */
 int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
 {
 	struct rproc *rproc = rvdev->rproc;
 	struct device *dev = &rproc->dev;
 	struct virtio_device *vdev = &rvdev->vdev;
 	int ret;

 	vdev->id.device	= id,
 	vdev->config = &rproc_virtio_config_ops,
 	vdev->dev.parent = dev;
 	vdev->dev.release = rproc_vdev_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);

 	ret = register_virtio_device(vdev);
 	if (ret) {
 		put_device(&rproc->dev);
 		dev_err(dev, "failed to register vdev: %d\n", ret);
 		goto out;
 	}

 	dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id);

 out:
 	return ret;
 }

 /**
  * rproc_remove_virtio_dev() - remove an rproc-induced virtio device
  * @rvdev: the remote vdev
  *
  * This function unregisters an existing virtio device.
  */
 void rproc_remove_virtio_dev(struct rproc_vdev *rvdev)
 {
 	unregister_virtio_device(&rvdev->vdev);
 }
	/*
	* Remote processor messaging transport (OMAP platform-specific bits)
	*
	* Copyright (C) 2011 Texas Instruments, Inc.
	* Copyright (C) 2011 Google, Inc.
	*
	* Ohad Ben-Cohen <ohad@wizery.com>
	* Brian Swetland <swetland@google.com>
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/export.h>
	#include <linux/remoteproc.h>
	#include <linux/virtio.h>
	#include <linux/virtio_config.h>
	#include <linux/virtio_ids.h>
	#include <linux/virtio_ring.h>
	#include <linux/err.h>
	#include <linux/kref.h>
	#include <linux/slab.h>

	#include "remoteproc_internal.h"

	/* kick the remote processor, and let it know which virtqueue to poke at */
	static bool rproc_virtio_notify(struct virtqueue *vq)
	{
	struct rproc_vring *rvring = vq->priv;
	struct rproc *rproc = rvring->rvdev->rproc;
	int notifyid = rvring->notifyid;

	dev_dbg(&rproc->dev, "kicking vq index: %d\n", notifyid);

	rproc->ops->kick(rproc, notifyid);
	return true;
	}

	/**
	* rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted
	* @rproc: handle to the remote processor
	* @notifyid: index of the signalled virtqueue (unique per this @rproc)
	*
	* This function should be called by the platform-specific rproc driver,
	* when the remote processor signals that a specific virtqueue has pending
	* messages available.
	*
	* Returns IRQ_NONE if no message was found in the @notifyid virtqueue,
	* and otherwise returns IRQ_HANDLED.
	*/
	irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid)
	{
	struct rproc_vring *rvring;

	dev_dbg(&rproc->dev, "vq index %d is interrupted\n", notifyid);

	rvring = idr_find(&rproc->notifyids, notifyid);
	if (!rvring \|\| !rvring->vq)
	return IRQ_NONE;

	return vring_interrupt(0, rvring->vq);
	}
	EXPORT_SYMBOL(rproc_vq_interrupt);

	static struct virtqueue rp_find_vq(struct virtio_device vdev,
	unsigned id,
	void (callback)(struct virtqueue vq),
	const char *name)
	{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct rproc *rproc = vdev_to_rproc(vdev);
	struct device *dev = &rproc->dev;
	struct rproc_vring *rvring;
	struct virtqueue *vq;
	void *addr;
	int len, size, ret;

	/* we're temporarily limited to two virtqueues per rvdev */
	if (id >= ARRAY_SIZE(rvdev->vring))
	return ERR_PTR(-EINVAL);

	if (!name)
	return NULL;

	ret = rproc_alloc_vring(rvdev, id);
	if (ret)
	return ERR_PTR(ret);

	rvring = &rvdev->vring[id];
	addr = rvring->va;
	len = rvring->len;

	/* zero vring */
	size = vring_size(len, rvring->align);
	memset(addr, 0, size);

	dev_dbg(dev, "vring%d: va %p qsz %d notifyid %d\n",
	id, addr, len, rvring->notifyid);

	/*
	* Create the new vq, and tell virtio we're not interested in
	* the 'weak' smp barriers, since we're talking with a real device.
	*/
	vq = vring_new_virtqueue(id, len, rvring->align, vdev, false, addr,
	rproc_virtio_notify, callback, name);
	if (!vq) {
	dev_err(dev, "vring_new_virtqueue %s failed\n", name);
	rproc_free_vring(rvring);
	return ERR_PTR(-ENOMEM);
	}

	rvring->vq = vq;
	vq->priv = rvring;

	return vq;
	}

	static void __rproc_virtio_del_vqs(struct virtio_device *vdev)
	{
	struct virtqueue vq, n;
	struct rproc_vring *rvring;

	list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
	rvring = vq->priv;
	rvring->vq = NULL;
	vring_del_virtqueue(vq);
	rproc_free_vring(rvring);
	}
	}

	static void rproc_virtio_del_vqs(struct virtio_device *vdev)
	{
	struct rproc *rproc = vdev_to_rproc(vdev);

	/* power down the remote processor before deleting vqs */
	rproc_shutdown(rproc);

	__rproc_virtio_del_vqs(vdev);
	}

	static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs,
	struct virtqueue *vqs[],
	vq_callback_t *callbacks[],
	const char * const names[])
	{
	struct rproc *rproc = vdev_to_rproc(vdev);
	int i, ret;

	for (i = 0; i < nvqs; ++i) {
	vqs[i] = rp_find_vq(vdev, i, callbacks[i], names[i]);
	if (IS_ERR(vqs[i])) {
	ret = PTR_ERR(vqs[i]);
	goto error;
	}
	}

	/* now that the vqs are all set, boot the remote processor */
	ret = rproc_boot_nowait(rproc);
	if (ret) {
	dev_err(&rproc->dev, "rproc_boot() failed %d\n", ret);
	goto error;
	}

	return 0;

	error:
	__rproc_virtio_del_vqs(vdev);
	return ret;
	}

	static u8 rproc_virtio_get_status(struct virtio_device *vdev)
	{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct fw_rsc_vdev *rsc;

	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

	return rsc->status;
	}

	static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status)
	{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct fw_rsc_vdev *rsc;

	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

	rsc->status = status;
	dev_dbg(&vdev->dev, "status: %d\n", status);
	}

	static void rproc_virtio_reset(struct virtio_device *vdev)
	{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct fw_rsc_vdev *rsc;

	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

	rsc->status = 0;
	dev_dbg(&vdev->dev, "reset !\n");
	}

	/* provide the vdev features as retrieved from the firmware */
	static u64 rproc_virtio_get_features(struct virtio_device *vdev)
	{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct fw_rsc_vdev *rsc;

	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

	return rsc->dfeatures;
	}

	static int rproc_virtio_finalize_features(struct virtio_device *vdev)
	{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct fw_rsc_vdev *rsc;

	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

	/* Give virtio_ring a chance to accept features */
	vring_transport_features(vdev);

	/* Make sure we don't have any features > 32 bits! */
	BUG_ON((u32)vdev->features != vdev->features);

	/*
	* Remember the finalized features of our vdev, and provide it
	* to the remote processor once it is powered on.
	*/
	rsc->gfeatures = vdev->features;

	return 0;
	}

	static void rproc_virtio_get(struct virtio_device *vdev, unsigned offset,
	void *buf, unsigned len)
	{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct fw_rsc_vdev *rsc;
	void *cfg;

	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
	cfg = &rsc->vring[rsc->num_of_vrings];

	if (offset + len > rsc->config_len \|\| offset + len < len) {
	dev_err(&vdev->dev, "rproc_virtio_get: access out of bounds\n");
	return;
	}

	memcpy(buf, cfg + offset, len);
	}

	static void rproc_virtio_set(struct virtio_device *vdev, unsigned offset,
	const void *buf, unsigned len)
	{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct fw_rsc_vdev *rsc;
	void *cfg;

	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
	cfg = &rsc->vring[rsc->num_of_vrings];

	if (offset + len > rsc->config_len \|\| offset + len < len) {
	dev_err(&vdev->dev, "rproc_virtio_set: access out of bounds\n");
	return;
	}

	memcpy(cfg + offset, buf, len);
	}

	static const struct virtio_config_ops rproc_virtio_config_ops = {
	.get_features = rproc_virtio_get_features,
	.finalize_features = rproc_virtio_finalize_features,
	.find_vqs = rproc_virtio_find_vqs,
	.del_vqs = rproc_virtio_del_vqs,
	.reset = rproc_virtio_reset,
	.set_status = rproc_virtio_set_status,
	.get_status = rproc_virtio_get_status,
	.get = rproc_virtio_get,
	.set = rproc_virtio_set,
	};

	/*
	* This function is called whenever vdev is released, and is responsible
	* to decrement the remote processor's refcount which was taken when vdev was
	* added.
	*
	* Never call this function directly; it will be called by the driver
	* core when needed.
	*/
	static void rproc_vdev_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);

	list_del(&rvdev->node);
	kfree(rvdev);

	put_device(&rproc->dev);
	}

	/**
	* rproc_add_virtio_dev() - register an rproc-induced virtio device
	* @rvdev: the remote vdev
	*
	* This function registers a virtio device. This vdev's partent is
	* the rproc device.
	*
	* Returns 0 on success or an appropriate error value otherwise.
	*/
	int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
	{
	struct rproc *rproc = rvdev->rproc;
	struct device *dev = &rproc->dev;
	struct virtio_device *vdev = &rvdev->vdev;
	int ret;

	vdev->id.device = id,
	vdev->config = &rproc_virtio_config_ops,
	vdev->dev.parent = dev;
	vdev->dev.release = rproc_vdev_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);

	ret = register_virtio_device(vdev);
	if (ret) {
	put_device(&rproc->dev);
	dev_err(dev, "failed to register vdev: %d\n", ret);
	goto out;
	}

	dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id);

	out:
	return ret;
	}

	/**
	* rproc_remove_virtio_dev() - remove an rproc-induced virtio device
	* @rvdev: the remote vdev
	*
	* This function unregisters an existing virtio device.
	*/
	void rproc_remove_virtio_dev(struct rproc_vdev *rvdev)
	{
	unregister_virtio_device(&rvdev->vdev);
	}