remoteproc_virtio.c - Android社区 - https://www.androidos.net.cn/

Kernel | 4.4

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/*
 * 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 *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(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;