Commit b4211138 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Michael S. Tsirkin
Browse files

virtio_mmio: Use the DMA API if enabled 



This switches to vring_create_virtqueue, simplifying the driver and
adding DMA API support.

Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 2a2d1382

drivers/virtio/virtio_mmio.c

+15 −52
Original line number Diff line number Diff line
@@ -99,12 +99,6 @@ struct virtio_mmio_vq_info { 
	/* the actual virtqueue */

	struct virtqueue *vq;



	/* the number of entries in the queue */

	unsigned int num;



	/* the virtual address of the ring queue */

	void *queue;



	/* the list node for the virtqueues list */

	struct list_head node;

};
@@ -322,15 +316,13 @@ static void vm_del_vq(struct virtqueue *vq) 
{

	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);

	struct virtio_mmio_vq_info *info = vq->priv;

	unsigned long flags, size;

	unsigned long flags;

	unsigned int index = vq->index;



	spin_lock_irqsave(&vm_dev->lock, flags);

	list_del(&info->node);

	spin_unlock_irqrestore(&vm_dev->lock, flags);



	vring_del_virtqueue(vq);



	/* Select and deactivate the queue */

	writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);

	if (vm_dev->version == 1) {
@@ -340,8 +332,8 @@ static void vm_del_vq(struct virtqueue *vq) 
		WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));

	}



	size = PAGE_ALIGN(vring_size(info->num, VIRTIO_MMIO_VRING_ALIGN));

	free_pages_exact(info->queue, size);

	vring_del_virtqueue(vq);



	kfree(info);

}
@@ -356,8 +348,6 @@ static void vm_del_vqs(struct virtio_device *vdev) 
	free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);

}







static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,

				  void (*callback)(struct virtqueue *vq),

				  const char *name)
@@ -365,7 +355,8 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, 
	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);

	struct virtio_mmio_vq_info *info;

	struct virtqueue *vq;

	unsigned long flags, size;

	unsigned long flags;

	unsigned int num;

	int err;



	if (!name)
@@ -388,66 +379,40 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, 
		goto error_kmalloc;

	}



	/* Allocate pages for the queue - start with a queue as big as

	 * possible (limited by maximum size allowed by device), drop down

	 * to a minimal size, just big enough to fit descriptor table

	 * and two rings (which makes it "alignment_size * 2")

	 */

	info->num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);



	/* If the device reports a 0 entry queue, we won't be able to

	 * use it to perform I/O, and vring_new_virtqueue() can't create

	 * empty queues anyway, so don't bother to set up the device.

	 */

	if (info->num == 0) {

	num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);

	if (num == 0) {

		err = -ENOENT;

		goto error_alloc_pages;

	}



	while (1) {

		size = PAGE_ALIGN(vring_size(info->num,

				VIRTIO_MMIO_VRING_ALIGN));

		/* Did the last iter shrink the queue below minimum size? */

		if (size < VIRTIO_MMIO_VRING_ALIGN * 2) {

			err = -ENOMEM;

			goto error_alloc_pages;

		}



		info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);

		if (info->queue)

			break;



		info->num /= 2;

		goto error_new_virtqueue;

	}



	/* Create the vring */

	vq = vring_new_virtqueue(index, info->num, VIRTIO_MMIO_VRING_ALIGN, vdev,

				 true, info->queue, vm_notify, callback, name);

	vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev,

				 true, true, vm_notify, callback, name);

	if (!vq) {

		err = -ENOMEM;

		goto error_new_virtqueue;

	}



	/* Activate the queue */

	writel(info->num, vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);

	writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);

	if (vm_dev->version == 1) {

		writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);

		writel(virt_to_phys(info->queue) >> PAGE_SHIFT,

		writel(virtqueue_get_desc_addr(vq) >> PAGE_SHIFT,

				vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);

	} else {

		u64 addr;



		addr = virt_to_phys(info->queue);

		addr = virtqueue_get_desc_addr(vq);

		writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW);

		writel((u32)(addr >> 32),

				vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH);



		addr = virt_to_phys(virtqueue_get_avail(vq));

		addr = virtqueue_get_avail_addr(vq);

		writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW);

		writel((u32)(addr >> 32),

				vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH);



		addr = virt_to_phys(virtqueue_get_used(vq));

		addr = virtqueue_get_used_addr(vq);

		writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW);

		writel((u32)(addr >> 32),

				vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH);
@@ -471,8 +436,6 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, 
		writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);

		WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));

	}

	free_pages_exact(info->queue, size);

error_alloc_pages:

	kfree(info);

error_kmalloc:

error_available: