[PATCH v4 6/6] virtio_pci: Use the DMA API
From: Andy Lutomirski
Date: Thu Oct 29 2015 - 21:11:05 EST
This switches to vring_create_virtqueue, simplifying the driver and
adding DMA API support.
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
drivers/virtio/virtio_pci_common.h | 7 -----
drivers/virtio/virtio_pci_legacy.c | 39 +++++++-----------------
drivers/virtio/virtio_pci_modern.c | 61 ++++++--------------------------------
3 files changed, 19 insertions(+), 88 deletions(-)
diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h
index cd6196b513ad..1a3c689d1b9e 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -35,13 +35,6 @@ struct virtio_pci_vq_info {
/* the actual virtqueue */
struct virtqueue *vq;
- /* the number of entries in the queue */
- int num;
-
- /* the ring queue */
- void *queue;
- dma_addr_t queue_dma_addr; /* bus address */
-
/* the list node for the virtqueues list */
struct list_head node;
diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c
index b5293e5f2af4..8c4e61783441 100644
--- a/drivers/virtio/virtio_pci_legacy.c
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -119,7 +119,6 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
u16 msix_vec)
{
struct virtqueue *vq;
- unsigned long size;
u16 num;
int err;
@@ -131,29 +130,19 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
return ERR_PTR(-ENOENT);
- info->num = num;
info->msix_vector = msix_vec;
- size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
- info->queue = dma_zalloc_coherent(&vp_dev->pci_dev->dev, size,
- &info->queue_dma_addr,
- GFP_KERNEL);
- if (info->queue == NULL)
+ /* create the vring */
+ vq = vring_create_virtqueue(index, num,
+ VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev,
+ true, false, vp_notify, callback, name);
+ if (!vq)
return ERR_PTR(-ENOMEM);
/* activate the queue */
- iowrite32(info->queue_dma_addr >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
+ iowrite32(virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
- /* create the vring */
- vq = vring_new_virtqueue(index, info->num,
- VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev,
- true, info->queue, vp_notify, callback, name);
- if (!vq) {
- err = -ENOMEM;
- goto out_activate_queue;
- }
-
vq->priv = (void __force *)vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
@@ -161,18 +150,15 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
err = -EBUSY;
- goto out_assign;
+ goto out_deactivate;
}
}
return vq;
-out_assign:
- vring_del_virtqueue(vq);
-out_activate_queue:
+out_deactivate:
iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
- dma_free_coherent(&vp_dev->pci_dev->dev, size,
- info->queue, info->queue_dma_addr);
+ vring_del_virtqueue(vq);
return ERR_PTR(err);
}
@@ -180,7 +166,6 @@ static void del_vq(struct virtio_pci_vq_info *info)
{
struct virtqueue *vq = info->vq;
struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
- unsigned long size;
iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
@@ -191,14 +176,10 @@ static void del_vq(struct virtio_pci_vq_info *info)
ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
}
- vring_del_virtqueue(vq);
-
/* Select and deactivate the queue */
iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
- size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN));
- dma_free_coherent(&vp_dev->pci_dev->dev, size,
- info->queue, info->queue_dma_addr);
+ vring_del_virtqueue(vq);
}
static const struct virtio_config_ops virtio_pci_config_ops = {
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index fbe0bd1c4881..50b0cd5a501e 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -287,35 +287,6 @@ static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
return vp_ioread16(&vp_dev->common->msix_config);
}
-static size_t vring_pci_size(u16 num)
-{
- /* We only need a cacheline separation. */
- return PAGE_ALIGN(vring_size(num, SMP_CACHE_BYTES));
-}
-
-static void *alloc_virtqueue_pages(struct virtio_pci_device *vp_dev,
- int *num, dma_addr_t *dma_addr)
-{
- void *pages;
-
- /* TODO: allocate each queue chunk individually */
- for (; *num && vring_pci_size(*num) > PAGE_SIZE; *num /= 2) {
- pages = dma_zalloc_coherent(
- &vp_dev->pci_dev->dev, vring_pci_size(*num),
- dma_addr, GFP_KERNEL|__GFP_NOWARN);
- if (pages)
- return pages;
- }
-
- if (!*num)
- return NULL;
-
- /* Try to get a single page. You are my only hope! */
- return dma_zalloc_coherent(
- &vp_dev->pci_dev->dev, vring_pci_size(*num),
- dma_addr, GFP_KERNEL);
-}
-
static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
struct virtio_pci_vq_info *info,
unsigned index,
@@ -347,30 +318,22 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
/* get offset of notification word for this vq */
off = vp_ioread16(&cfg->queue_notify_off);
- info->num = num;
info->msix_vector = msix_vec;
- info->queue = alloc_virtqueue_pages(vp_dev, &info->num,
- &info->queue_dma_addr);
- if (info->queue == NULL)
- return ERR_PTR(-ENOMEM);
-
/* create the vring */
- vq = vring_new_virtqueue(index, info->num,
- SMP_CACHE_BYTES, &vp_dev->vdev,
- true, info->queue, vp_notify, callback, name);
- if (!vq) {
- err = -ENOMEM;
- goto err_new_queue;
- }
+ vq = vring_create_virtqueue(index, num,
+ SMP_CACHE_BYTES, &vp_dev->vdev,
+ true, true, vp_notify, callback, name);
+ if (!vq)
+ return ERR_PTR(-ENOMEM);
/* activate the queue */
- vp_iowrite16(num, &cfg->queue_size);
- vp_iowrite64_twopart(info->queue_dma_addr,
+ vp_iowrite16(virtqueue_get_vring_size(vq), &cfg->queue_size);
+ vp_iowrite64_twopart(virtqueue_get_desc_addr(vq),
&cfg->queue_desc_lo, &cfg->queue_desc_hi);
- vp_iowrite64_twopart(info->queue_dma_addr + ((char *)virtqueue_get_avail(vq) - (char *)info->queue),
+ vp_iowrite64_twopart(virtqueue_get_avail_addr(vq),
&cfg->queue_avail_lo, &cfg->queue_avail_hi);
- vp_iowrite64_twopart(info->queue_dma_addr + ((char *)virtqueue_get_used(vq) - (char *)info->queue),
+ vp_iowrite64_twopart(virtqueue_get_used_addr(vq),
&cfg->queue_used_lo, &cfg->queue_used_hi);
if (vp_dev->notify_base) {
@@ -415,9 +378,6 @@ err_assign_vector:
pci_iounmap(vp_dev->pci_dev, (void __iomem __force *)vq->priv);
err_map_notify:
vring_del_virtqueue(vq);
-err_new_queue:
- dma_free_coherent(&vp_dev->pci_dev->dev, vring_pci_size(info->num),
- info->queue, info->queue_dma_addr);
return ERR_PTR(err);
}
@@ -462,9 +422,6 @@ static void del_vq(struct virtio_pci_vq_info *info)
pci_iounmap(vp_dev->pci_dev, (void __force __iomem *)vq->priv);
vring_del_virtqueue(vq);
-
- dma_free_coherent(&vp_dev->pci_dev->dev, vring_pci_size(info->num),
- info->queue, info->queue_dma_addr);
}
static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
--
2.4.3
--
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