[PATCH v7 09/46] virtio_ring: switch to new memory access APIs

Michael S. Tsirkin
2014-11-30T15:10:21Z

Use virtioXX_to_cpu and friends for access to
all multibyte structures in memory.

Note: this is intentionally mechanical.
A follow-up patch will split long lines etc.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
drivers/virtio/virtio_ring.c | 89 ++++++++++++++++++++++----------------------
1 file changed, 45 insertions(+), 44 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 839247c..0d3c737 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -99,7 +99,8 @@ struct vring_virtqueue

#define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq)

-static struct vring_desc *alloc_indirect(unsigned int total_sg, gfp_t gfp)
+static struct vring_desc *alloc_indirect(struct virtqueue *_vq,
+ unsigned int total_sg, gfp_t gfp)
{
struct vring_desc *desc;
unsigned int i;
@@ -116,7 +117,7 @@ static struct vring_desc *alloc_indirect(unsigned int total_sg, gfp_t gfp)
return NULL;

for (i = 0; i < total_sg; i++)
- desc[i].next = i+1;
+ desc[i].next = cpu_to_virtio16(_vq->vdev, i + 1);
return desc;
}

@@ -165,17 +166,17 @@ static inline int virtqueue_add(struct virtqueue *_vq,
/* If the host supports indirect descriptor tables, and we have multiple
* buffers, then go indirect. FIXME: tune this threshold */
if (vq->indirect && total_sg > 1 && vq->vq.num_free)
- desc = alloc_indirect(total_sg, gfp);
+ desc = alloc_indirect(_vq, total_sg, gfp);
else
desc = NULL;

if (desc) {
/* Use a single buffer which doesn't continue */
- vq->vring.desc[head].flags = VRING_DESC_F_INDIRECT;
- vq->vring.desc[head].addr = virt_to_phys(desc);
+ vq->vring.desc[head].flags = cpu_to_virtio16(_vq->vdev, VRING_DESC_F_INDIRECT);
+ vq->vring.desc[head].addr = cpu_to_virtio64(_vq->vdev, virt_to_phys(desc));
/* avoid kmemleak false positive (hidden by virt_to_phys) */
kmemleak_ignore(desc);
- vq->vring.desc[head].len = total_sg * sizeof(struct vring_desc);
+ vq->vring.desc[head].len = cpu_to_virtio32(_vq->vdev, total_sg * sizeof(struct vring_desc));

/* Set up rest to use this indirect table. */
i = 0;
@@ -205,28 +206,28 @@ static inline int virtqueue_add(struct virtqueue *_vq,

for (n = 0; n < out_sgs; n++) {
for (sg = sgs[n]; sg; sg = sg_next(sg)) {
- desc[i].flags = VRING_DESC_F_NEXT;
- desc[i].addr = sg_phys(sg);
- desc[i].len = sg->length;
+ desc[i].flags = cpu_to_virtio16(_vq->vdev, VRING_DESC_F_NEXT);
+ desc[i].addr = cpu_to_virtio64(_vq->vdev, sg_phys(sg));
+ desc[i].len = cpu_to_virtio32(_vq->vdev, sg->length);
prev = i;
- i = desc[i].next;
+ i = virtio16_to_cpu(_vq->vdev, desc[i].next);
}
}
for (; n < (out_sgs + in_sgs); n++) {
for (sg = sgs[n]; sg; sg = sg_next(sg)) {
- desc[i].flags = VRING_DESC_F_NEXT|VRING_DESC_F_WRITE;
- desc[i].addr = sg_phys(sg);
- desc[i].len = sg->length;
+ desc[i].flags = cpu_to_virtio16(_vq->vdev, VRING_DESC_F_NEXT | VRING_DESC_F_WRITE);
+ desc[i].addr = cpu_to_virtio64(_vq->vdev, sg_phys(sg));
+ desc[i].len = cpu_to_virtio32(_vq->vdev, sg->length);
prev = i;
- i = desc[i].next;
+ i = virtio16_to_cpu(_vq->vdev, desc[i].next);
}
}
/* Last one doesn't continue. */
- desc[prev].flags &= ~VRING_DESC_F_NEXT;
+ desc[prev].flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT);

/* Update free pointer */
if (indirect)
- vq->free_head = vq->vring.desc[head].next;
+ vq->free_head = virtio16_to_cpu(_vq->vdev, vq->vring.desc[head].next);
else
vq->free_head = i;

@@ -235,13 +236,13 @@ static inline int virtqueue_add(struct virtqueue *_vq,

/* Put entry in available array (but don't update avail->idx until they
* do sync). */
- avail = (vq->vring.avail->idx & (vq->vring.num-1));
- vq->vring.avail->ring[avail] = head;
+ avail = virtio16_to_cpu(_vq->vdev, vq->vring.avail->idx) & (vq->vring.num - 1);
+ vq->vring.avail->ring[avail] = cpu_to_virtio16(_vq->vdev, head);

/* Descriptors and available array need to be set before we expose the
* new available array entries. */
virtio_wmb(vq->weak_barriers);
- vq->vring.avail->idx++;
+ vq->vring.avail->idx = cpu_to_virtio16(_vq->vdev, virtio16_to_cpu(_vq->vdev, vq->vring.avail->idx) + 1);
vq->num_added++;

/* This is very unlikely, but theoretically possible. Kick
@@ -354,8 +355,8 @@ bool virtqueue_kick_prepare(struct virtqueue *_vq)
* event. */
virtio_mb(vq->weak_barriers);

- old = vq->vring.avail->idx - vq->num_added;
- new = vq->vring.avail->idx;
+ old = virtio16_to_cpu(_vq->vdev, vq->vring.avail->idx) - vq->num_added;
+ new = virtio16_to_cpu(_vq->vdev, vq->vring.avail->idx);
vq->num_added = 0;

#ifdef DEBUG
@@ -367,10 +368,10 @@ bool virtqueue_kick_prepare(struct virtqueue *_vq)
#endif

if (vq->event) {
- needs_kick = vring_need_event(vring_avail_event(&vq->vring),
+ needs_kick = vring_need_event(virtio16_to_cpu(_vq->vdev, vring_avail_event(&vq->vring)),
new, old);
} else {
- needs_kick = !(vq->vring.used->flags & VRING_USED_F_NO_NOTIFY);
+ needs_kick = !(vq->vring.used->flags & cpu_to_virtio16(_vq->vdev, VRING_USED_F_NO_NOTIFY));
}
END_USE(vq);
return needs_kick;
@@ -432,15 +433,15 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head)
i = head;

/* Free the indirect table */
- if (vq->vring.desc[i].flags & VRING_DESC_F_INDIRECT)
- kfree(phys_to_virt(vq->vring.desc[i].addr));
+ if (vq->vring.desc[i].flags & cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_INDIRECT))
+ kfree(phys_to_virt(virtio64_to_cpu(vq->vq.vdev, vq->vring.desc[i].addr)));

- while (vq->vring.desc[i].flags & VRING_DESC_F_NEXT) {
- i = vq->vring.desc[i].next;
+ while (vq->vring.desc[i].flags & cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT)) {
+ i = virtio16_to_cpu(vq->vq.vdev, vq->vring.desc[i].next);
vq->vq.num_free++;
}

- vq->vring.desc[i].next = vq->free_head;
+ vq->vring.desc[i].next = cpu_to_virtio16(vq->vq.vdev, vq->free_head);
vq->free_head = head;
/* Plus final descriptor */
vq->vq.num_free++;
@@ -448,7 +449,7 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head)

static inline bool more_used(const struct vring_virtqueue *vq)
{
- return vq->last_used_idx != vq->vring.used->idx;
+ return vq->last_used_idx != virtio16_to_cpu(vq->vq.vdev, vq->vring.used->idx);
}

/**
@@ -491,8 +492,8 @@ void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
virtio_rmb(vq->weak_barriers);

last_used = (vq->last_used_idx & (vq->vring.num - 1));
- i = vq->vring.used->ring[last_used].id;
- *len = vq->vring.used->ring[last_used].len;
+ i = virtio32_to_cpu(_vq->vdev, vq->vring.used->ring[last_used].id);
+ *len = virtio32_to_cpu(_vq->vdev, vq->vring.used->ring[last_used].len);

if (unlikely(i >= vq->vring.num)) {
BAD_RING(vq, "id %u out of range\n", i);
@@ -510,8 +511,8 @@ void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
/* If we expect an interrupt for the next entry, tell host
* by writing event index and flush out the write before
* the read in the next get_buf call. */
- if (!(vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT)) {
- vring_used_event(&vq->vring) = vq->last_used_idx;
+ if (!(vq->vring.avail->flags & cpu_to_virtio16(_vq->vdev, VRING_AVAIL_F_NO_INTERRUPT))) {
+ vring_used_event(&vq->vring) = cpu_to_virtio16(_vq->vdev, vq->last_used_idx);
virtio_mb(vq->weak_barriers);
}

@@ -537,7 +538,7 @@ void virtqueue_disable_cb(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);

- vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
+ vq->vring.avail->flags |= cpu_to_virtio16(_vq->vdev, VRING_AVAIL_F_NO_INTERRUPT);
}
EXPORT_SYMBOL_GPL(virtqueue_disable_cb);

@@ -565,8 +566,8 @@ unsigned virtqueue_enable_cb_prepare(struct virtqueue *_vq)
/* Depending on the VIRTIO_RING_F_EVENT_IDX feature, we need to
* either clear the flags bit or point the event index at the next
* entry. Always do both to keep code simple. */
- vq->vring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
- vring_used_event(&vq->vring) = last_used_idx = vq->last_used_idx;
+ vq->vring.avail->flags &= cpu_to_virtio16(_vq->vdev, ~VRING_AVAIL_F_NO_INTERRUPT);
+ vring_used_event(&vq->vring) = cpu_to_virtio16(_vq->vdev, last_used_idx = vq->last_used_idx);
END_USE(vq);
return last_used_idx;
}
@@ -586,7 +587,7 @@ bool virtqueue_poll(struct virtqueue *_vq, unsigned last_used_idx)
struct vring_virtqueue *vq = to_vvq(_vq);

virtio_mb(vq->weak_barriers);
- return (u16)last_used_idx != vq->vring.used->idx;
+ return (u16)last_used_idx != virtio16_to_cpu(_vq->vdev, vq->vring.used->idx);
}
EXPORT_SYMBOL_GPL(virtqueue_poll);

@@ -633,12 +634,12 @@ bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
/* Depending on the VIRTIO_RING_F_USED_EVENT_IDX feature, we need to
* either clear the flags bit or point the event index at the next
* entry. Always do both to keep code simple. */
- vq->vring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
+ vq->vring.avail->flags &= cpu_to_virtio16(_vq->vdev, ~VRING_AVAIL_F_NO_INTERRUPT);
/* TODO: tune this threshold */
- bufs = (u16)(vq->vring.avail->idx - vq->last_used_idx) * 3 / 4;
- vring_used_event(&vq->vring) = vq->last_used_idx + bufs;
+ bufs = (u16)(virtio16_to_cpu(_vq->vdev, vq->vring.avail->idx) - vq->last_used_idx) * 3 / 4;
+ vring_used_event(&vq->vring) = cpu_to_virtio16(_vq->vdev, vq->last_used_idx + bufs);
virtio_mb(vq->weak_barriers);
- if (unlikely((u16)(vq->vring.used->idx - vq->last_used_idx) > bufs)) {
+ if (unlikely((u16)(virtio16_to_cpu(_vq->vdev, vq->vring.used->idx) - vq->last_used_idx) > bufs)) {
END_USE(vq);
return false;
}
@@ -670,7 +671,7 @@ void *virtqueue_detach_unused_buf(struct virtqueue *_vq)
/* detach_buf clears data, so grab it now. */
buf = vq->data[i];
detach_buf(vq, i);
- vq->vring.avail->idx--;
+ vq->vring.avail->idx = cpu_to_virtio16(_vq->vdev, virtio16_to_cpu(_vq->vdev, vq->vring.avail->idx) - 1);
END_USE(vq);
return buf;
}
@@ -747,12 +748,12 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,

/* No callback? Tell other side not to bother us. */
if (!callback)
- vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
+ vq->vring.avail->flags |= cpu_to_virtio16(vdev, VRING_AVAIL_F_NO_INTERRUPT);

/* Put everything in free lists. */
vq->free_head = 0;
for (i = 0; i < num-1; i++) {
- vq->vring.desc[i].next = i+1;
+ vq->vring.desc[i].next = cpu_to_virtio16(vdev, i + 1);
vq->data[i] = NULL;
}
vq->data[i] = NULL;
--
MST