[RFC 3/3] virtio_ring: use new vring flags

From: Tiwei Bie
Date: Fri Dec 07 2018 - 03:51:11 EST


Switch to using the _SPLIT_ and _PACKED_ variants of vring flags
in split ring and packed ring respectively.

Signed-off-by: Tiwei Bie <tiwei.bie@xxxxxxxxx>
---
drivers/virtio/virtio_ring.c | 100 +++++++++++++++++++++--------------
1 file changed, 59 insertions(+), 41 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index cd7e755484e3..2806f69c6c9f 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -371,17 +371,17 @@ static void vring_unmap_one_split(const struct vring_virtqueue *vq,

flags = virtio16_to_cpu(vq->vq.vdev, desc->flags);

- if (flags & VRING_DESC_F_INDIRECT) {
+ if (flags & BIT(VRING_SPLIT_DESC_F_INDIRECT)) {
dma_unmap_single(vring_dma_dev(vq),
virtio64_to_cpu(vq->vq.vdev, desc->addr),
virtio32_to_cpu(vq->vq.vdev, desc->len),
- (flags & VRING_DESC_F_WRITE) ?
+ (flags & BIT(VRING_SPLIT_DESC_F_WRITE)) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
} else {
dma_unmap_page(vring_dma_dev(vq),
virtio64_to_cpu(vq->vq.vdev, desc->addr),
virtio32_to_cpu(vq->vq.vdev, desc->len),
- (flags & VRING_DESC_F_WRITE) ?
+ (flags & BIT(VRING_SPLIT_DESC_F_WRITE)) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
}
@@ -481,7 +481,8 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
if (vring_mapping_error(vq, addr))
goto unmap_release;

- desc[i].flags = cpu_to_virtio16(_vq->vdev, VRING_DESC_F_NEXT);
+ desc[i].flags = cpu_to_virtio16(_vq->vdev,
+ BIT(VRING_SPLIT_DESC_F_NEXT));
desc[i].addr = cpu_to_virtio64(_vq->vdev, addr);
desc[i].len = cpu_to_virtio32(_vq->vdev, sg->length);
prev = i;
@@ -494,7 +495,9 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
if (vring_mapping_error(vq, addr))
goto unmap_release;

- desc[i].flags = cpu_to_virtio16(_vq->vdev, VRING_DESC_F_NEXT | VRING_DESC_F_WRITE);
+ desc[i].flags = cpu_to_virtio16(_vq->vdev,
+ BIT(VRING_SPLIT_DESC_F_NEXT) |
+ BIT(VRING_SPLIT_DESC_F_WRITE));
desc[i].addr = cpu_to_virtio64(_vq->vdev, addr);
desc[i].len = cpu_to_virtio32(_vq->vdev, sg->length);
prev = i;
@@ -502,7 +505,8 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
}
}
/* Last one doesn't continue. */
- desc[prev].flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT);
+ desc[prev].flags &= cpu_to_virtio16(_vq->vdev,
+ (u16)~BIT(VRING_SPLIT_DESC_F_NEXT));

if (indirect) {
/* Now that the indirect table is filled in, map it. */
@@ -513,7 +517,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
goto unmap_release;

vq->split.vring.desc[head].flags = cpu_to_virtio16(_vq->vdev,
- VRING_DESC_F_INDIRECT);
+ BIT(VRING_SPLIT_DESC_F_INDIRECT));
vq->split.vring.desc[head].addr = cpu_to_virtio64(_vq->vdev,
addr);

@@ -603,8 +607,8 @@ static bool virtqueue_kick_prepare_split(struct virtqueue *_vq)
new, old);
} else {
needs_kick = !(vq->split.vring.used->flags &
- cpu_to_virtio16(_vq->vdev,
- VRING_USED_F_NO_NOTIFY));
+ cpu_to_virtio16(_vq->vdev,
+ BIT(VRING_SPLIT_USED_F_NO_NOTIFY)));
}
END_USE(vq);
return needs_kick;
@@ -614,7 +618,8 @@ static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head,
void **ctx)
{
unsigned int i, j;
- __virtio16 nextflag = cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT);
+ __virtio16 nextflag = cpu_to_virtio16(vq->vq.vdev,
+ BIT(VRING_SPLIT_DESC_F_NEXT));

/* Clear data ptr. */
vq->split.desc_state[head].data = NULL;
@@ -649,7 +654,8 @@ static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head,
vq->split.vring.desc[head].len);

BUG_ON(!(vq->split.vring.desc[head].flags &
- cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_INDIRECT)));
+ cpu_to_virtio16(vq->vq.vdev,
+ BIT(VRING_SPLIT_DESC_F_INDIRECT))));
BUG_ON(len == 0 || len % sizeof(struct vring_desc));

for (j = 0; j < len / sizeof(struct vring_desc); j++)
@@ -715,7 +721,8 @@ static void *virtqueue_get_buf_ctx_split(struct virtqueue *_vq,
/* 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->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT))
+ if (!(vq->split.avail_flags_shadow &
+ BIT(VRING_SPLIT_AVAIL_F_NO_INTERRUPT)))
virtio_store_mb(vq->weak_barriers,
&vring_used_event(&vq->split.vring),
cpu_to_virtio16(_vq->vdev, vq->last_used_idx));
@@ -730,8 +737,10 @@ static void virtqueue_disable_cb_split(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);

- if (!(vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT)) {
- vq->split.avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
+ if (!(vq->split.avail_flags_shadow &
+ BIT(VRING_SPLIT_AVAIL_F_NO_INTERRUPT))) {
+ vq->split.avail_flags_shadow |=
+ BIT(VRING_SPLIT_AVAIL_F_NO_INTERRUPT);
if (!vq->event)
vq->split.vring.avail->flags =
cpu_to_virtio16(_vq->vdev,
@@ -751,8 +760,10 @@ static unsigned virtqueue_enable_cb_prepare_split(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. */
- if (vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) {
- vq->split.avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT;
+ if (vq->split.avail_flags_shadow &
+ BIT(VRING_SPLIT_AVAIL_F_NO_INTERRUPT)) {
+ vq->split.avail_flags_shadow &=
+ ~BIT(VRING_SPLIT_AVAIL_F_NO_INTERRUPT);
if (!vq->event)
vq->split.vring.avail->flags =
cpu_to_virtio16(_vq->vdev,
@@ -784,8 +795,10 @@ static bool virtqueue_enable_cb_delayed_split(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 update the event index to keep code simple. */
- if (vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) {
- vq->split.avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT;
+ if (vq->split.avail_flags_shadow &
+ BIT(VRING_SPLIT_AVAIL_F_NO_INTERRUPT)) {
+ vq->split.avail_flags_shadow &=
+ ~BIT(VRING_SPLIT_AVAIL_F_NO_INTERRUPT);
if (!vq->event)
vq->split.vring.avail->flags =
cpu_to_virtio16(_vq->vdev,
@@ -912,15 +925,15 @@ static void vring_unmap_state_packed(const struct vring_virtqueue *vq,

flags = state->flags;

- if (flags & VRING_DESC_F_INDIRECT) {
+ if (flags & BIT(VRING_PACKED_DESC_F_INDIRECT)) {
dma_unmap_single(vring_dma_dev(vq),
state->addr, state->len,
- (flags & VRING_DESC_F_WRITE) ?
+ (flags & BIT(VRING_PACKED_DESC_F_WRITE)) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
} else {
dma_unmap_page(vring_dma_dev(vq),
state->addr, state->len,
- (flags & VRING_DESC_F_WRITE) ?
+ (flags & BIT(VRING_PACKED_DESC_F_WRITE)) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
}
@@ -935,17 +948,17 @@ static void vring_unmap_desc_packed(const struct vring_virtqueue *vq,

flags = le16_to_cpu(desc->flags);

- if (flags & VRING_DESC_F_INDIRECT) {
+ if (flags & BIT(VRING_PACKED_DESC_F_INDIRECT)) {
dma_unmap_single(vring_dma_dev(vq),
le64_to_cpu(desc->addr),
le32_to_cpu(desc->len),
- (flags & VRING_DESC_F_WRITE) ?
+ (flags & BIT(VRING_PACKED_DESC_F_WRITE)) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
} else {
dma_unmap_page(vring_dma_dev(vq),
le64_to_cpu(desc->addr),
le32_to_cpu(desc->len),
- (flags & VRING_DESC_F_WRITE) ?
+ (flags & BIT(VRING_PACKED_DESC_F_WRITE)) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
}
@@ -1002,7 +1015,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
goto unmap_release;

desc[i].flags = cpu_to_le16(n < out_sgs ?
- 0 : VRING_DESC_F_WRITE);
+ 0 : BIT(VRING_PACKED_DESC_F_WRITE));
desc[i].addr = cpu_to_le64(addr);
desc[i].len = cpu_to_le32(sg->length);
i++;
@@ -1025,8 +1038,9 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
vq->packed.desc_extra[id].addr = addr;
vq->packed.desc_extra[id].len = total_sg *
sizeof(struct vring_packed_desc);
- vq->packed.desc_extra[id].flags = VRING_DESC_F_INDIRECT |
- vq->packed.avail_used_flags;
+ vq->packed.desc_extra[id].flags =
+ BIT(VRING_PACKED_DESC_F_INDIRECT) |
+ vq->packed.avail_used_flags;
}

/*
@@ -1035,8 +1049,9 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
* the list are made available.
*/
virtio_wmb(vq->weak_barriers);
- vq->packed.vring.desc[head].flags = cpu_to_le16(VRING_DESC_F_INDIRECT |
- vq->packed.avail_used_flags);
+ vq->packed.vring.desc[head].flags =
+ cpu_to_le16(BIT(VRING_PACKED_DESC_F_INDIRECT) |
+ vq->packed.avail_used_flags);

/* We're using some buffers from the free list. */
vq->vq.num_free -= 1;
@@ -1047,8 +1062,8 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
n = 0;
vq->packed.avail_wrap_counter ^= 1;
vq->packed.avail_used_flags ^=
- 1 << VRING_PACKED_DESC_F_AVAIL |
- 1 << VRING_PACKED_DESC_F_USED;
+ BIT(VRING_PACKED_DESC_F_AVAIL) |
+ BIT(VRING_PACKED_DESC_F_USED);
}
vq->packed.next_avail_idx = n;
vq->free_head = vq->packed.desc_state[id].next;
@@ -1141,8 +1156,10 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
goto unmap_release;

flags = cpu_to_le16(vq->packed.avail_used_flags |
- (++c == total_sg ? 0 : VRING_DESC_F_NEXT) |
- (n < out_sgs ? 0 : VRING_DESC_F_WRITE));
+ (++c == total_sg ? 0 :
+ BIT(VRING_PACKED_DESC_F_NEXT)) |
+ (n < out_sgs ? 0 :
+ BIT(VRING_PACKED_DESC_F_WRITE)));
if (i == head)
head_flags = flags;
else
@@ -1164,8 +1181,8 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
if ((unlikely(++i >= vq->packed.vring.num))) {
i = 0;
vq->packed.avail_used_flags ^=
- 1 << VRING_PACKED_DESC_F_AVAIL |
- 1 << VRING_PACKED_DESC_F_USED;
+ BIT(VRING_PACKED_DESC_F_AVAIL) |
+ BIT(VRING_PACKED_DESC_F_USED);
}
}
}
@@ -1258,7 +1275,7 @@ static bool virtqueue_kick_prepare_packed(struct virtqueue *_vq)
off_wrap = le16_to_cpu(snapshot.off_wrap);

wrap_counter = off_wrap >> VRING_PACKED_EVENT_F_WRAP_CTR;
- event_idx = off_wrap & ~(1 << VRING_PACKED_EVENT_F_WRAP_CTR);
+ event_idx = off_wrap & ~BIT(VRING_PACKED_EVENT_F_WRAP_CTR);
if (wrap_counter != vq->packed.avail_wrap_counter)
event_idx -= vq->packed.vring.num;

@@ -1321,8 +1338,8 @@ static inline bool is_used_desc_packed(const struct vring_virtqueue *vq,
u16 flags;

flags = le16_to_cpu(vq->packed.vring.desc[idx].flags);
- avail = !!(flags & (1 << VRING_PACKED_DESC_F_AVAIL));
- used = !!(flags & (1 << VRING_PACKED_DESC_F_USED));
+ avail = !!(flags & BIT(VRING_PACKED_DESC_F_AVAIL));
+ used = !!(flags & BIT(VRING_PACKED_DESC_F_USED));

return avail == used && used == used_wrap_counter;
}
@@ -1452,7 +1469,7 @@ static bool virtqueue_poll_packed(struct virtqueue *_vq, u16 off_wrap)
u16 used_idx;

wrap_counter = off_wrap >> VRING_PACKED_EVENT_F_WRAP_CTR;
- used_idx = off_wrap & ~(1 << VRING_PACKED_EVENT_F_WRAP_CTR);
+ used_idx = off_wrap & ~BIT(VRING_PACKED_EVENT_F_WRAP_CTR);

return is_used_desc_packed(vq, used_idx, wrap_counter);
}
@@ -1625,7 +1642,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
vq->packed.avail_wrap_counter = 1;
vq->packed.used_wrap_counter = 1;
vq->packed.event_flags_shadow = 0;
- vq->packed.avail_used_flags = 1 << VRING_PACKED_DESC_F_AVAIL;
+ vq->packed.avail_used_flags = BIT(VRING_PACKED_DESC_F_AVAIL);

vq->packed.desc_state = kmalloc_array(num,
sizeof(struct vring_desc_state_packed),
@@ -2088,7 +2105,8 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,

/* No callback? Tell other side not to bother us. */
if (!callback) {
- vq->split.avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
+ vq->split.avail_flags_shadow |=
+ BIT(VRING_SPLIT_AVAIL_F_NO_INTERRUPT);
if (!vq->event)
vq->split.vring.avail->flags = cpu_to_virtio16(vdev,
vq->split.avail_flags_shadow);
--
2.17.1