In Linux, virtqueue_get_buf doesn't return the buffer, but the cookie
value specified when the entry was first added to the virtqueue via
virtqueue_add_sgs.
To make it easier to port Linux drivers that keep around metadata for
requests, adopt the Linux API.
No functional change expected.
Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
---
drivers/block/virtio_blk.c | 2 +-
drivers/hw_random/virtio-rng.c | 2 +-
drivers/input/virtio_input.c | 4 ++--
drivers/net/virtio.c | 6 +++---
drivers/serial/virtio_console.c | 4 ++--
drivers/virtio/virtio_ring.c | 24 +++++++++++++-----------
include/linux/virtio_ring.h | 24 ++++++++++++++++++------
7 files changed, 40 insertions(+), 26 deletions(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 3ee7972fe859..11111f174142 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -49,7 +49,7 @@ static int virtio_blk_do_req(struct virtio_blk_priv *priv, void *buffer,
sg_init_one(&status_sg, &status, sizeof(status));
sgs[num_out + num_in++] = &status_sg;
- ret = virtqueue_add_sgs(priv->vq, sgs, num_out, num_in);
+ ret = virtqueue_add_sgs(priv->vq, sgs, num_out, num_in, &out_hdr);
if (ret)
return ret;
diff --git a/drivers/hw_random/virtio-rng.c b/drivers/hw_random/virtio-rng.c
index 6c283c784fb7..1ce321352935 100644
--- a/drivers/hw_random/virtio-rng.c
+++ b/drivers/hw_random/virtio-rng.c
@@ -41,7 +41,7 @@ static int virtio_rng_read(struct hwrng *hwrng, void *data, size_t len, bool wai
while (remaining) {
sg_init_one(&sg, buf, min(remaining, sizeof(buf)));
- ret = virtqueue_add_inbuf(vi->rng_vq, &sg, 1);
+ ret = virtqueue_add_inbuf(vi->rng_vq, &sg, 1, buf);
if (ret)
return ret;
diff --git a/drivers/input/virtio_input.c b/drivers/input/virtio_input.c
index cdcee556a6c7..6e73e7873986 100644
--- a/drivers/input/virtio_input.c
+++ b/drivers/input/virtio_input.c
@@ -27,7 +27,7 @@ static void virtinput_queue_evtbuf(struct virtio_input *vi,
{
struct scatterlist sg;
sg_init_one(&sg, evtbuf, sizeof(*evtbuf));
- virtqueue_add_inbuf(vi->evt, &sg, 1);
+ virtqueue_add_inbuf(vi->evt, &sg, 1, evtbuf);
}
static int virtinput_recv_events(struct virtio_input *vi)
@@ -78,7 +78,7 @@ static int virtinput_send_status(struct sound_card *beeper, unsigned freq, unsig
stsbuf->value = cpu_to_le32(freq);
sg_init_one(&sg, stsbuf, sizeof(*stsbuf));
- rc = virtqueue_add_outbuf(vi->sts, &sg, 1);
+ rc = virtqueue_add_outbuf(vi->sts, &sg, 1, stsbuf);
virtqueue_kick(vi->sts);
if (rc != 0)
diff --git a/drivers/net/virtio.c b/drivers/net/virtio.c
index 26a1dde5199a..73afbc7645bd 100644
--- a/drivers/net/virtio.c
+++ b/drivers/net/virtio.c
@@ -57,7 +57,7 @@ static int virtio_net_start(struct eth_device *edev)
sg.length = VIRTIO_NET_RX_BUF_SIZE;
sg_init_one(&sg, priv->rx_buff[i], VIRTIO_NET_RX_BUF_SIZE);
- virtqueue_add_inbuf(priv->rx_vq, &sg, 1);
+ virtqueue_add_inbuf(priv->rx_vq, &sg, 1, priv->rx_buff[i]);
}
virtqueue_kick(priv->rx_vq);
@@ -86,7 +86,7 @@ static int virtio_net_send(struct eth_device *edev, void *packet, int length)
sg_set_buf(&sgs[1], packet, length);
- ret = virtqueue_add_outbuf(priv->tx_vq, sgs, ARRAY_SIZE(sgs));
+ ret = virtqueue_add_outbuf(priv->tx_vq, sgs, ARRAY_SIZE(sgs), &sgs[0].address);
if (ret)
return ret;
@@ -119,7 +119,7 @@ static void virtio_net_recv(struct eth_device *edev)
net_receive(edev, buf, len);
/* Put the buffer back to the rx ring */
- virtqueue_add_inbuf(priv->rx_vq, &sg, 1);
+ virtqueue_add_inbuf(priv->rx_vq, &sg, 1, addr);
}
static void virtio_net_stop(struct eth_device *dev)
diff --git a/drivers/serial/virtio_console.c b/drivers/serial/virtio_console.c
index eb3b1158171d..09249aef7a14 100644
--- a/drivers/serial/virtio_console.c
+++ b/drivers/serial/virtio_console.c
@@ -49,7 +49,7 @@ static void put_chars(struct virtio_console *virtcons, const char *buf, int coun
* add_buf wants a token to identify this buffer: we hand it
* any non-NULL pointer, since there's only ever one buffer.
*/
- if (virtqueue_add_outbuf(out_vq, &sg, 1) >= 0) {
+ if (virtqueue_add_outbuf(out_vq, &sg, 1, (void *)buf) >= 0) {
/* Tell Host to go! */
virtqueue_kick(out_vq);
/* Chill out until it's done with the buffer. */
@@ -76,7 +76,7 @@ static void add_inbuf(struct virtio_console *virtcons)
sg_init_one(&sg, virtcons->inbuf, sizeof(virtcons->inbuf));
/* We should always be able to add one buffer to an empty queue. */
- if (virtqueue_add_inbuf(virtcons->in_vq, &sg, 1) < 0)
+ if (virtqueue_add_inbuf(virtcons->in_vq, &sg, 1, virtcons->inbuf) < 0)
BUG();
virtqueue_kick(virtcons->in_vq);
}
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index cd3677ff73f9..29d7bb9ef662 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -58,7 +58,8 @@ static void vring_unmap_one(struct virtqueue *vq,
}
int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[],
- unsigned int out_sgs, unsigned int in_sgs)
+ unsigned int out_sgs, unsigned int in_sgs,
+ void *data)
{
struct vring_desc *desc;
unsigned int total_sg = out_sgs + in_sgs;
@@ -67,6 +68,7 @@ int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[],
int head;
WARN_ON(total_sg == 0);
+ BUG_ON(data == NULL);
head = vq->free_head;
@@ -128,6 +130,9 @@ int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[],
/* Update free pointer */
vq->free_head = i;
+ /* Store token. */
+ vq->desc_state[head].data = data;
+
/*
* Put entry in available array (but don't update avail->idx
* until they do sync).
@@ -204,6 +209,9 @@ static void detach_buf(struct virtqueue *vq, unsigned int head)
unsigned int i;
__virtio16 nextflag = cpu_to_virtio16(vq->vdev, VRING_DESC_F_NEXT);
+ /* Clear data ptr. */
+ vq->desc_state[head].data = NULL;
+
/* Put back on free list: unmap first-level descriptors and find end */
i = head;
@@ -230,6 +238,7 @@ void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len)
{
unsigned int i;
u16 last_used;
+ void *ret;
if (!more_used(vq)) {
vq_debug(vq, "No more buffers in queue\n");
@@ -252,6 +261,7 @@ void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len)
return NULL;
}
+ ret = vq->desc_state[i].data;
detach_buf(vq, i);
vq->last_used_idx++;
/*
@@ -263,8 +273,7 @@ void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len)
virtio_store_mb(&vring_used_event(&vq->vring),
cpu_to_virtio16(vq->vdev, vq->last_used_idx));
- return IOMEM((uintptr_t)virtio64_to_cpu(vq->vdev,
- vq->vring.desc[i].addr));
+ return ret;
}
static struct virtqueue *__vring_new_virtqueue(unsigned int index,
@@ -274,7 +283,7 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
unsigned int i;
struct virtqueue *vq;
- vq = malloc(sizeof(*vq));
+ vq = calloc(1, struct_size(vq, desc_state, vring.num));
if (!vq)
return NULL;
@@ -282,12 +291,6 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
vq->index = index;
vq->num_free = vring.num;
vq->vring = vring;
- vq->last_used_idx = 0;
- vq->avail_flags_shadow = 0;
- vq->avail_idx_shadow = 0;
- vq->num_added = 0;
- vq->queue_dma_addr = 0;
- vq->queue_size_in_bytes = 0;
list_add_tail(&vq->list, &vdev->vqs);
vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
@@ -299,7 +302,6 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
vq->avail_flags_shadow);
/* Put everything in free lists */
- vq->free_head = 0;
for (i = 0; i < vring.num - 1; i++)
vq->vring.desc[i].next = cpu_to_virtio16(vdev, i + 1);
diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
index 1fa9c2ed7428..04a2ad0cb1f9 100644
--- a/include/linux/virtio_ring.h
+++ b/include/linux/virtio_ring.h
@@ -82,6 +82,10 @@ struct vring {
struct vring_used *used;
};
+struct vring_desc_state_split {
+ void *data; /* Data for callback. */
+};
+
/**
* virtqueue - a queue to register buffers for sending or receiving.
*
@@ -96,6 +100,7 @@ struct vring {
* @last_used_idx: last used index we've seen
* @avail_flags_shadow: last written value to avail->flags
* @avail_idx_shadow: last written value to avail->idx in guest byte order
+ * @desc_state: cookie data associated with descritptors
*/
struct virtqueue {
struct list_head list;
@@ -111,6 +116,7 @@ struct virtqueue {
u16 avail_idx_shadow;
dma_addr_t queue_dma_addr;
size_t queue_size_in_bytes;
+ struct vring_desc_state_split desc_state[];
};
/*
@@ -170,6 +176,7 @@ static inline int vring_need_event(__u16 event_idx, __u16 new_idx, __u16 old)
* @out_sgs: the number of scatterlists readable by other side
* @in_sgs: the number of scatterlists which are writable
* (after readable ones)
+ * @data: the token identifying the buffer.
*
* Caller must ensure we don't call this with other virtqueue operations
* at the same time (except where noted).
@@ -177,13 +184,15 @@ static inline int vring_need_event(__u16 event_idx, __u16 new_idx, __u16 old)
* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
*/
int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[],
- unsigned int out_sgs, unsigned int in_sgs);
+ unsigned int out_sgs, unsigned int in_sgs,
+ void *data);
/**
* virtqueue_add_outbuf - expose output buffers to other end
* @vq: the struct virtqueue we're talking about.
* @sg: scatterlist (must be well-formed and terminated!)
* @num: the number of entries in @sg readable by other side
+ * @data: the token identifying the buffer.
*
* Caller must ensure we don't call this with other virtqueue operations
* at the same time (except where noted).
@@ -191,9 +200,10 @@ int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[],
* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
*/
static inline int virtqueue_add_outbuf(struct virtqueue *vq,
- struct scatterlist *sg, unsigned int num)
+ struct scatterlist *sg, unsigned int num,
+ void *data)
{
- return virtqueue_add_sgs(vq, &sg, num, 0);
+ return virtqueue_add_sgs(vq, &sg, num, 0, data);
}
/**
@@ -201,6 +211,7 @@ static inline int virtqueue_add_outbuf(struct virtqueue *vq,
* @vq: the struct virtqueue we're talking about.
* @sg: scatterlist (must be well-formed and terminated!)
* @num: the number of entries in @sg writable by other side
+ * @data: the token identifying the buffer.
*
* Caller must ensure we don't call this with other virtqueue operations
* at the same time (except where noted).
@@ -208,9 +219,10 @@ static inline int virtqueue_add_outbuf(struct virtqueue *vq,
* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
*/
static inline int virtqueue_add_inbuf(struct virtqueue *vq,
- struct scatterlist *sg, unsigned int num)
+ struct scatterlist *sg, unsigned int num,
+ void *data)
{
- return virtqueue_add_sgs(vq, &sg, 0, num);
+ return virtqueue_add_sgs(vq, &sg, 0, num, data);
}
/**
@@ -240,7 +252,7 @@ void virtqueue_kick(struct virtqueue *vq);
* Caller must ensure we don't call this with other virtqueue
* operations at the same time (except where noted).
*
- * Returns NULL if there are no used buffers, or the memory buffer
+ * Returns NULL if there are no used buffers, or the "data" token
* handed to virtqueue_add_*().
*/
void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
--
2.39.5
