static int
p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
{
int in, out;
struct virtio_chan *chan = client->trans;
char *rdata = (char *)req->rc+sizeof(struct p9_fcall);
P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request\n");
out = pack_sg_list(chan->sg, 0, VIRTQUEUE_NUM, req->tc->sdata,
req->tc->size);
in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM-out, rdata,
client->msize);
req->status = REQ_STATUS_SENT;
if (chan->vq->vq_ops->add_buf(chan->vq, chan->sg, out, in, req->tc) < 0) {
P9_DPRINTK(P9_DEBUG_TRANS,
"9p debug: virtio rpc add_buf returned failure");
return -EIO;
}
chan->vq->vq_ops->kick(chan->vq);
P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request kicked\n");
return 0;
}
static int
p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
{
int err;
int in, out, out_sgs, in_sgs;
unsigned long flags;
struct virtio_chan *chan = client->trans;
struct scatterlist *sgs[2];
p9_debug(P9_DEBUG_TRANS, "9p debug: virtio request\n");
req->status = REQ_STATUS_SENT;
req_retry:
spin_lock_irqsave(&chan->lock, flags);
out_sgs = in_sgs = 0;
/* Handle out VirtIO ring buffers */
out = pack_sg_list(chan->sg, 0,
VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
if (out)
sgs[out_sgs++] = chan->sg;
in = pack_sg_list(chan->sg, out,
VIRTQUEUE_NUM, req->rc->sdata, req->rc->capacity);
if (in)
sgs[out_sgs + in_sgs++] = chan->sg + out;
err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req->tc,
GFP_ATOMIC);
if (err < 0) {
if (err == -ENOSPC) {
chan->ring_bufs_avail = 0;
spin_unlock_irqrestore(&chan->lock, flags);
err = wait_event_interruptible(*chan->vc_wq,
chan->ring_bufs_avail);
if (err == -ERESTARTSYS)
return err;
p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n");
goto req_retry;
} else {
spin_unlock_irqrestore(&chan->lock, flags);
p9_debug(P9_DEBUG_TRANS,
"virtio rpc add_sgs returned failure\n");
return -EIO;
}
}
virtqueue_kick(chan->vq);
spin_unlock_irqrestore(&chan->lock, flags);
p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
return 0;
}
/**
* p9_virtio_zc_request - issue a zero copy request
* @client: client instance issuing the request
* @req: request to be issued
* @uidata: user bffer that should be ued for zero copy read
* @uodata: user buffer that shoud be user for zero copy write
* @inlen: read buffer size
* @olen: write buffer size
* @hdrlen: reader header size, This is the size of response protocol data
*
*/
static int
p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
char *uidata, char *uodata, int inlen,
int outlen, int in_hdr_len, int kern_buf)
{
int in, out, err, out_sgs, in_sgs;
unsigned long flags;
int in_nr_pages = 0, out_nr_pages = 0;
struct page **in_pages = NULL, **out_pages = NULL;
struct virtio_chan *chan = client->trans;
struct scatterlist *sgs[4];
p9_debug(P9_DEBUG_TRANS, "virtio request\n");
if (uodata) {
out_nr_pages = p9_nr_pages(uodata, outlen);
out_pages = kmalloc(sizeof(struct page *) * out_nr_pages,
GFP_NOFS);
if (!out_pages) {
err = -ENOMEM;
goto err_out;
}
out_nr_pages = p9_get_mapped_pages(chan, out_pages, uodata,
out_nr_pages, 0, kern_buf);
if (out_nr_pages < 0) {
err = out_nr_pages;
kfree(out_pages);
out_pages = NULL;
goto err_out;
}
}
if (uidata) {
in_nr_pages = p9_nr_pages(uidata, inlen);
in_pages = kmalloc(sizeof(struct page *) * in_nr_pages,
GFP_NOFS);
if (!in_pages) {
err = -ENOMEM;
goto err_out;
}
in_nr_pages = p9_get_mapped_pages(chan, in_pages, uidata,
in_nr_pages, 1, kern_buf);
if (in_nr_pages < 0) {
err = in_nr_pages;
kfree(in_pages);
in_pages = NULL;
goto err_out;
}
}
req->status = REQ_STATUS_SENT;
req_retry_pinned:
spin_lock_irqsave(&chan->lock, flags);
out_sgs = in_sgs = 0;
/* out data */
out = pack_sg_list(chan->sg, 0,
VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
if (out)
sgs[out_sgs++] = chan->sg;
if (out_pages) {
sgs[out_sgs++] = chan->sg + out;
out += pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM,
out_pages, out_nr_pages, uodata, outlen);
}
/*
* Take care of in data
* For example TREAD have 11.
* 11 is the read/write header = PDU Header(7) + IO Size (4).
* Arrange in such a way that server places header in the
* alloced memory and payload onto the user buffer.
*/
in = pack_sg_list(chan->sg, out,
VIRTQUEUE_NUM, req->rc->sdata, in_hdr_len);
if (in)
sgs[out_sgs + in_sgs++] = chan->sg + out;
if (in_pages) {
sgs[out_sgs + in_sgs++] = chan->sg + out + in;
in += pack_sg_list_p(chan->sg, out + in, VIRTQUEUE_NUM,
in_pages, in_nr_pages, uidata, inlen);
}
BUG_ON(out_sgs + in_sgs > ARRAY_SIZE(sgs));
err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req->tc,
GFP_ATOMIC);
if (err < 0) {
if (err == -ENOSPC) {
chan->ring_bufs_avail = 0;
spin_unlock_irqrestore(&chan->lock, flags);
err = wait_event_interruptible(*chan->vc_wq,
chan->ring_bufs_avail);
if (err == -ERESTARTSYS)
goto err_out;
p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n");
goto req_retry_pinned;
} else {
spin_unlock_irqrestore(&chan->lock, flags);
p9_debug(P9_DEBUG_TRANS,
"virtio rpc add_sgs returned failure\n");
err = -EIO;
goto err_out;
}
}
virtqueue_kick(chan->vq);
spin_unlock_irqrestore(&chan->lock, flags);
p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
err = wait_event_interruptible(*req->wq,
req->status >= REQ_STATUS_RCVD);
/*
* Non kernel buffers are pinned, unpin them
*/
err_out:
if (!kern_buf) {
if (in_pages) {
p9_release_pages(in_pages, in_nr_pages);
atomic_sub(in_nr_pages, &vp_pinned);
}
if (out_pages) {
p9_release_pages(out_pages, out_nr_pages);
atomic_sub(out_nr_pages, &vp_pinned);
}
/* wakeup anybody waiting for slots to pin pages */
wake_up(&vp_wq);
}
kfree(in_pages);
kfree(out_pages);
return err;
}
