#include <linux/scatterlist.h>
#include <linux/virtio.h>
#include <linux/virtio_9p.h>
+#include "trans_common.h"
#define VIRTQUEUE_NUM 128
struct p9_client *client;
struct virtio_device *vdev;
struct virtqueue *vq;
+ int ring_bufs_avail;
+ wait_queue_head_t *vc_wq;
/* Scatterlist: can be too big for stack. */
struct scatterlist sg[VIRTQUEUE_NUM];
struct p9_fcall *rc;
unsigned int len;
struct p9_req_t *req;
+ unsigned long flags;
P9_DPRINTK(P9_DEBUG_TRANS, ": request done\n");
- while ((rc = virtqueue_get_buf(chan->vq, &len)) != NULL) {
- P9_DPRINTK(P9_DEBUG_TRANS, ": rc %p\n", rc);
- P9_DPRINTK(P9_DEBUG_TRANS, ": lookup tag %d\n", rc->tag);
- req = p9_tag_lookup(chan->client, rc->tag);
- req->status = REQ_STATUS_RCVD;
- p9_client_cb(chan->client, req);
- }
+ do {
+ spin_lock_irqsave(&chan->lock, flags);
+ rc = virtqueue_get_buf(chan->vq, &len);
+
+ if (rc != NULL) {
+ chan->ring_bufs_avail = 1;
+ spin_unlock_irqrestore(&chan->lock, flags);
+ /* Wakeup if anyone waiting for VirtIO ring space. */
+ wake_up(chan->vc_wq);
+ P9_DPRINTK(P9_DEBUG_TRANS, ": rc %p\n", rc);
+ P9_DPRINTK(P9_DEBUG_TRANS, ": lookup tag %d\n",
+ rc->tag);
+ req = p9_tag_lookup(chan->client, rc->tag);
+ req->status = REQ_STATUS_RCVD;
+ if (req->tc->private) {
+ struct trans_rpage_info *rp = req->tc->private;
+ /*Release pages */
+ p9_release_req_pages(rp);
+ if (rp->rp_alloc)
+ kfree(rp);
+ req->tc->private = NULL;
+ }
+ p9_client_cb(chan->client, req);
+ } else {
+ spin_unlock_irqrestore(&chan->lock, flags);
+ }
+ } while (rc != NULL);
}
/**
return 1;
}
+/**
+ * pack_sg_list_p - Just like pack_sg_list. Instead of taking a buffer,
+ * this takes a list of pages.
+ * @sg: scatter/gather list to pack into
+ * @start: which segment of the sg_list to start at
+ * @pdata_off: Offset into the first page
+ * @**pdata: a list of pages to add into sg.
+ * @count: amount of data to pack into the scatter/gather list
+ */
+static int
+pack_sg_list_p(struct scatterlist *sg, int start, int limit, size_t pdata_off,
+ struct page **pdata, int count)
+{
+ int s;
+ int i = 0;
+ int index = start;
+
+ if (pdata_off) {
+ s = min((int)(PAGE_SIZE - pdata_off), count);
+ sg_set_page(&sg[index++], pdata[i++], s, pdata_off);
+ count -= s;
+ }
+
+ while (count) {
+ BUG_ON(index > limit);
+ s = min((int)PAGE_SIZE, count);
+ sg_set_page(&sg[index++], pdata[i++], s, 0);
+ count -= s;
+ }
+ return index-start;
+}
+
/**
* p9_virtio_request - issue a request
* @client: client instance issuing the request
static int
p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
{
- int in, out;
+ int in, out, inp, outp;
struct virtio_chan *chan = client->trans;
char *rdata = (char *)req->rc+sizeof(struct p9_fcall);
+ unsigned long flags;
+ size_t pdata_off = 0;
+ struct trans_rpage_info *rpinfo = NULL;
+ int err, pdata_len = 0;
P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request\n");
+req_retry:
+ req->status = REQ_STATUS_SENT;
+
+ if (req->tc->pbuf_size && (req->tc->pubuf && P9_IS_USER_CONTEXT)) {
+ int nr_pages = p9_nr_pages(req);
+ int rpinfo_size = sizeof(struct trans_rpage_info) +
+ sizeof(struct page *) * nr_pages;
+
+ if (rpinfo_size <= (req->tc->capacity - req->tc->size)) {
+ /* We can use sdata */
+ req->tc->private = req->tc->sdata + req->tc->size;
+ rpinfo = (struct trans_rpage_info *)req->tc->private;
+ rpinfo->rp_alloc = 0;
+ } else {
+ req->tc->private = kmalloc(rpinfo_size, GFP_NOFS);
+ if (!req->tc->private) {
+ P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: "
+ "private kmalloc returned NULL");
+ return -ENOMEM;
+ }
+ rpinfo = (struct trans_rpage_info *)req->tc->private;
+ rpinfo->rp_alloc = 1;
+ }
+
+ err = p9_payload_gup(req, &pdata_off, &pdata_len, nr_pages,
+ req->tc->id == P9_TREAD ? 1 : 0);
+ if (err < 0) {
+ if (rpinfo->rp_alloc)
+ kfree(rpinfo);
+ return err;
+ }
+ }
+
+ spin_lock_irqsave(&chan->lock, flags);
+
+ /* Handle out VirtIO ring buffers */
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->tc->size);
+
+ if (req->tc->pbuf_size && (req->tc->id == P9_TWRITE)) {
+ /* We have additional write payload buffer to take care */
+ if (req->tc->pubuf && P9_IS_USER_CONTEXT) {
+ outp = pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM,
+ pdata_off, rpinfo->rp_data, pdata_len);
+ } else {
+ char *pbuf = req->tc->pubuf ? req->tc->pubuf :
+ req->tc->pkbuf;
+ outp = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM, pbuf,
+ req->tc->pbuf_size);
+ }
+ out += outp;
+ }
- req->status = REQ_STATUS_SENT;
+ /* Handle in VirtIO ring buffers */
+ if (req->tc->pbuf_size &&
+ ((req->tc->id == P9_TREAD) || (req->tc->id == P9_TREADDIR))) {
+ /*
+ * Take care of additional Read payload.
+ * 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.
+ */
+ inp = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM, rdata, 11);
+ /*
+ * Running executables in the filesystem may result in
+ * a read request with kernel buffer as opposed to user buffer.
+ */
+ if (req->tc->pubuf && P9_IS_USER_CONTEXT) {
+ in = pack_sg_list_p(chan->sg, out+inp, VIRTQUEUE_NUM,
+ pdata_off, rpinfo->rp_data, pdata_len);
+ } else {
+ char *pbuf = req->tc->pubuf ? req->tc->pubuf :
+ req->tc->pkbuf;
+ in = pack_sg_list(chan->sg, out+inp, VIRTQUEUE_NUM,
+ pbuf, req->tc->pbuf_size);
+ }
+ in += inp;
+ } else {
+ in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM, rdata,
+ client->msize);
+ }
- if (virtqueue_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;
+ err = virtqueue_add_buf(chan->vq, chan->sg, out, in, req->tc);
+ 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_DPRINTK(P9_DEBUG_TRANS, "9p:Retry virtio request\n");
+ goto req_retry;
+ } else {
+ spin_unlock_irqrestore(&chan->lock, flags);
+ P9_DPRINTK(P9_DEBUG_TRANS,
+ "9p debug: "
+ "virtio rpc add_buf returned failure");
+ if (rpinfo && rpinfo->rp_alloc)
+ kfree(rpinfo);
+ return -EIO;
+ }
}
virtqueue_kick(chan->vq);
+ spin_unlock_irqrestore(&chan->lock, flags);
P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request kicked\n");
return 0;
chan->tag_len = tag_len;
err = sysfs_create_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
if (err) {
- kfree(tag);
- goto out_free_vq;
+ goto out_free_tag;
}
+ chan->vc_wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
+ if (!chan->vc_wq) {
+ err = -ENOMEM;
+ goto out_free_tag;
+ }
+ init_waitqueue_head(chan->vc_wq);
+ chan->ring_bufs_avail = 1;
+
mutex_lock(&virtio_9p_lock);
list_add_tail(&chan->chan_list, &virtio_chan_list);
mutex_unlock(&virtio_9p_lock);
return 0;
+out_free_tag:
+ kfree(tag);
out_free_vq:
vdev->config->del_vqs(vdev);
kfree(chan);
mutex_unlock(&virtio_9p_lock);
sysfs_remove_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
kfree(chan->tag);
+ kfree(chan->vc_wq);
kfree(chan);
}
.request = p9_virtio_request,
.cancel = p9_virtio_cancel,
.maxsize = PAGE_SIZE*16,
+ .pref = P9_TRANS_PREF_PAYLOAD_SEP,
.def = 0,
.owner = THIS_MODULE,
};
git.openpandora.org / pandora-kernel.git / blobdiff