X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=net%2F9p%2Ftrans_virtio.c;h=cb50f4ae5eefa1f5cde720f43daaf6f19e9034eb;hb=d817f4e18cf54ae7d662cf2f33e51685e81ad254;hp=94912e077a55e0ecdfdd137c9a9848256edd66b3;hpb=72029fe85d8d060b3f966f2dbc36b3c75b5a6532;p=safe%2Fjmp%2Flinux-2.6 diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index 94912e0..cb50f4a 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -1,12 +1,10 @@ /* - * The Guest 9p transport driver + * The Virtio 9p transport driver * * This is a block based transport driver based on the lguest block driver * code. * - */ -/* - * Copyright (C) 2007 Eric Van Hensbergen, IBM Corporation + * Copyright (C) 2007, 2008 Eric Van Hensbergen, IBM Corporation * * Based on virtio console driver * Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation @@ -41,6 +39,7 @@ #include #include #include +#include #include #include #include @@ -53,60 +52,14 @@ static DEFINE_MUTEX(virtio_9p_lock); /* global which tracks highest initialized channel */ static int chan_index; -#define P9_INIT_MAXTAG 16 - - -/** - * enum p9_req_status_t - virtio request status - * @REQ_STATUS_IDLE: request slot unused - * @REQ_STATUS_SENT: request sent to server - * @REQ_STATUS_RCVD: response received from server - * @REQ_STATUS_FLSH: request has been flushed - * - * The @REQ_STATUS_IDLE state is used to mark a request slot as unused - * but use is actually tracked by the idpool structure which handles tag - * id allocation. - * - */ - -enum p9_req_status_t { - REQ_STATUS_IDLE, - REQ_STATUS_SENT, - REQ_STATUS_RCVD, - REQ_STATUS_FLSH, -}; - -/** - * struct p9_req_t - virtio request slots - * @status: status of this request slot - * @wq: wait_queue for the client to block on for this request - * - * The virtio transport uses an array to track outstanding requests - * instead of a list. While this may incurr overhead during initial - * allocation or expansion, it makes request lookup much easier as the - * tag id is a index into an array. (We use tag+1 so that we can accomodate - * the -1 tag for the T_VERSION request). - * This also has the nice effect of only having to allocate wait_queues - * once, instead of constantly allocating and freeing them. Its possible - * other resources could benefit from this scheme as well. - * - */ - -struct p9_req_t { - int status; - wait_queue_head_t *wq; -}; - /** * struct virtio_chan - per-instance transport information * @initialized: whether the channel is initialized * @inuse: whether the channel is in use * @lock: protects multiple elements within this structure + * @client: client instance * @vdev: virtio dev associated with this channel * @vq: virtio queue associated with this channel - * @tagpool: accounting for tag ids (and request slots) - * @reqs: array of request slots - * @max_tag: current number of request_slots allocated * @sg: scatter gather list which is used to pack a request (protected?) * * We keep all per-channel information in a structure. @@ -121,67 +74,14 @@ static struct virtio_chan { spinlock_t lock; + struct p9_client *client; struct virtio_device *vdev; struct virtqueue *vq; - struct p9_idpool *tagpool; - struct p9_req_t *reqs; - int max_tag; - /* Scatterlist: can be too big for stack. */ struct scatterlist sg[VIRTQUEUE_NUM]; } channels[MAX_9P_CHAN]; -/** - * p9_lookup_tag - Lookup requests by tag - * @c: virtio channel to lookup tag within - * @tag: numeric id for transaction - * - * this is a simple array lookup, but will grow the - * request_slots as necessary to accomodate transaction - * ids which did not previously have a slot. - * - * Bugs: there is currently no upper limit on request slots set - * here, but that should be constrained by the id accounting. - */ - -static struct p9_req_t *p9_lookup_tag(struct virtio_chan *c, u16 tag) -{ - /* This looks up the original request by tag so we know which - * buffer to read the data into */ - tag++; - - while (tag >= c->max_tag) { - int old_max = c->max_tag; - int count; - - if (c->max_tag) - c->max_tag *= 2; - else - c->max_tag = P9_INIT_MAXTAG; - - c->reqs = krealloc(c->reqs, sizeof(struct p9_req_t)*c->max_tag, - GFP_ATOMIC); - if (!c->reqs) { - printk(KERN_ERR "Couldn't grow tag array\n"); - BUG(); - } - for (count = old_max; count < c->max_tag; count++) { - c->reqs[count].status = REQ_STATUS_IDLE; - c->reqs[count].wq = kmalloc(sizeof(wait_queue_head_t), - GFP_ATOMIC); - if (!c->reqs[count].wq) { - printk(KERN_ERR "Couldn't grow tag array\n"); - BUG(); - } - init_waitqueue_head(c->reqs[count].wq); - } - } - - return &c->reqs[tag]; -} - - /* How many bytes left in this page. */ static unsigned int rest_of_page(void *data) { @@ -190,32 +90,21 @@ static unsigned int rest_of_page(void *data) /** * p9_virtio_close - reclaim resources of a channel - * @trans: transport state + * @client: client instance * * This reclaims a channel by freeing its resources and * reseting its inuse flag. * */ -static void p9_virtio_close(struct p9_trans *trans) +static void p9_virtio_close(struct p9_client *client) { - struct virtio_chan *chan = trans->priv; - int count; - unsigned long flags; - - spin_lock_irqsave(&chan->lock, flags); - p9_idpool_destroy(chan->tagpool); - for (count = 0; count < chan->max_tag; count++) - kfree(chan->reqs[count].wq); - kfree(chan->reqs); - chan->max_tag = 0; - spin_unlock_irqrestore(&chan->lock, flags); + struct virtio_chan *chan = client->trans; mutex_lock(&virtio_9p_lock); - chan->inuse = false; + if (chan) + chan->inuse = false; mutex_unlock(&virtio_9p_lock); - - kfree(trans); } /** @@ -236,17 +125,17 @@ static void req_done(struct virtqueue *vq) struct virtio_chan *chan = vq->vdev->priv; struct p9_fcall *rc; unsigned int len; - unsigned long flags; struct p9_req_t *req; - spin_lock_irqsave(&chan->lock, flags); + P9_DPRINTK(P9_DEBUG_TRANS, ": request done\n"); + while ((rc = chan->vq->vq_ops->get_buf(chan->vq, &len)) != NULL) { - req = p9_lookup_tag(chan, rc->tag); + 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; - wake_up(req->wq); + p9_client_cb(chan->client, req); } - /* In case queue is stopped waiting for more buffers. */ - spin_unlock_irqrestore(&chan->lock, flags); } /** @@ -283,53 +172,36 @@ pack_sg_list(struct scatterlist *sg, int start, int limit, char *data, return index-start; } +/* We don't currently allow canceling of virtio requests */ +static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req) +{ + return 1; +} + /** - * p9_virtio_rpc - issue a request and wait for a response - * @t: transport state - * @tc: &p9_fcall request to transmit - * @rc: &p9_fcall to put reponse into + * p9_virtio_request - issue a request + * @client: client instance issuing the request + * @req: request to be issued * */ static int -p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc) +p9_virtio_request(struct p9_client *client, struct p9_req_t *req) { int in, out; - int n, err, size; - struct virtio_chan *chan = t->priv; - char *rdata; - struct p9_req_t *req; - unsigned long flags; - - if (*rc == NULL) { - *rc = kmalloc(sizeof(struct p9_fcall) + t->msize, GFP_KERNEL); - if (!*rc) - return -ENOMEM; - } - - rdata = (char *)*rc+sizeof(struct p9_fcall); - - n = P9_NOTAG; - if (tc->id != P9_TVERSION) { - n = p9_idpool_get(chan->tagpool); - if (n < 0) - return -ENOMEM; - } - - spin_lock_irqsave(&chan->lock, flags); - req = p9_lookup_tag(chan, n); - spin_unlock_irqrestore(&chan->lock, flags); - - p9_set_tag(tc, n); + struct virtio_chan *chan = client->trans; + char *rdata = (char *)req->rc+sizeof(struct p9_fcall); - P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio rpc tag %d\n", n); + P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request\n"); - out = pack_sg_list(chan->sg, 0, VIRTQUEUE_NUM, tc->sdata, tc->size); - in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM-out, rdata, t->msize); + 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, tc)) { + 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; @@ -337,31 +209,7 @@ p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc) chan->vq->vq_ops->kick(chan->vq); - wait_event(*req->wq, req->status == REQ_STATUS_RCVD); - - size = le32_to_cpu(*(__le32 *) rdata); - - err = p9_deserialize_fcall(rdata, size, *rc, t->extended); - if (err < 0) { - P9_DPRINTK(P9_DEBUG_TRANS, - "9p debug: virtio rpc deserialize returned %d\n", err); - return err; - } - -#ifdef CONFIG_NET_9P_DEBUG - if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) { - char buf[150]; - - p9_printfcall(buf, sizeof(buf), *rc, t->extended); - printk(KERN_NOTICE ">>> %p %s\n", t, buf); - } -#endif - - if (n != P9_NOTAG && p9_idpool_check(n, chan->tagpool)) - p9_idpool_put(n, chan->tagpool); - - req->status = REQ_STATUS_IDLE; - + P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request kicked\n"); return 0; } @@ -396,7 +244,7 @@ static int p9_virtio_probe(struct virtio_device *vdev) chan->vdev = vdev; /* We expect one virtqueue, for requests. */ - chan->vq = vdev->config->find_vq(vdev, 0, req_done); + chan->vq = virtio_find_single_vq(vdev, req_done, "requests"); if (IS_ERR(chan->vq)) { err = PTR_ERR(chan->vq); goto out_free_vq; @@ -411,7 +259,7 @@ static int p9_virtio_probe(struct virtio_device *vdev) return 0; out_free_vq: - vdev->config->del_vq(chan->vq); + vdev->config->del_vqs(vdev); fail: mutex_lock(&virtio_9p_lock); chan_index--; @@ -422,10 +270,9 @@ fail: /** * p9_virtio_create - allocate a new virtio channel + * @client: client instance invoking this transport * @devname: string identifying the channel to connect to (unused) * @args: args passed from sys_mount() for per-transport options (unused) - * @msize: requested maximum packet size - * @extended: 9p2000.u enabled flag * * This sets up a transport channel for 9p communication. Right now * we only match the first available channel, but eventually we couldlook up @@ -441,11 +288,9 @@ fail: * */ -static struct p9_trans * -p9_virtio_create(const char *devname, char *args, int msize, - unsigned char extended) +static int +p9_virtio_create(struct p9_client *client, const char *devname, char *args) { - struct p9_trans *trans; struct virtio_chan *chan = channels; int index = 0; @@ -463,30 +308,14 @@ p9_virtio_create(const char *devname, char *args, int msize, if (index >= MAX_9P_CHAN) { printk(KERN_ERR "9p: no channels available\n"); - return ERR_PTR(-ENODEV); + return -ENODEV; } - chan->tagpool = p9_idpool_create(); - if (IS_ERR(chan->tagpool)) { - printk(KERN_ERR "9p: couldn't allocate tagpool\n"); - return ERR_PTR(-ENOMEM); - } - p9_idpool_get(chan->tagpool); /* reserve tag 0 */ - chan->max_tag = 0; - chan->reqs = NULL; - - trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL); - if (!trans) { - printk(KERN_ERR "9p: couldn't allocate transport\n"); - return ERR_PTR(-ENOMEM); - } - trans->extended = extended; - trans->msize = msize; - trans->close = p9_virtio_close; - trans->rpc = p9_virtio_rpc; - trans->priv = chan; + client->trans = (void *)chan; + client->status = Connected; + chan->client = client; - return trans; + return 0; } /** @@ -502,13 +331,11 @@ static void p9_virtio_remove(struct virtio_device *vdev) BUG_ON(chan->inuse); if (chan->initialized) { - vdev->config->del_vq(chan->vq); + vdev->config->del_vqs(vdev); chan->initialized = false; } } -#define VIRTIO_ID_9P 9 - static struct virtio_device_id id_table[] = { { VIRTIO_ID_9P, VIRTIO_DEV_ANY_ID }, { 0 }, @@ -526,6 +353,9 @@ static struct virtio_driver p9_virtio_drv = { static struct p9_trans_module p9_virtio_trans = { .name = "virtio", .create = p9_virtio_create, + .close = p9_virtio_close, + .request = p9_virtio_request, + .cancel = p9_virtio_cancel, .maxsize = PAGE_SIZE*16, .def = 0, .owner = THIS_MODULE,