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-rw-r--r--net/9p/trans_virtio.c136
1 files changed, 9 insertions, 127 deletions
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 72493f04a76..36bce45e4e4 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
@@ -54,49 +52,6 @@ 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
@@ -121,67 +76,14 @@ 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)
{
@@ -200,22 +102,10 @@ static unsigned int rest_of_page(void *data)
static void p9_virtio_close(struct p9_client *client)
{
struct virtio_chan *chan = client->trans;
- 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);
mutex_lock(&virtio_9p_lock);
chan->inuse = false;
mutex_unlock(&virtio_9p_lock);
-
- client->trans = NULL;
}
/**
@@ -241,7 +131,7 @@ static void req_done(struct virtqueue *vq)
spin_lock_irqsave(&chan->lock, flags);
while ((rc = chan->vq->vq_ops->get_buf(chan->vq, &len)) != NULL) {
- req = p9_lookup_tag(chan, rc->tag);
+ req = p9_tag_lookup(chan->client, rc->tag);
req->status = REQ_STATUS_RCVD;
wake_up(req->wq);
}
@@ -311,13 +201,13 @@ p9_virtio_rpc(struct p9_client *c, struct p9_fcall *tc, struct p9_fcall **rc)
n = P9_NOTAG;
if (tc->id != P9_TVERSION) {
- n = p9_idpool_get(chan->tagpool);
+ n = p9_idpool_get(c->tagpool);
if (n < 0)
return -ENOMEM;
}
spin_lock_irqsave(&chan->lock, flags);
- req = p9_lookup_tag(chan, n);
+ req = p9_tag_alloc(c, n);
spin_unlock_irqrestore(&chan->lock, flags);
p9_set_tag(tc, n);
@@ -357,8 +247,8 @@ p9_virtio_rpc(struct p9_client *c, struct p9_fcall *tc, struct p9_fcall **rc)
}
#endif
- if (n != P9_NOTAG && p9_idpool_check(n, chan->tagpool))
- p9_idpool_put(n, chan->tagpool);
+ if (n != P9_NOTAG && p9_idpool_check(n, c->tagpool))
+ p9_idpool_put(n, c->tagpool);
req->status = REQ_STATUS_IDLE;
@@ -463,16 +353,8 @@ p9_virtio_create(struct p9_client *client, const char *devname, char *args)
return -ENODEV;
}
- chan->tagpool = p9_idpool_create();
- if (IS_ERR(chan->tagpool)) {
- printk(KERN_ERR "9p: couldn't allocate tagpool\n");
- return -ENOMEM;
- }
- p9_idpool_get(chan->tagpool); /* reserve tag 0 */
- chan->max_tag = 0;
- chan->reqs = NULL;
-
client->trans = (void *)chan;
+ chan->client = client;
return 0;
}