9p: block-based virtio client (e2735b77) · Commits · e / devices / android_kernel_fairphone_FP4

include/net/9p/transport.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -40,7 +40,7 @@ struct p9_trans {
		void (close) (struct p9_trans );
		unsigned int (poll)(struct p9_trans , struct poll_table_struct *);
		int (rpc) (struct p9_trans t, struct p9_fcall *tc,
		struct p9_fcall **rc);
		struct p9_fcall **rc, int msize, int dotu);
		};

		struct p9_trans_module {

net/9p/client.c

+17 −17

Original line number	Diff line number	Diff line
		@@ -51,7 +51,7 @@ p9_client_rpc(struct p9_client c, struct p9_fcall tc,
		struct p9_fcall **rc)
		{
		if (c->trans->rpc)
		return c->trans->rpc(c->trans, tc, rc);
		return c->trans->rpc(c->trans, tc, rc, c->msize, c->dotu);
		else
		return p9_conn_rpc(c->conn, tc, rc);
		}
		@@ -99,7 +99,7 @@ struct p9_client p9_client_create(struct p9_trans trans, int msize,
		goto error;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
		goto error;

		@@ -191,7 +191,7 @@ struct p9_fid p9_client_attach(struct p9_client clnt, struct p9_fid *afid,
		goto error;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
		goto error;

		@@ -236,7 +236,7 @@ struct p9_fid p9_client_auth(struct p9_client clnt, char *uname,
		goto error;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
		goto error;

		@@ -287,7 +287,7 @@ struct p9_fid p9_client_walk(struct p9_fid oldfid, int nwname, char **wnames,
		goto error;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);
		if (err) {
		if (rc && rc->id == P9_RWALK)
		goto clunk_fid;
		@@ -322,7 +322,7 @@ struct p9_fid p9_client_walk(struct p9_fid oldfid, int nwname, char **wnames,
		goto error;
		}

		p9_client_rpc(clnt->conn, tc, &rc);
		p9_client_rpc(clnt, tc, &rc);

		error:
		kfree(tc);
		@@ -356,7 +356,7 @@ int p9_client_open(struct p9_fid *fid, int mode)
		goto done;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
		goto done;

		@@ -395,7 +395,7 @@ int p9_client_fcreate(struct p9_fid fid, char name, u32 perm, int mode,
		goto done;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
		goto done;

		@@ -428,7 +428,7 @@ int p9_client_clunk(struct p9_fid *fid)
		goto done;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
		goto done;

		@@ -460,7 +460,7 @@ int p9_client_remove(struct p9_fid *fid)
		goto done;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
		goto done;

		@@ -502,7 +502,7 @@ int p9_client_read(struct p9_fid fid, char data, u64 offset, u32 count)
		goto error;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
		goto error;

		@@ -559,7 +559,7 @@ int p9_client_write(struct p9_fid fid, char data, u64 offset, u32 count)
		goto error;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
		goto error;

		@@ -613,7 +613,7 @@ p9_client_uread(struct p9_fid fid, char __user data, u64 offset, u32 count)
		goto error;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
		goto error;

		@@ -677,7 +677,7 @@ p9_client_uwrite(struct p9_fid fid, const char __user data, u64 offset,
		goto error;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
		goto error;

		@@ -748,7 +748,7 @@ struct p9_stat p9_client_stat(struct p9_fid fid)
		goto error;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
		goto error;

		@@ -790,7 +790,7 @@ int p9_client_wstat(struct p9_fid fid, struct p9_wstat wst)
		goto done;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);

		done:
		kfree(tc);
		@@ -847,7 +847,7 @@ struct p9_stat p9_client_dirread(struct p9_fid fid, u64 offset)
		goto error;
		}

		err = p9_client_rpc(clnt->conn, tc, &rc);
		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
		goto error;

net/9p/trans_virtio.c

+210 −134

Original line number	Diff line number	Diff line
		/*
		* The Guest 9p transport driver
		*
		* This is a trivial pipe-based transport driver based on the lguest console
		* code: we use lguest's DMA mechanism to send bytes out, and register a
		* DMA buffer to receive bytes in. It is assumed to be present and available
		* from the very beginning of boot.
		*
		* This may be have been done by just instaniating another HVC console,
		* but HVC's blocksize of 16 bytes is annoying and painful to performance.
		*
		* A more efficient transport could be built based on the virtio block driver
		* but it requires some changes in the 9p transport model (which are in
		* progress)
		* This is a block based transport driver based on the lguest block driver
		* code.
		*
		*/
		/*
		@@ -55,11 +46,25 @@
		#include <linux/virtio.h>
		#include <linux/virtio_9p.h>

		#define VIRTQUEUE_NUM 128

		/* a single mutex to manage channel initialization and attachment */
		static DECLARE_MUTEX(virtio_9p_lock);
		/* global which tracks highest initialized channel */
		static int chan_index;

		#define P9_INIT_MAXTAG 16

		#define REQ_STATUS_IDLE 0
		#define REQ_STATUS_SENT 1
		#define REQ_STATUS_RCVD 2
		#define REQ_STATUS_FLSH 3

		struct p9_req_t {
		int status;
		wait_queue_head_t *wq;
		};

		/* We keep all per-channel information in a structure.
		* This structure is allocated within the devices dev->mem space.
		* A pointer to the structure will get put in the transport private.
		@@ -68,16 +73,57 @@ static struct virtio_chan {
		bool initialized; /* channel is initialized */
		bool inuse; /* channel is in use */

		struct virtqueue in_vq, out_vq;
		spinlock_t lock;

		struct virtio_device *vdev;
		struct virtqueue *vq;

		/* This is our input buffer, and how much data is left in it. */
		unsigned int in_len;
		char in, inbuf;
		struct p9_idpool *tagpool;
		struct p9_req_t *reqs;
		int max_tag;

		wait_queue_head_t wq; /* waitq for buffer */
		/* Scatterlist: can be too big for stack. */
		struct scatterlist sg[VIRTQUEUE_NUM];
		} channels[MAX_9P_CHAN];

		/* Lookup requests by tag */
		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_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)
		{
		@@ -86,128 +132,163 @@ static unsigned int rest_of_page(void *data)

		static int p9_virtio_write(struct p9_trans trans, void buf, int count)
		{
		struct virtio_chan chan = (struct virtio_chan ) trans->priv;
		struct virtqueue *out_vq = chan->out_vq;
		struct scatterlist sg[1];
		unsigned int len;
		/* Only use the rpc mechanism for now */
		return count;
		}

		P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio write (%d)\n", count);
		static int p9_virtio_read(struct p9_trans trans, void buf, int count)
		{
		/* Only use the rpc mechanism for now */
		return 0;
		}

		/* keep it simple - make sure we don't overflow a page */
		if (rest_of_page(buf) < count)
		count = rest_of_page(buf);
		/* The poll function is used by 9p transports to determine if there
		* is there is activity available on a particular channel. In our case
		* we use it to wait for a callback from the input routines.
		*/
		static unsigned int
		p9_virtio_poll(struct p9_trans trans, struct poll_table_struct pt)
		{
		/* Only use the rpc mechanism for now */
		return 0;
		}

		sg_init_one(sg, buf, count);
		static void p9_virtio_close(struct p9_trans *trans)
		{
		struct virtio_chan *chan = trans->priv;
		int count;
		unsigned int flags;

		/* add_buf wants a token to identify this buffer: we hand it any
		* non-NULL pointer, since there's only ever one buffer. */
		if (out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, (void *)1) == 0) {
		/* Tell Host to go! */
		out_vq->vq_ops->kick(out_vq);
		/* Chill out until it's done with the buffer. */
		while (!out_vq->vq_ops->get_buf(out_vq, &len))
		cpu_relax();
		}
		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);

		P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio wrote (%d)\n", count);
		down(&virtio_9p_lock);
		chan->inuse = false;
		up(&virtio_9p_lock);

		/* We're expected to return the amount of data we wrote: all of it. */
		return count;
		kfree(trans);
		}

		/* Create a scatter-gather list representing our input buffer and put it in the
		* queue. */
		static void add_inbuf(struct virtio_chan *chan)
		static void req_done(struct virtqueue *vq)
		{
		struct scatterlist sg[1];

		sg_init_one(sg, chan->inbuf, PAGE_SIZE);
		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);
		while ((rc = chan->vq->vq_ops->get_buf(chan->vq, &len)) != NULL) {
		req = p9_lookup_tag(chan, rc->tag);
		req->status = REQ_STATUS_RCVD;
		wake_up(req->wq);
		}
		/* In case queue is stopped waiting for more buffers. */
		spin_unlock_irqrestore(&chan->lock, flags);
		}

		/* We should always be able to add one buffer to an empty queue. */
		if (chan->in_vq->vq_ops->add_buf(chan->in_vq, sg, 0, 1, chan->inbuf))
		static int
		pack_sg_list(struct scatterlist sg, int start, int limit, char data,
		int count)
		{
		int s;
		int index = start;

		while (count) {
		s = rest_of_page(data);
		if (s > count)
		s = count;
		sg_set_buf(&sg[index++], data, s);
		count -= s;
		data += s;
		if (index > limit)
		BUG();
		chan->in_vq->vq_ops->kick(chan->in_vq);
		}

		static int p9_virtio_read(struct p9_trans trans, void buf, int count)
		{
		struct virtio_chan chan = (struct virtio_chan ) trans->priv;
		struct virtqueue *in_vq = chan->in_vq;
		return index-start;
		}

		P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio read (%d)\n", count);
		static int
		p9_virtio_rpc(struct p9_trans t, struct p9_fcall tc, struct p9_fcall **rc,
		int msize, int dotu)
		{
		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) + msize, GFP_KERNEL);
		if (!*rc)
		return -ENOMEM;
		}

		/* If we don't have an input queue yet, we can't get input. */
		BUG_ON(!in_vq);
		rdata = (char )rc+sizeof(struct p9_fcall);

		/* No buffer? Try to get one. */
		if (!chan->in_len) {
		chan->in = in_vq->vq_ops->get_buf(in_vq, &chan->in_len);
		if (!chan->in)
		return 0;
		spin_lock_irqsave(&chan->lock, flags);
		n = P9_NOTAG;
		if (tc->id != P9_TVERSION) {
		n = p9_idpool_get(chan->tagpool);
		if (n < 0)
		return -ENOMEM;
		}

		/* You want more than we have to give? Well, try wanting less! */
		if (chan->in_len < count)
		count = chan->in_len;
		req = p9_lookup_tag(chan, n);
		spin_unlock_irqrestore(&chan->lock, flags);

		/* Copy across to their buffer and increment offset. */
		memcpy(buf, chan->in, count);
		chan->in += count;
		chan->in_len -= count;
		p9_set_tag(tc, n);

		/* Finished? Re-register buffer so Host will use it again. */
		if (chan->in_len == 0)
		add_inbuf(chan);
		P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio rpc tag %d\n", n);

		P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio finished read (%d)\n",
		count);
		out = pack_sg_list(chan->sg, 0, VIRTQUEUE_NUM, tc->sdata, tc->size);
		in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM-out, rdata, msize);

		return count;
		}
		req->status = REQ_STATUS_SENT;

		/* The poll function is used by 9p transports to determine if there
		* is there is activity available on a particular channel. In our case
		* we use it to wait for a callback from the input routines.
		*/
		static unsigned int
		p9_virtio_poll(struct p9_trans trans, struct poll_table_struct pt)
		{
		struct virtio_chan chan = (struct virtio_chan )trans->priv;
		struct virtqueue *in_vq = chan->in_vq;
		int ret = POLLOUT; /* we can always handle more output */
		if (chan->vq->vq_ops->add_buf(chan->vq, chan->sg, out, in, tc)) {
		P9_DPRINTK(P9_DEBUG_TRANS,
		"9p debug: virtio rpc add_buf returned failure");
		return -EIO;
		}

		poll_wait(NULL, &chan->wq, pt);
		chan->vq->vq_ops->kick(chan->vq);

		/* No buffer? Try to get one. */
		if (!chan->in_len)
		chan->in = in_vq->vq_ops->get_buf(in_vq, &chan->in_len);
		wait_event(*req->wq, req->status == REQ_STATUS_RCVD);

		if (chan->in_len)
		ret \|= POLLIN;
		size = le32_to_cpu((__le32 ) rdata);

		return ret;
		err = p9_deserialize_fcall(rdata, size, *rc, dotu);
		if (err < 0) {
		P9_DPRINTK(P9_DEBUG_TRANS,
		"9p debug: virtio rpc deserialize returned %d\n", err);
		return err;
		}

		static void p9_virtio_close(struct p9_trans *trans)
		{
		struct virtio_chan *chan = trans->priv;

		down(&virtio_9p_lock);
		chan->inuse = false;
		up(&virtio_9p_lock);
		#ifdef CONFIG_NET_9P_DEBUG
		if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
		char buf[150];

		kfree(trans);
		p9_printfcall(buf, sizeof(buf), *rc, dotu);
		printk(KERN_NOTICE ">>> %p %s\n", t, buf);
		}
		#endif

		static void p9_virtio_intr(struct virtqueue *q)
		{
		struct virtio_chan *chan = q->vdev->priv;
		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 poll_wakeup: %p\n", &chan->wq);
		wake_up_interruptible(&chan->wq);
		return 0;
		}

		static int p9_virtio_probe(struct virtio_device *dev)
		static int p9_virtio_probe(struct virtio_device *vdev)
		{
		int err;
		struct virtio_chan *chan;
		@@ -221,44 +302,29 @@ static int p9_virtio_probe(struct virtio_device *dev)
		if (chan_index > MAX_9P_CHAN) {
		printk(KERN_ERR "9p: virtio: Maximum channels exceeded\n");
		BUG();
		}

		chan->vdev = dev;

		/* This is the scratch page we use to receive console input */
		chan->inbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
		if (!chan->inbuf) {
		err = -ENOMEM;
		goto fail;
		}

		/* Find the input queue. */
		dev->priv = chan;
		chan->in_vq = dev->config->find_vq(dev, 0, p9_virtio_intr);
		if (IS_ERR(chan->in_vq)) {
		err = PTR_ERR(chan->in_vq);
		goto free;
		}
		chan->vdev = vdev;

		chan->out_vq = dev->config->find_vq(dev, 1, NULL);
		if (IS_ERR(chan->out_vq)) {
		err = PTR_ERR(chan->out_vq);
		goto free_in_vq;
		/* We expect one virtqueue, for requests. */
		chan->vq = vdev->config->find_vq(vdev, 0, req_done);
		if (IS_ERR(chan->vq)) {
		err = PTR_ERR(chan->vq);
		goto out_free_vq;
		}
		chan->vq->vdev->priv = chan;
		spin_lock_init(&chan->lock);

		init_waitqueue_head(&chan->wq);
		sg_init_table(chan->sg, VIRTQUEUE_NUM);

		/* Register the input buffer the first time. */
		add_inbuf(chan);
		chan->inuse = false;
		chan->initialized = true;

		return 0;

		free_in_vq:
		dev->config->del_vq(chan->in_vq);
		free:
		kfree(chan->inbuf);
		out_free_vq:
		vdev->config->del_vq(chan->vq);
		fail:
		down(&virtio_9p_lock);
		chan_index--;
		@@ -274,8 +340,8 @@ static int p9_virtio_probe(struct virtio_device *dev)
		static struct p9_trans p9_virtio_create(const char devname, char *args)
		{
		struct p9_trans *trans;
		int index = 0;
		struct virtio_chan *chan = channels;
		int index = 0;

		down(&virtio_9p_lock);
		while (index < MAX_9P_CHAN) {
		@@ -290,9 +356,18 @@ static struct p9_trans p9_virtio_create(const char devname, char *args)
		up(&virtio_9p_lock);

		if (index >= MAX_9P_CHAN) {
		printk(KERN_ERR "9p: virtio: couldn't find a free channel\n");
		return NULL;
		printk(KERN_ERR "9p: no channels available\n");
		return ERR_PTR(-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) {
		@@ -304,6 +379,7 @@ static struct p9_trans p9_virtio_create(const char devname, char *args)
		trans->read = p9_virtio_read;
		trans->close = p9_virtio_close;
		trans->poll = p9_virtio_poll;
		trans->rpc = p9_virtio_rpc;
		trans->priv = chan;

		return trans;
		@@ -327,7 +403,7 @@ static struct virtio_driver p9_virtio_drv = {
		static struct p9_trans_module p9_virtio_trans = {
		.name = "virtio",
		.create = p9_virtio_create,
		.maxsize = PAGE_SIZE,
		.maxsize = PAGE_SIZE*16,
		.def = 0,
		};