struct usb_gadget *gadget;
struct usb_composite_dev *cdev;
struct fsg_dev *fsg, *new_fsg;
+ wait_queue_head_t io_wait;
wait_queue_head_t fsg_wait;
/* filesem protects: backing files in use */
struct rw_semaphore filesem;
- /* lock protects: state, all the req_busy's */
+ /* lock protects: state and thread_task */
spinlock_t lock;
struct usb_ep *ep0; /* Copy of gadget->ep0 */
unsigned int running:1;
unsigned int sysfs:1;
- int thread_wakeup_needed;
struct completion thread_notifier;
struct task_struct *thread_task;
/* These routines may be called in process context or in_irq */
-/* Caller must hold fsg->lock */
-static void wakeup_thread(struct fsg_common *common)
-{
- smp_wmb(); /* ensure the write of bh->state is complete */
- /* Tell the main thread that something has happened */
- common->thread_wakeup_needed = 1;
- if (common->thread_task)
- wake_up_process(common->thread_task);
-}
-
static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
{
unsigned long flags;
if (req->status == -ECONNRESET) /* Request was cancelled */
usb_ep_fifo_flush(ep);
- /* Hold the lock while we update the request and buffer states */
- smp_wmb();
- spin_lock(&common->lock);
- bh->inreq_busy = 0;
- bh->state = BUF_STATE_EMPTY;
- wakeup_thread(common);
- spin_unlock(&common->lock);
+ /* Synchronize with the smp_load_acquire() in sleep_thread() */
+ smp_store_release(&bh->state, BUF_STATE_EMPTY);
+ wake_up(&common->io_wait);
}
static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
if (req->status == -ECONNRESET) /* Request was cancelled */
usb_ep_fifo_flush(ep);
- /* Hold the lock while we update the request and buffer states */
- smp_wmb();
- spin_lock(&common->lock);
- bh->outreq_busy = 0;
- bh->state = BUF_STATE_FULL;
- wakeup_thread(common);
- spin_unlock(&common->lock);
+ /* Synchronize with the smp_load_acquire() in sleep_thread() */
+ smp_store_release(&bh->state, BUF_STATE_FULL);
+ wake_up(&common->io_wait);
}
static int _fsg_common_get_max_lun(struct fsg_common *common)
/* All the following routines run in process context */
/* Use this for bulk or interrupt transfers, not ep0 */
-static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
- struct usb_request *req, int *pbusy,
- enum fsg_buffer_state *state)
+static int start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
+ struct usb_request *req)
{
int rc;
if (ep == fsg->bulk_in)
dump_msg(fsg, "bulk-in", req->buf, req->length);
- spin_lock_irq(&fsg->common->lock);
- *pbusy = 1;
- *state = BUF_STATE_BUSY;
- spin_unlock_irq(&fsg->common->lock);
-
rc = usb_ep_queue(ep, req, GFP_KERNEL);
- if (rc == 0)
- return; /* All good, we're done */
-
- *pbusy = 0;
- *state = BUF_STATE_EMPTY;
+ if (rc) {
- /* We can't do much more than wait for a reset */
+ /* We can't do much more than wait for a reset */
+ req->status = rc;
- /*
- * Note: currently the net2280 driver fails zero-length
- * submissions if DMA is enabled.
- */
- if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP && req->length == 0))
- WARNING(fsg, "error in submission: %s --> %d\n", ep->name, rc);
+ /*
+ * Note: currently the net2280 driver fails zero-length
+ * submissions if DMA is enabled.
+ */
+ if (rc != -ESHUTDOWN &&
+ !(rc == -EOPNOTSUPP && req->length == 0))
+ WARNING(fsg, "error in submission: %s --> %d\n",
+ ep->name, rc);
+ }
+ return rc;
}
static bool start_in_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
{
if (!fsg_is_set(common))
return false;
- start_transfer(common->fsg, common->fsg->bulk_in,
- bh->inreq, &bh->inreq_busy, &bh->state);
+ bh->state = BUF_STATE_SENDING;
+ if (start_transfer(common->fsg, common->fsg->bulk_in, bh->inreq))
+ bh->state = BUF_STATE_EMPTY;
return true;
}
{
if (!fsg_is_set(common))
return false;
- start_transfer(common->fsg, common->fsg->bulk_out,
- bh->outreq, &bh->outreq_busy, &bh->state);
+ bh->state = BUF_STATE_RECEIVING;
+ if (start_transfer(common->fsg, common->fsg->bulk_out, bh->outreq))
+ bh->state = BUF_STATE_FULL;
return true;
}
-static int sleep_thread(struct fsg_common *common, bool can_freeze)
+static int sleep_thread(struct fsg_common *common, bool can_freeze,
+ struct fsg_buffhd *bh)
{
- int rc = 0;
+ int rc;
- /* Wait until a signal arrives or we are woken up */
- for (;;) {
- if (can_freeze)
- try_to_freeze();
- set_current_state(TASK_INTERRUPTIBLE);
- if (signal_pending(current)) {
- rc = -EINTR;
- break;
- }
- if (common->thread_wakeup_needed)
- break;
- schedule();
- }
- __set_current_state(TASK_RUNNING);
- common->thread_wakeup_needed = 0;
- smp_rmb(); /* ensure the latest bh->state is visible */
- return rc;
+ /* Wait until a signal arrives or bh is no longer busy */
+ if (can_freeze)
+ /*
+ * synchronize with the smp_store_release(&bh->state) in
+ * bulk_in_complete() or bulk_out_complete()
+ */
+ rc = wait_event_freezable(common->io_wait,
+ bh && smp_load_acquire(&bh->state) >=
+ BUF_STATE_EMPTY);
+ else
+ rc = wait_event_interruptible(common->io_wait,
+ bh && smp_load_acquire(&bh->state) >=
+ BUF_STATE_EMPTY);
+ return rc ? -EINTR : 0;
}
/* Wait for the next buffer to become available */
bh = common->next_buffhd_to_fill;
- while (bh->state != BUF_STATE_EMPTY) {
- rc = sleep_thread(common, false);
- if (rc)
- return rc;
- }
+ rc = sleep_thread(common, false, bh);
+ if (rc)
+ return rc;
/*
* If we were asked to read past the end of file,
bh = common->next_buffhd_to_drain;
if (bh->state == BUF_STATE_EMPTY && !get_some_more)
break; /* We stopped early */
- if (bh->state == BUF_STATE_FULL) {
- smp_rmb();
- common->next_buffhd_to_drain = bh->next;
- bh->state = BUF_STATE_EMPTY;
-
- /* Did something go wrong with the transfer? */
- if (bh->outreq->status != 0) {
- curlun->sense_data = SS_COMMUNICATION_FAILURE;
- curlun->sense_data_info =
+
+ /* Wait for the data to be received */
+ rc = sleep_thread(common, false, bh);
+ if (rc)
+ return rc;
+
+ common->next_buffhd_to_drain = bh->next;
+ bh->state = BUF_STATE_EMPTY;
+
+ /* Did something go wrong with the transfer? */
+ if (bh->outreq->status != 0) {
+ curlun->sense_data = SS_COMMUNICATION_FAILURE;
+ curlun->sense_data_info =
file_offset >> curlun->blkbits;
- curlun->info_valid = 1;
- break;
- }
+ curlun->info_valid = 1;
+ break;
+ }
- amount = bh->outreq->actual;
- if (curlun->file_length - file_offset < amount) {
- LERROR(curlun,
- "write %u @ %llu beyond end %llu\n",
+ amount = bh->outreq->actual;
+ if (curlun->file_length - file_offset < amount) {
+ LERROR(curlun, "write %u @ %llu beyond end %llu\n",
amount, (unsigned long long)file_offset,
(unsigned long long)curlun->file_length);
- amount = curlun->file_length - file_offset;
- }
+ amount = curlun->file_length - file_offset;
+ }
- /* Don't accept excess data. The spec doesn't say
- * what to do in this case. We'll ignore the error.
- */
- amount = min(amount, bh->bulk_out_intended_length);
-
- /* Don't write a partial block */
- amount = round_down(amount, curlun->blksize);
- if (amount == 0)
- goto empty_write;
-
- /* Perform the write */
- file_offset_tmp = file_offset;
- nwritten = vfs_write(curlun->filp,
- (char __user *)bh->buf,
- amount, &file_offset_tmp);
- VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
- (unsigned long long)file_offset, (int)nwritten);
- if (signal_pending(current))
- return -EINTR; /* Interrupted! */
-
- if (nwritten < 0) {
- LDBG(curlun, "error in file write: %d\n",
- (int)nwritten);
- nwritten = 0;
- } else if (nwritten < amount) {
- LDBG(curlun, "partial file write: %d/%u\n",
- (int)nwritten, amount);
- nwritten = round_down(nwritten, curlun->blksize);
- }
- file_offset += nwritten;
- amount_left_to_write -= nwritten;
- common->residue -= nwritten;
+ /*
+ * Don't accept excess data. The spec doesn't say
+ * what to do in this case. We'll ignore the error.
+ */
+ amount = min(amount, bh->bulk_out_intended_length);
- /* If an error occurred, report it and its position */
- if (nwritten < amount) {
- curlun->sense_data = SS_WRITE_ERROR;
- curlun->sense_data_info =
+ /* Don't write a partial block */
+ amount = round_down(amount, curlun->blksize);
+ if (amount == 0)
+ goto empty_write;
+
+ /* Perform the write */
+ file_offset_tmp = file_offset;
+ nwritten = vfs_write(curlun->filp, (char __user *)bh->buf,
+ amount, &file_offset_tmp);
+ VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
+ (unsigned long long)file_offset, (int)nwritten);
+ if (signal_pending(current))
+ return -EINTR; /* Interrupted! */
+
+ if (nwritten < 0) {
+ LDBG(curlun, "error in file write: %d\n",
+ (int) nwritten);
+ nwritten = 0;
+ } else if (nwritten < amount) {
+ LDBG(curlun, "partial file write: %d/%u\n",
+ (int) nwritten, amount);
+ nwritten = round_down(nwritten, curlun->blksize);
+ }
+ file_offset += nwritten;
+ amount_left_to_write -= nwritten;
+ common->residue -= nwritten;
+
+ /* If an error occurred, report it and its position */
+ if (nwritten < amount) {
+ curlun->sense_data = SS_WRITE_ERROR;
+ curlun->sense_data_info =
file_offset >> curlun->blkbits;
- curlun->info_valid = 1;
- break;
- }
+ curlun->info_valid = 1;
+ break;
+ }
empty_write:
- /* Did the host decide to stop early? */
- if (bh->outreq->actual < bh->bulk_out_intended_length) {
- common->short_packet_received = 1;
- break;
- }
- continue;
+ /* Did the host decide to stop early? */
+ if (bh->outreq->actual < bh->bulk_out_intended_length) {
+ common->short_packet_received = 1;
+ break;
}
-
- /* Wait for something to happen */
- rc = sleep_thread(common, false);
- if (rc)
- return rc;
}
return -EIO; /* No default reply */
static int throw_away_data(struct fsg_common *common)
{
- struct fsg_buffhd *bh;
+ struct fsg_buffhd *bh, *bh2;
u32 amount;
int rc;
bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
bh = common->next_buffhd_to_drain) {
- /* Throw away the data in a filled buffer */
- if (bh->state == BUF_STATE_FULL) {
- smp_rmb();
- bh->state = BUF_STATE_EMPTY;
- common->next_buffhd_to_drain = bh->next;
-
- /* A short packet or an error ends everything */
- if (bh->outreq->actual < bh->bulk_out_intended_length ||
- bh->outreq->status != 0) {
- raise_exception(common,
- FSG_STATE_ABORT_BULK_OUT);
- return -EINTR;
- }
- continue;
- }
-
/* Try to submit another request if we need one */
- bh = common->next_buffhd_to_fill;
- if (bh->state == BUF_STATE_EMPTY
- && common->usb_amount_left > 0) {
+ bh2 = common->next_buffhd_to_fill;
+ if (bh2->state == BUF_STATE_EMPTY &&
+ common->usb_amount_left > 0) {
amount = min(common->usb_amount_left, FSG_BUFLEN);
/*
* equal to the buffer size, which is divisible by
* the bulk-out maxpacket size.
*/
- set_bulk_out_req_length(common, bh, amount);
- if (!start_out_transfer(common, bh))
+ set_bulk_out_req_length(common, bh2, amount);
+ if (!start_out_transfer(common, bh2))
/* Dunno what to do if common->fsg is NULL */
return -EIO;
- common->next_buffhd_to_fill = bh->next;
+ common->next_buffhd_to_fill = bh2->next;
common->usb_amount_left -= amount;
continue;
}
- /* Otherwise wait for something to happen */
- rc = sleep_thread(common, true);
+ /* Wait for the data to be received */
+ rc = sleep_thread(common, false, bh);
if (rc)
return rc;
+
+ /* Throw away the data in a filled buffer */
+ bh->state = BUF_STATE_EMPTY;
+ common->next_buffhd_to_drain = bh->next;
+
+ /* A short packet or an error ends everything */
+ if (bh->outreq->actual < bh->bulk_out_intended_length ||
+ bh->outreq->status != 0) {
+ raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
+ return -EINTR;
+ }
}
return 0;
}
/* Wait for the next buffer to become available */
bh = common->next_buffhd_to_fill;
- while (bh->state != BUF_STATE_EMPTY) {
- rc = sleep_thread(common, true);
- if (rc)
- return;
- }
+ rc = sleep_thread(common, false, bh);
+ if (rc)
+ return;
if (curlun) {
sd = curlun->sense_data;
/* Wait for the next buffer to become available for data or status */
bh = common->next_buffhd_to_fill;
common->next_buffhd_to_drain = bh;
- while (bh->state != BUF_STATE_EMPTY) {
- rc = sleep_thread(common, true);
- if (rc)
- return rc;
- }
+ rc = sleep_thread(common, false, bh);
+ if (rc)
+ return rc;
+
common->phase_error = 0;
common->short_packet_received = 0;
/* Wait for the next buffer to become available */
bh = common->next_buffhd_to_fill;
- while (bh->state != BUF_STATE_EMPTY) {
- rc = sleep_thread(common, true);
- if (rc)
- return rc;
- }
+ rc = sleep_thread(common, true, bh);
+ if (rc)
+ return rc;
/* Queue a request to read a Bulk-only CBW */
set_bulk_out_req_length(common, bh, US_BULK_CB_WRAP_LEN);
*/
/* Wait for the CBW to arrive */
- while (bh->state != BUF_STATE_FULL) {
- rc = sleep_thread(common, true);
- if (rc)
- return rc;
- }
- smp_rmb();
+ rc = sleep_thread(common, true, bh);
+ if (rc)
+ return rc;
+
rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
bh->state = BUF_STATE_EMPTY;
if (likely(common->fsg)) {
for (i = 0; i < common->fsg_num_buffers; ++i) {
bh = &common->buffhds[i];
- if (bh->inreq_busy)
+ if (bh->state == BUF_STATE_SENDING)
usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
- if (bh->outreq_busy)
+ if (bh->state == BUF_STATE_RECEIVING)
usb_ep_dequeue(common->fsg->bulk_out,
bh->outreq);
- }
- /* Wait until everything is idle */
- for (;;) {
- int num_active = 0;
- for (i = 0; i < common->fsg_num_buffers; ++i) {
- bh = &common->buffhds[i];
- num_active += bh->inreq_busy + bh->outreq_busy;
- }
- if (num_active == 0)
- break;
- if (sleep_thread(common, true))
+ /* Wait for a transfer to become idle */
+ if (sleep_thread(common, false, bh))
return;
}
}
if (!common->running) {
- sleep_thread(common, true);
+ sleep_thread(common, true, NULL);
continue;
}
spin_lock_init(&common->lock);
kref_init(&common->ref);
init_completion(&common->thread_notifier);
+ init_waitqueue_head(&common->io_wait);
init_waitqueue_head(&common->fsg_wait);
common->state = FSG_STATE_TERMINATED;
memset(common->luns, 0, sizeof(common->luns));
projects / users / griffoul / linux.git / commitdiff