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path: root/drivers/usb/gadget/function/u_serial.c
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Diffstat (limited to 'drivers/usb/gadget/function/u_serial.c')
-rw-r--r--drivers/usb/gadget/function/u_serial.c516
1 files changed, 263 insertions, 253 deletions
diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c
index 65f634ec7fc2..f986e5c55974 100644
--- a/drivers/usb/gadget/function/u_serial.c
+++ b/drivers/usb/gadget/function/u_serial.c
@@ -82,14 +82,13 @@
#define GS_CONSOLE_BUF_SIZE 8192
/* console info */
-struct gscons_info {
- struct gs_port *port;
- struct task_struct *console_thread;
- struct kfifo con_buf;
- /* protect the buf and busy flag */
- spinlock_t con_lock;
- int req_busy;
- struct usb_request *console_req;
+struct gs_console {
+ struct console console;
+ struct work_struct work;
+ spinlock_t lock;
+ struct usb_request *req;
+ struct kfifo buf;
+ size_t missed;
};
/*
@@ -101,8 +100,10 @@ struct gs_port {
spinlock_t port_lock; /* guard port_* access */
struct gserial *port_usb;
+#ifdef CONFIG_U_SERIAL_CONSOLE
+ struct gs_console *console;
+#endif
- bool openclose; /* open/close in progress */
u8 port_num;
struct list_head read_pool;
@@ -586,82 +587,45 @@ static int gs_open(struct tty_struct *tty, struct file *file)
{
int port_num = tty->index;
struct gs_port *port;
- int status;
-
- do {
- mutex_lock(&ports[port_num].lock);
- port = ports[port_num].port;
- if (!port)
- status = -ENODEV;
- else {
- spin_lock_irq(&port->port_lock);
-
- /* already open? Great. */
- if (port->port.count) {
- status = 0;
- port->port.count++;
-
- /* currently opening/closing? wait ... */
- } else if (port->openclose) {
- status = -EBUSY;
-
- /* ... else we do the work */
- } else {
- status = -EAGAIN;
- port->openclose = true;
- }
- spin_unlock_irq(&port->port_lock);
- }
- mutex_unlock(&ports[port_num].lock);
+ int status = 0;
- switch (status) {
- default:
- /* fully handled */
- return status;
- case -EAGAIN:
- /* must do the work */
- break;
- case -EBUSY:
- /* wait for EAGAIN task to finish */
- msleep(1);
- /* REVISIT could have a waitchannel here, if
- * concurrent open performance is important
- */
- break;
- }
- } while (status != -EAGAIN);
+ mutex_lock(&ports[port_num].lock);
+ port = ports[port_num].port;
+ if (!port) {
+ status = -ENODEV;
+ goto out;
+ }
- /* Do the "real open" */
spin_lock_irq(&port->port_lock);
/* allocate circular buffer on first open */
if (!kfifo_initialized(&port->port_write_buf)) {
spin_unlock_irq(&port->port_lock);
+
+ /*
+ * portmaster's mutex still protects from simultaneous open(),
+ * and close() can't happen, yet.
+ */
+
status = kfifo_alloc(&port->port_write_buf,
WRITE_BUF_SIZE, GFP_KERNEL);
- spin_lock_irq(&port->port_lock);
-
if (status) {
pr_debug("gs_open: ttyGS%d (%p,%p) no buffer\n",
- port->port_num, tty, file);
- port->openclose = false;
- goto exit_unlock_port;
+ port_num, tty, file);
+ goto out;
}
- }
- /* REVISIT if REMOVED (ports[].port NULL), abort the open
- * to let rmmod work faster (but this way isn't wrong).
- */
+ spin_lock_irq(&port->port_lock);
+ }
- /* REVISIT maybe wait for "carrier detect" */
+ /* already open? Great. */
+ if (port->port.count++)
+ goto exit_unlock_port;
tty->driver_data = port;
port->port.tty = tty;
- port->port.count = 1;
- port->openclose = false;
-
/* if connected, start the I/O stream */
if (port->port_usb) {
struct gserial *gser = port->port_usb;
@@ -675,20 +639,21 @@ static int gs_open(struct tty_struct *tty, struct file *file)
pr_debug("gs_open: ttyGS%d (%p,%p)\n", port->port_num, tty, file);
- status = 0;
-
exit_unlock_port:
spin_unlock_irq(&port->port_lock);
+out:
+ mutex_unlock(&ports[port_num].lock);
return status;
}
-static int gs_writes_finished(struct gs_port *p)
+static int gs_close_flush_done(struct gs_port *p)
{
int cond;
- /* return true on disconnect or empty buffer */
+ /* return true on disconnect or empty buffer or if raced with open() */
spin_lock_irq(&p->port_lock);
- cond = (p->port_usb == NULL) || !kfifo_len(&p->port_write_buf);
+ cond = p->port_usb == NULL || !kfifo_len(&p->port_write_buf) ||
+ p->port.count > 1;
spin_unlock_irq(&p->port_lock);
return cond;
@@ -702,6 +667,7 @@ static void gs_close(struct tty_struct *tty, struct file *file)
spin_lock_irq(&port->port_lock);
if (port->port.count != 1) {
+raced_with_open:
if (port->port.count == 0)
WARN_ON(1);
else
@@ -711,12 +677,6 @@ static void gs_close(struct tty_struct *tty, struct file *file)
pr_debug("gs_close: ttyGS%d (%p,%p) ...\n", port->port_num, tty, file);
- /* mark port as closing but in use; we can drop port lock
- * and sleep if necessary
- */
- port->openclose = true;
- port->port.count = 0;
-
gser = port->port_usb;
if (gser && gser->disconnect)
gser->disconnect(gser);
@@ -727,9 +687,13 @@ static void gs_close(struct tty_struct *tty, struct file *file)
if (kfifo_len(&port->port_write_buf) > 0 && gser) {
spin_unlock_irq(&port->port_lock);
wait_event_interruptible_timeout(port->drain_wait,
- gs_writes_finished(port),
+ gs_close_flush_done(port),
GS_CLOSE_TIMEOUT * HZ);
spin_lock_irq(&port->port_lock);
+
+ if (port->port.count != 1)
+ goto raced_with_open;
+
gser = port->port_usb;
}
@@ -742,10 +706,9 @@ static void gs_close(struct tty_struct *tty, struct file *file)
else
kfifo_reset(&port->port_write_buf);
+ port->port.count = 0;
port->port.tty = NULL;
- port->openclose = false;
-
pr_debug("gs_close: ttyGS%d (%p,%p) done!\n",
port->port_num, tty, file);
@@ -889,36 +852,9 @@ static struct tty_driver *gs_tty_driver;
#ifdef CONFIG_U_SERIAL_CONSOLE
-static struct gscons_info gscons_info;
-static struct console gserial_cons;
-
-static struct usb_request *gs_request_new(struct usb_ep *ep)
-{
- struct usb_request *req = usb_ep_alloc_request(ep, GFP_ATOMIC);
- if (!req)
- return NULL;
-
- req->buf = kmalloc(ep->maxpacket, GFP_ATOMIC);
- if (!req->buf) {
- usb_ep_free_request(ep, req);
- return NULL;
- }
-
- return req;
-}
-
-static void gs_request_free(struct usb_request *req, struct usb_ep *ep)
+static void gs_console_complete_out(struct usb_ep *ep, struct usb_request *req)
{
- if (!req)
- return;
-
- kfree(req->buf);
- usb_ep_free_request(ep, req);
-}
-
-static void gs_complete_out(struct usb_ep *ep, struct usb_request *req)
-{
- struct gscons_info *info = &gscons_info;
+ struct gs_console *cons = req->context;
switch (req->status) {
default:
@@ -927,12 +863,12 @@ static void gs_complete_out(struct usb_ep *ep, struct usb_request *req)
/* fall through */
case 0:
/* normal completion */
- spin_lock(&info->con_lock);
- info->req_busy = 0;
- spin_unlock(&info->con_lock);
-
- wake_up_process(info->console_thread);
+ spin_lock(&cons->lock);
+ req->length = 0;
+ schedule_work(&cons->work);
+ spin_unlock(&cons->lock);
break;
+ case -ECONNRESET:
case -ESHUTDOWN:
/* disconnect */
pr_vdebug("%s: %s shutdown\n", __func__, ep->name);
@@ -940,190 +876,250 @@ static void gs_complete_out(struct usb_ep *ep, struct usb_request *req)
}
}
-static int gs_console_connect(int port_num)
+static void __gs_console_push(struct gs_console *cons)
{
- struct gscons_info *info = &gscons_info;
- struct gs_port *port;
+ struct usb_request *req = cons->req;
struct usb_ep *ep;
+ size_t size;
- if (port_num != gserial_cons.index) {
- pr_err("%s: port num [%d] is not support console\n",
- __func__, port_num);
- return -ENXIO;
- }
+ if (!req)
+ return; /* disconnected */
- port = ports[port_num].port;
- ep = port->port_usb->in;
- if (!info->console_req) {
- info->console_req = gs_request_new(ep);
- if (!info->console_req)
- return -ENOMEM;
- info->console_req->complete = gs_complete_out;
+ if (req->length)
+ return; /* busy */
+
+ ep = cons->console.data;
+ size = kfifo_out(&cons->buf, req->buf, ep->maxpacket);
+ if (!size)
+ return;
+
+ if (cons->missed && ep->maxpacket >= 64) {
+ char buf[64];
+ size_t len;
+
+ len = sprintf(buf, "\n[missed %zu bytes]\n", cons->missed);
+ kfifo_in(&cons->buf, buf, len);
+ cons->missed = 0;
}
- info->port = port;
- spin_lock(&info->con_lock);
- info->req_busy = 0;
- spin_unlock(&info->con_lock);
- pr_vdebug("port[%d] console connect!\n", port_num);
- return 0;
+ req->length = size;
+ if (usb_ep_queue(ep, req, GFP_ATOMIC))
+ req->length = 0;
}
-static void gs_console_disconnect(struct usb_ep *ep)
+static void gs_console_work(struct work_struct *work)
{
- struct gscons_info *info = &gscons_info;
- struct usb_request *req = info->console_req;
+ struct gs_console *cons = container_of(work, struct gs_console, work);
+
+ spin_lock_irq(&cons->lock);
- gs_request_free(req, ep);
- info->console_req = NULL;
+ __gs_console_push(cons);
+
+ spin_unlock_irq(&cons->lock);
}
-static int gs_console_thread(void *data)
+static void gs_console_write(struct console *co,
+ const char *buf, unsigned count)
{
- struct gscons_info *info = &gscons_info;
- struct gs_port *port;
+ struct gs_console *cons = container_of(co, struct gs_console, console);
+ unsigned long flags;
+ size_t n;
+
+ spin_lock_irqsave(&cons->lock, flags);
+
+ n = kfifo_in(&cons->buf, buf, count);
+ if (n < count)
+ cons->missed += count - n;
+
+ if (cons->req && !cons->req->length)
+ schedule_work(&cons->work);
+
+ spin_unlock_irqrestore(&cons->lock, flags);
+}
+
+static struct tty_driver *gs_console_device(struct console *co, int *index)
+{
+ *index = co->index;
+ return gs_tty_driver;
+}
+
+static int gs_console_connect(struct gs_port *port)
+{
+ struct gs_console *cons = port->console;
struct usb_request *req;
struct usb_ep *ep;
- int xfer, ret, count, size;
-
- do {
- port = info->port;
- set_current_state(TASK_INTERRUPTIBLE);
- if (!port || !port->port_usb
- || !port->port_usb->in || !info->console_req)
- goto sched;
-
- req = info->console_req;
- ep = port->port_usb->in;
-
- spin_lock_irq(&info->con_lock);
- count = kfifo_len(&info->con_buf);
- size = ep->maxpacket;
-
- if (count > 0 && !info->req_busy) {
- set_current_state(TASK_RUNNING);
- if (count < size)
- size = count;
-
- xfer = kfifo_out(&info->con_buf, req->buf, size);
- req->length = xfer;
-
- spin_unlock(&info->con_lock);
- ret = usb_ep_queue(ep, req, GFP_ATOMIC);
- spin_lock(&info->con_lock);
- if (ret < 0)
- info->req_busy = 0;
- else
- info->req_busy = 1;
-
- spin_unlock_irq(&info->con_lock);
- } else {
- spin_unlock_irq(&info->con_lock);
-sched:
- if (kthread_should_stop()) {
- set_current_state(TASK_RUNNING);
- break;
- }
- schedule();
- }
- } while (1);
+
+ if (!cons)
+ return 0;
+
+ ep = port->port_usb->in;
+ req = gs_alloc_req(ep, ep->maxpacket, GFP_ATOMIC);
+ if (!req)
+ return -ENOMEM;
+ req->complete = gs_console_complete_out;
+ req->context = cons;
+ req->length = 0;
+
+ spin_lock(&cons->lock);
+ cons->req = req;
+ cons->console.data = ep;
+ spin_unlock(&cons->lock);
+
+ pr_debug("ttyGS%d: console connected!\n", port->port_num);
+
+ schedule_work(&cons->work);
return 0;
}
-static int gs_console_setup(struct console *co, char *options)
+static void gs_console_disconnect(struct gs_port *port)
{
- struct gscons_info *info = &gscons_info;
- int status;
+ struct gs_console *cons = port->console;
+ struct usb_request *req;
+ struct usb_ep *ep;
+
+ if (!cons)
+ return;
- info->port = NULL;
- info->console_req = NULL;
- info->req_busy = 0;
- spin_lock_init(&info->con_lock);
+ spin_lock(&cons->lock);
- status = kfifo_alloc(&info->con_buf, GS_CONSOLE_BUF_SIZE, GFP_KERNEL);
- if (status) {
- pr_err("%s: allocate console buffer failed\n", __func__);
- return status;
- }
+ req = cons->req;
+ ep = cons->console.data;
+ cons->req = NULL;
+
+ spin_unlock(&cons->lock);
- info->console_thread = kthread_create(gs_console_thread,
- co, "gs_console");
- if (IS_ERR(info->console_thread)) {
- pr_err("%s: cannot create console thread\n", __func__);
- kfifo_free(&info->con_buf);
- return PTR_ERR(info->console_thread);
+ if (!req)
+ return;
+
+ usb_ep_dequeue(ep, req);
+ gs_free_req(ep, req);
+}
+
+static int gs_console_init(struct gs_port *port)
+{
+ struct gs_console *cons;
+ int err;
+
+ if (port->console)
+ return 0;
+
+ cons = kzalloc(sizeof(*port->console), GFP_KERNEL);
+ if (!cons)
+ return -ENOMEM;
+
+ strcpy(cons->console.name, "ttyGS");
+ cons->console.write = gs_console_write;
+ cons->console.device = gs_console_device;
+ cons->console.flags = CON_PRINTBUFFER;
+ cons->console.index = port->port_num;
+
+ INIT_WORK(&cons->work, gs_console_work);
+ spin_lock_init(&cons->lock);
+
+ err = kfifo_alloc(&cons->buf, GS_CONSOLE_BUF_SIZE, GFP_KERNEL);
+ if (err) {
+ pr_err("ttyGS%d: allocate console buffer failed\n", port->port_num);
+ kfree(cons);
+ return err;
}
- wake_up_process(info->console_thread);
+
+ port->console = cons;
+ register_console(&cons->console);
+
+ spin_lock_irq(&port->port_lock);
+ if (port->port_usb)
+ gs_console_connect(port);
+ spin_unlock_irq(&port->port_lock);
return 0;
}
-static void gs_console_write(struct console *co,
- const char *buf, unsigned count)
+static void gs_console_exit(struct gs_port *port)
{
- struct gscons_info *info = &gscons_info;
- unsigned long flags;
+ struct gs_console *cons = port->console;
+
+ if (!cons)
+ return;
+
+ unregister_console(&cons->console);
- spin_lock_irqsave(&info->con_lock, flags);
- kfifo_in(&info->con_buf, buf, count);
- spin_unlock_irqrestore(&info->con_lock, flags);
+ spin_lock_irq(&port->port_lock);
+ if (cons->req)
+ gs_console_disconnect(port);
+ spin_unlock_irq(&port->port_lock);
- wake_up_process(info->console_thread);
+ cancel_work_sync(&cons->work);
+ kfifo_free(&cons->buf);
+ kfree(cons);
+ port->console = NULL;
}
-static struct tty_driver *gs_console_device(struct console *co, int *index)
+ssize_t gserial_set_console(unsigned char port_num, const char *page, size_t count)
{
- struct tty_driver **p = (struct tty_driver **)co->data;
+ struct gs_port *port;
+ bool enable;
+ int ret;
- if (!*p)
- return NULL;
+ ret = strtobool(page, &enable);
+ if (ret)
+ return ret;
- *index = co->index;
- return *p;
-}
+ mutex_lock(&ports[port_num].lock);
+ port = ports[port_num].port;
-static struct console gserial_cons = {
- .name = "ttyGS",
- .write = gs_console_write,
- .device = gs_console_device,
- .setup = gs_console_setup,
- .flags = CON_PRINTBUFFER,
- .index = -1,
- .data = &gs_tty_driver,
-};
+ if (WARN_ON(port == NULL)) {
+ ret = -ENXIO;
+ goto out;
+ }
-static void gserial_console_init(void)
-{
- register_console(&gserial_cons);
+ if (enable)
+ ret = gs_console_init(port);
+ else
+ gs_console_exit(port);
+out:
+ mutex_unlock(&ports[port_num].lock);
+
+ return ret < 0 ? ret : count;
}
+EXPORT_SYMBOL_GPL(gserial_set_console);
-static void gserial_console_exit(void)
+ssize_t gserial_get_console(unsigned char port_num, char *page)
{
- struct gscons_info *info = &gscons_info;
+ struct gs_port *port;
+ ssize_t ret;
- unregister_console(&gserial_cons);
- if (!IS_ERR_OR_NULL(info->console_thread))
- kthread_stop(info->console_thread);
- kfifo_free(&info->con_buf);
+ mutex_lock(&ports[port_num].lock);
+ port = ports[port_num].port;
+
+ if (WARN_ON(port == NULL))
+ ret = -ENXIO;
+ else
+ ret = sprintf(page, "%u\n", !!port->console);
+
+ mutex_unlock(&ports[port_num].lock);
+
+ return ret;
}
+EXPORT_SYMBOL_GPL(gserial_get_console);
#else
-static int gs_console_connect(int port_num)
+static int gs_console_connect(struct gs_port *port)
{
return 0;
}
-static void gs_console_disconnect(struct usb_ep *ep)
+static void gs_console_disconnect(struct gs_port *port)
{
}
-static void gserial_console_init(void)
+static int gs_console_init(struct gs_port *port)
{
+ return -ENOSYS;
}
-static void gserial_console_exit(void)
+static void gs_console_exit(struct gs_port *port)
{
}
@@ -1172,8 +1168,9 @@ static int gs_closed(struct gs_port *port)
int cond;
spin_lock_irq(&port->port_lock);
- cond = (port->port.count == 0) && !port->openclose;
+ cond = port->port.count == 0;
spin_unlock_irq(&port->port_lock);
+
return cond;
}
@@ -1197,18 +1194,19 @@ void gserial_free_line(unsigned char port_num)
return;
}
port = ports[port_num].port;
+ gs_console_exit(port);
ports[port_num].port = NULL;
mutex_unlock(&ports[port_num].lock);
gserial_free_port(port);
tty_unregister_device(gs_tty_driver, port_num);
- gserial_console_exit();
}
EXPORT_SYMBOL_GPL(gserial_free_line);
-int gserial_alloc_line(unsigned char *line_num)
+int gserial_alloc_line_no_console(unsigned char *line_num)
{
struct usb_cdc_line_coding coding;
+ struct gs_port *port;
struct device *tty_dev;
int ret;
int port_num;
@@ -1231,24 +1229,35 @@ int gserial_alloc_line(unsigned char *line_num)
/* ... and sysfs class devices, so mdev/udev make /dev/ttyGS* */
- tty_dev = tty_port_register_device(&ports[port_num].port->port,
+ port = ports[port_num].port;
+ tty_dev = tty_port_register_device(&port->port,
gs_tty_driver, port_num, NULL);
if (IS_ERR(tty_dev)) {
- struct gs_port *port;
pr_err("%s: failed to register tty for port %d, err %ld\n",
__func__, port_num, PTR_ERR(tty_dev));
ret = PTR_ERR(tty_dev);
- port = ports[port_num].port;
+ mutex_lock(&ports[port_num].lock);
ports[port_num].port = NULL;
+ mutex_unlock(&ports[port_num].lock);
gserial_free_port(port);
goto err;
}
*line_num = port_num;
- gserial_console_init();
err:
return ret;
}
+EXPORT_SYMBOL_GPL(gserial_alloc_line_no_console);
+
+int gserial_alloc_line(unsigned char *line_num)
+{
+ int ret = gserial_alloc_line_no_console(line_num);
+
+ if (!ret && !*line_num)
+ gs_console_init(ports[*line_num].port);
+
+ return ret;
+}
EXPORT_SYMBOL_GPL(gserial_alloc_line);
/**
@@ -1327,7 +1336,7 @@ int gserial_connect(struct gserial *gser, u8 port_num)
gser->disconnect(gser);
}
- status = gs_console_connect(port_num);
+ status = gs_console_connect(port);
spin_unlock_irqrestore(&port->port_lock, flags);
return status;
@@ -1359,12 +1368,14 @@ void gserial_disconnect(struct gserial *gser)
/* tell the TTY glue not to do I/O here any more */
spin_lock_irqsave(&port->port_lock, flags);
+ gs_console_disconnect(port);
+
/* REVISIT as above: how best to track this? */
port->port_line_coding = gser->port_line_coding;
port->port_usb = NULL;
gser->ioport = NULL;
- if (port->port.count > 0 || port->openclose) {
+ if (port->port.count > 0) {
wake_up_interruptible(&port->drain_wait);
if (port->port.tty)
tty_hangup(port->port.tty);
@@ -1377,7 +1388,7 @@ void gserial_disconnect(struct gserial *gser)
/* finally, free any unused/unusable I/O buffers */
spin_lock_irqsave(&port->port_lock, flags);
- if (port->port.count == 0 && !port->openclose)
+ if (port->port.count == 0)
kfifo_free(&port->port_write_buf);
gs_free_requests(gser->out, &port->read_pool, NULL);
gs_free_requests(gser->out, &port->read_queue, NULL);
@@ -1386,7 +1397,6 @@ void gserial_disconnect(struct gserial *gser)
port->read_allocated = port->read_started =
port->write_allocated = port->write_started = 0;
- gs_console_disconnect(gser->in);
spin_unlock_irqrestore(&port->port_lock, flags);
}
EXPORT_SYMBOL_GPL(gserial_disconnect);