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Release 4.11 drivers/tty/tty_port.c

Directory: drivers/tty
/*
 * Tty port functions
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/sched/signal.h>
#include <linux/wait.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/serdev.h>


static int tty_port_default_receive_buf(struct tty_port *port, const unsigned char *p, const unsigned char *f, size_t count) { int ret; struct tty_struct *tty; struct tty_ldisc *disc; tty = READ_ONCE(port->itty); if (!tty) return 0; disc = tty_ldisc_ref(tty); if (!disc) return 0; ret = tty_ldisc_receive_buf(disc, p, (char *)f, count); tty_ldisc_deref(disc); return ret; }

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static void tty_port_default_wakeup(struct tty_port *port) { struct tty_struct *tty = tty_port_tty_get(port); if (tty) { tty_wakeup(tty); tty_kref_put(tty); } }

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static const struct tty_port_client_operations default_client_ops = { .receive_buf = tty_port_default_receive_buf, .write_wakeup = tty_port_default_wakeup, };
void tty_port_init(struct tty_port *port) { memset(port, 0, sizeof(*port)); tty_buffer_init(port); init_waitqueue_head(&port->open_wait); init_waitqueue_head(&port->delta_msr_wait); mutex_init(&port->mutex); mutex_init(&port->buf_mutex); spin_lock_init(&port->lock); port->close_delay = (50 * HZ) / 100; port->closing_wait = (3000 * HZ) / 100; port->client_ops = &default_client_ops; kref_init(&port->kref); }

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EXPORT_SYMBOL(tty_port_init); /** * tty_port_link_device - link tty and tty_port * @port: tty_port of the device * @driver: tty_driver for this device * @index: index of the tty * * Provide the tty layer wit ha link from a tty (specified by @index) to a * tty_port (@port). Use this only if neither tty_port_register_device nor * tty_port_install is used in the driver. If used, this has to be called before * tty_register_driver. */
void tty_port_link_device(struct tty_port *port, struct tty_driver *driver, unsigned index) { if (WARN_ON(index >= driver->num)) return; driver->ports[index] = port; }

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Jiri Slaby39100.00%1100.00%
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EXPORT_SYMBOL_GPL(tty_port_link_device); /** * tty_port_register_device - register tty device * @port: tty_port of the device * @driver: tty_driver for this device * @index: index of the tty * @device: parent if exists, otherwise NULL * * It is the same as tty_register_device except the provided @port is linked to * a concrete tty specified by @index. Use this or tty_port_install (or both). * Call tty_port_link_device as a last resort. */
struct device *tty_port_register_device(struct tty_port *port, struct tty_driver *driver, unsigned index, struct device *device) { return tty_port_register_device_attr(port, driver, index, device, NULL, NULL); }

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Jiri Slaby3585.37%266.67%
Rob Herring614.63%133.33%
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EXPORT_SYMBOL_GPL(tty_port_register_device); /** * tty_port_register_device_attr - register tty device * @port: tty_port of the device * @driver: tty_driver for this device * @index: index of the tty * @device: parent if exists, otherwise NULL * @drvdata: Driver data to be set to device. * @attr_grp: Attribute group to be set on device. * * It is the same as tty_register_device_attr except the provided @port is * linked to a concrete tty specified by @index. Use this or tty_port_install * (or both). Call tty_port_link_device as a last resort. */
struct device *tty_port_register_device_attr(struct tty_port *port, struct tty_driver *driver, unsigned index, struct device *device, void *drvdata, const struct attribute_group **attr_grp) { struct device *dev; tty_port_link_device(port, driver, index); dev = serdev_tty_port_register(port, device, driver, index); if (PTR_ERR(dev) != -ENODEV) /* Skip creating cdev if we registered a serdev device */ return dev; return tty_register_device_attr(driver, index, device, drvdata, attr_grp); }

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Tomas Hlavacek5964.84%150.00%
Rob Herring3235.16%150.00%
Total91100.00%2100.00%

EXPORT_SYMBOL_GPL(tty_port_register_device_attr);
int tty_port_alloc_xmit_buf(struct tty_port *port) { /* We may sleep in get_zeroed_page() */ mutex_lock(&port->buf_mutex); if (port->xmit_buf == NULL) port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); mutex_unlock(&port->buf_mutex); if (port->xmit_buf == NULL) return -ENOMEM; return 0; }

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Alan Cox64100.00%2100.00%
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EXPORT_SYMBOL(tty_port_alloc_xmit_buf);
void tty_port_free_xmit_buf(struct tty_port *port) { mutex_lock(&port->buf_mutex); if (port->xmit_buf != NULL) { free_page((unsigned long)port->xmit_buf); port->xmit_buf = NULL; } mutex_unlock(&port->buf_mutex); }

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Alan Cox53100.00%2100.00%
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EXPORT_SYMBOL(tty_port_free_xmit_buf); /** * tty_port_destroy -- destroy inited port * @port: tty port to be doestroyed * * When a port was initialized using tty_port_init, one has to destroy the * port by this function. Either indirectly by using tty_port refcounting * (tty_port_put) or directly if refcounting is not used. */
void tty_port_destroy(struct tty_port *port) { tty_buffer_cancel_work(port); tty_buffer_free_all(port); }

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Jiri Slaby1575.00%133.33%
Peter Hurley525.00%266.67%
Total20100.00%3100.00%

EXPORT_SYMBOL(tty_port_destroy);
static void tty_port_destructor(struct kref *kref) { struct tty_port *port = container_of(kref, struct tty_port, kref); /* check if last port ref was dropped before tty release */ if (WARN_ON(port->itty)) return; serdev_tty_port_unregister(port); if (port->xmit_buf) free_page((unsigned long)port->xmit_buf); tty_port_destroy(port); if (port->ops && port->ops->destruct) port->ops->destruct(port); else kfree(port); }

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Alan Cox6672.53%116.67%
Peter Hurley1112.09%116.67%
Jiri Slaby99.89%350.00%
Rob Herring55.49%116.67%
Total91100.00%6100.00%


void tty_port_put(struct tty_port *port) { if (port) kref_put(&port->kref, tty_port_destructor); }

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Alan Cox24100.00%1100.00%
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EXPORT_SYMBOL(tty_port_put); /** * tty_port_tty_get - get a tty reference * @port: tty port * * Return a refcount protected tty instance or NULL if the port is not * associated with a tty (eg due to close or hangup) */
struct tty_struct *tty_port_tty_get(struct tty_port *port) { unsigned long flags; struct tty_struct *tty; spin_lock_irqsave(&port->lock, flags); tty = tty_kref_get(port->tty); spin_unlock_irqrestore(&port->lock, flags); return tty; }

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Alan Cox53100.00%1100.00%
Total53100.00%1100.00%

EXPORT_SYMBOL(tty_port_tty_get); /** * tty_port_tty_set - set the tty of a port * @port: tty port * @tty: the tty * * Associate the port and tty pair. Manages any internal refcounts. * Pass NULL to deassociate a port */
void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty) { unsigned long flags; spin_lock_irqsave(&port->lock, flags); tty_kref_put(port->tty); port->tty = tty_kref_get(tty); spin_unlock_irqrestore(&port->lock, flags); }

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Alan Cox55100.00%2100.00%
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EXPORT_SYMBOL(tty_port_tty_set);
static void tty_port_shutdown(struct tty_port *port, struct tty_struct *tty) { mutex_lock(&port->mutex); if (port->console) goto out; if (tty_port_initialized(port)) { tty_port_set_initialized(port, 0); /* * Drop DTR/RTS if HUPCL is set. This causes any attached * modem to hang up the line. */ if (tty && C_HUPCL(tty)) tty_port_lower_dtr_rts(port); if (port->ops->shutdown) port->ops->shutdown(port); } out: mutex_unlock(&port->mutex); }

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Alan Cox4448.35%233.33%
Johan Hovold3841.76%233.33%
Peter Hurley88.79%116.67%
Jason Wessel11.10%116.67%
Total91100.00%6100.00%

/** * tty_port_hangup - hangup helper * @port: tty port * * Perform port level tty hangup flag and count changes. Drop the tty * reference. * * Caller holds tty lock. */
void tty_port_hangup(struct tty_port *port) { struct tty_struct *tty; unsigned long flags; spin_lock_irqsave(&port->lock, flags); port->count = 0; tty = port->tty; if (tty) set_bit(TTY_IO_ERROR, &tty->flags); port->tty = NULL; spin_unlock_irqrestore(&port->lock, flags); tty_port_set_active(port, 0); tty_port_shutdown(port, tty); tty_kref_put(tty); wake_up_interruptible(&port->open_wait); wake_up_interruptible(&port->delta_msr_wait); }

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Alan Cox7671.70%350.00%
Johan Hovold2321.70%233.33%
Peter Hurley76.60%116.67%
Total106100.00%6100.00%

EXPORT_SYMBOL(tty_port_hangup); /** * tty_port_tty_hangup - helper to hang up a tty * * @port: tty port * @check_clocal: hang only ttys with CLOCAL unset? */
void tty_port_tty_hangup(struct tty_port *port, bool check_clocal) { struct tty_struct *tty = tty_port_tty_get(port); if (tty && (!check_clocal || !C_CLOCAL(tty))) tty_hangup(tty); tty_kref_put(tty); }

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Jiri Slaby48100.00%1100.00%
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EXPORT_SYMBOL_GPL(tty_port_tty_hangup); /** * tty_port_tty_wakeup - helper to wake up a tty * * @port: tty port */
void tty_port_tty_wakeup(struct tty_port *port) { port->client_ops->write_wakeup(port); }

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Jiri Slaby1473.68%150.00%
Rob Herring526.32%150.00%
Total19100.00%2100.00%

EXPORT_SYMBOL_GPL(tty_port_tty_wakeup); /** * tty_port_carrier_raised - carrier raised check * @port: tty port * * Wrapper for the carrier detect logic. For the moment this is used * to hide some internal details. This will eventually become entirely * internal to the tty port. */
int tty_port_carrier_raised(struct tty_port *port) { if (port->ops->carrier_raised == NULL) return 1; return port->ops->carrier_raised(port); }

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Alan Cox33100.00%1100.00%
Total33100.00%1100.00%

EXPORT_SYMBOL(tty_port_carrier_raised); /** * tty_port_raise_dtr_rts - Raise DTR/RTS * @port: tty port * * Wrapper for the DTR/RTS raise logic. For the moment this is used * to hide some internal details. This will eventually become entirely * internal to the tty port. */
void tty_port_raise_dtr_rts(struct tty_port *port) { if (port->ops->dtr_rts) port->ops->dtr_rts(port, 1); }

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Alan Cox29100.00%2100.00%
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EXPORT_SYMBOL(tty_port_raise_dtr_rts); /** * tty_port_lower_dtr_rts - Lower DTR/RTS * @port: tty port * * Wrapper for the DTR/RTS raise logic. For the moment this is used * to hide some internal details. This will eventually become entirely * internal to the tty port. */
void tty_port_lower_dtr_rts(struct tty_port *port) { if (port->ops->dtr_rts) port->ops->dtr_rts(port, 0); }

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Alan Cox29100.00%1100.00%
Total29100.00%1100.00%

EXPORT_SYMBOL(tty_port_lower_dtr_rts); /** * tty_port_block_til_ready - Waiting logic for tty open * @port: the tty port being opened * @tty: the tty device being bound * @filp: the file pointer of the opener or NULL * * Implement the core POSIX/SuS tty behaviour when opening a tty device. * Handles: * - hangup (both before and during) * - non blocking open * - rts/dtr/dcd * - signals * - port flags and counts * * The passed tty_port must implement the carrier_raised method if it can * do carrier detect and the dtr_rts method if it supports software * management of these lines. Note that the dtr/rts raise is done each * iteration as a hangup may have previously dropped them while we wait. * * Caller holds tty lock. * * NB: May drop and reacquire tty lock when blocking, so tty and tty_port * may have changed state (eg., may have been hung up). */
int tty_port_block_til_ready(struct tty_port *port, struct tty_struct *tty, struct file *filp) { int do_clocal = 0, retval; unsigned long flags; DEFINE_WAIT(wait); /* if non-blocking mode is set we can pass directly to open unless the port has just hung up or is in another error state */ if (tty_io_error(tty)) { tty_port_set_active(port, 1); return 0; } if (filp == NULL || (filp->f_flags & O_NONBLOCK)) { /* Indicate we are open */ if (C_BAUD(tty)) tty_port_raise_dtr_rts(port); tty_port_set_active(port, 1); return 0; } if (C_CLOCAL(tty)) do_clocal = 1; /* Block waiting until we can proceed. We may need to wait for the carrier, but we must also wait for any close that is in progress before the next open may complete */ retval = 0; /* The port lock protects the port counts */ spin_lock_irqsave(&port->lock, flags); port->count--; port->blocked_open++; spin_unlock_irqrestore(&port->lock, flags); while (1) { /* Indicate we are open */ if (C_BAUD(tty) && tty_port_initialized(port)) tty_port_raise_dtr_rts(port); prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE); /* Check for a hangup or uninitialised port. Return accordingly */ if (tty_hung_up_p(filp) || !tty_port_initialized(port)) { if (port->flags & ASYNC_HUP_NOTIFY) retval = -EAGAIN; else retval = -ERESTARTSYS; break; } /* * Probe the carrier. For devices with no carrier detect * tty_port_carrier_raised will always return true. * Never ask drivers if CLOCAL is set, this causes troubles * on some hardware. */ if (do_clocal || tty_port_carrier_raised(port)) break; if (signal_pending(current)) { retval = -ERESTARTSYS; break; } tty_unlock(tty); schedule(); tty_lock(tty); } finish_wait(&port->open_wait, &wait); /* Update counts. A parallel hangup will have set count to zero and we must not mess that up further */ spin_lock_irqsave(&port->lock, flags); if (!tty_hung_up_p(filp)) port->count++; port->blocked_open--; spin_unlock_irqrestore(&port->lock, flags); if (retval == 0) tty_port_set_active(port, 1); return retval; }

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Alan Cox26181.56%847.06%
Peter Hurley3210.00%423.53%
Jiri Slaby165.00%317.65%
Johan Hovold72.19%15.88%
Arnd Bergmann41.25%15.88%
Total320100.00%17100.00%

EXPORT_SYMBOL(tty_port_block_til_ready);
static void tty_port_drain_delay(struct tty_port *port, struct tty_struct *tty) { unsigned int bps = tty_get_baud_rate(tty); long timeout; if (bps > 1200) { timeout = (HZ * 10 * port->drain_delay) / bps; timeout = max_t(long, timeout, HZ / 10); } else { timeout = 2 * HZ; } schedule_timeout_interruptible(timeout); }

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Johan Hovold77100.00%1100.00%
Total77100.00%1100.00%

/* Caller holds tty lock. */
int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct file *filp) { unsigned long flags; if (tty_hung_up_p(filp)) return 0; spin_lock_irqsave(&port->lock, flags); if (tty->count == 1 && port->count != 1) { tty_warn(tty, "%s: tty->count = 1 port count = %d\n", __func__, port->count); port->count = 1; } if (--port->count < 0) { tty_warn(tty, "%s: bad port count (%d)\n", __func__, port->count); port->count = 0; } if (port->count) { spin_unlock_irqrestore(&port->lock, flags); return 0; } spin_unlock_irqrestore(&port->lock, flags); tty->closing = 1; if (tty_port_initialized(port)) { /* Don't block on a stalled port, just pull the chain */ if (tty->flow_stopped) tty_driver_flush_buffer(tty); if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) tty_wait_until_sent(tty, port->closing_wait); if (port->drain_delay) tty_port_drain_delay(port, tty); } /* Flush the ldisc buffering */ tty_ldisc_flush(tty); /* Report to caller this is the last port reference */ return 1; }

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Alan Cox17283.09%538.46%
Peter Hurley2512.08%646.15%
Johan Hovold104.83%215.38%
Total207100.00%13100.00%

EXPORT_SYMBOL(tty_port_close_start); /* Caller holds tty lock */
void tty_port_close_end(struct tty_port *port, struct tty_struct *tty) { unsigned long flags; tty_ldisc_flush(tty); tty->closing = 0; spin_lock_irqsave(&port->lock, flags); if (port->blocked_open) { spin_unlock_irqrestore(&port->lock, flags); if (port->close_delay) msleep_interruptible(jiffies_to_msecs(port->close_delay)); spin_lock_irqsave(&port->lock, flags); wake_up_interruptible(&port->open_wait); } spin_unlock_irqrestore(&port->lock, flags); tty_port_set_active(port, 0); }

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Alan Cox9183.49%125.00%
Peter Hurley1816.51%375.00%
Total109100.00%4100.00%

EXPORT_SYMBOL(tty_port_close_end); /** * tty_port_close * * Caller holds tty lock */
void tty_port_close(struct tty_port *port, struct tty_struct *tty, struct file *filp) { if (tty_port_close_start(port, tty, filp) == 0) return; tty_port_shutdown(port, tty); set_bit(TTY_IO_ERROR, &tty->flags); tty_port_close_end(port, tty); tty_port_tty_set(port, NULL); }

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Alan Cox6396.92%266.67%
Johan Hovold23.08%133.33%
Total65100.00%3100.00%

EXPORT_SYMBOL(tty_port_close); /** * tty_port_install - generic tty->ops->install handler * @port: tty_port of the device * @driver: tty_driver for this device * @tty: tty to be installed * * It is the same as tty_standard_install except the provided @port is linked * to a concrete tty specified by @tty. Use this or tty_port_register_device * (or both). Call tty_port_link_device as a last resort. */
int tty_port_install(struct tty_port *port, struct tty_driver *driver, struct tty_struct *tty) { tty->port = port; return tty_standard_install(driver, tty); }

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Jiri Slaby34100.00%1100.00%
Total34100.00%1100.00%

EXPORT_SYMBOL_GPL(tty_port_install); /** * tty_port_open * * Caller holds tty lock. * * NB: may drop and reacquire tty lock (in tty_port_block_til_ready()) so * tty and tty_port may have changed state (eg., may be hung up now) */
int tty_port_open(struct tty_port *port, struct tty_struct *tty, struct file *filp) { spin_lock_irq(&port->lock); ++port->count; spin_unlock_irq(&port->lock); tty_port_tty_set(port, tty); /* * Do the device-specific open only if the hardware isn't * already initialized. Serialize open and shutdown using the * port mutex. */ mutex_lock(&port->mutex); if (!tty_port_initialized(port)) { clear_bit(TTY_IO_ERROR, &tty->flags); if (port->ops->activate) { int retval = port->ops->activate(port, tty); if (retval) { mutex_unlock(&port->mutex); return retval; } } tty_port_set_initialized(port, 1); } mutex_unlock(&port->mutex); return tty_port_block_til_ready(port, tty, filp); }

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Alan Cox13997.20%266.67%
Peter Hurley42.80%133.33%
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EXPORT_SYMBOL(tty_port_open);

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Alan Cox147064.67%2739.71%
Jiri Slaby25111.04%1217.65%
Rob Herring2099.19%34.41%
Johan Hovold1576.91%68.82%
Peter Hurley1155.06%1623.53%
Tomas Hlavacek652.86%11.47%
Arnd Bergmann40.18%11.47%
Ingo Molnar10.04%11.47%
Jason Wessel10.04%11.47%
Total2273100.00%68100.00%
Directory: drivers/tty
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