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-rw-r--r--drivers/tty/pty.c14
-rw-r--r--drivers/tty/tty_buffer.c8
-rw-r--r--drivers/tty/tty_io.c21
-rw-r--r--drivers/tty/tty_port.c23
-rw-r--r--include/linux/tty_buffer.h1
-rw-r--r--include/linux/tty_driver.h7
-rw-r--r--include/linux/tty_port.h13
7 files changed, 78 insertions, 9 deletions
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 6120d827a797..1f17575f8fe0 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -403,6 +403,8 @@ static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
o_tty->link = tty;
tty_port_init(ports[0]);
tty_port_init(ports[1]);
+ tty_port_link_wq(ports[0], system_dfl_wq);
+ tty_port_link_wq(ports[1], system_dfl_wq);
tty_buffer_set_limit(ports[0], 8192);
tty_buffer_set_limit(ports[1], 8192);
o_tty->port = ports[0];
@@ -532,14 +534,16 @@ static void __init legacy_pty_init(void)
pty_driver = tty_alloc_driver(legacy_count,
TTY_DRIVER_RESET_TERMIOS |
TTY_DRIVER_REAL_RAW |
- TTY_DRIVER_DYNAMIC_ALLOC);
+ TTY_DRIVER_DYNAMIC_ALLOC |
+ TTY_DRIVER_CUSTOM_WORKQUEUE);
if (IS_ERR(pty_driver))
panic("Couldn't allocate pty driver");
pty_slave_driver = tty_alloc_driver(legacy_count,
TTY_DRIVER_RESET_TERMIOS |
TTY_DRIVER_REAL_RAW |
- TTY_DRIVER_DYNAMIC_ALLOC);
+ TTY_DRIVER_DYNAMIC_ALLOC |
+ TTY_DRIVER_CUSTOM_WORKQUEUE);
if (IS_ERR(pty_slave_driver))
panic("Couldn't allocate pty slave driver");
@@ -849,7 +853,8 @@ static void __init unix98_pty_init(void)
TTY_DRIVER_REAL_RAW |
TTY_DRIVER_DYNAMIC_DEV |
TTY_DRIVER_DEVPTS_MEM |
- TTY_DRIVER_DYNAMIC_ALLOC);
+ TTY_DRIVER_DYNAMIC_ALLOC |
+ TTY_DRIVER_CUSTOM_WORKQUEUE);
if (IS_ERR(ptm_driver))
panic("Couldn't allocate Unix98 ptm driver");
pts_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
@@ -857,7 +862,8 @@ static void __init unix98_pty_init(void)
TTY_DRIVER_REAL_RAW |
TTY_DRIVER_DYNAMIC_DEV |
TTY_DRIVER_DEVPTS_MEM |
- TTY_DRIVER_DYNAMIC_ALLOC);
+ TTY_DRIVER_DYNAMIC_ALLOC |
+ TTY_DRIVER_CUSTOM_WORKQUEUE);
if (IS_ERR(pts_driver))
panic("Couldn't allocate Unix98 pts driver");
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 1a5673acd9b1..86e1e7178e90 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -76,7 +76,7 @@ void tty_buffer_unlock_exclusive(struct tty_port *port)
mutex_unlock(&buf->lock);
if (restart)
- queue_work(system_dfl_wq, &buf->work);
+ queue_work(buf->flip_wq, &buf->work);
}
EXPORT_SYMBOL_GPL(tty_buffer_unlock_exclusive);
@@ -530,7 +530,7 @@ void tty_flip_buffer_push(struct tty_port *port)
struct tty_bufhead *buf = &port->buf;
tty_flip_buffer_commit(buf->tail);
- queue_work(system_dfl_wq, &buf->work);
+ queue_work(buf->flip_wq, &buf->work);
}
EXPORT_SYMBOL(tty_flip_buffer_push);
@@ -560,7 +560,7 @@ int tty_insert_flip_string_and_push_buffer(struct tty_port *port,
tty_flip_buffer_commit(buf->tail);
spin_unlock_irqrestore(&port->lock, flags);
- queue_work(system_dfl_wq, &buf->work);
+ queue_work(buf->flip_wq, &buf->work);
return size;
}
@@ -613,7 +613,7 @@ void tty_buffer_set_lock_subclass(struct tty_port *port)
bool tty_buffer_restart_work(struct tty_port *port)
{
- return queue_work(system_dfl_wq, &port->buf.work);
+ return queue_work(port->buf.flip_wq, &port->buf.work);
}
bool tty_buffer_cancel_work(struct tty_port *port)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index e2d92cf70eb7..d64fb08baa17 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -3446,10 +3446,23 @@ int tty_register_driver(struct tty_driver *driver)
if (error < 0)
goto err;
+ if (!(driver->flags & TTY_DRIVER_CUSTOM_WORKQUEUE)) {
+ driver->flip_wq = alloc_workqueue("%s-flip-wq", WQ_UNBOUND | WQ_SYSFS,
+ 0, driver->name);
+ if (!driver->flip_wq) {
+ error = -ENOMEM;
+ goto err_unreg_char;
+ }
+ for (i = 0; i < driver->num; i++) {
+ if (driver->ports[i])
+ tty_port_link_driver_wq(driver->ports[i], driver);
+ }
+ }
+
if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) {
error = tty_cdev_add(driver, dev, 0, driver->num);
if (error)
- goto err_unreg_char;
+ goto err_destroy_wq;
}
scoped_guard(mutex, &tty_mutex)
@@ -3475,6 +3488,10 @@ err_unreg_devs:
scoped_guard(mutex, &tty_mutex)
list_del(&driver->tty_drivers);
+err_destroy_wq:
+ if (!(driver->flags & TTY_DRIVER_CUSTOM_WORKQUEUE))
+ destroy_workqueue(driver->flip_wq);
+
err_unreg_char:
unregister_chrdev_region(dev, driver->num);
err:
@@ -3494,6 +3511,8 @@ void tty_unregister_driver(struct tty_driver *driver)
driver->num);
scoped_guard(mutex, &tty_mutex)
list_del(&driver->tty_drivers);
+ if (!(driver->flags & TTY_DRIVER_CUSTOM_WORKQUEUE))
+ destroy_workqueue(driver->flip_wq);
}
EXPORT_SYMBOL(tty_unregister_driver);
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index fe67c5cb0a3f..611f878149f8 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -100,6 +100,26 @@ void tty_port_init(struct tty_port *port)
EXPORT_SYMBOL(tty_port_init);
/**
+ * tty_port_link_wq - link tty_port and flip workqueue
+ * @port: tty_port of the device
+ * @flip_wq: workqueue to queue flip buffer work on
+ *
+ * When %TTY_DRIVER_CUSTOM_WORKQUEUE is used, every tty_port shall be linked to
+ * a workqueue manually by this function, otherwise tty_flip_buffer_push() will
+ * see %NULL flip_wq pointer on queue_work.
+ * When %TTY_DRIVER_CUSTOM_WORKQUEUE is NOT used, the function can be used to
+ * link a certain port to a specific workqueue, instead of using the workqueue
+ * allocated in tty_register_driver().
+ *
+ * Note that TTY port API will NOT destroy the workqueue.
+ */
+void tty_port_link_wq(struct tty_port *port, struct workqueue_struct *flip_wq)
+{
+ port->buf.flip_wq = flip_wq;
+}
+EXPORT_SYMBOL_GPL(tty_port_link_wq);
+
+/**
* tty_port_link_device - link tty and tty_port
* @port: tty_port of the device
* @driver: tty_driver for this device
@@ -157,6 +177,7 @@ struct device *tty_port_register_device_attr(struct tty_port *port,
const struct attribute_group **attr_grp)
{
tty_port_link_device(port, driver, index);
+ tty_port_link_driver_wq(port, driver);
return tty_register_device_attr(driver, index, device, drvdata,
attr_grp);
}
@@ -183,6 +204,7 @@ struct device *tty_port_register_device_attr_serdev(struct tty_port *port,
struct device *dev;
tty_port_link_device(port, driver, index);
+ tty_port_link_driver_wq(port, driver);
dev = serdev_tty_port_register(port, host, parent, driver, index);
if (PTR_ERR(dev) != -ENODEV) {
@@ -703,6 +725,7 @@ int tty_port_install(struct tty_port *port, struct tty_driver *driver,
struct tty_struct *tty)
{
tty->port = port;
+ tty_port_link_driver_wq(port, driver);
return tty_standard_install(driver, tty);
}
EXPORT_SYMBOL_GPL(tty_port_install);
diff --git a/include/linux/tty_buffer.h b/include/linux/tty_buffer.h
index 31125e3be3c5..48adcb0e8ff3 100644
--- a/include/linux/tty_buffer.h
+++ b/include/linux/tty_buffer.h
@@ -34,6 +34,7 @@ static inline u8 *flag_buf_ptr(struct tty_buffer *b, unsigned int ofs)
struct tty_bufhead {
struct tty_buffer *head; /* Queue head */
+ struct workqueue_struct *flip_wq;
struct work_struct work;
struct mutex lock;
atomic_t priority;
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index 188ee9b768eb..9c65854f7d94 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -69,6 +69,10 @@ struct serial_struct;
* Do not create numbered ``/dev`` nodes. For example, create
* ``/dev/ttyprintk`` and not ``/dev/ttyprintk0``. Applicable only when a
* driver for a single tty device is being allocated.
+ *
+ * @TTY_DRIVER_CUSTOM_WORKQUEUE:
+ * Do not create workqueue when tty_register_driver(). When set, flip
+ * buffer workqueue shall be set by tty_port_link_wq() for every port.
*/
enum tty_driver_flag {
TTY_DRIVER_INSTALLED = BIT(0),
@@ -79,6 +83,7 @@ enum tty_driver_flag {
TTY_DRIVER_HARDWARE_BREAK = BIT(5),
TTY_DRIVER_DYNAMIC_ALLOC = BIT(6),
TTY_DRIVER_UNNUMBERED_NODE = BIT(7),
+ TTY_DRIVER_CUSTOM_WORKQUEUE = BIT(8),
};
enum tty_driver_type {
@@ -506,6 +511,7 @@ struct tty_operations {
* @flags: tty driver flags (%TTY_DRIVER_)
* @proc_entry: proc fs entry, used internally
* @other: driver of the linked tty; only used for the PTY driver
+ * @flip_wq: workqueue to queue flip buffer work on
* @ttys: array of active &struct tty_struct, set by tty_standard_install()
* @ports: array of &struct tty_port; can be set during initialization by
* tty_port_link_device() and similar
@@ -539,6 +545,7 @@ struct tty_driver {
unsigned long flags;
struct proc_dir_entry *proc_entry;
struct tty_driver *other;
+ struct workqueue_struct *flip_wq;
/*
* Pointer to the tty data structures
diff --git a/include/linux/tty_port.h b/include/linux/tty_port.h
index 660c254f1efe..c1b87f3c5603 100644
--- a/include/linux/tty_port.h
+++ b/include/linux/tty_port.h
@@ -138,6 +138,7 @@ struct tty_port {
kernel */
void tty_port_init(struct tty_port *port);
+void tty_port_link_wq(struct tty_port *port, struct workqueue_struct *flip_wq);
void tty_port_link_device(struct tty_port *port, struct tty_driver *driver,
unsigned index);
struct device *tty_port_register_device(struct tty_port *port,
@@ -165,6 +166,18 @@ static inline struct tty_port *tty_port_get(struct tty_port *port)
return NULL;
}
+/*
+ * Never overwrite the workqueue set by tty_port_link_wq().
+ * No effect when %TTY_DRIVER_CUSTOM_WORKQUEUE is set, as driver->flip_wq is
+ * %NULL.
+ */
+static inline void tty_port_link_driver_wq(struct tty_port *port,
+ struct tty_driver *driver)
+{
+ if (!port->buf.flip_wq)
+ port->buf.flip_wq = driver->flip_wq;
+}
+
/* If the cts flow control is enabled, return true. */
static inline bool tty_port_cts_enabled(const struct tty_port *port)
{
generated by cgit v1.2.3 (git 2.0.4) at 2026-02-28 08:06:42 +0000