Commit c3485ee0 authored by Rob Herring's avatar Rob Herring Committed by Greg Kroah-Hartman

tty_port: Add port client functions

Introduce a client (upward direction) operations struct for tty_port
clients. Initially supported operations are for receiving data and write
wake-up. This will allow for having clients other than an ldisc.

Convert the calls to the ldisc to use the client ops as the default
operations.
Signed-off-by: default avatarRob Herring <robh@kernel.org>
Reviewed-By: default avatarSebastian Reichel <sre@kernel.org>
Tested-By: default avatarSebastian Reichel <sre@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a380ed46
......@@ -437,7 +437,7 @@ int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p,
EXPORT_SYMBOL_GPL(tty_ldisc_receive_buf);
static int
receive_buf(struct tty_ldisc *ld, struct tty_buffer *head, int count)
receive_buf(struct tty_port *port, struct tty_buffer *head, int count)
{
unsigned char *p = char_buf_ptr(head, head->read);
char *f = NULL;
......@@ -445,7 +445,7 @@ receive_buf(struct tty_ldisc *ld, struct tty_buffer *head, int count)
if (~head->flags & TTYB_NORMAL)
f = flag_buf_ptr(head, head->read);
return tty_ldisc_receive_buf(ld, p, f, count);
return port->client_ops->receive_buf(port, p, f, count);
}
/**
......@@ -465,16 +465,6 @@ static void flush_to_ldisc(struct work_struct *work)
{
struct tty_port *port = container_of(work, struct tty_port, buf.work);
struct tty_bufhead *buf = &port->buf;
struct tty_struct *tty;
struct tty_ldisc *disc;
tty = READ_ONCE(port->itty);
if (tty == NULL)
return;
disc = tty_ldisc_ref(tty);
if (disc == NULL)
return;
mutex_lock(&buf->lock);
......@@ -504,7 +494,7 @@ static void flush_to_ldisc(struct work_struct *work)
continue;
}
count = receive_buf(disc, head, count);
count = receive_buf(port, head, count);
if (!count)
break;
head->read += count;
......@@ -512,7 +502,6 @@ static void flush_to_ldisc(struct work_struct *work)
mutex_unlock(&buf->lock);
tty_ldisc_deref(disc);
}
/**
......
......@@ -17,6 +17,44 @@
#include <linux/delay.h>
#include <linux/module.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;
}
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);
}
}
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));
......@@ -28,6 +66,7 @@ void tty_port_init(struct tty_port *port)
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);
}
EXPORT_SYMBOL(tty_port_init);
......@@ -272,12 +311,7 @@ EXPORT_SYMBOL_GPL(tty_port_tty_hangup);
*/
void tty_port_tty_wakeup(struct tty_port *port)
{
struct tty_struct *tty = tty_port_tty_get(port);
if (tty) {
tty_wakeup(tty);
tty_kref_put(tty);
}
port->client_ops->write_wakeup(port);
}
EXPORT_SYMBOL_GPL(tty_port_tty_wakeup);
......
......@@ -218,11 +218,17 @@ struct tty_port_operations {
void (*destruct)(struct tty_port *port);
};
struct tty_port_client_operations {
int (*receive_buf)(struct tty_port *port, const unsigned char *, const unsigned char *, size_t);
void (*write_wakeup)(struct tty_port *port);
};
struct tty_port {
struct tty_bufhead buf; /* Locked internally */
struct tty_struct *tty; /* Back pointer */
struct tty_struct *itty; /* internal back ptr */
const struct tty_port_operations *ops; /* Port operations */
const struct tty_port_client_operations *client_ops; /* Port client operations */
spinlock_t lock; /* Lock protecting tty field */
int blocked_open; /* Waiting to open */
int count; /* Usage count */
......@@ -241,6 +247,7 @@ struct tty_port {
based drain is needed else
set to size of fifo */
struct kref kref; /* Ref counter */
void *client_data;
};
/* tty_port::iflags bits -- use atomic bit ops */
......
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