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tty: We want the port object to be persistent

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Move the tty_port and uart_info bits around a little. By embedding the uart_info
into the uart_port we get rid of lots of corner case testing and also get the
ability to go port<->state<->info which is a bit more elegant than the current
data structures.

Downsides - we allocate a tiny bit more memory for unused ports, upside we've
removed as much code as it saved for most users..

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alan Cox
2009-01-02 13:49:21 +00:00
committed by Linus Torvalds
parent 6ef53066ff
commit f751928e0d
3 changed files with 96 additions and 112 deletions
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62
include/linux/serial_core.h
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@@ -315,36 +315,14 @@ struct uart_port {
void *private_data; /* generic platform data pointer */
};
/*
* This is the state information which is persistent across opens.
* The low level driver must not to touch any elements contained
* within.
*/
struct uart_state {
unsigned int close_delay; /* msec */
unsigned int closing_wait; /* msec */
#define USF_CLOSING_WAIT_INF (0)
#define USF_CLOSING_WAIT_NONE (~0U)
int count;
int pm_state;
struct uart_info *info;
struct uart_port *port;
struct mutex mutex;
};
#define UART_XMIT_SIZE PAGE_SIZE
typedef unsigned int __bitwise__ uif_t;
/*
* This is the state information which is only valid when the port
* is open; it may be freed by the core driver once the device has
* is open; it may be cleared the core driver once the device has
* been closed. Either the low level driver or the core can modify
* stuff here.
*/
typedef unsigned int __bitwise__ uif_t;
struct uart_info {
struct tty_port port;
struct circ_buf xmit;
@@ -366,6 +344,29 @@ struct uart_info {
wait_queue_head_t delta_msr_wait;
};
/*
* This is the state information which is persistent across opens.
* The low level driver must not to touch any elements contained
* within.
*/
struct uart_state {
unsigned int close_delay; /* msec */
unsigned int closing_wait; /* msec */
#define USF_CLOSING_WAIT_INF (0)
#define USF_CLOSING_WAIT_NONE (~0U)
int count;
int pm_state;
struct uart_info info;
struct uart_port *port;
struct mutex mutex;
};
#define UART_XMIT_SIZE PAGE_SIZE
/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256
@@ -439,8 +440,13 @@ int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
#define uart_circ_chars_free(circ) \
(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
#define uart_tx_stopped(portp) \
((portp)->info->port.tty->stopped || (portp)->info->port.tty->hw_stopped)
static inline int uart_tx_stopped(struct uart_port *port)
{
struct tty_struct *tty = port->info->port.tty;
if(tty->stopped || tty->hw_stopped)
return 1;
return 0;
}
/*
* The following are helper functions for the low level drivers.
@@ -451,7 +457,7 @@ uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
#ifdef SUPPORT_SYSRQ
if (port->sysrq) {
if (ch && time_before(jiffies, port->sysrq)) {
handle_sysrq(ch, port->info ? port->info->port.tty : NULL);
handle_sysrq(ch, port->info->port.tty);
port->sysrq = 0;
return 1;
}