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Merge master.kernel.org:/home/rmk/linux-2.6-serial
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* master.kernel.org:/home/rmk/linux-2.6-serial:
  [SERIAL] 8250: add locking to console write function
  [SERIAL] Remove unconditional enable of TX irq for console
  [SERIAL] 8250: set divisor register correctly for AMD Alchemy SoC uart
  [SERIAL] AMD Alchemy UART: claim memory range
  [SERIAL] Clean up serial locking when obtaining a reference to a port
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Linus Torvalds committed May 11, 2006
2 parents 6572b20 + d8a5a8d commit 2bf9d6d
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Showing 4 changed files with 122 additions and 72 deletions.
74 changes: 59 additions & 15 deletions drivers/serial/8250.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -362,6 +362,40 @@ serial_out(struct uart_8250_port *up, int offset, int value)
#define serial_inp(up, offset) serial_in(up, offset)
#define serial_outp(up, offset, value) serial_out(up, offset, value)

/* Uart divisor latch read */
static inline int _serial_dl_read(struct uart_8250_port *up)
{
return serial_inp(up, UART_DLL) | serial_inp(up, UART_DLM) << 8;
}

/* Uart divisor latch write */
static inline void _serial_dl_write(struct uart_8250_port *up, int value)
{
serial_outp(up, UART_DLL, value & 0xff);
serial_outp(up, UART_DLM, value >> 8 & 0xff);
}

#ifdef CONFIG_SERIAL_8250_AU1X00
/* Au1x00 haven't got a standard divisor latch */
static int serial_dl_read(struct uart_8250_port *up)
{
if (up->port.iotype == UPIO_AU)
return __raw_readl(up->port.membase + 0x28);
else
return _serial_dl_read(up);
}

static void serial_dl_write(struct uart_8250_port *up, int value)
{
if (up->port.iotype == UPIO_AU)
__raw_writel(value, up->port.membase + 0x28);
else
_serial_dl_write(up, value);
}
#else
#define serial_dl_read(up) _serial_dl_read(up)
#define serial_dl_write(up, value) _serial_dl_write(up, value)
#endif

/*
* For the 16C950
Expand Down Expand Up @@ -494,7 +528,8 @@ static void disable_rsa(struct uart_8250_port *up)
*/
static int size_fifo(struct uart_8250_port *up)
{
unsigned char old_fcr, old_mcr, old_dll, old_dlm, old_lcr;
unsigned char old_fcr, old_mcr, old_lcr;
unsigned short old_dl;
int count;

old_lcr = serial_inp(up, UART_LCR);
Expand All @@ -505,10 +540,8 @@ static int size_fifo(struct uart_8250_port *up)
UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
serial_outp(up, UART_MCR, UART_MCR_LOOP);
serial_outp(up, UART_LCR, UART_LCR_DLAB);
old_dll = serial_inp(up, UART_DLL);
old_dlm = serial_inp(up, UART_DLM);
serial_outp(up, UART_DLL, 0x01);
serial_outp(up, UART_DLM, 0x00);
old_dl = serial_dl_read(up);
serial_dl_write(up, 0x0001);
serial_outp(up, UART_LCR, 0x03);
for (count = 0; count < 256; count++)
serial_outp(up, UART_TX, count);
Expand All @@ -519,8 +552,7 @@ static int size_fifo(struct uart_8250_port *up)
serial_outp(up, UART_FCR, old_fcr);
serial_outp(up, UART_MCR, old_mcr);
serial_outp(up, UART_LCR, UART_LCR_DLAB);
serial_outp(up, UART_DLL, old_dll);
serial_outp(up, UART_DLM, old_dlm);
serial_dl_write(up, old_dl);
serial_outp(up, UART_LCR, old_lcr);

return count;
Expand Down Expand Up @@ -750,17 +782,15 @@ static void autoconfig_16550a(struct uart_8250_port *up)

serial_outp(up, UART_LCR, 0xE0);

quot = serial_inp(up, UART_DLM) << 8;
quot += serial_inp(up, UART_DLL);
quot = serial_dl_read(up);
quot <<= 3;

status1 = serial_in(up, 0x04); /* EXCR1 */
status1 &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
status1 |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
serial_outp(up, 0x04, status1);

serial_outp(up, UART_DLL, quot & 0xff);
serial_outp(up, UART_DLM, quot >> 8);
serial_dl_write(up, quot);

serial_outp(up, UART_LCR, 0);

Expand Down Expand Up @@ -1862,8 +1892,7 @@ serial8250_set_termios(struct uart_port *port, struct termios *termios,
serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
}

serial_outp(up, UART_DLL, quot & 0xff); /* LS of divisor */
serial_outp(up, UART_DLM, quot >> 8); /* MS of divisor */
serial_dl_write(up, quot);

/*
* LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
Expand Down Expand Up @@ -1906,6 +1935,9 @@ static int serial8250_request_std_resource(struct uart_8250_port *up)
int ret = 0;

switch (up->port.iotype) {
case UPIO_AU:
size = 0x100000;
/* fall thru */
case UPIO_MEM:
if (!up->port.mapbase)
break;
Expand Down Expand Up @@ -1938,6 +1970,9 @@ static void serial8250_release_std_resource(struct uart_8250_port *up)
unsigned int size = 8 << up->port.regshift;

switch (up->port.iotype) {
case UPIO_AU:
size = 0x100000;
/* fall thru */
case UPIO_MEM:
if (!up->port.mapbase)
break;
Expand Down Expand Up @@ -2200,10 +2235,17 @@ static void
serial8250_console_write(struct console *co, const char *s, unsigned int count)
{
struct uart_8250_port *up = &serial8250_ports[co->index];
unsigned long flags;
unsigned int ier;
int locked = 1;

touch_nmi_watchdog();

if (oops_in_progress) {
locked = spin_trylock_irqsave(&up->port.lock, flags);
} else
spin_lock_irqsave(&up->port.lock, flags);

/*
* First save the IER then disable the interrupts
*/
Expand All @@ -2221,8 +2263,10 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count)
* and restore the IER
*/
wait_for_xmitr(up, BOTH_EMPTY);
up->ier |= UART_IER_THRI;
serial_out(up, UART_IER, ier | UART_IER_THRI);
serial_out(up, UART_IER, ier);

if (locked)
spin_unlock_irqrestore(&up->port.lock, flags);
}

static int serial8250_console_setup(struct console *co, char *options)
Expand Down
5 changes: 2 additions & 3 deletions drivers/serial/8250_au1x00.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,13 +30,12 @@
{ \
.iobase = _base, \
.membase = (void __iomem *)_base,\
.mapbase = _base, \
.mapbase = CPHYSADDR(_base), \
.irq = _irq, \
.uartclk = 0, /* filled */ \
.regshift = 2, \
.iotype = UPIO_AU, \
.flags = UPF_SKIP_TEST | \
UPF_IOREMAP, \
.flags = UPF_SKIP_TEST \
}

static struct plat_serial8250_port au1x00_data[] = {
Expand Down
114 changes: 60 additions & 54 deletions drivers/serial/serial_core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1500,20 +1500,18 @@ uart_block_til_ready(struct file *filp, struct uart_state *state)
static struct uart_state *uart_get(struct uart_driver *drv, int line)
{
struct uart_state *state;
int ret = 0;

mutex_lock(&port_mutex);
state = drv->state + line;
if (mutex_lock_interruptible(&state->mutex)) {
state = ERR_PTR(-ERESTARTSYS);
goto out;
ret = -ERESTARTSYS;
goto err;
}

state->count++;
if (!state->port) {
state->count--;
mutex_unlock(&state->mutex);
state = ERR_PTR(-ENXIO);
goto out;
if (!state->port || state->port->flags & UPF_DEAD) {
ret = -ENXIO;
goto err_unlock;
}

if (!state->info) {
Expand All @@ -1531,15 +1529,17 @@ static struct uart_state *uart_get(struct uart_driver *drv, int line)
tasklet_init(&state->info->tlet, uart_tasklet_action,
(unsigned long)state);
} else {
state->count--;
mutex_unlock(&state->mutex);
state = ERR_PTR(-ENOMEM);
ret = -ENOMEM;
goto err_unlock;
}
}

out:
mutex_unlock(&port_mutex);
return state;

err_unlock:
state->count--;
mutex_unlock(&state->mutex);
err:
return ERR_PTR(ret);
}

/*
Expand Down Expand Up @@ -2085,45 +2085,6 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
}
}

/*
* This reverses the effects of uart_configure_port, hanging up the
* port before removal.
*/
static void
uart_unconfigure_port(struct uart_driver *drv, struct uart_state *state)
{
struct uart_port *port = state->port;
struct uart_info *info = state->info;

if (info && info->tty)
tty_vhangup(info->tty);

mutex_lock(&state->mutex);

state->info = NULL;

/*
* Free the port IO and memory resources, if any.
*/
if (port->type != PORT_UNKNOWN)
port->ops->release_port(port);

/*
* Indicate that there isn't a port here anymore.
*/
port->type = PORT_UNKNOWN;

/*
* Kill the tasklet, and free resources.
*/
if (info) {
tasklet_kill(&info->tlet);
kfree(info);
}

mutex_unlock(&state->mutex);
}

static struct tty_operations uart_ops = {
.open = uart_open,
.close = uart_close,
Expand Down Expand Up @@ -2270,6 +2231,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
state = drv->state + port->line;

mutex_lock(&port_mutex);
mutex_lock(&state->mutex);
if (state->port) {
ret = -EINVAL;
goto out;
Expand Down Expand Up @@ -2304,7 +2266,13 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
port->cons && !(port->cons->flags & CON_ENABLED))
register_console(port->cons);

/*
* Ensure UPF_DEAD is not set.
*/
port->flags &= ~UPF_DEAD;

out:
mutex_unlock(&state->mutex);
mutex_unlock(&port_mutex);

return ret;
Expand All @@ -2322,6 +2290,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
{
struct uart_state *state = drv->state + port->line;
struct uart_info *info;

BUG_ON(in_interrupt());

Expand All @@ -2331,12 +2300,49 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)

mutex_lock(&port_mutex);

/*
* Mark the port "dead" - this prevents any opens from
* succeeding while we shut down the port.
*/
mutex_lock(&state->mutex);
port->flags |= UPF_DEAD;
mutex_unlock(&state->mutex);

/*
* Remove the devices from devfs
*/
tty_unregister_device(drv->tty_driver, port->line);

uart_unconfigure_port(drv, state);
info = state->info;
if (info && info->tty)
tty_vhangup(info->tty);

/*
* All users of this port should now be disconnected from
* this driver, and the port shut down. We should be the
* only thread fiddling with this port from now on.
*/
state->info = NULL;

/*
* Free the port IO and memory resources, if any.
*/
if (port->type != PORT_UNKNOWN)
port->ops->release_port(port);

/*
* Indicate that there isn't a port here anymore.
*/
port->type = PORT_UNKNOWN;

/*
* Kill the tasklet, and free resources.
*/
if (info) {
tasklet_kill(&info->tlet);
kfree(info);
}

state->port = NULL;
mutex_unlock(&port_mutex);

Expand Down
1 change: 1 addition & 0 deletions include/linux/serial_core.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -254,6 +254,7 @@ struct uart_port {
#define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
#define UPF_SHARE_IRQ ((__force upf_t) (1 << 24))
#define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28))
#define UPF_DEAD ((__force upf_t) (1 << 30))
#define UPF_IOREMAP ((__force upf_t) (1 << 31))

#define UPF_CHANGE_MASK ((__force upf_t) (0x17fff))
Expand Down

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