The serial subsystem used struct circ_buf as provided by
circ_buf.h. Use kfifo instead as suggested by Alan Cox.
Signed-off-by: Bill Pemberton <wfp5p@xxxxxxxxxxxx>
---
drivers/serial/8250.c | 20 ++++++----
drivers/serial/jsm/jsm_tty.c | 26 +++++--------
drivers/serial/serial_core.c | 78 +++++++++--------------------------------
include/linux/serial_core.h | 4 +-
4 files changed, 41 insertions(+), 87 deletions(-)
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 4d8e14b..69c68d2 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -1461,8 +1461,10 @@ ignore_char:
static void transmit_chars(struct uart_8250_port *up)
{
- struct circ_buf *xmit = &up->port.state->xmit;
+ struct kfifo *xmit_fifo = &up->port.state->xmit_fifo;
+ u8 iobuf;
int count;
+ int len;
if (up->port.x_char) {
serial_outp(up, UART_TX, up->port.x_char);
@@ -1474,26 +1476,28 @@ static void transmit_chars(struct uart_8250_port *up)
serial8250_stop_tx(&up->port);
return;
}
- if (uart_circ_empty(xmit)) {
+ if (kfifo_is_empty(xmit_fifo)) {
__stop_tx(up);
return;
}
count = up->tx_loadsz;
do {
- serial_out(up, UART_TX, xmit->buf[xmit->tail]);
- xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ len = kfifo_out(xmit_fifo, &iobuf, 1);
+ if (!len)
+ break;
+ serial_out(up, UART_TX, iobuf);
up->port.icount.tx++;
- if (uart_circ_empty(xmit))
+ if (kfifo_is_empty(xmit_fifo))
break;
} while (--count > 0);
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ if (kfifo_len(xmit_fifo) < WAKEUP_CHARS)
uart_write_wakeup(&up->port);
DEBUG_INTR("THRE...");
- if (uart_circ_empty(xmit))
+ if (kfifo_is_empty(xmit_fifo))
__stop_tx(up);
}
@@ -1762,7 +1766,7 @@ static void serial8250_backup_timeout(unsigned long data)
up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
spin_unlock_irqrestore(&up->port.lock, flags);
if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
- (!uart_circ_empty(&up->port.state->xmit) || up->port.x_char) &&
+ (!kfifo_is_empty(&up->port.state->xmit_fifo ) || up->port.x_char) &&
(lsr & UART_LSR_THRE)) {
iir &= ~(UART_IIR_ID | UART_IIR_NO_INT);
iir |= UART_IIR_THRI;
diff --git a/drivers/serial/jsm/jsm_tty.c b/drivers/serial/jsm/jsm_tty.c
index 7a4a914..3eb54ee 100644
--- a/drivers/serial/jsm/jsm_tty.c
+++ b/drivers/serial/jsm/jsm_tty.c
@@ -846,12 +846,14 @@ void jsm_check_queue_flow_control(struct jsm_channel *ch)
int jsm_tty_write(struct uart_port *port)
{
int bufcount;
+ int len;
+ u8 c;
int data_count = 0,data_count1 =0;
u16 head;
u16 tail;
u16 tmask;
u32 remain;
- int temp_tail = port->state->xmit.tail;
+ struct kfifo *xmit_fifo = &port->state->xmit_fifo;
struct jsm_channel *channel = (struct jsm_channel *)port;
tmask = WQUEUEMASK;
@@ -867,13 +869,10 @@ int jsm_tty_write(struct uart_port *port)
data_count = 0;
if (bufcount >= remain) {
bufcount -= remain;
- while ((port->state->xmit.head != temp_tail) &&
- (data_count < remain)) {
- channel->ch_wqueue[head++] =
- port->state->xmit.buf[temp_tail];
-
- temp_tail++;
- temp_tail &= (UART_XMIT_SIZE - 1);
+ while ((!kfifo_is_empty(xmit_fifo)) &&
+ (data_count < remain)) {
+ len = kfifo_out(xmit_fifo, &c, 1);
+ channel->ch_wqueue[head++] = c;
data_count++;
}
if (data_count == remain) head = 0;
@@ -882,20 +881,15 @@ int jsm_tty_write(struct uart_port *port)
data_count1 = 0;
if (bufcount > 0) {
remain = bufcount;
- while ((port->state->xmit.head != temp_tail) &&
+ while ((!kfifo_is_empty(xmit_fifo)) &&
(data_count1 < remain)) {
- channel->ch_wqueue[head++] =
- port->state->xmit.buf[temp_tail];
-
- temp_tail++;
- temp_tail &= (UART_XMIT_SIZE - 1);
+ len = kfifo_out(xmit_fifo, &c, 1);
+ channel->ch_wqueue[head++] = c;
data_count1++;
}
}
- port->state->xmit.tail = temp_tail;
-
data_count += data_count1;
if (data_count) {
head &= tmask;
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index c4ea146..5ef653b 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -94,7 +94,7 @@ static void __uart_start(struct tty_struct *tty)
struct uart_state *state = tty->driver_data;
struct uart_port *port = state->uart_port;
- if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
+ if (!kfifo_is_empty(&state->xmit_fifo) &&
!tty->stopped && !tty->hw_stopped)
port->ops->start_tx(port);
}
@@ -141,7 +141,6 @@ static int uart_startup(struct tty_struct *tty, struct uart_state *state, int in
{
struct uart_port *uport = state->uart_port;
struct tty_port *port = &state->port;
- unsigned long page;
int retval = 0;
if (port->flags & ASYNC_INITIALIZED)
@@ -161,14 +160,10 @@ static int uart_startup(struct tty_struct *tty, struct uart_state *state, int in
* Initialise and allocate the transmit and temporary
* buffer.
*/
- if (!state->xmit.buf) {
- /* This is protected by the per port mutex */
- page = get_zeroed_page(GFP_KERNEL);
- if (!page)
+ if (!kfifo_initialized(&state->xmit_fifo)) {
+ retval = kfifo_alloc(&state->xmit_fifo, PAGE_SIZE, GFP_KERNEL);
+ if (retval)
return -ENOMEM;
-
- state->xmit.buf = (unsigned char *) page;
- uart_circ_clear(&state->xmit);
}
retval = uport->ops->startup(uport);
@@ -256,10 +251,7 @@ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
/*
* Free the transmit buffer page.
*/
- if (state->xmit.buf) {
- free_page((unsigned long)state->xmit.buf);
- state->xmit.buf = NULL;
- }
+ kfifo_free(&state->xmit_fifo);
}
/**
@@ -462,21 +454,13 @@ static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
}
static inline int __uart_put_char(struct uart_port *port,
- struct circ_buf *circ, unsigned char c)
+ struct kfifo *fifo, unsigned char c)
{
- unsigned long flags;
int ret = 0;
- if (!circ->buf)
+ if (!kfifo_initialized(fifo))
return 0;
-
- spin_lock_irqsave(&port->lock, flags);
- if (uart_circ_chars_free(circ) != 0) {
- circ->buf[circ->head] = c;
- circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
- ret = 1;
- }
- spin_unlock_irqrestore(&port->lock, flags);
+ kfifo_in_locked(fifo, &c, sizeof(c), &port->lock);
return ret;
}
@@ -484,7 +468,7 @@ static int uart_put_char(struct tty_struct *tty, unsigned char ch)
{
struct uart_state *state = tty->driver_data;
- return __uart_put_char(state->uart_port, &state->xmit, ch);
+ return __uart_put_char(state->uart_port, &state->xmit_fifo, ch);
}
static void uart_flush_chars(struct tty_struct *tty)
@@ -493,13 +477,11 @@ static void uart_flush_chars(struct tty_struct *tty)
}
static int uart_write(struct tty_struct *tty,
- const unsigned char *buf, int count)
+ const unsigned char *buf, int count)
{
struct uart_state *state = tty->driver_data;
struct uart_port *port;
- struct circ_buf *circ;
- unsigned long flags;
- int c, ret = 0;
+ int ret = 0;
/*
* This means you called this function _after_ the port was
@@ -511,25 +493,11 @@ static int uart_write(struct tty_struct *tty,
}
port = state->uart_port;
- circ = &state->xmit;
- if (!circ->buf)
+ if (!kfifo_initialized(&state->xmit_fifo))
return 0;
- spin_lock_irqsave(&port->lock, flags);
- while (1) {
- c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
- if (count < c)
- c = count;
- if (c <= 0)
- break;
- memcpy(circ->buf + circ->head, buf, c);
- circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
- buf += c;
- count -= c;
- ret += c;
- }
- spin_unlock_irqrestore(&port->lock, flags);
+ ret = kfifo_in_locked(&state->xmit_fifo, buf, count, &port->lock);
uart_start(tty);
return ret;
@@ -538,25 +506,13 @@ static int uart_write(struct tty_struct *tty,
static int uart_write_room(struct tty_struct *tty)
{
struct uart_state *state = tty->driver_data;
- unsigned long flags;
- int ret;
-
- spin_lock_irqsave(&state->uart_port->lock, flags);
- ret = uart_circ_chars_free(&state->xmit);
- spin_unlock_irqrestore(&state->uart_port->lock, flags);
- return ret;
+ return PAGE_SIZE - kfifo_len(&state->xmit_fifo);
}
static int uart_chars_in_buffer(struct tty_struct *tty)
{
struct uart_state *state = tty->driver_data;
- unsigned long flags;
- int ret;
-
- spin_lock_irqsave(&state->uart_port->lock, flags);
- ret = uart_circ_chars_pending(&state->xmit);
- spin_unlock_irqrestore(&state->uart_port->lock, flags);
- return ret;
+ return kfifo_len(&state->xmit_fifo);
}
static void uart_flush_buffer(struct tty_struct *tty)
@@ -578,7 +534,7 @@ static void uart_flush_buffer(struct tty_struct *tty)
pr_debug("uart_flush_buffer(%d) called\n", tty->index);
spin_lock_irqsave(&port->lock, flags);
- uart_circ_clear(&state->xmit);
+ kfifo_reset(&state->xmit_fifo);
if (port->ops->flush_buffer)
port->ops->flush_buffer(port);
spin_unlock_irqrestore(&port->lock, flags);
@@ -899,7 +855,7 @@ static int uart_get_lsr_info(struct tty_struct *tty,
* interrupt happens).
*/
if (uport->x_char ||
- ((uart_circ_chars_pending(&state->xmit) > 0) &&
+ ((!kfifo_is_empty(&state->xmit_fifo)) &&
!tty->stopped && !tty->hw_stopped))
result &= ~TIOCSER_TEMT;
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 41603d6..cf07aa7 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -206,7 +206,7 @@
#include <linux/compiler.h>
#include <linux/interrupt.h>
-#include <linux/circ_buf.h>
+#include <linux/kfifo.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/tty.h>
@@ -375,7 +375,7 @@ struct uart_state {
struct tty_port port;
int pm_state;
- struct circ_buf xmit;
+ struct kfifo xmit_fifo;
struct tasklet_struct tlet;
struct uart_port *uart_port;
--
1.7.3.2
--
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