From 8b197a5ce7a7218bb9fc721647ba0d5734f27348 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 8 Feb 2010 10:08:39 +0000 Subject: [PATCH] sdio_uart: Use kfifo instead of the messy circ stuff Revised patch to use the new kfifo API. This replaces the one that was dropped from -next due to collisions with the kfifo API changes. Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/mmc/card/sdio_uart.c | 93 ++++++++++++++------------------------------ 1 file changed, 30 insertions(+), 63 deletions(-) diff --git a/drivers/mmc/card/sdio_uart.c b/drivers/mmc/card/sdio_uart.c index f537555..3fab78b 100644 --- a/drivers/mmc/card/sdio_uart.c +++ b/drivers/mmc/card/sdio_uart.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include @@ -47,19 +48,9 @@ #define UART_NR 8 /* Number of UARTs this driver can handle */ -#define UART_XMIT_SIZE PAGE_SIZE +#define FIFO_SIZE PAGE_SIZE #define WAKEUP_CHARS 256 -#define circ_empty(circ) ((circ)->head == (circ)->tail) -#define circ_clear(circ) ((circ)->head = (circ)->tail = 0) - -#define circ_chars_pending(circ) \ - (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE)) - -#define circ_chars_free(circ) \ - (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE)) - - struct uart_icount { __u32 cts; __u32 dsr; @@ -82,7 +73,7 @@ struct sdio_uart_port { struct mutex func_lock; struct task_struct *in_sdio_uart_irq; unsigned int regs_offset; - struct circ_buf xmit; + struct kfifo xmit_fifo; spinlock_t write_lock; struct uart_icount icount; unsigned int uartclk; @@ -105,6 +96,8 @@ static int sdio_uart_add_port(struct sdio_uart_port *port) kref_init(&port->kref); mutex_init(&port->func_lock); spin_lock_init(&port->write_lock); + if (kfifo_alloc(&port->xmit_fifo, FIFO_SIZE, GFP_KERNEL)) + return -ENOMEM; spin_lock(&sdio_uart_table_lock); for (index = 0; index < UART_NR; index++) { @@ -140,6 +133,7 @@ static void sdio_uart_port_destroy(struct kref *kref) { struct sdio_uart_port *port = container_of(kref, struct sdio_uart_port, kref); + kfifo_free(&port->xmit_fifo); kfree(port); } @@ -456,9 +450,11 @@ static void sdio_uart_receive_chars(struct sdio_uart_port *port, static void sdio_uart_transmit_chars(struct sdio_uart_port *port) { - struct circ_buf *xmit = &port->xmit; + struct kfifo *xmit = &port->xmit_fifo; int count; struct tty_struct *tty; + u8 iobuf[16]; + int len; if (port->x_char) { sdio_out(port, UART_TX, port->x_char); @@ -469,27 +465,25 @@ static void sdio_uart_transmit_chars(struct sdio_uart_port *port) tty = tty_port_tty_get(&port->port); - if (tty == NULL || circ_empty(xmit) || + if (tty == NULL || !kfifo_len(xmit) || tty->stopped || tty->hw_stopped) { sdio_uart_stop_tx(port); tty_kref_put(tty); return; } - count = 16; - do { - sdio_out(port, UART_TX, xmit->buf[xmit->tail]); - xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + len = kfifo_out_locked(xmit, iobuf, 16, &port->write_lock); + for (count = 0; count < len; count++) { + sdio_out(port, UART_TX, iobuf[count]); port->icount.tx++; - if (circ_empty(xmit)) - break; - } while (--count > 0); + } - if (circ_chars_pending(xmit) < WAKEUP_CHARS) + len = kfifo_len(xmit); + if (len < WAKEUP_CHARS) { tty_wakeup(tty); - - if (circ_empty(xmit)) - sdio_uart_stop_tx(port); + if (len == 0) + sdio_uart_stop_tx(port); + } tty_kref_put(tty); } @@ -632,7 +626,6 @@ static int sdio_uart_activate(struct tty_port *tport, struct tty_struct *tty) { struct sdio_uart_port *port = container_of(tport, struct sdio_uart_port, port); - unsigned long page; int ret; /* @@ -641,22 +634,17 @@ static int sdio_uart_activate(struct tty_port *tport, struct tty_struct *tty) */ set_bit(TTY_IO_ERROR, &tty->flags); - /* Initialise and allocate the transmit buffer. */ - page = __get_free_page(GFP_KERNEL); - if (!page) - return -ENOMEM; - port->xmit.buf = (unsigned char *)page; - circ_clear(&port->xmit); + kfifo_reset(&port->xmit_fifo); ret = sdio_uart_claim_func(port); if (ret) - goto err1; + return ret; ret = sdio_enable_func(port->func); if (ret) - goto err2; + goto err1; ret = sdio_claim_irq(port->func, sdio_uart_irq); if (ret) - goto err3; + goto err2; /* * Clear the FIFO buffers and disable them. @@ -700,12 +688,10 @@ static int sdio_uart_activate(struct tty_port *tport, struct tty_struct *tty) sdio_uart_release_func(port); return 0; -err3: - sdio_disable_func(port->func); err2: - sdio_uart_release_func(port); + sdio_disable_func(port->func); err1: - free_page((unsigned long)port->xmit.buf); + sdio_uart_release_func(port); return ret; } @@ -727,7 +713,7 @@ static void sdio_uart_shutdown(struct tty_port *tport) ret = sdio_uart_claim_func(port); if (ret) - goto skip; + return; sdio_uart_stop_rx(port); @@ -749,10 +735,6 @@ static void sdio_uart_shutdown(struct tty_port *tport) sdio_disable_func(port->func); sdio_uart_release_func(port); - -skip: - /* Free the transmit buffer page. */ - free_page((unsigned long)port->xmit.buf); } /** @@ -822,27 +804,12 @@ static int sdio_uart_write(struct tty_struct *tty, const unsigned char *buf, int count) { struct sdio_uart_port *port = tty->driver_data; - struct circ_buf *circ = &port->xmit; - int c, ret = 0; + int ret; if (!port->func) return -ENODEV; - spin_lock(&port->write_lock); - 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(&port->write_lock); - + ret = kfifo_in_locked(&port->xmit_fifo, buf, count, &port->write_lock); if (!(port->ier & UART_IER_THRI)) { int err = sdio_uart_claim_func(port); if (!err) { @@ -859,13 +826,13 @@ static int sdio_uart_write(struct tty_struct *tty, const unsigned char *buf, static int sdio_uart_write_room(struct tty_struct *tty) { struct sdio_uart_port *port = tty->driver_data; - return port ? circ_chars_free(&port->xmit) : 0; + return FIFO_SIZE - kfifo_len(&port->xmit_fifo); } static int sdio_uart_chars_in_buffer(struct tty_struct *tty) { struct sdio_uart_port *port = tty->driver_data; - return port ? circ_chars_pending(&port->xmit) : 0; + return kfifo_len(&port->xmit_fifo); } static void sdio_uart_send_xchar(struct tty_struct *tty, char ch) -- 1.8.2.3