Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753640AbZKCOb6 (ORCPT ); Tue, 3 Nov 2009 09:31:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753436AbZKCOb4 (ORCPT ); Tue, 3 Nov 2009 09:31:56 -0500 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:55425 "EHLO bob.linux.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752011AbZKCOby (ORCPT ); Tue, 3 Nov 2009 09:31:54 -0500 From: Alan Cox Subject: [PATCH 08/11] sdio_uart: Use kfifo instead of the messy circ stuff To: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, nico@cam.org Date: Tue, 03 Nov 2009 14:18:32 +0000 Message-ID: <20091103141827.31032.40688.stgit@localhost.localdomain> In-Reply-To: <20091103141525.31032.45206.stgit@localhost.localdomain> References: <20091103141525.31032.45206.stgit@localhost.localdomain> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6151 Lines: 220 Probably all the tty code should switch to this, especially when the new lockless kfifo is merged. Signed-off-by: Alan Cox --- drivers/mmc/card/sdio_uart.c | 86 +++++++++++++----------------------------- 1 files changed, 27 insertions(+), 59 deletions(-) diff --git a/drivers/mmc/card/sdio_uart.c b/drivers/mmc/card/sdio_uart.c index d41aa35..674f3bf 100644 --- a/drivers/mmc/card/sdio_uart.c +++ b/drivers/mmc/card/sdio_uart.c @@ -32,7 +32,7 @@ #include #include #include -#include +#include #include #include #include @@ -46,18 +46,9 @@ #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; @@ -81,7 +72,7 @@ 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; @@ -103,6 +94,9 @@ 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); + port->xmit_fifo = kfifo_alloc(FIFO_SIZE, GFP_KERNEL, &port->write_lock); + if (port->xmit_fifo == NULL) + return -ENOMEM; spin_lock(&sdio_uart_table_lock); for (index = 0; index < UART_NR; index++) { @@ -452,9 +446,11 @@ 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); @@ -465,24 +461,21 @@ static void sdio_uart_transmit_chars(struct sdio_uart_port *port) tty = tty_port_tty_get(&port->port); - if (tty == NULL || circ_empty(xmit) || tty->stopped || tty->hw_stopped) { + if (tty == NULL || !kfifo_len(xmit) || tty->stopped || tty->hw_stopped) { sdio_uart_stop_tx(port); return; } - count = 16; - do { - sdio_out(port, UART_TX, xmit->buf[xmit->tail]); - xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + len = kfifo_get(xmit, iobuf, 16); + 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) + if (len < WAKEUP_CHARS) tty_wakeup(tty); - if (circ_empty(xmit)) + if (len == 0) sdio_uart_stop_tx(port); tty_kref_put(tty); } @@ -605,22 +598,17 @@ 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. @@ -664,12 +652,10 @@ 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; } @@ -692,7 +678,7 @@ static void sdio_uart_shutdown(struct tty_port *tport) ret = sdio_uart_claim_func(port); if (ret) - goto skip; + return ret; sdio_uart_stop_rx(port); @@ -714,10 +700,6 @@ 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); } /** @@ -788,26 +770,12 @@ 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_put(port->xmit_fifo, buf, count); if ( !(port->ier & UART_IER_THRI)) { int err = sdio_uart_claim_func(port); @@ -825,13 +793,13 @@ 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) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/