From da3564ee027e788a5ff8e520fb2d2b00a78b2464 Mon Sep 17 00:00:00 2001 From: Tomoya MORINAGA Date: Wed, 23 Feb 2011 10:03:12 +0900 Subject: [PATCH] pch_uart: add multi-scatter processing Currently, this driver can handle only single scatterlist. Thus, it can't send data beyond FIFO size. This patch enables this driver can handle multiple scatter list. Signed-off-by: Tomoya MORINAGA Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/pch_uart.c | 117 ++++++++++++++++++++++++++++++++---------- 1 file changed, 89 insertions(+), 28 deletions(-) diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c index 3b2fb93..c1386eb 100644 --- a/drivers/tty/serial/pch_uart.c +++ b/drivers/tty/serial/pch_uart.c @@ -226,7 +226,8 @@ struct eg20t_port { struct pch_dma_slave param_rx; struct dma_chan *chan_tx; struct dma_chan *chan_rx; - struct scatterlist sg_tx; + struct scatterlist *sg_tx_p; + int nent; struct scatterlist sg_rx; int tx_dma_use; void *rx_buf_virt; @@ -595,16 +596,20 @@ static void pch_dma_rx_complete(void *arg) struct eg20t_port *priv = arg; struct uart_port *port = &priv->port; struct tty_struct *tty = tty_port_tty_get(&port->state->port); + int count; if (!tty) { pr_debug("%s:tty is busy now", __func__); return; } - if (dma_push_rx(priv, priv->trigger_level)) + dma_sync_sg_for_cpu(port->dev, &priv->sg_rx, 1, DMA_FROM_DEVICE); + count = dma_push_rx(priv, priv->trigger_level); + if (count) tty_flip_buffer_push(tty); - tty_kref_put(tty); + async_tx_ack(priv->desc_rx); + pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_RX_INT); } static void pch_dma_tx_complete(void *arg) @@ -612,13 +617,21 @@ static void pch_dma_tx_complete(void *arg) struct eg20t_port *priv = arg; struct uart_port *port = &priv->port; struct circ_buf *xmit = &port->state->xmit; + struct scatterlist *sg = priv->sg_tx_p; + int i; - xmit->tail += sg_dma_len(&priv->sg_tx); + for (i = 0; i < priv->nent; i++, sg++) { + xmit->tail += sg_dma_len(sg); + port->icount.tx += sg_dma_len(sg); + } xmit->tail &= UART_XMIT_SIZE - 1; - port->icount.tx += sg_dma_len(&priv->sg_tx); - async_tx_ack(priv->desc_tx); + dma_unmap_sg(port->dev, sg, priv->nent, DMA_TO_DEVICE); priv->tx_dma_use = 0; + priv->nent = 0; + kfree(priv->sg_tx_p); + if (uart_circ_chars_pending(xmit)) + pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_TX_INT); } static int pop_tx(struct eg20t_port *priv, unsigned char *buf, int size) @@ -682,7 +695,7 @@ static int dma_handle_rx(struct eg20t_port *priv) sg_init_table(&priv->sg_rx, 1); /* Initialize SG table */ - sg_dma_len(sg) = priv->fifo_size; + sg_dma_len(sg) = priv->trigger_level; sg_set_page(&priv->sg_rx, virt_to_page(priv->rx_buf_virt), sg_dma_len(sg), (unsigned long)priv->rx_buf_virt & @@ -692,7 +705,8 @@ static int dma_handle_rx(struct eg20t_port *priv) desc = priv->chan_rx->device->device_prep_slave_sg(priv->chan_rx, sg, 1, DMA_FROM_DEVICE, - DMA_PREP_INTERRUPT); + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) return 0; @@ -731,6 +745,9 @@ static unsigned int handle_tx(struct eg20t_port *priv) fifo_size--; } size = min(xmit->head - xmit->tail, fifo_size); + if (size < 0) + size = fifo_size; + tx_size = pop_tx(priv, xmit->buf, size); if (tx_size > 0) { ret = pch_uart_hal_write(priv, xmit->buf, tx_size); @@ -740,8 +757,10 @@ static unsigned int handle_tx(struct eg20t_port *priv) priv->tx_empty = tx_empty; - if (tx_empty) + if (tx_empty) { pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT); + uart_write_wakeup(port); + } return PCH_UART_HANDLED_TX_INT; } @@ -750,11 +769,16 @@ static unsigned int dma_handle_tx(struct eg20t_port *priv) { struct uart_port *port = &priv->port; struct circ_buf *xmit = &port->state->xmit; - struct scatterlist *sg = &priv->sg_tx; + struct scatterlist *sg; int nent; int fifo_size; int tx_empty; struct dma_async_tx_descriptor *desc; + int num; + int i; + int bytes; + int size; + int rem; if (!priv->start_tx) { pr_info("%s:Tx isn't started. (%lu)\n", __func__, jiffies); @@ -772,37 +796,68 @@ static unsigned int dma_handle_tx(struct eg20t_port *priv) fifo_size--; } - pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT); + bytes = min((int)CIRC_CNT(xmit->head, xmit->tail, + UART_XMIT_SIZE), CIRC_CNT_TO_END(xmit->head, + xmit->tail, UART_XMIT_SIZE)); + if (!bytes) { + pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT); + uart_write_wakeup(port); + return 0; + } + + if (bytes > fifo_size) { + num = bytes / fifo_size + 1; + size = fifo_size; + rem = bytes % fifo_size; + } else { + num = 1; + size = bytes; + rem = bytes; + } priv->tx_dma_use = 1; - sg_init_table(&priv->sg_tx, 1); /* Initialize SG table */ + priv->sg_tx_p = kzalloc(sizeof(struct scatterlist)*num, GFP_ATOMIC); + + sg_init_table(priv->sg_tx_p, num); /* Initialize SG table */ + sg = priv->sg_tx_p; - sg_set_page(&priv->sg_tx, virt_to_page(xmit->buf), - UART_XMIT_SIZE, (int)xmit->buf & ~PAGE_MASK); + for (i = 0; i < num; i++, sg++) { + if (i == (num - 1)) + sg_set_page(sg, virt_to_page(xmit->buf), + rem, fifo_size * i); + else + sg_set_page(sg, virt_to_page(xmit->buf), + size, fifo_size * i); + } - nent = dma_map_sg(port->dev, &priv->sg_tx, 1, DMA_TO_DEVICE); + sg = priv->sg_tx_p; + nent = dma_map_sg(port->dev, sg, num, DMA_TO_DEVICE); if (!nent) { pr_err("%s:dma_map_sg Failed\n", __func__); return 0; } - - sg->offset = xmit->tail & (UART_XMIT_SIZE - 1); - sg_dma_address(sg) = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) + - sg->offset; - sg_dma_len(sg) = min((int)CIRC_CNT(xmit->head, xmit->tail, - UART_XMIT_SIZE), CIRC_CNT_TO_END(xmit->head, - xmit->tail, UART_XMIT_SIZE)); + priv->nent = nent; + + for (i = 0; i < nent; i++, sg++) { + sg->offset = (xmit->tail & (UART_XMIT_SIZE - 1)) + + fifo_size * i; + sg_dma_address(sg) = (sg_dma_address(sg) & + ~(UART_XMIT_SIZE - 1)) + sg->offset; + if (i == (nent - 1)) + sg_dma_len(sg) = rem; + else + sg_dma_len(sg) = size; + } desc = priv->chan_tx->device->device_prep_slave_sg(priv->chan_tx, - sg, nent, DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + priv->sg_tx_p, nent, DMA_TO_DEVICE, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!desc) { pr_err("%s:device_prep_slave_sg Failed\n", __func__); return 0; } - - dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE); - + dma_sync_sg_for_device(port->dev, priv->sg_tx_p, nent, DMA_TO_DEVICE); priv->desc_tx = desc; desc->callback = pch_dma_tx_complete; desc->callback_param = priv; @@ -857,10 +912,16 @@ static irqreturn_t pch_uart_interrupt(int irq, void *dev_id) } break; case PCH_UART_IID_RDR: /* Received Data Ready */ - if (priv->use_dma) + if (priv->use_dma) { + pch_uart_hal_disable_interrupt(priv, + PCH_UART_HAL_RX_INT); ret = dma_handle_rx(priv); - else + if (!ret) + pch_uart_hal_enable_interrupt(priv, + PCH_UART_HAL_RX_INT); + } else { ret = handle_rx(priv); + } break; case PCH_UART_IID_RDR_TO: /* Received Data Ready (FIFO Timeout) */ -- 2.7.4