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 <tomoya-linux@dsn.okisemi.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Tomoya MORINAGA
Greg Kroah-Hartman
Родитель
4c37705877
Коммит
da3564ee02
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@ -226,7 +226,8 @@ struct eg20t_port {
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struct pch_dma_slave param_rx;
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struct dma_chan *chan_tx;
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struct dma_chan *chan_rx;
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struct scatterlist sg_tx;
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struct scatterlist *sg_tx_p;
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int nent;
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struct scatterlist sg_rx;
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int tx_dma_use;
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void *rx_buf_virt;
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@ -595,16 +596,20 @@ static void pch_dma_rx_complete(void *arg)
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struct eg20t_port *priv = arg;
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struct uart_port *port = &priv->port;
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struct tty_struct *tty = tty_port_tty_get(&port->state->port);
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int count;
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if (!tty) {
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pr_debug("%s:tty is busy now", __func__);
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return;
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}
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if (dma_push_rx(priv, priv->trigger_level))
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dma_sync_sg_for_cpu(port->dev, &priv->sg_rx, 1, DMA_FROM_DEVICE);
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count = dma_push_rx(priv, priv->trigger_level);
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if (count)
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tty_flip_buffer_push(tty);
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tty_kref_put(tty);
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async_tx_ack(priv->desc_rx);
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pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_RX_INT);
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}
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static void pch_dma_tx_complete(void *arg)
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@ -612,13 +617,21 @@ static void pch_dma_tx_complete(void *arg)
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struct eg20t_port *priv = arg;
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struct uart_port *port = &priv->port;
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struct circ_buf *xmit = &port->state->xmit;
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struct scatterlist *sg = priv->sg_tx_p;
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int i;
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xmit->tail += sg_dma_len(&priv->sg_tx);
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for (i = 0; i < priv->nent; i++, sg++) {
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xmit->tail += sg_dma_len(sg);
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port->icount.tx += sg_dma_len(sg);
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}
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xmit->tail &= UART_XMIT_SIZE - 1;
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port->icount.tx += sg_dma_len(&priv->sg_tx);
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async_tx_ack(priv->desc_tx);
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dma_unmap_sg(port->dev, sg, priv->nent, DMA_TO_DEVICE);
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priv->tx_dma_use = 0;
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priv->nent = 0;
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kfree(priv->sg_tx_p);
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if (uart_circ_chars_pending(xmit))
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pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_TX_INT);
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}
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static int pop_tx(struct eg20t_port *priv, unsigned char *buf, int size)
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@ -682,7 +695,7 @@ static int dma_handle_rx(struct eg20t_port *priv)
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sg_init_table(&priv->sg_rx, 1); /* Initialize SG table */
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sg_dma_len(sg) = priv->fifo_size;
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sg_dma_len(sg) = priv->trigger_level;
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sg_set_page(&priv->sg_rx, virt_to_page(priv->rx_buf_virt),
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sg_dma_len(sg), (unsigned long)priv->rx_buf_virt &
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@ -692,7 +705,8 @@ static int dma_handle_rx(struct eg20t_port *priv)
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desc = priv->chan_rx->device->device_prep_slave_sg(priv->chan_rx,
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sg, 1, DMA_FROM_DEVICE,
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DMA_PREP_INTERRUPT);
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DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
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if (!desc)
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return 0;
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@ -731,6 +745,9 @@ static unsigned int handle_tx(struct eg20t_port *priv)
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fifo_size--;
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}
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size = min(xmit->head - xmit->tail, fifo_size);
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if (size < 0)
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size = fifo_size;
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tx_size = pop_tx(priv, xmit->buf, size);
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if (tx_size > 0) {
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ret = pch_uart_hal_write(priv, xmit->buf, tx_size);
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@ -740,8 +757,10 @@ static unsigned int handle_tx(struct eg20t_port *priv)
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priv->tx_empty = tx_empty;
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if (tx_empty)
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if (tx_empty) {
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pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
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uart_write_wakeup(port);
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}
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return PCH_UART_HANDLED_TX_INT;
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}
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@ -750,11 +769,16 @@ static unsigned int dma_handle_tx(struct eg20t_port *priv)
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{
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struct uart_port *port = &priv->port;
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struct circ_buf *xmit = &port->state->xmit;
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struct scatterlist *sg = &priv->sg_tx;
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struct scatterlist *sg;
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int nent;
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int fifo_size;
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int tx_empty;
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struct dma_async_tx_descriptor *desc;
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int num;
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int i;
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int bytes;
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int size;
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int rem;
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if (!priv->start_tx) {
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pr_info("%s:Tx isn't started. (%lu)\n", __func__, jiffies);
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@ -772,37 +796,68 @@ static unsigned int dma_handle_tx(struct eg20t_port *priv)
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fifo_size--;
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}
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pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
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bytes = min((int)CIRC_CNT(xmit->head, xmit->tail,
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UART_XMIT_SIZE), CIRC_CNT_TO_END(xmit->head,
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xmit->tail, UART_XMIT_SIZE));
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if (!bytes) {
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pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
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uart_write_wakeup(port);
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return 0;
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}
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if (bytes > fifo_size) {
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num = bytes / fifo_size + 1;
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size = fifo_size;
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rem = bytes % fifo_size;
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} else {
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num = 1;
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size = bytes;
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rem = bytes;
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}
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priv->tx_dma_use = 1;
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sg_init_table(&priv->sg_tx, 1); /* Initialize SG table */
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priv->sg_tx_p = kzalloc(sizeof(struct scatterlist)*num, GFP_ATOMIC);
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sg_set_page(&priv->sg_tx, virt_to_page(xmit->buf),
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UART_XMIT_SIZE, (int)xmit->buf & ~PAGE_MASK);
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sg_init_table(priv->sg_tx_p, num); /* Initialize SG table */
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sg = priv->sg_tx_p;
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nent = dma_map_sg(port->dev, &priv->sg_tx, 1, DMA_TO_DEVICE);
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for (i = 0; i < num; i++, sg++) {
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if (i == (num - 1))
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sg_set_page(sg, virt_to_page(xmit->buf),
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rem, fifo_size * i);
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else
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sg_set_page(sg, virt_to_page(xmit->buf),
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size, fifo_size * i);
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}
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sg = priv->sg_tx_p;
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nent = dma_map_sg(port->dev, sg, num, DMA_TO_DEVICE);
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if (!nent) {
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pr_err("%s:dma_map_sg Failed\n", __func__);
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return 0;
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}
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priv->nent = nent;
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sg->offset = xmit->tail & (UART_XMIT_SIZE - 1);
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sg_dma_address(sg) = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) +
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sg->offset;
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sg_dma_len(sg) = min((int)CIRC_CNT(xmit->head, xmit->tail,
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UART_XMIT_SIZE), CIRC_CNT_TO_END(xmit->head,
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xmit->tail, UART_XMIT_SIZE));
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for (i = 0; i < nent; i++, sg++) {
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sg->offset = (xmit->tail & (UART_XMIT_SIZE - 1)) +
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fifo_size * i;
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sg_dma_address(sg) = (sg_dma_address(sg) &
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~(UART_XMIT_SIZE - 1)) + sg->offset;
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if (i == (nent - 1))
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sg_dma_len(sg) = rem;
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else
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sg_dma_len(sg) = size;
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}
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desc = priv->chan_tx->device->device_prep_slave_sg(priv->chan_tx,
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sg, nent, DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
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priv->sg_tx_p, nent, DMA_TO_DEVICE,
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DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
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if (!desc) {
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pr_err("%s:device_prep_slave_sg Failed\n", __func__);
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return 0;
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}
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dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE);
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dma_sync_sg_for_device(port->dev, priv->sg_tx_p, nent, DMA_TO_DEVICE);
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priv->desc_tx = desc;
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desc->callback = pch_dma_tx_complete;
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desc->callback_param = priv;
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@ -857,10 +912,16 @@ static irqreturn_t pch_uart_interrupt(int irq, void *dev_id)
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}
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break;
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case PCH_UART_IID_RDR: /* Received Data Ready */
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if (priv->use_dma)
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if (priv->use_dma) {
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pch_uart_hal_disable_interrupt(priv,
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PCH_UART_HAL_RX_INT);
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ret = dma_handle_rx(priv);
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else
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if (!ret)
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pch_uart_hal_enable_interrupt(priv,
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PCH_UART_HAL_RX_INT);
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} else {
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ret = handle_rx(priv);
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}
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break;
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case PCH_UART_IID_RDR_TO: /* Received Data Ready
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(FIFO Timeout) */
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