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author | Jiri Slaby (SUSE) <jirislaby@kernel.org> | 2024-04-05 09:08:22 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-09 16:28:03 +0300 |
commit | f8fef2fa419febbfed2d04f0518111565df2673d (patch) | |
tree | d3cff979b5fa693eaef08965e6681d0b1ca76b56 | |
parent | 9054605ab8468936a514298211d9e9bb68bf24bd (diff) | |
download | linux-f8fef2fa419febbfed2d04f0518111565df2673d.tar.xz |
tty: msm_serial: use dmaengine_prep_slave_sg()
This is a preparatory for the serial-to-kfifo switch. kfifo understands
only scatter-gatter approach, so switch to that.
No functional change intended, it's just dmaengine_prep_slave_single()
inline expanded.
And in this case, switch from dma_map_single() to dma_map_sg() too. This
needs struct msm_dma changes. I split the rx and tx parts into an union.
TX is now struct scatterlist, RX remains the old good phys-virt-count
triple.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Konrad Dybcio <konrad.dybcio@linaro.org>
Cc: linux-arm-msm@vger.kernel.org
Link: https://lore.kernel.org/r/20240405060826.2521-12-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | drivers/tty/serial/msm_serial.c | 86 |
1 files changed, 49 insertions, 37 deletions
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c index d27c4c8c84e1..7bf30e632313 100644 --- a/drivers/tty/serial/msm_serial.c +++ b/drivers/tty/serial/msm_serial.c @@ -161,11 +161,16 @@ enum { struct msm_dma { struct dma_chan *chan; enum dma_data_direction dir; - dma_addr_t phys; - unsigned char *virt; + union { + struct { + dma_addr_t phys; + unsigned char *virt; + unsigned int count; + } rx; + struct scatterlist tx_sg; + }; dma_cookie_t cookie; u32 enable_bit; - unsigned int count; struct dma_async_tx_descriptor *desc; }; @@ -249,8 +254,12 @@ static void msm_stop_dma(struct uart_port *port, struct msm_dma *dma) unsigned int mapped; u32 val; - mapped = dma->count; - dma->count = 0; + if (dma->dir == DMA_TO_DEVICE) { + mapped = sg_dma_len(&dma->tx_sg); + } else { + mapped = dma->rx.count; + dma->rx.count = 0; + } dmaengine_terminate_all(dma->chan); @@ -265,8 +274,13 @@ static void msm_stop_dma(struct uart_port *port, struct msm_dma *dma) val &= ~dma->enable_bit; msm_write(port, val, UARTDM_DMEN); - if (mapped) - dma_unmap_single(dev, dma->phys, mapped, dma->dir); + if (mapped) { + if (dma->dir == DMA_TO_DEVICE) { + dma_unmap_sg(dev, &dma->tx_sg, 1, dma->dir); + sg_init_table(&dma->tx_sg, 1); + } else + dma_unmap_single(dev, dma->rx.phys, mapped, dma->dir); + } } static void msm_release_dma(struct msm_port *msm_port) @@ -285,7 +299,7 @@ static void msm_release_dma(struct msm_port *msm_port) if (dma->chan) { msm_stop_dma(&msm_port->uart, dma); dma_release_channel(dma->chan); - kfree(dma->virt); + kfree(dma->rx.virt); } memset(dma, 0, sizeof(*dma)); @@ -357,8 +371,8 @@ static void msm_request_rx_dma(struct msm_port *msm_port, resource_size_t base) of_property_read_u32(dev->of_node, "qcom,rx-crci", &crci); - dma->virt = kzalloc(UARTDM_RX_SIZE, GFP_KERNEL); - if (!dma->virt) + dma->rx.virt = kzalloc(UARTDM_RX_SIZE, GFP_KERNEL); + if (!dma->rx.virt) goto rel_rx; memset(&conf, 0, sizeof(conf)); @@ -385,7 +399,7 @@ static void msm_request_rx_dma(struct msm_port *msm_port, resource_size_t base) return; err: - kfree(dma->virt); + kfree(dma->rx.virt); rel_rx: dma_release_channel(dma->chan); no_rx: @@ -420,7 +434,7 @@ static void msm_start_tx(struct uart_port *port) struct msm_dma *dma = &msm_port->tx_dma; /* Already started in DMA mode */ - if (dma->count) + if (sg_dma_len(&dma->tx_sg)) return; msm_port->imr |= MSM_UART_IMR_TXLEV; @@ -448,12 +462,12 @@ static void msm_complete_tx_dma(void *args) uart_port_lock_irqsave(port, &flags); /* Already stopped */ - if (!dma->count) + if (!sg_dma_len(&dma->tx_sg)) goto done; dmaengine_tx_status(dma->chan, dma->cookie, &state); - dma_unmap_single(port->dev, dma->phys, dma->count, dma->dir); + dma_unmap_sg(port->dev, &dma->tx_sg, 1, dma->dir); val = msm_read(port, UARTDM_DMEN); val &= ~dma->enable_bit; @@ -464,9 +478,9 @@ static void msm_complete_tx_dma(void *args) msm_write(port, MSM_UART_CR_TX_ENABLE, MSM_UART_CR); } - count = dma->count - state.residue; + count = sg_dma_len(&dma->tx_sg) - state.residue; uart_xmit_advance(port, count); - dma->count = 0; + sg_init_table(&dma->tx_sg, 1); /* Restore "Tx FIFO below watermark" interrupt */ msm_port->imr |= MSM_UART_IMR_TXLEV; @@ -485,19 +499,18 @@ static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count) struct circ_buf *xmit = &msm_port->uart.state->xmit; struct uart_port *port = &msm_port->uart; struct msm_dma *dma = &msm_port->tx_dma; - void *cpu_addr; int ret; u32 val; - cpu_addr = &xmit->buf[xmit->tail]; + sg_init_table(&dma->tx_sg, 1); + sg_set_buf(&dma->tx_sg, &xmit->buf[xmit->tail], count); - dma->phys = dma_map_single(port->dev, cpu_addr, count, dma->dir); - ret = dma_mapping_error(port->dev, dma->phys); + ret = dma_map_sg(port->dev, &dma->tx_sg, 1, dma->dir); if (ret) return ret; - dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys, - count, DMA_MEM_TO_DEV, + dma->desc = dmaengine_prep_slave_sg(dma->chan, &dma->tx_sg, 1, + DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_PREP_FENCE); if (!dma->desc) { @@ -520,8 +533,6 @@ static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count) msm_port->imr &= ~MSM_UART_IMR_TXLEV; msm_write(port, msm_port->imr, MSM_UART_IMR); - dma->count = count; - val = msm_read(port, UARTDM_DMEN); val |= dma->enable_bit; @@ -536,7 +547,8 @@ static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count) dma_async_issue_pending(dma->chan); return 0; unmap: - dma_unmap_single(port->dev, dma->phys, count, dma->dir); + dma_unmap_sg(port->dev, &dma->tx_sg, 1, dma->dir); + sg_init_table(&dma->tx_sg, 1); return ret; } @@ -553,7 +565,7 @@ static void msm_complete_rx_dma(void *args) uart_port_lock_irqsave(port, &flags); /* Already stopped */ - if (!dma->count) + if (!dma->rx.count) goto done; val = msm_read(port, UARTDM_DMEN); @@ -570,14 +582,14 @@ static void msm_complete_rx_dma(void *args) port->icount.rx += count; - dma->count = 0; + dma->rx.count = 0; - dma_unmap_single(port->dev, dma->phys, UARTDM_RX_SIZE, dma->dir); + dma_unmap_single(port->dev, dma->rx.phys, UARTDM_RX_SIZE, dma->dir); for (i = 0; i < count; i++) { char flag = TTY_NORMAL; - if (msm_port->break_detected && dma->virt[i] == 0) { + if (msm_port->break_detected && dma->rx.virt[i] == 0) { port->icount.brk++; flag = TTY_BREAK; msm_port->break_detected = false; @@ -588,9 +600,9 @@ static void msm_complete_rx_dma(void *args) if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK)) flag = TTY_NORMAL; - sysrq = uart_prepare_sysrq_char(port, dma->virt[i]); + sysrq = uart_prepare_sysrq_char(port, dma->rx.virt[i]); if (!sysrq) - tty_insert_flip_char(tport, dma->virt[i], flag); + tty_insert_flip_char(tport, dma->rx.virt[i], flag); } msm_start_rx_dma(msm_port); @@ -614,13 +626,13 @@ static void msm_start_rx_dma(struct msm_port *msm_port) if (!dma->chan) return; - dma->phys = dma_map_single(uart->dev, dma->virt, + dma->rx.phys = dma_map_single(uart->dev, dma->rx.virt, UARTDM_RX_SIZE, dma->dir); - ret = dma_mapping_error(uart->dev, dma->phys); + ret = dma_mapping_error(uart->dev, dma->rx.phys); if (ret) goto sw_mode; - dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys, + dma->desc = dmaengine_prep_slave_single(dma->chan, dma->rx.phys, UARTDM_RX_SIZE, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); if (!dma->desc) @@ -648,7 +660,7 @@ static void msm_start_rx_dma(struct msm_port *msm_port) msm_write(uart, msm_port->imr, MSM_UART_IMR); - dma->count = UARTDM_RX_SIZE; + dma->rx.count = UARTDM_RX_SIZE; dma_async_issue_pending(dma->chan); @@ -668,7 +680,7 @@ static void msm_start_rx_dma(struct msm_port *msm_port) return; unmap: - dma_unmap_single(uart->dev, dma->phys, UARTDM_RX_SIZE, dma->dir); + dma_unmap_single(uart->dev, dma->rx.phys, UARTDM_RX_SIZE, dma->dir); sw_mode: /* @@ -955,7 +967,7 @@ static irqreturn_t msm_uart_irq(int irq, void *dev_id) } if (misr & (MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE)) { - if (dma->count) { + if (dma->rx.count) { val = MSM_UART_CR_CMD_STALE_EVENT_DISABLE; msm_write(port, val, MSM_UART_CR); val = MSM_UART_CR_CMD_RESET_STALE_INT; |