From a092ab25fdaa445b821f5959e458350696fce44c Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Fri, 6 Mar 2020 22:44:31 +0100 Subject: tty: serial: fsl_lpuart: fix DMA mapping Use the correct device to request the DMA mapping. Otherwise the IOMMU doesn't get the mapping and it will generate a page fault. The error messages look like: [ 19.012140] arm-smmu 5000000.iommu: Unhandled context fault: fsr=0x402, iova=0xbbfff800, fsynr=0x3e0021, cbfrsynra=0x828, cb=9 [ 19.023593] arm-smmu 5000000.iommu: Unhandled context fault: fsr=0x402, iova=0xbbfff800, fsynr=0x3e0021, cbfrsynra=0x828, cb=9 This was tested on a custom board with a LS1028A SoC. Signed-off-by: Michael Walle Link: https://lore.kernel.org/r/20200306214433.23215-3-michael@walle.cc Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/fsl_lpuart.c | 48 ++++++++++++++++++++++++----------------- 1 file changed, 28 insertions(+), 20 deletions(-) (limited to 'drivers/tty/serial/fsl_lpuart.c') diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 33798df4d727..f45f97cb769c 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -409,6 +409,7 @@ static void lpuart_dma_tx(struct lpuart_port *sport) struct circ_buf *xmit = &sport->port.state->xmit; struct scatterlist *sgl = sport->tx_sgl; struct device *dev = sport->port.dev; + struct dma_chan *chan = sport->dma_tx_chan; int ret; if (sport->dma_tx_in_progress) @@ -427,17 +428,19 @@ static void lpuart_dma_tx(struct lpuart_port *sport) sg_set_buf(sgl + 1, xmit->buf, xmit->head); } - ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); + ret = dma_map_sg(chan->device->dev, sgl, sport->dma_tx_nents, + DMA_TO_DEVICE); if (!ret) { dev_err(dev, "DMA mapping error for TX.\n"); return; } - sport->dma_tx_desc = dmaengine_prep_slave_sg(sport->dma_tx_chan, sgl, + sport->dma_tx_desc = dmaengine_prep_slave_sg(chan, sgl, ret, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT); if (!sport->dma_tx_desc) { - dma_unmap_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); + dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents, + DMA_TO_DEVICE); dev_err(dev, "Cannot prepare TX slave DMA!\n"); return; } @@ -446,7 +449,7 @@ static void lpuart_dma_tx(struct lpuart_port *sport) sport->dma_tx_desc->callback_param = sport; sport->dma_tx_in_progress = true; sport->dma_tx_cookie = dmaengine_submit(sport->dma_tx_desc); - dma_async_issue_pending(sport->dma_tx_chan); + dma_async_issue_pending(chan); } static bool lpuart_stopped_or_empty(struct uart_port *port) @@ -459,11 +462,13 @@ static void lpuart_dma_tx_complete(void *arg) struct lpuart_port *sport = arg; struct scatterlist *sgl = &sport->tx_sgl[0]; struct circ_buf *xmit = &sport->port.state->xmit; + struct dma_chan *chan = sport->dma_tx_chan; unsigned long flags; spin_lock_irqsave(&sport->port.lock, flags); - dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); + dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents, + DMA_TO_DEVICE); xmit->tail = (xmit->tail + sport->dma_tx_bytes) & (UART_XMIT_SIZE - 1); @@ -529,15 +534,16 @@ static bool lpuart_is_32(struct lpuart_port *sport) static void lpuart_flush_buffer(struct uart_port *port) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); + struct dma_chan *chan = sport->dma_tx_chan; u32 val; if (sport->lpuart_dma_tx_use) { if (sport->dma_tx_in_progress) { - dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0], + dma_unmap_sg(chan->device->dev, &sport->tx_sgl[0], sport->dma_tx_nents, DMA_TO_DEVICE); sport->dma_tx_in_progress = false; } - dmaengine_terminate_all(sport->dma_tx_chan); + dmaengine_terminate_all(chan); } if (lpuart_is_32(sport)) { @@ -993,6 +999,7 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport) struct tty_port *port = &sport->port.state->port; struct dma_tx_state state; enum dma_status dmastat; + struct dma_chan *chan = sport->dma_rx_chan; struct circ_buf *ring = &sport->rx_ring; unsigned long flags; int count = 0; @@ -1053,10 +1060,7 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport) spin_lock_irqsave(&sport->port.lock, flags); - dmastat = dmaengine_tx_status(sport->dma_rx_chan, - sport->dma_rx_cookie, - &state); - + dmastat = dmaengine_tx_status(chan, sport->dma_rx_cookie, &state); if (dmastat == DMA_ERROR) { dev_err(sport->port.dev, "Rx DMA transfer failed!\n"); spin_unlock_irqrestore(&sport->port.lock, flags); @@ -1064,7 +1068,8 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport) } /* CPU claims ownership of RX DMA buffer */ - dma_sync_sg_for_cpu(sport->port.dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE); + dma_sync_sg_for_cpu(chan->device->dev, &sport->rx_sgl, 1, + DMA_FROM_DEVICE); /* * ring->head points to the end of data already written by the DMA. @@ -1106,7 +1111,7 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport) sport->port.icount.rx += count; } - dma_sync_sg_for_device(sport->port.dev, &sport->rx_sgl, 1, + dma_sync_sg_for_device(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE); spin_unlock_irqrestore(&sport->port.lock, flags); @@ -1138,6 +1143,7 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport) struct tty_port *port = &sport->port.state->port; struct tty_struct *tty = port->tty; struct ktermios *termios = &tty->termios; + struct dma_chan *chan = sport->dma_rx_chan; baud = tty_get_baud_rate(tty); @@ -1159,7 +1165,8 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport) return -ENOMEM; sg_init_one(&sport->rx_sgl, ring->buf, sport->rx_dma_rng_buf_len); - nent = dma_map_sg(sport->port.dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE); + nent = dma_map_sg(chan->device->dev, &sport->rx_sgl, 1, + DMA_FROM_DEVICE); if (!nent) { dev_err(sport->port.dev, "DMA Rx mapping error\n"); @@ -1170,7 +1177,7 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport) dma_rx_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; dma_rx_sconfig.src_maxburst = 1; dma_rx_sconfig.direction = DMA_DEV_TO_MEM; - ret = dmaengine_slave_config(sport->dma_rx_chan, &dma_rx_sconfig); + ret = dmaengine_slave_config(chan, &dma_rx_sconfig); if (ret < 0) { dev_err(sport->port.dev, @@ -1178,7 +1185,7 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport) return ret; } - sport->dma_rx_desc = dmaengine_prep_dma_cyclic(sport->dma_rx_chan, + sport->dma_rx_desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(&sport->rx_sgl), sport->rx_sgl.length, sport->rx_sgl.length / 2, @@ -1192,7 +1199,7 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport) sport->dma_rx_desc->callback = lpuart_dma_rx_complete; sport->dma_rx_desc->callback_param = sport; sport->dma_rx_cookie = dmaengine_submit(sport->dma_rx_desc); - dma_async_issue_pending(sport->dma_rx_chan); + dma_async_issue_pending(chan); if (lpuart_is_32(sport)) { unsigned long temp = lpuart32_read(&sport->port, UARTBAUD); @@ -1210,11 +1217,12 @@ static void lpuart_dma_rx_free(struct uart_port *port) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); + struct dma_chan *chan = sport->dma_rx_chan; - if (sport->dma_rx_chan) - dmaengine_terminate_all(sport->dma_rx_chan); + if (chan) + dmaengine_terminate_all(chan); - dma_unmap_sg(sport->port.dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE); + dma_unmap_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE); kfree(sport->rx_ring.buf); sport->rx_ring.tail = 0; sport->rx_ring.head = 0; -- cgit v1.2.3