ARM: PL011: Fix DMA support
commit 58ac1b3799799069d53f5bf95c093f2fe8dd3cc5 upstream.
Since there is no guarantee that the memory returned by
dma_alloc_coherent() is associated with a 'struct page', using the
architecture specific phys_to_page() is wrong, but using
virt_to_page() would be as well.
Stop using sg lists altogether and just use the *_single() functions
instead. This also simplifies the code a bit since the scatterlists in
this driver always have only one entry anyway.
https://lore.kernel.org/lkml/86db0fe5-930d-4cbb-bd7d-03367da38951@app.fastmail.com/
Use consistent names for dma buffers
gc: Add a commit log from the initial thread:
https://lore.kernel.org/lkml/86db0fe5-930d-4cbb-bd7d-03367da38951@app.fastmail.com/
Use consistent names for dma buffers
Fixes: cb06ff102e
("ARM: PL011: Add support for Rx DMA buffer polling.")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20231122171503.235649-1-gregory.clement@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Родитель
9402252dda
Коммит
87ac270412
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@ -222,17 +222,18 @@ static struct vendor_data vendor_zte = {
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/* Deals with DMA transactions */
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struct pl011_sgbuf {
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struct scatterlist sg;
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char *buf;
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struct pl011_dmabuf {
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dma_addr_t dma;
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size_t len;
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char *buf;
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};
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struct pl011_dmarx_data {
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struct dma_chan *chan;
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struct completion complete;
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bool use_buf_b;
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struct pl011_sgbuf sgbuf_a;
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struct pl011_sgbuf sgbuf_b;
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struct pl011_dmabuf dbuf_a;
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struct pl011_dmabuf dbuf_b;
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dma_cookie_t cookie;
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bool running;
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struct timer_list timer;
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@ -245,7 +246,8 @@ struct pl011_dmarx_data {
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struct pl011_dmatx_data {
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struct dma_chan *chan;
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struct scatterlist sg;
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dma_addr_t dma;
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size_t len;
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char *buf;
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bool queued;
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};
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@ -370,32 +372,24 @@ static int pl011_fifo_to_tty(struct uart_amba_port *uap)
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#define PL011_DMA_BUFFER_SIZE PAGE_SIZE
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static int pl011_sgbuf_init(struct dma_chan *chan, struct pl011_sgbuf *sg,
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static int pl011_dmabuf_init(struct dma_chan *chan, struct pl011_dmabuf *db,
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enum dma_data_direction dir)
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{
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dma_addr_t dma_addr;
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sg->buf = dma_alloc_coherent(chan->device->dev,
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PL011_DMA_BUFFER_SIZE, &dma_addr, GFP_KERNEL);
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if (!sg->buf)
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db->buf = dma_alloc_coherent(chan->device->dev, PL011_DMA_BUFFER_SIZE,
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&db->dma, GFP_KERNEL);
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if (!db->buf)
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return -ENOMEM;
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sg_init_table(&sg->sg, 1);
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sg_set_page(&sg->sg, phys_to_page(dma_addr),
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PL011_DMA_BUFFER_SIZE, offset_in_page(dma_addr));
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sg_dma_address(&sg->sg) = dma_addr;
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sg_dma_len(&sg->sg) = PL011_DMA_BUFFER_SIZE;
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db->len = PL011_DMA_BUFFER_SIZE;
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return 0;
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}
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static void pl011_sgbuf_free(struct dma_chan *chan, struct pl011_sgbuf *sg,
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static void pl011_dmabuf_free(struct dma_chan *chan, struct pl011_dmabuf *db,
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enum dma_data_direction dir)
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{
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if (sg->buf) {
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if (db->buf) {
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dma_free_coherent(chan->device->dev,
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PL011_DMA_BUFFER_SIZE, sg->buf,
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sg_dma_address(&sg->sg));
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PL011_DMA_BUFFER_SIZE, db->buf, db->dma);
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}
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}
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@ -556,8 +550,8 @@ static void pl011_dma_tx_callback(void *data)
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spin_lock_irqsave(&uap->port.lock, flags);
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if (uap->dmatx.queued)
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dma_unmap_sg(dmatx->chan->device->dev, &dmatx->sg, 1,
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DMA_TO_DEVICE);
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dma_unmap_single(dmatx->chan->device->dev, dmatx->dma,
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dmatx->len, DMA_TO_DEVICE);
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dmacr = uap->dmacr;
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uap->dmacr = dmacr & ~UART011_TXDMAE;
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@ -643,18 +637,19 @@ static int pl011_dma_tx_refill(struct uart_amba_port *uap)
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memcpy(&dmatx->buf[first], &xmit->buf[0], second);
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}
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dmatx->sg.length = count;
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if (dma_map_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE) != 1) {
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dmatx->len = count;
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dmatx->dma = dma_map_single(dma_dev->dev, dmatx->buf, count,
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DMA_TO_DEVICE);
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if (dmatx->dma == DMA_MAPPING_ERROR) {
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uap->dmatx.queued = false;
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dev_dbg(uap->port.dev, "unable to map TX DMA\n");
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return -EBUSY;
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}
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desc = dmaengine_prep_slave_sg(chan, &dmatx->sg, 1, DMA_MEM_TO_DEV,
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desc = dmaengine_prep_slave_single(chan, dmatx->dma, dmatx->len, DMA_MEM_TO_DEV,
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DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
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if (!desc) {
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dma_unmap_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE);
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dma_unmap_single(dma_dev->dev, dmatx->dma, dmatx->len, DMA_TO_DEVICE);
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uap->dmatx.queued = false;
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/*
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* If DMA cannot be used right now, we complete this
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@ -818,8 +813,8 @@ __acquires(&uap->port.lock)
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dmaengine_terminate_async(uap->dmatx.chan);
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if (uap->dmatx.queued) {
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dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1,
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DMA_TO_DEVICE);
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dma_unmap_single(uap->dmatx.chan->device->dev, uap->dmatx.dma,
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uap->dmatx.len, DMA_TO_DEVICE);
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uap->dmatx.queued = false;
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uap->dmacr &= ~UART011_TXDMAE;
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pl011_write(uap->dmacr, uap, REG_DMACR);
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@ -833,15 +828,15 @@ static int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap)
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struct dma_chan *rxchan = uap->dmarx.chan;
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struct pl011_dmarx_data *dmarx = &uap->dmarx;
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struct dma_async_tx_descriptor *desc;
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struct pl011_sgbuf *sgbuf;
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struct pl011_dmabuf *dbuf;
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if (!rxchan)
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return -EIO;
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/* Start the RX DMA job */
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sgbuf = uap->dmarx.use_buf_b ?
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&uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a;
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desc = dmaengine_prep_slave_sg(rxchan, &sgbuf->sg, 1,
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dbuf = uap->dmarx.use_buf_b ?
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&uap->dmarx.dbuf_b : &uap->dmarx.dbuf_a;
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desc = dmaengine_prep_slave_single(rxchan, dbuf->dma, dbuf->len,
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DMA_DEV_TO_MEM,
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DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
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/*
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@ -881,8 +876,8 @@ static void pl011_dma_rx_chars(struct uart_amba_port *uap,
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bool readfifo)
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{
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struct tty_port *port = &uap->port.state->port;
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struct pl011_sgbuf *sgbuf = use_buf_b ?
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&uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a;
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struct pl011_dmabuf *dbuf = use_buf_b ?
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&uap->dmarx.dbuf_b : &uap->dmarx.dbuf_a;
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int dma_count = 0;
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u32 fifotaken = 0; /* only used for vdbg() */
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@ -891,7 +886,7 @@ static void pl011_dma_rx_chars(struct uart_amba_port *uap,
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if (uap->dmarx.poll_rate) {
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/* The data can be taken by polling */
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dmataken = sgbuf->sg.length - dmarx->last_residue;
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dmataken = dbuf->len - dmarx->last_residue;
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/* Recalculate the pending size */
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if (pending >= dmataken)
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pending -= dmataken;
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@ -905,7 +900,7 @@ static void pl011_dma_rx_chars(struct uart_amba_port *uap,
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* Note that tty_insert_flip_buf() tries to take as many chars
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* as it can.
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*/
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dma_count = tty_insert_flip_string(port, sgbuf->buf + dmataken,
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dma_count = tty_insert_flip_string(port, dbuf->buf + dmataken,
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pending);
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uap->port.icount.rx += dma_count;
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@ -916,7 +911,7 @@ static void pl011_dma_rx_chars(struct uart_amba_port *uap,
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/* Reset the last_residue for Rx DMA poll */
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if (uap->dmarx.poll_rate)
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dmarx->last_residue = sgbuf->sg.length;
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dmarx->last_residue = dbuf->len;
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/*
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* Only continue with trying to read the FIFO if all DMA chars have
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@ -951,8 +946,8 @@ static void pl011_dma_rx_irq(struct uart_amba_port *uap)
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{
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struct pl011_dmarx_data *dmarx = &uap->dmarx;
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struct dma_chan *rxchan = dmarx->chan;
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struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ?
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&dmarx->sgbuf_b : &dmarx->sgbuf_a;
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struct pl011_dmabuf *dbuf = dmarx->use_buf_b ?
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&dmarx->dbuf_b : &dmarx->dbuf_a;
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size_t pending;
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struct dma_tx_state state;
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enum dma_status dmastat;
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@ -974,7 +969,7 @@ static void pl011_dma_rx_irq(struct uart_amba_port *uap)
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pl011_write(uap->dmacr, uap, REG_DMACR);
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uap->dmarx.running = false;
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pending = sgbuf->sg.length - state.residue;
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pending = dbuf->len - state.residue;
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BUG_ON(pending > PL011_DMA_BUFFER_SIZE);
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/* Then we terminate the transfer - we now know our residue */
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dmaengine_terminate_all(rxchan);
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@ -1001,8 +996,8 @@ static void pl011_dma_rx_callback(void *data)
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struct pl011_dmarx_data *dmarx = &uap->dmarx;
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struct dma_chan *rxchan = dmarx->chan;
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bool lastbuf = dmarx->use_buf_b;
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struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ?
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&dmarx->sgbuf_b : &dmarx->sgbuf_a;
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struct pl011_dmabuf *dbuf = dmarx->use_buf_b ?
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&dmarx->dbuf_b : &dmarx->dbuf_a;
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size_t pending;
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struct dma_tx_state state;
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int ret;
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@ -1020,7 +1015,7 @@ static void pl011_dma_rx_callback(void *data)
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* the DMA irq handler. So we check the residue here.
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*/
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rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state);
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pending = sgbuf->sg.length - state.residue;
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pending = dbuf->len - state.residue;
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BUG_ON(pending > PL011_DMA_BUFFER_SIZE);
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/* Then we terminate the transfer - we now know our residue */
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dmaengine_terminate_all(rxchan);
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@ -1072,16 +1067,16 @@ static void pl011_dma_rx_poll(struct timer_list *t)
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unsigned long flags;
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unsigned int dmataken = 0;
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unsigned int size = 0;
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struct pl011_sgbuf *sgbuf;
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struct pl011_dmabuf *dbuf;
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int dma_count;
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struct dma_tx_state state;
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sgbuf = dmarx->use_buf_b ? &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a;
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dbuf = dmarx->use_buf_b ? &uap->dmarx.dbuf_b : &uap->dmarx.dbuf_a;
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rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state);
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if (likely(state.residue < dmarx->last_residue)) {
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dmataken = sgbuf->sg.length - dmarx->last_residue;
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dmataken = dbuf->len - dmarx->last_residue;
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size = dmarx->last_residue - state.residue;
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dma_count = tty_insert_flip_string(port, sgbuf->buf + dmataken,
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dma_count = tty_insert_flip_string(port, dbuf->buf + dmataken,
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size);
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if (dma_count == size)
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dmarx->last_residue = state.residue;
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@ -1128,7 +1123,7 @@ static void pl011_dma_startup(struct uart_amba_port *uap)
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return;
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}
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sg_init_one(&uap->dmatx.sg, uap->dmatx.buf, PL011_DMA_BUFFER_SIZE);
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uap->dmatx.len = PL011_DMA_BUFFER_SIZE;
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/* The DMA buffer is now the FIFO the TTY subsystem can use */
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uap->port.fifosize = PL011_DMA_BUFFER_SIZE;
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@ -1138,7 +1133,7 @@ static void pl011_dma_startup(struct uart_amba_port *uap)
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goto skip_rx;
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/* Allocate and map DMA RX buffers */
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ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_a,
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ret = pl011_dmabuf_init(uap->dmarx.chan, &uap->dmarx.dbuf_a,
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DMA_FROM_DEVICE);
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if (ret) {
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dev_err(uap->port.dev, "failed to init DMA %s: %d\n",
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@ -1146,12 +1141,12 @@ static void pl011_dma_startup(struct uart_amba_port *uap)
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goto skip_rx;
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}
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ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_b,
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ret = pl011_dmabuf_init(uap->dmarx.chan, &uap->dmarx.dbuf_b,
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DMA_FROM_DEVICE);
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if (ret) {
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dev_err(uap->port.dev, "failed to init DMA %s: %d\n",
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"RX buffer B", ret);
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pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a,
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pl011_dmabuf_free(uap->dmarx.chan, &uap->dmarx.dbuf_a,
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DMA_FROM_DEVICE);
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goto skip_rx;
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}
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@ -1205,8 +1200,9 @@ static void pl011_dma_shutdown(struct uart_amba_port *uap)
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/* In theory, this should already be done by pl011_dma_flush_buffer */
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dmaengine_terminate_all(uap->dmatx.chan);
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if (uap->dmatx.queued) {
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dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1,
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DMA_TO_DEVICE);
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dma_unmap_single(uap->dmatx.chan->device->dev,
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uap->dmatx.dma, uap->dmatx.len,
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DMA_TO_DEVICE);
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uap->dmatx.queued = false;
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}
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@ -1217,8 +1213,8 @@ static void pl011_dma_shutdown(struct uart_amba_port *uap)
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if (uap->using_rx_dma) {
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dmaengine_terminate_all(uap->dmarx.chan);
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/* Clean up the RX DMA */
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pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a, DMA_FROM_DEVICE);
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pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_b, DMA_FROM_DEVICE);
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pl011_dmabuf_free(uap->dmarx.chan, &uap->dmarx.dbuf_a, DMA_FROM_DEVICE);
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pl011_dmabuf_free(uap->dmarx.chan, &uap->dmarx.dbuf_b, DMA_FROM_DEVICE);
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if (uap->dmarx.poll_rate)
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del_timer_sync(&uap->dmarx.timer);
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uap->using_rx_dma = false;
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