serial: sh-sci: Use incrementing pointers instead of stack array

There's no need to keep all buffer and DMA pointers on the stack.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 57b1cc1da67d228a7f5bacfe8b06786c4229a9d0..681e52a087c2e821e32de20231db21c450cc24e6 100644 (file)
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1734,18 +1734,16 @@ static void sci_request_dma(struct uart_port *port)
        chan = dma_request_channel(mask, filter, param);
        dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
        if (chan) {
-               dma_addr_t dma[2];
-               void *buf[2];
-               int i;
+               unsigned int i;
+               dma_addr_t dma;
+               void *buf;
 
                s->chan_rx = chan;
 
                s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
-               buf[0] = dma_alloc_coherent(chan->device->dev,
-                                           s->buf_len_rx * 2, &dma[0],
-                                           GFP_KERNEL);
-
-               if (!buf[0]) {
+               buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
+                                        &dma, GFP_KERNEL);
+               if (!buf) {
                        dev_warn(port->dev,
                                 "Failed to allocate Rx dma buffer, using PIO\n");
                        dma_release_channel(chan);
@@ -1754,16 +1752,16 @@ static void sci_request_dma(struct uart_port *port)
                        return;
                }
 
-               buf[1] = buf[0] + s->buf_len_rx;
-               dma[1] = dma[0] + s->buf_len_rx;
-
                for (i = 0; i < 2; i++) {
                        struct scatterlist *sg = &s->sg_rx[i];
 
                        sg_init_table(sg, 1);
-                       sg_set_page(sg, virt_to_page(buf[i]), s->buf_len_rx,
-                                   (uintptr_t)buf[i] & ~PAGE_MASK);
-                       sg_dma_address(sg) = dma[i];
+                       sg_set_page(sg, virt_to_page(buf), s->buf_len_rx,
+                                   (uintptr_t)buf & ~PAGE_MASK);
+                       sg_dma_address(sg) = dma;
+
+                       buf += s->buf_len_rx;
+                       dma += s->buf_len_rx;
                }
 
                INIT_WORK(&s->work_rx, work_fn_rx);