kgdb: kgdboc console poll hooks for mpsc uart

Add in console polling hooks for the mpsc uart for use with kgdb and
kgdboc.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>

diff --git a/drivers/serial/mpsc.c b/drivers/serial/mpsc.c
index c9f53e71f252eb2833db26f645a9621f0f68f7ba..61d3ade5286c6a50a55d7735b03f93284a631de4 100644 (file)
--- a/drivers/serial/mpsc.c
+++ b/drivers/serial/mpsc.c
@@ -921,6 +921,10 @@ static int mpsc_make_ready(struct mpsc_port_info *pi)
        return 0;
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+static int serial_polled;
+#endif
+
 /*
  ******************************************************************************
  *
@@ -956,7 +960,12 @@ static int mpsc_rx_intr(struct mpsc_port_info *pi)
        while (!((cmdstat = be32_to_cpu(rxre->cmdstat))
                                & SDMA_DESC_CMDSTAT_O)) {
                bytes_in = be16_to_cpu(rxre->bytecnt);
-
+#ifdef CONFIG_CONSOLE_POLL
+               if (unlikely(serial_polled)) {
+                       serial_polled = 0;
+                       return 0;
+               }
+#endif
                /* Following use of tty struct directly is deprecated */
                if (unlikely(tty_buffer_request_room(tty, bytes_in)
                                        < bytes_in)) {
@@ -1017,6 +1026,12 @@ static int mpsc_rx_intr(struct mpsc_port_info *pi)
                if (uart_handle_sysrq_char(&pi->port, *bp)) {
                        bp++;
                        bytes_in--;
+#ifdef CONFIG_CONSOLE_POLL
+                       if (unlikely(serial_polled)) {
+                               serial_polled = 0;
+                               return 0;
+                       }
+#endif
                        goto next_frame;
                }
 
@@ -1519,6 +1534,133 @@ static int mpsc_verify_port(struct uart_port *port, struct serial_struct *ser)
 
        return rc;
 }
+#ifdef CONFIG_CONSOLE_POLL
+/* Serial polling routines for writing and reading from the uart while
+ * in an interrupt or debug context.
+ */
+
+static char poll_buf[2048];
+static int poll_ptr;
+static int poll_cnt;
+static void mpsc_put_poll_char(struct uart_port *port,
+                                                          unsigned char c);
+
+static int mpsc_get_poll_char(struct uart_port *port)
+{
+       struct mpsc_port_info *pi = (struct mpsc_port_info *)port;
+       struct mpsc_rx_desc *rxre;
+       u32     cmdstat, bytes_in, i;
+       u8      *bp;
+
+       if (!serial_polled)
+               serial_polled = 1;
+
+       pr_debug("mpsc_rx_intr[%d]: Handling Rx intr\n", pi->port.line);
+
+       if (poll_cnt) {
+               poll_cnt--;
+               return poll_buf[poll_ptr++];
+       }
+       poll_ptr = 0;
+       poll_cnt = 0;
+
+       while (poll_cnt == 0) {
+               rxre = (struct mpsc_rx_desc *)(pi->rxr +
+                      (pi->rxr_posn*MPSC_RXRE_SIZE));
+               dma_cache_sync(pi->port.dev, (void *)rxre,
+                              MPSC_RXRE_SIZE, DMA_FROM_DEVICE);
+#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
+               if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
+                       invalidate_dcache_range((ulong)rxre,
+                       (ulong)rxre + MPSC_RXRE_SIZE);
+#endif
+               /*
+                * Loop through Rx descriptors handling ones that have
+                * been completed.
+                */
+               while (poll_cnt == 0 &&
+                      !((cmdstat = be32_to_cpu(rxre->cmdstat)) &
+                        SDMA_DESC_CMDSTAT_O)){
+                       bytes_in = be16_to_cpu(rxre->bytecnt);
+                       bp = pi->rxb + (pi->rxr_posn * MPSC_RXBE_SIZE);
+                       dma_cache_sync(pi->port.dev, (void *) bp,
+                                      MPSC_RXBE_SIZE, DMA_FROM_DEVICE);
+#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
+                       if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
+                               invalidate_dcache_range((ulong)bp,
+                                       (ulong)bp + MPSC_RXBE_SIZE);
+#endif
+                       if ((unlikely(cmdstat & (SDMA_DESC_CMDSTAT_BR |
+                        SDMA_DESC_CMDSTAT_FR | SDMA_DESC_CMDSTAT_OR))) &&
+                               !(cmdstat & pi->port.ignore_status_mask)) {
+                               poll_buf[poll_cnt] = *bp;
+                               poll_cnt++;
+                       } else {
+                               for (i = 0; i < bytes_in; i++) {
+                                       poll_buf[poll_cnt] = *bp++;
+                                       poll_cnt++;
+                               }
+                               pi->port.icount.rx += bytes_in;
+                       }
+                       rxre->bytecnt = cpu_to_be16(0);
+                       wmb();
+                       rxre->cmdstat = cpu_to_be32(SDMA_DESC_CMDSTAT_O |
+                                                   SDMA_DESC_CMDSTAT_EI |
+                                                   SDMA_DESC_CMDSTAT_F |
+                                                   SDMA_DESC_CMDSTAT_L);
+                       wmb();
+                       dma_cache_sync(pi->port.dev, (void *)rxre,
+                                      MPSC_RXRE_SIZE, DMA_BIDIRECTIONAL);
+#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
+                       if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
+                               flush_dcache_range((ulong)rxre,
+                                          (ulong)rxre + MPSC_RXRE_SIZE);
+#endif
+
+                       /* Advance to next descriptor */
+                       pi->rxr_posn = (pi->rxr_posn + 1) &
+                               (MPSC_RXR_ENTRIES - 1);
+                       rxre = (struct mpsc_rx_desc *)(pi->rxr +
+                                      (pi->rxr_posn * MPSC_RXRE_SIZE));
+                       dma_cache_sync(pi->port.dev, (void *)rxre,
+                                      MPSC_RXRE_SIZE, DMA_FROM_DEVICE);
+#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
+                       if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
+                               invalidate_dcache_range((ulong)rxre,
+                                               (ulong)rxre + MPSC_RXRE_SIZE);
+#endif
+               }
+
+               /* Restart rx engine, if its stopped */
+               if ((readl(pi->sdma_base + SDMA_SDCM) & SDMA_SDCM_ERD) == 0)
+                       mpsc_start_rx(pi);
+       }
+       if (poll_cnt) {
+               poll_cnt--;
+               return poll_buf[poll_ptr++];
+       }
+
+       return 0;
+}
+
+
+static void mpsc_put_poll_char(struct uart_port *port,
+                        unsigned char c)
+{
+       struct mpsc_port_info *pi = (struct mpsc_port_info *)port;
+       u32 data;
+
+       data = readl(pi->mpsc_base + MPSC_MPCR);
+       writeb(c, pi->mpsc_base + MPSC_CHR_1);
+       mb();
+       data = readl(pi->mpsc_base + MPSC_CHR_2);
+       data |= MPSC_CHR_2_TTCS;
+       writel(data, pi->mpsc_base + MPSC_CHR_2);
+       mb();
+
+       while (readl(pi->mpsc_base + MPSC_CHR_2) & MPSC_CHR_2_TTCS);
+}
+#endif
 
 static struct uart_ops mpsc_pops = {
        .tx_empty       = mpsc_tx_empty,
@@ -1537,6 +1679,10 @@ static struct uart_ops mpsc_pops = {
        .request_port   = mpsc_request_port,
        .config_port    = mpsc_config_port,
        .verify_port    = mpsc_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+       .poll_get_char = mpsc_get_poll_char,
+       .poll_put_char = mpsc_put_poll_char,
+#endif
 };
 
 /*