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Subject[PATCH 5/5] kgdb: kgdboc console poll hooks for mpsc uart
Date
Add in console polling hooks for the mpsc uart for use with kgdb and
kgdboc.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
---
drivers/serial/mpsc.c | 148 ++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 147 insertions(+), 1 deletions(-)
diff --git a/drivers/serial/mpsc.c b/drivers/serial/mpsc.c
index c9f53e7..61d3ade 100644
--- 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
};

/*
--
1.5.5.1


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