[RFC PATCH 1/3] hw/sd/sdhci: Honor failed DMA transactions

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

From: Philippe Mathieu-Daudé <f4bug@amsat.org>

DMA transactions might fail. The DMA API returns a MemTxResult,
indicating such failures. Do not ignore it. On failure, raise
the ADMA error flag and eventually triggering an IRQ (see spec
chapter 1.13.5: "ADMA2 States").

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/sd/sdhci.c | 34 +++++++++++++++++++++++++---------
 1 file changed, 25 insertions(+), 9 deletions(-)

diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
index e0bbc903446..fe2f21f0c37 100644
--- a/hw/sd/sdhci.c
+++ b/hw/sd/sdhci.c
@@ -742,6 +742,7 @@ static void sdhci_do_adma(SDHCIState *s)
     unsigned int begin, length;
     const uint16_t block_size = s->blksize & BLOCK_SIZE_MASK;
     ADMADescr dscr = {};
+    MemTxResult res;
     int i;
 
     if (s->trnmod & SDHC_TRNS_BLK_CNT_EN && !s->blkcnt) {
@@ -790,10 +791,13 @@ static void sdhci_do_adma(SDHCIState *s)
                         s->data_count = block_size;
                         length -= block_size - begin;
                     }
-                    dma_memory_write(s->dma_as, dscr.addr,
-                                     &s->fifo_buffer[begin],
-                                     s->data_count - begin,
-                                     MEMTXATTRS_UNSPECIFIED);
+                    res = dma_memory_write(s->dma_as, dscr.addr,
+                                           &s->fifo_buffer[begin],
+                                           s->data_count - begin,
+                                           MEMTXATTRS_UNSPECIFIED);
+                    if (res != MEMTX_OK) {
+                        break;
+                    }
                     dscr.addr += s->data_count - begin;
                     if (s->data_count == block_size) {
                         s->data_count = 0;
@@ -816,10 +820,13 @@ static void sdhci_do_adma(SDHCIState *s)
                         s->data_count = block_size;
                         length -= block_size - begin;
                     }
-                    dma_memory_read(s->dma_as, dscr.addr,
-                                    &s->fifo_buffer[begin],
-                                    s->data_count - begin,
-                                    MEMTXATTRS_UNSPECIFIED);
+                    res = dma_memory_read(s->dma_as, dscr.addr,
+                                          &s->fifo_buffer[begin],
+                                          s->data_count - begin,
+                                          MEMTXATTRS_UNSPECIFIED);
+                    if (res != MEMTX_OK) {
+                        break;
+                    }
                     dscr.addr += s->data_count - begin;
                     if (s->data_count == block_size) {
                         sdbus_write_data(&s->sdbus, s->fifo_buffer, block_size);
@@ -833,7 +840,16 @@ static void sdhci_do_adma(SDHCIState *s)
                     }
                 }
             }
-            s->admasysaddr += dscr.incr;
+            if (res != MEMTX_OK) {
+                if (s->errintstsen & SDHC_EISEN_ADMAERR) {
+                    trace_sdhci_error("Set ADMA error flag");
+                    s->errintsts |= SDHC_EIS_ADMAERR;
+                    s->norintsts |= SDHC_NIS_ERR;
+                }
+                sdhci_update_irq(s);
+            } else {
+                s->admasysaddr += dscr.incr;
+            }
             break;
         case SDHC_ADMA_ATTR_ACT_LINK:   /* link to next descriptor table */
             s->admasysaddr = dscr.addr;
-- 
2.33.1