sdhci: add warnings for bad buffers in ADMA path

The ADMA code path assumes that the 3 byte alignment fix doesn't cross
a page boundary. I'm not convinced this is worth supporting, but at
least print a warning in the off chance we'll actually see such a request.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 17701c3da733..b27c1a28a7ca 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -389,6 +389,7 @@ static int sdhci_adma_table_pre(struct sdhci_host *host,
                 if (offset) {
                         if (data->flags & MMC_DATA_WRITE) {
                                 buffer = sdhci_kmap_atomic(sg, &flags);
+                                WARN_ON(((long)buffer & PAGE_MASK) > (PAGE_SIZE - 3));
                                 memcpy(align, buffer, offset);
                                 sdhci_kunmap_atomic(buffer, &flags);
                         }
@@ -510,6 +511,7 @@ static void sdhci_adma_table_post(struct sdhci_host *host,
                                 size = 4 - (sg_dma_address(sg) & 0x3);
 
                                 buffer = sdhci_kmap_atomic(sg, &flags);
+                                WARN_ON(((long)buffer & PAGE_MASK) > (PAGE_SIZE - 3));
                                 memcpy(buffer, align, size);
                                 sdhci_kunmap_atomic(buffer, &flags);