sdhci: graceful handling of bad addresses

Be a bit more robust and fall back to PIO if someone is feeding us
bogus addresses.

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

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index b802044ea940a7e597ed46927a7f72c92bff1400..d3e4a391e35156abb10b0479eff088f64b148936 100644 (file)
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -327,7 +327,7 @@ static void sdhci_kunmap_atomic(void *buffer, unsigned long *flags)
        local_irq_restore(*flags);
 }
 
-static void sdhci_adma_table_pre(struct sdhci_host *host,
+static int sdhci_adma_table_pre(struct sdhci_host *host,
        struct mmc_data *data)
 {
        int direction;
@@ -360,10 +360,14 @@ static void sdhci_adma_table_pre(struct sdhci_host *host,
 
        host->align_addr = dma_map_single(mmc_dev(host->mmc),
                host->align_buffer, 128 * 4, direction);
+       if (dma_mapping_error(host->align_addr))
+               goto fail;
        BUG_ON(host->align_addr & 0x3);
 
        host->sg_count = dma_map_sg(mmc_dev(host->mmc),
                data->sg, data->sg_len, direction);
+       if (host->sg_count == 0)
+               goto unmap_align;
 
        desc = host->adma_desc;
        align = host->align_buffer;
@@ -457,7 +461,20 @@ static void sdhci_adma_table_pre(struct sdhci_host *host,
 
        host->adma_addr = dma_map_single(mmc_dev(host->mmc),
                host->adma_desc, (128 * 2 + 1) * 4, DMA_TO_DEVICE);
+       if (dma_mapping_error(host->align_addr))
+               goto unmap_entries;
        BUG_ON(host->adma_addr & 0x3);
+
+       return 0;
+
+unmap_entries:
+       dma_unmap_sg(mmc_dev(host->mmc), data->sg,
+               data->sg_len, direction);
+unmap_align:
+       dma_unmap_single(mmc_dev(host->mmc), host->align_addr,
+               128 * 4, direction);
+fail:
+       return -EINVAL;
 }
 
 static void sdhci_adma_table_post(struct sdhci_host *host,
@@ -555,6 +572,7 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data)
 {
        u8 count;
        u8 ctrl;
+       int ret;
 
        WARN_ON(host->data);
 
@@ -639,6 +657,43 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data)
                }
        }
 
+       if (host->flags & SDHCI_REQ_USE_DMA) {
+               if (host->flags & SDHCI_USE_ADMA) {
+                       ret = sdhci_adma_table_pre(host, data);
+                       if (ret) {
+                               /*
+                                * This only happens when someone fed
+                                * us an invalid request.
+                                */
+                               WARN_ON(1);
+                               host->flags &= ~SDHCI_USE_DMA;
+                       } else {
+                               writel(host->adma_addr,
+                                       host->ioaddr + SDHCI_ADMA_ADDRESS);
+                       }
+               } else {
+                       int count;
+
+                       count = dma_map_sg(mmc_dev(host->mmc),
+                                       data->sg, data->sg_len,
+                                       (data->flags & MMC_DATA_READ) ?
+                                               DMA_FROM_DEVICE :
+                                               DMA_TO_DEVICE);
+                       if (count == 0) {
+                               /*
+                                * This only happens when someone fed
+                                * us an invalid request.
+                                */
+                               WARN_ON(1);
+                               host->flags &= ~SDHCI_USE_DMA;
+                       } else {
+                               WARN_ON(count != 1);
+                               writel(sg_dma_address(data->sg),
+                                       host->ioaddr + SDHCI_DMA_ADDRESS);
+                       }
+               }
+       }
+
        /*
         * Always adjust the DMA selection as some controllers
         * (e.g. JMicron) can't do PIO properly when the selection
@@ -655,25 +710,7 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data)
                writeb(ctrl, host->ioaddr + SDHCI_HOST_CONTROL);
        }
 
-       if (host->flags & SDHCI_REQ_USE_DMA) {
-               if (host->flags & SDHCI_USE_ADMA) {
-                       sdhci_adma_table_pre(host, data);
-                       writel(host->adma_addr,
-                               host->ioaddr + SDHCI_ADMA_ADDRESS);
-               } else {
-                       int count;
-
-                       count = dma_map_sg(mmc_dev(host->mmc),
-                                       data->sg, data->sg_len,
-                                       (data->flags & MMC_DATA_READ) ?
-                                               DMA_FROM_DEVICE :
-                                               DMA_TO_DEVICE);
-                       WARN_ON(count != 1);
-
-                       writel(sg_dma_address(data->sg),
-                               host->ioaddr + SDHCI_DMA_ADDRESS);
-               }
-       } else {
+       if (!(host->flags & SDHCI_REQ_USE_DMA)) {
                host->cur_sg = data->sg;
                host->num_sg = data->sg_len;