[PATCH 17/22] mmc: sdhci: Make use of the new sg_map helper function

[Logan Gunthorpe]

Straightforward conversion, except due to the lack of error path we
have to WARN if the memory in the SGL is not mappable.

Signed-off-by: Logan Gunthorpe <log...@deltatee.com>
---
 drivers/mmc/host/sdhci.c | 35 ++++++++++++++++++++++++++++++-----
 1 file changed, 30 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 63bc33a..af0c107 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -497,15 +497,34 @@ static int sdhci_pre_dma_transfer(struct sdhci_host *host,
        return sg_count;
 }
 
+/*
+ * Note this function may return PTR_ERR and must be checked.
+ */
 static char *sdhci_kmap_atomic(struct scatterlist *sg, unsigned long *flags)
 {
+       void *ret;
+
        local_irq_save(*flags);
-       return kmap_atomic(sg_page(sg)) + sg->offset;
+
+       ret = sg_map(sg, SG_KMAP_ATOMIC);
+       if (IS_ERR(ret)) {
+               /*
+                * This should really never happen unless the code is changed
+                * to use memory that is not mappable in the sg. Seeing there
+                * doesn't seem to be any error path out of here, we can only
+                * WARN.
+                */
+               WARN(1, "Non-mappable memory used in sg!");
+               local_irq_restore(*flags);
+       }
+
+       return ret;
 }
 
-static void sdhci_kunmap_atomic(void *buffer, unsigned long *flags)
+static void sdhci_kunmap_atomic(struct scatterlist *sg, void *buffer,
+                               unsigned long *flags)
 {
-       kunmap_atomic(buffer);
+       sg_unmap(sg, buffer, SG_KMAP_ATOMIC);
        local_irq_restore(*flags);
 }
 
@@ -568,8 +587,11 @@ static void sdhci_adma_table_pre(struct sdhci_host *host,
                if (offset) {
                        if (data->flags & MMC_DATA_WRITE) {
                                buffer = sdhci_kmap_atomic(sg, &flags);
+                               if (IS_ERR(buffer))
+                                       return;
+
                                memcpy(align, buffer, offset);
-                               sdhci_kunmap_atomic(buffer, &flags);
+                               sdhci_kunmap_atomic(sg, buffer, &flags);
                        }
 
                        /* tran, valid */
@@ -646,8 +668,11 @@ static void sdhci_adma_table_post(struct sdhci_host *host,
                                               (sg_dma_address(sg) & 
SDHCI_ADMA2_MASK);
 
                                        buffer = sdhci_kmap_atomic(sg, &flags);
+                                       if (IS_ERR(buffer))
+                                               return;
+
                                        memcpy(buffer, align, size);
-                                       sdhci_kunmap_atomic(buffer, &flags);
+                                       sdhci_kunmap_atomic(sg, buffer, &flags);
 
                                        align += SDHCI_ADMA2_ALIGN;
                                }
-- 
2.1.4