1 files changed, 18 insertions, 10 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 2f14334e42df..e9290a3439d5 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -21,6 +21,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/slab.h>
 #include <linux/scatterlist.h>
+#include <linux/swiotlb.h>
 #include <linux/regulator/consumer.h>
 #include <linux/pm_runtime.h>
 #include <linux/of.h>
@@ -3651,22 +3652,29 @@ int sdhci_setup_host(struct sdhci_host *host)
         spin_lock_init(&host->lock);
 
         /*
+         * Maximum number of sectors in one transfer. Limited by SDMA boundary
+         * size (512KiB). Note some tuning modes impose a 4MiB limit, but this
+         * is less anyway.
+         */
+        mmc->max_req_size = 524288;
+
+        /*
          * Maximum number of segments. Depends on if the hardware
          * can do scatter/gather or not.
          */
-        if (host->flags & SDHCI_USE_ADMA)
+        if (host->flags & SDHCI_USE_ADMA) {
                 mmc->max_segs = SDHCI_MAX_SEGS;
-        else if (host->flags & SDHCI_USE_SDMA)
+        } else if (host->flags & SDHCI_USE_SDMA) {
                 mmc->max_segs = 1;
-        else /* PIO */
+                if (swiotlb_max_segment()) {
+                        unsigned int max_req_size = (1 << IO_TLB_SHIFT) *
+                                                IO_TLB_SEGSIZE;
+                        mmc->max_req_size = min(mmc->max_req_size,
+                                                max_req_size);
+                }
+        } else { /* PIO */
                 mmc->max_segs = SDHCI_MAX_SEGS;
-
-        /*
-         * Maximum number of sectors in one transfer. Limited by SDMA boundary
-         * size (512KiB). Note some tuning modes impose a 4MiB limit, but this
-         * is less anyway.
-         */
-        mmc->max_req_size = 524288;
+        }
 
         /*
          * Maximum segment size. Could be one segment with the maximum number