sdhci: stop poking into swiotlb internals

Use the proper API to query the max mapping size instead of guessing
it based on swiotlb internals.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

drivers/mmc/host/sdhci.c

@@ -20,7 +20,6 @@
 #include <linux/slab.h>
 #include <linux/scatterlist.h>
 #include <linux/sizes.h>
-#include <linux/swiotlb.h>
 #include <linux/regulator/consumer.h>
 #include <linux/pm_runtime.h>
 #include <linux/of.h>
@@ -4582,12 +4581,8 @@ int sdhci_setup_host(struct sdhci_host *host)
 		mmc->max_segs = SDHCI_MAX_SEGS;
 	} else if (host->flags & SDHCI_USE_SDMA) {
 		mmc->max_segs = 1;
-		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);
-		}
+		mmc->max_req_size = min_t(size_t, mmc->max_req_size,
+					  dma_max_mapping_size(mmc_dev(mmc)));
 	} else { /* PIO */
 		mmc->max_segs = SDHCI_MAX_SEGS;
 	}