iommu: bcm2712-iommu: Map and unmap multiple pages in a single call

For efficiency, the map_pages() and unmap_pages() calls now pay
attention to their "count" argument, at least in successful cases.

Fix a bugette where we omitted to set mapped to 0 in case of error.
Minor style fix.

Signed-off-by: Nick Hollinghurst <[email protected]>

Author: njhollinghurst

drivers/iommu/bcm2712-iommu.c

@@ -265,7 +265,11 @@ static int bcm2712_iommu_map(struct iommu_domain *domain, unsigned long iova,
 			mmu->dirty = true;
 		}
 
+		/* Make iova relative to table base; amalgamate count pages */
 		iova -= APERTURE_BASE;
+		bytes = min(APERTURE_SIZE - iova, count * bytes);
+
+		/* Iterate over table by smallest native IOMMU page size */
 		for (p = iova >> MMU_PAGE_SHIFT;
 		     p < (iova + bytes) >> MMU_PAGE_SHIFT; p++) {
 			mmu->nmapped_pages += !(mmu->tables[p]);
@@ -275,6 +279,8 @@ static int bcm2712_iommu_map(struct iommu_domain *domain, unsigned long iova,
 		dev_warn(mmu->dev, "%s: iova=0x%lx pa=0x%llx size=0x%llx OUT OF RANGE!\n",
 			 __func__, iova,
 			 (unsigned long long)pa, (unsigned long long)bytes);
+		*mapped = 0;
+
 		return -EINVAL;
 	}
 	*mapped = bytes;
@@ -308,8 +314,11 @@ static size_t bcm2712_iommu_unmap(struct iommu_domain *domain, unsigned long iov
 			mmu->dirty = true;
 		}
 
-		/* Clear table entries, this marks the addresses as illegal */
+		/* Make iova relative to table base; amalgamate count pages */
 		iova -= (mmu->dma_iova_offset + APERTURE_BASE);
+		bytes = min(APERTURE_SIZE - iova, bytes * count);
+
+		/* Clear table entries, this marks the addresses as illegal */
 		for (p = iova >> MMU_PAGE_SHIFT;
 		     p < (iova + bytes) >> MMU_PAGE_SHIFT;
 		     p++) {
@@ -322,7 +331,7 @@ static size_t bcm2712_iommu_unmap(struct iommu_domain *domain, unsigned long iov
 }
 
 static int bcm2712_iommu_sync_range(struct iommu_domain *domain,
-				     unsigned long iova, size_t size)
+				    unsigned long iova, size_t size)
 {
 	struct bcm2712_iommu *mmu = domain_to_mmu(domain);
 	unsigned long iova_end;