diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 7a2953d8f12e..b278458d5816 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
+#define pr_fmt(fmt)    "%s: " fmt, __func__
+
 #include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/bug.h>
@@ -47,6 +49,16 @@ int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops)
 	if (bus->iommu_ops != NULL)
 		return -EBUSY;
 
+	/*
+	 * Set the default pgsize values, which retain the existing
+	 * IOMMU API behavior: drivers will be called to map
+	 * regions that are sized/aligned to order of 4KiB pages.
+	 *
+	 * This will be removed once all drivers are migrated.
+	 */
+	if (!ops->pgsize_bitmap)
+		ops->pgsize_bitmap = ~0xFFFUL;
+
 	bus->iommu_ops = ops;
 
 	/* Do IOMMU specific setup for this bus-type */
@@ -157,34 +169,125 @@ int iommu_domain_has_cap(struct iommu_domain *domain,
 EXPORT_SYMBOL_GPL(iommu_domain_has_cap);
 
 int iommu_map(struct iommu_domain *domain, unsigned long iova,
-	      phys_addr_t paddr, int gfp_order, int prot)
+	      phys_addr_t paddr, size_t size, int prot)
 {
-	size_t size;
+	unsigned long orig_iova = iova;
+	unsigned int min_pagesz;
+	size_t orig_size = size;
+	int ret = 0;
 
 	if (unlikely(domain->ops->map == NULL))
 		return -ENODEV;
 
-	size         = PAGE_SIZE << gfp_order;
+	/* find out the minimum page size supported */
+	min_pagesz = 1 << __ffs(domain->ops->pgsize_bitmap);
 
-	BUG_ON(!IS_ALIGNED(iova | paddr, size));
+	/*
+	 * both the virtual address and the physical one, as well as
+	 * the size of the mapping, must be aligned (at least) to the
+	 * size of the smallest page supported by the hardware
+	 */
+	if (!IS_ALIGNED(iova | paddr | size, min_pagesz)) {
+		pr_err("unaligned: iova 0x%lx pa 0x%lx size 0x%lx min_pagesz "
+			"0x%x\n", iova, (unsigned long)paddr,
+			(unsigned long)size, min_pagesz);
+		return -EINVAL;
+	}
 
-	return domain->ops->map(domain, iova, paddr, size, prot);
+	pr_debug("map: iova 0x%lx pa 0x%lx size 0x%lx\n", iova,
+				(unsigned long)paddr, (unsigned long)size);
+
+	while (size) {
+		unsigned long pgsize, addr_merge = iova | paddr;
+		unsigned int pgsize_idx;
+
+		/* Max page size that still fits into 'size' */
+		pgsize_idx = __fls(size);
+
+		/* need to consider alignment requirements ? */
+		if (likely(addr_merge)) {
+			/* Max page size allowed by both iova and paddr */
+			unsigned int align_pgsize_idx = __ffs(addr_merge);
+
+			pgsize_idx = min(pgsize_idx, align_pgsize_idx);
+		}
+
+		/* build a mask of acceptable page sizes */
+		pgsize = (1UL << (pgsize_idx + 1)) - 1;
+
+		/* throw away page sizes not supported by the hardware */
+		pgsize &= domain->ops->pgsize_bitmap;
+
+		/* make sure we're still sane */
+		BUG_ON(!pgsize);
+
+		/* pick the biggest page */
+		pgsize_idx = __fls(pgsize);
+		pgsize = 1UL << pgsize_idx;
+
+		pr_debug("mapping: iova 0x%lx pa 0x%lx pgsize %lu\n", iova,
+					(unsigned long)paddr, pgsize);
+
+		ret = domain->ops->map(domain, iova, paddr, pgsize, prot);
+		if (ret)
+			break;
+
+		iova += pgsize;
+		paddr += pgsize;
+		size -= pgsize;
+	}
+
+	/* unroll mapping in case something went wrong */
+	if (ret)
+		iommu_unmap(domain, orig_iova, orig_size - size);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(iommu_map);
 
-int iommu_unmap(struct iommu_domain *domain, unsigned long iova, int gfp_order)
+size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size)
 {
-	size_t size, unmapped;
+	size_t unmapped_page, unmapped = 0;
+	unsigned int min_pagesz;
 
 	if (unlikely(domain->ops->unmap == NULL))
 		return -ENODEV;
 
-	size         = PAGE_SIZE << gfp_order;
+	/* find out the minimum page size supported */
+	min_pagesz = 1 << __ffs(domain->ops->pgsize_bitmap);
 
-	BUG_ON(!IS_ALIGNED(iova, size));
+	/*
+	 * The virtual address, as well as the size of the mapping, must be
+	 * aligned (at least) to the size of the smallest page supported
+	 * by the hardware
+	 */
+	if (!IS_ALIGNED(iova | size, min_pagesz)) {
+		pr_err("unaligned: iova 0x%lx size 0x%lx min_pagesz 0x%x\n",
+					iova, (unsigned long)size, min_pagesz);
+		return -EINVAL;
+	}
 
-	unmapped = domain->ops->unmap(domain, iova, size);
+	pr_debug("unmap this: iova 0x%lx size 0x%lx\n", iova,
+							(unsigned long)size);
 
-	return get_order(unmapped);
+	/*
+	 * Keep iterating until we either unmap 'size' bytes (or more)
+	 * or we hit an area that isn't mapped.
+	 */
+	while (unmapped < size) {
+		size_t left = size - unmapped;
+
+		unmapped_page = domain->ops->unmap(domain, iova, left);
+		if (!unmapped_page)
+			break;
+
+		pr_debug("unmapped: iova 0x%lx size %lx\n", iova,
+					(unsigned long)unmapped_page);
+
+		iova += unmapped_page;
+		unmapped += unmapped_page;
+	}
+
+	return unmapped;
 }
 EXPORT_SYMBOL_GPL(iommu_unmap);
diff --git a/drivers/iommu/omap-iovmm.c b/drivers/iommu/omap-iovmm.c
index e8fdb8830f69..0b7b14cb030b 100644
--- a/drivers/iommu/omap-iovmm.c
+++ b/drivers/iommu/omap-iovmm.c
@@ -409,7 +409,6 @@ static int map_iovm_area(struct iommu_domain *domain, struct iovm_struct *new,
 	unsigned int i, j;
 	struct scatterlist *sg;
 	u32 da = new->da_start;
-	int order;
 
 	if (!domain || !sgt)
 		return -EINVAL;
@@ -428,12 +427,10 @@ static int map_iovm_area(struct iommu_domain *domain, struct iovm_struct *new,
 		if (bytes_to_iopgsz(bytes) < 0)
 			goto err_out;
 
-		order = get_order(bytes);
-
 		pr_debug("%s: [%d] %08x %08x(%x)\n", __func__,
 			 i, da, pa, bytes);
 
-		err = iommu_map(domain, da, pa, order, flags);
+		err = iommu_map(domain, da, pa, bytes, flags);
 		if (err)
 			goto err_out;
 
@@ -448,10 +445,9 @@ static int map_iovm_area(struct iommu_domain *domain, struct iovm_struct *new,
 		size_t bytes;
 
 		bytes = sg->length + sg->offset;
-		order = get_order(bytes);
 
 		/* ignore failures.. we're already handling one */
-		iommu_unmap(domain, da, order);
+		iommu_unmap(domain, da, bytes);
 
 		da += bytes;
 	}
@@ -466,7 +462,8 @@ static void unmap_iovm_area(struct iommu_domain *domain, struct omap_iommu *obj,
 	size_t total = area->da_end - area->da_start;
 	const struct sg_table *sgt = area->sgt;
 	struct scatterlist *sg;
-	int i, err;
+	int i;
+	size_t unmapped;
 
 	BUG_ON(!sgtable_ok(sgt));
 	BUG_ON((!total) || !IS_ALIGNED(total, PAGE_SIZE));
@@ -474,13 +471,11 @@ static void unmap_iovm_area(struct iommu_domain *domain, struct omap_iommu *obj,
 	start = area->da_start;
 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 		size_t bytes;
-		int order;
 
 		bytes = sg->length + sg->offset;
-		order = get_order(bytes);
 
-		err = iommu_unmap(domain, start, order);
-		if (err < 0)
+		unmapped = iommu_unmap(domain, start, bytes);
+		if (unmapped < bytes)
 			break;
 
 		dev_dbg(obj->dev, "%s: unmap %08x(%x) %08x\n",
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index d5ebf3f4dd53..cc26f89c4ee6 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -48,6 +48,19 @@ struct iommu_domain {
 
 #ifdef CONFIG_IOMMU_API
 
+/**
+ * struct iommu_ops - iommu ops and capabilities
+ * @domain_init: init iommu domain
+ * @domain_destroy: destroy iommu domain
+ * @attach_dev: attach device to an iommu domain
+ * @detach_dev: detach device from an iommu domain
+ * @map: map a physically contiguous memory region to an iommu domain
+ * @unmap: unmap a physically contiguous memory region from an iommu domain
+ * @iova_to_phys: translate iova to physical address
+ * @domain_has_cap: domain capabilities query
+ * @commit: commit iommu domain
+ * @pgsize_bitmap: bitmap of supported page sizes
+ */
 struct iommu_ops {
 	int (*domain_init)(struct iommu_domain *domain);
 	void (*domain_destroy)(struct iommu_domain *domain);
@@ -61,6 +74,7 @@ struct iommu_ops {
 				    unsigned long iova);
 	int (*domain_has_cap)(struct iommu_domain *domain,
 			      unsigned long cap);
+	unsigned long pgsize_bitmap;
 };
 
 extern int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops);
@@ -72,9 +86,9 @@ extern int iommu_attach_device(struct iommu_domain *domain,
 extern void iommu_detach_device(struct iommu_domain *domain,
 				struct device *dev);
 extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
-		     phys_addr_t paddr, int gfp_order, int prot);
-extern int iommu_unmap(struct iommu_domain *domain, unsigned long iova,
-		       int gfp_order);
+		     phys_addr_t paddr, size_t size, int prot);
+extern size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova,
+		       size_t size);
 extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
 				      unsigned long iova);
 extern int iommu_domain_has_cap(struct iommu_domain *domain,
diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c
index a195c07fa829..304d7e5717e9 100644
--- a/virt/kvm/iommu.c
+++ b/virt/kvm/iommu.c
@@ -113,7 +113,7 @@ int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
 
 		/* Map into IO address space */
 		r = iommu_map(domain, gfn_to_gpa(gfn), pfn_to_hpa(pfn),
-			      get_order(page_size), flags);
+			      page_size, flags);
 		if (r) {
 			printk(KERN_ERR "kvm_iommu_map_address:"
 			       "iommu failed to map pfn=%llx\n", pfn);
@@ -292,15 +292,15 @@ static void kvm_iommu_put_pages(struct kvm *kvm,
 
 	while (gfn < end_gfn) {
 		unsigned long unmap_pages;
-		int order;
+		size_t size;
 
 		/* Get physical address */
 		phys = iommu_iova_to_phys(domain, gfn_to_gpa(gfn));
 		pfn  = phys >> PAGE_SHIFT;
 
 		/* Unmap address from IO address space */
-		order       = iommu_unmap(domain, gfn_to_gpa(gfn), 0);
-		unmap_pages = 1ULL << order;
+		size       = iommu_unmap(domain, gfn_to_gpa(gfn), PAGE_SIZE);
+		unmap_pages = 1ULL << get_order(size);
 
 		/* Unpin all pages we just unmapped to not leak any memory */
 		kvm_unpin_pages(kvm, pfn, unmap_pages);