iommu/core: stop converting bytes to page order back and forth

Express sizes in bytes rather than in page order, to eliminate the
size->order->size conversions we have whenever the IOMMU API is calling
the low level drivers' map/unmap methods.

Adopt all existing drivers.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Joerg Roedel <Joerg.Roedel@amd.com>
Cc: Stepan Moskovchenko <stepanm@codeaurora.org>
Cc: KyongHo Cho <pullip.cho@samsung.com>
Cc: Hiroshi DOYU <hdoyu@nvidia.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

drivers/iommu/iommu.c

@@ -168,13 +168,13 @@ int iommu_map(struct iommu_domain *domain, unsigned long iova,
 
 	BUG_ON(!IS_ALIGNED(iova | paddr, size));
 
-	return domain->ops->map(domain, iova, paddr, gfp_order, prot);
+	return domain->ops->map(domain, iova, paddr, size, prot);
 }
 EXPORT_SYMBOL_GPL(iommu_map);
 
 int iommu_unmap(struct iommu_domain *domain, unsigned long iova, int gfp_order)
 {
-	size_t size;
+	size_t size, unmapped;
 
 	if (unlikely(domain->ops->unmap == NULL))
 		return -ENODEV;
@@ -183,6 +183,8 @@ int iommu_unmap(struct iommu_domain *domain, unsigned long iova, int gfp_order)
 
 	BUG_ON(!IS_ALIGNED(iova, size));
 
-	return domain->ops->unmap(domain, iova, gfp_order);
+	unmapped = domain->ops->unmap(domain, iova, size);
+
+	return get_order(unmapped);
 }
 EXPORT_SYMBOL_GPL(iommu_unmap);