1 files changed, 117 insertions, 14 deletions

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 7a2953d..b278458 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);
+
+	/*
+	 * 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;
+	}
+
+	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;
 
-	BUG_ON(!IS_ALIGNED(iova | paddr, size));
+		/* make sure we're still sane */
+		BUG_ON(!pgsize);
 
-	return domain->ops->map(domain, iova, paddr, size, prot);
+		/* 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;
-
-	BUG_ON(!IS_ALIGNED(iova, size));
-
-	unmapped = domain->ops->unmap(domain, iova, size);
-
-	return get_order(unmapped);
+	/* find out the minimum page size supported */
+	min_pagesz = 1 << __ffs(domain->ops->pgsize_bitmap);
+
+	/*
+	 * 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;
+	}
+
+	pr_debug("unmap this: iova 0x%lx size 0x%lx\n", iova,
+							(unsigned long)size);
+
+	/*
+	 * 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);