iommu-common: Fix error code used in iommu_tbl_range_{alloc,free}().

The value returned from iommu_tbl_range_alloc() (and the one passed
in as a fourth argument to iommu_tbl_range_free) is not a DMA address,
it is rather an index into the IOMMU page table.

Therefore using DMA_ERROR_CODE is not appropriate.

Use a more type matching error code define, IOMMU_ERROR_CODE, and
update all users of this interface.
Reported-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/kernel/iommu.c

@@ -161,7 +161,7 @@ static inline iopte_t *alloc_npages(struct device *dev,
 
 	entry = iommu_tbl_range_alloc(dev, &iommu->tbl, npages, NULL,
 				      (unsigned long)(-1), 0);
-	if (unlikely(entry == DMA_ERROR_CODE))
+	if (unlikely(entry == IOMMU_ERROR_CODE))
 		return NULL;
 
 	return iommu->page_table + entry;
@@ -253,7 +253,7 @@ static void dma_4u_free_coherent(struct device *dev, size_t size,
 	npages = IO_PAGE_ALIGN(size) >> IO_PAGE_SHIFT;
 	iommu = dev->archdata.iommu;
 
-	iommu_tbl_range_free(&iommu->tbl, dvma, npages, DMA_ERROR_CODE);
+	iommu_tbl_range_free(&iommu->tbl, dvma, npages, IOMMU_ERROR_CODE);
 
 	order = get_order(size);
 	if (order < 10)
@@ -426,7 +426,7 @@ static void dma_4u_unmap_page(struct device *dev, dma_addr_t bus_addr,
 	iommu_free_ctx(iommu, ctx);
 	spin_unlock_irqrestore(&iommu->lock, flags);
 
-	iommu_tbl_range_free(&iommu->tbl, bus_addr, npages, DMA_ERROR_CODE);
+	iommu_tbl_range_free(&iommu->tbl, bus_addr, npages, IOMMU_ERROR_CODE);
 }
 
 static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
@@ -492,7 +492,7 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
 					      &handle, (unsigned long)(-1), 0);
 
 		/* Handle failure */
-		if (unlikely(entry == DMA_ERROR_CODE)) {
+		if (unlikely(entry == IOMMU_ERROR_CODE)) {
 			if (printk_ratelimit())
 				printk(KERN_INFO "iommu_alloc failed, iommu %p paddr %lx"
 				       " npages %lx\n", iommu, paddr, npages);
@@ -571,7 +571,7 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
 				iopte_make_dummy(iommu, base + j);
 
 			iommu_tbl_range_free(&iommu->tbl, vaddr, npages,
-					     DMA_ERROR_CODE);
+					     IOMMU_ERROR_CODE);
 
 			s->dma_address = DMA_ERROR_CODE;
 			s->dma_length = 0;
@@ -648,7 +648,7 @@ static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
 			iopte_make_dummy(iommu, base + i);
 
 		iommu_tbl_range_free(&iommu->tbl, dma_handle, npages,
-				     DMA_ERROR_CODE);
+				     IOMMU_ERROR_CODE);
 		sg = sg_next(sg);
 	}
 

arch/sparc/kernel/ldc.c

@@ -1953,7 +1953,7 @@ static struct ldc_mtable_entry *alloc_npages(struct ldc_iommu *iommu,
 
 	entry = iommu_tbl_range_alloc(NULL, &iommu->iommu_map_table,
 				      npages, NULL, (unsigned long)-1, 0);
-	if (unlikely(entry < 0))
+	if (unlikely(entry == IOMMU_ERROR_CODE))
 		return NULL;
 
 	return iommu->page_table + entry;

arch/sparc/kernel/pci_sun4v.c

@@ -159,7 +159,7 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size,
 	entry = iommu_tbl_range_alloc(dev, &iommu->tbl, npages, NULL,
 				      (unsigned long)(-1), 0);
 
-	if (unlikely(entry == DMA_ERROR_CODE))
+	if (unlikely(entry == IOMMU_ERROR_CODE))
 		goto range_alloc_fail;
 
 	*dma_addrp = (iommu->tbl.table_map_base + (entry << IO_PAGE_SHIFT));
@@ -187,7 +187,7 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size,
 	return ret;
 
 iommu_map_fail:
-	iommu_tbl_range_free(&iommu->tbl, *dma_addrp, npages, DMA_ERROR_CODE);
+	iommu_tbl_range_free(&iommu->tbl, *dma_addrp, npages, IOMMU_ERROR_CODE);
 
 range_alloc_fail:
 	free_pages(first_page, order);
@@ -226,7 +226,7 @@ static void dma_4v_free_coherent(struct device *dev, size_t size, void *cpu,
 	devhandle = pbm->devhandle;
 	entry = ((dvma - iommu->tbl.table_map_base) >> IO_PAGE_SHIFT);
 	dma_4v_iommu_demap(&devhandle, entry, npages);
-	iommu_tbl_range_free(&iommu->tbl, dvma, npages, DMA_ERROR_CODE);
+	iommu_tbl_range_free(&iommu->tbl, dvma, npages, IOMMU_ERROR_CODE);
 	order = get_order(size);
 	if (order < 10)
 		free_pages((unsigned long)cpu, order);
@@ -256,7 +256,7 @@ static dma_addr_t dma_4v_map_page(struct device *dev, struct page *page,
 	entry = iommu_tbl_range_alloc(dev, &iommu->tbl, npages, NULL,
 				      (unsigned long)(-1), 0);
 
-	if (unlikely(entry == DMA_ERROR_CODE))
+	if (unlikely(entry == IOMMU_ERROR_CODE))
 		goto bad;
 
 	bus_addr = (iommu->tbl.table_map_base + (entry << IO_PAGE_SHIFT));
@@ -288,7 +288,7 @@ static dma_addr_t dma_4v_map_page(struct device *dev, struct page *page,
 	return DMA_ERROR_CODE;
 
 iommu_map_fail:
-	iommu_tbl_range_free(&iommu->tbl, bus_addr, npages, DMA_ERROR_CODE);
+	iommu_tbl_range_free(&iommu->tbl, bus_addr, npages, IOMMU_ERROR_CODE);
 	return DMA_ERROR_CODE;
 }
 
@@ -317,7 +317,7 @@ static void dma_4v_unmap_page(struct device *dev, dma_addr_t bus_addr,
 	bus_addr &= IO_PAGE_MASK;
 	entry = (bus_addr - iommu->tbl.table_map_base) >> IO_PAGE_SHIFT;
 	dma_4v_iommu_demap(&devhandle, entry, npages);
-	iommu_tbl_range_free(&iommu->tbl, bus_addr, npages, DMA_ERROR_CODE);
+	iommu_tbl_range_free(&iommu->tbl, bus_addr, npages, IOMMU_ERROR_CODE);
 }
 
 static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
@@ -376,7 +376,7 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
 					      &handle, (unsigned long)(-1), 0);
 
 		/* Handle failure */
-		if (unlikely(entry == DMA_ERROR_CODE)) {
+		if (unlikely(entry == IOMMU_ERROR_CODE)) {
 			if (printk_ratelimit())
 				printk(KERN_INFO "iommu_alloc failed, iommu %p paddr %lx"
 				       " npages %lx\n", iommu, paddr, npages);
@@ -451,7 +451,7 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
 			npages = iommu_num_pages(s->dma_address, s->dma_length,
 						 IO_PAGE_SIZE);
 			iommu_tbl_range_free(&iommu->tbl, vaddr, npages,
-					     DMA_ERROR_CODE);
+					     IOMMU_ERROR_CODE);
 			/* XXX demap? XXX */
 			s->dma_address = DMA_ERROR_CODE;
 			s->dma_length = 0;
@@ -496,7 +496,7 @@ static void dma_4v_unmap_sg(struct device *dev, struct scatterlist *sglist,
 		entry = ((dma_handle - tbl->table_map_base) >> shift);
 		dma_4v_iommu_demap(&devhandle, entry, npages);
 		iommu_tbl_range_free(&iommu->tbl, dma_handle, npages,
-				     DMA_ERROR_CODE);
+				     IOMMU_ERROR_CODE);
 		sg = sg_next(sg);
 	}
 

include/linux/iommu-common.h

@@ -7,6 +7,7 @@
 
 #define IOMMU_POOL_HASHBITS     4
 #define IOMMU_NR_POOLS          (1 << IOMMU_POOL_HASHBITS)
+#define IOMMU_ERROR_CODE	(~(unsigned long) 0)
 
 struct iommu_pool {
 	unsigned long	start;

lib/iommu-common.c

@@ -11,10 +11,6 @@
 #include <linux/dma-mapping.h>
 #include <linux/hash.h>
 
-#ifndef	DMA_ERROR_CODE
-#define	DMA_ERROR_CODE (~(dma_addr_t)0x0)
-#endif
-
 static unsigned long iommu_large_alloc = 15;
 
 static	DEFINE_PER_CPU(unsigned int, iommu_hash_common);
@@ -124,7 +120,7 @@ unsigned long iommu_tbl_range_alloc(struct device *dev,
 	/* Sanity check */
 	if (unlikely(npages == 0)) {
 		WARN_ON_ONCE(1);
-		return DMA_ERROR_CODE;
+		return IOMMU_ERROR_CODE;
 	}
 
 	if (largealloc) {
@@ -207,7 +203,7 @@ unsigned long iommu_tbl_range_alloc(struct device *dev,
 			goto again;
 		} else {
 			/* give up */
-			n = DMA_ERROR_CODE;
+			n = IOMMU_ERROR_CODE;
 			goto bail;
 		}
 	}
@@ -259,7 +255,7 @@ void iommu_tbl_range_free(struct iommu_map_table *iommu, u64 dma_addr,
 	unsigned long flags;
 	unsigned long shift = iommu->table_shift;
 
-	if (entry == DMA_ERROR_CODE) /* use default addr->entry mapping */
+	if (entry == IOMMU_ERROR_CODE) /* use default addr->entry mapping */
 		entry = (dma_addr - iommu->table_map_base) >> shift;
 	pool = get_pool(iommu, entry);