diff --git a/arch/parisc/include/asm/dma-mapping.h b/arch/parisc/include/asm/dma-mapping.h
index 5404c6a..9a2a895 100644
--- a/arch/parisc/include/asm/dma-mapping.h
+++ b/arch/parisc/include/asm/dma-mapping.h
@@ -20,6 +20,8 @@
 ** flush/purge and allocate "regular" cacheable pages for everything.
 */
 
+#define DMA_ERROR_CODE	(~(dma_addr_t)0)
+
 #ifdef CONFIG_PA11
 extern const struct dma_map_ops pcxl_dma_ops;
 extern const struct dma_map_ops pcx_dma_ops;
@@ -54,12 +56,13 @@ parisc_walk_tree(struct device *dev)
 			break;
 		}
 	}
-	BUG_ON(!dev->platform_data);
 	return dev->platform_data;
 }
-		
-#define GET_IOC(dev) (HBA_DATA(parisc_walk_tree(dev))->iommu)
-	
+
+#define GET_IOC(dev) ({					\
+	void *__pdata = parisc_walk_tree(dev);		\
+	__pdata ? HBA_DATA(__pdata)->iommu : NULL;	\
+})
 
 #ifdef CONFIG_IOMMU_CCIO
 struct parisc_device;
diff --git a/drivers/parisc/ccio-dma.c b/drivers/parisc/ccio-dma.c
index e32ca2e..56c93f0 100644
--- a/drivers/parisc/ccio-dma.c
+++ b/drivers/parisc/ccio-dma.c
@@ -741,6 +741,8 @@ ccio_map_single(struct device *dev, void *addr, size_t size,
 
 	BUG_ON(!dev);
 	ioc = GET_IOC(dev);
+	if (!ioc)
+		return DMA_ERROR_CODE;
 
 	BUG_ON(size <= 0);
 
@@ -814,6 +816,10 @@ ccio_unmap_page(struct device *dev, dma_addr_t iova, size_t size,
 	
 	BUG_ON(!dev);
 	ioc = GET_IOC(dev);
+	if (!ioc) {
+		WARN_ON(!ioc);
+		return;
+	}
 
 	DBG_RUN("%s() iovp 0x%lx/%x\n",
 		__func__, (long)iova, size);
@@ -918,6 +924,8 @@ ccio_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
 	
 	BUG_ON(!dev);
 	ioc = GET_IOC(dev);
+	if (!ioc)
+		return 0;
 	
 	DBG_RUN_SG("%s() START %d entries\n", __func__, nents);
 
@@ -990,6 +998,10 @@ ccio_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents,
 
 	BUG_ON(!dev);
 	ioc = GET_IOC(dev);
+	if (!ioc) {
+		WARN_ON(!ioc);
+		return;
+	}
 
 	DBG_RUN_SG("%s() START %d entries, %p,%x\n",
 		__func__, nents, sg_virt(sglist), sglist->length);
diff --git a/drivers/parisc/dino.c b/drivers/parisc/dino.c
index 1133b5c..5c63b92 100644
--- a/drivers/parisc/dino.c
+++ b/drivers/parisc/dino.c
@@ -154,7 +154,10 @@ struct dino_device
 };
 
 /* Looks nice and keeps the compiler happy */
-#define DINO_DEV(d) ((struct dino_device *) d)
+#define DINO_DEV(d) ({				\
+	void *__pdata = d;			\
+	BUG_ON(!__pdata);			\
+	(struct dino_device *)__pdata; })
 
 
 /*
diff --git a/drivers/parisc/lba_pci.c b/drivers/parisc/lba_pci.c
index 2ec2aef..bc286cb 100644
--- a/drivers/parisc/lba_pci.c
+++ b/drivers/parisc/lba_pci.c
@@ -111,8 +111,10 @@ static u32 lba_t32;
 
 
 /* Looks nice and keeps the compiler happy */
-#define LBA_DEV(d) ((struct lba_device *) (d))
-
+#define LBA_DEV(d) ({				\
+	void *__pdata = d;			\
+	BUG_ON(!__pdata);			\
+	(struct lba_device *)__pdata; })
 
 /*
 ** Only allow 8 subsidiary busses per LBA
diff --git a/drivers/parisc/sba_iommu.c b/drivers/parisc/sba_iommu.c
index 33385e5..87ad5fd 100644
--- a/drivers/parisc/sba_iommu.c
+++ b/drivers/parisc/sba_iommu.c
@@ -691,6 +691,8 @@ static int sba_dma_supported( struct device *dev, u64 mask)
 		return 0;
 
 	ioc = GET_IOC(dev);
+	if (!ioc)
+		return 0;
 
 	/*
 	 * check if mask is >= than the current max IO Virt Address
@@ -722,6 +724,8 @@ sba_map_single(struct device *dev, void *addr, size_t size,
 	int pide;
 
 	ioc = GET_IOC(dev);
+	if (!ioc)
+		return DMA_ERROR_CODE;
 
 	/* save offset bits */
 	offset = ((dma_addr_t) (long) addr) & ~IOVP_MASK;
@@ -813,6 +817,10 @@ sba_unmap_page(struct device *dev, dma_addr_t iova, size_t size,
 	DBG_RUN("%s() iovp 0x%lx/%x\n", __func__, (long) iova, size);
 
 	ioc = GET_IOC(dev);
+	if (!ioc) {
+		WARN_ON(!ioc);
+		return;
+	}
 	offset = iova & ~IOVP_MASK;
 	iova ^= offset;        /* clear offset bits */
 	size += offset;
@@ -952,6 +960,8 @@ sba_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
 	DBG_RUN_SG("%s() START %d entries\n", __func__, nents);
 
 	ioc = GET_IOC(dev);
+	if (!ioc)
+		return 0;
 
 	/* Fast path single entry scatterlists. */
 	if (nents == 1) {
@@ -1037,6 +1047,10 @@ sba_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents,
 		__func__, nents, sg_virt(sglist), sglist->length);
 
 	ioc = GET_IOC(dev);
+	if (!ioc) {
+		WARN_ON(!ioc);
+		return;
+	}
 
 #ifdef SBA_COLLECT_STATS
 	ioc->usg_calls++;