[PATCH] ppc64: implement pci_dma_error

From: Anton Blanchard <anton@samba.org>

Implement pci_dma_error.  Create PCI_DMA_ERROR_CODE like sparc64, it will
allow us to find and fix out of tree drivers using NO_TCE directly.

ibmveth needs some surgery, fix it temporarily until the guys come up with
a decent fix.

arch/ppc64/kernel/iommu.c

@@ -73,7 +73,7 @@ static unsigned long iommu_range_alloc(struct iommu_table *tbl, unsigned long np
 	if (unlikely(npages) == 0) {
 		if (printk_ratelimit())
 			WARN_ON(1);
-		return NO_TCE;
+		return PCI_DMA_ERROR_CODE;
 	}
 
 	if (handle && *handle)
@@ -109,7 +109,7 @@ static unsigned long iommu_range_alloc(struct iommu_table *tbl, unsigned long np
 			goto again;
 		} else {
 			/* Third failure, give up */
-			return NO_TCE;
+			return PCI_DMA_ERROR_CODE;
 		}
 	}
 
@@ -143,15 +143,15 @@ dma_addr_t iommu_alloc(struct iommu_table *tbl, void *page,
 		       unsigned int npages, int direction)
 {
 	unsigned long entry, flags;
-	dma_addr_t ret = NO_TCE;
+	dma_addr_t ret = PCI_DMA_ERROR_CODE;
 	
 	spin_lock_irqsave(&(tbl->it_lock), flags);
 
 	entry = iommu_range_alloc(tbl, npages, NULL);
 
-	if (unlikely(entry == NO_TCE)) {
+	if (unlikely(entry == PCI_DMA_ERROR_CODE)) {
 		spin_unlock_irqrestore(&(tbl->it_lock), flags);
-		return NO_TCE;
+		return PCI_DMA_ERROR_CODE;
 	}
 
 	entry += tbl->it_offset;	/* Offset into real TCE table */
@@ -262,7 +262,7 @@ int iommu_alloc_sg(struct iommu_table *tbl, struct device *dev,
 		DBG("  - vaddr: %lx, size: %lx\n", vaddr, slen);
 
 		/* Handle failure */
-		if (unlikely(entry == NO_TCE)) {
+		if (unlikely(entry == PCI_DMA_ERROR_CODE)) {
 			if (printk_ratelimit())
 				printk(KERN_INFO "iommu_alloc failed, tbl %p vaddr %lx"
 				       " npages %lx\n", tbl, vaddr, npages);
@@ -326,7 +326,7 @@ int iommu_alloc_sg(struct iommu_table *tbl, struct device *dev,
 	 */
 	if (outcount < nelems) {
 		outs++;
-		outs->dma_address = NO_TCE;
+		outs->dma_address = PCI_DMA_ERROR_CODE;
 		outs->dma_length = 0;
 	}
 	return outcount;

arch/ppc64/kernel/pci_iommu.c

@@ -82,7 +82,7 @@ void *pci_iommu_alloc_consistent(struct pci_dev *hwdev, size_t size,
 	if (order >= IOMAP_MAX_ORDER) {
 		printk("PCI_DMA: pci_alloc_consistent size too large: 0x%lx\n",
 			size);
-		return (void *)NO_TCE;
+		return (void *)PCI_DMA_ERROR_CODE;
 	}
 
 	tbl = devnode_table(hwdev); 
@@ -101,7 +101,7 @@ void *pci_iommu_alloc_consistent(struct pci_dev *hwdev, size_t size,
 	/* Set up tces to cover the allocated range */
 	mapping = iommu_alloc(tbl, ret, npages, PCI_DMA_BIDIRECTIONAL);
 
-	if (mapping == NO_TCE) {
+	if (mapping == PCI_DMA_ERROR_CODE) {
 		free_pages((unsigned long)ret, order);
 		ret = NULL;
 	} else
@@ -139,7 +139,7 @@ dma_addr_t pci_iommu_map_single(struct pci_dev *hwdev, void *vaddr,
 				size_t size, int direction)
 {
 	struct iommu_table * tbl;
-	dma_addr_t dma_handle = NO_TCE;
+	dma_addr_t dma_handle = PCI_DMA_ERROR_CODE;
 	unsigned long uaddr;
 	unsigned int npages;
 
@@ -153,7 +153,7 @@ dma_addr_t pci_iommu_map_single(struct pci_dev *hwdev, void *vaddr,
 
 	if (tbl) {
 		dma_handle = iommu_alloc(tbl, vaddr, npages, direction);
-		if (dma_handle == NO_TCE) {
+		if (dma_handle == PCI_DMA_ERROR_CODE) {
 			if (printk_ratelimit())  {
 				printk(KERN_INFO "iommu_alloc failed, tbl %p vaddr %p npages %d\n",
 				       tbl, vaddr, npages);

arch/ppc64/kernel/vio.c

@@ -419,7 +419,7 @@ dma_addr_t vio_map_single(struct vio_dev *dev, void *vaddr,
 			  size_t size, int direction )
 {
 	struct iommu_table *tbl;
-	dma_addr_t dma_handle = NO_TCE;
+	dma_addr_t dma_handle = PCI_DMA_ERROR_CODE;
 	unsigned long uaddr;
 	unsigned int npages;
 
@@ -504,7 +504,7 @@ void *vio_alloc_consistent(struct vio_dev *dev, size_t size,
 	/* It is easier to debug here for the drivers than in the tce tables.*/
  	if(order >= IOMAP_MAX_ORDER) {
  		printk("VIO_DMA: vio_alloc_consistent size to large: 0x%lx \n", size);
- 		return (void *)NO_TCE;
+ 		return (void *)PCI_DMA_ERROR_CODE;
  	}
 
 	tbl = dev->iommu_table;
@@ -517,7 +517,7 @@ void *vio_alloc_consistent(struct vio_dev *dev, size_t size,
 			memset(ret, 0, npages << PAGE_SHIFT);
 			/* Set up tces to cover the allocated range */
 			tce = iommu_alloc(tbl, ret, npages, PCI_DMA_BIDIRECTIONAL);
-			if (tce == NO_TCE) {
+			if (tce == PCI_DMA_ERROR_CODE) {
 				PPCDBG(PPCDBG_TCE, "vio_alloc_consistent: iommu_alloc failed\n" );
 				free_pages((unsigned long)ret, order);
 				ret = NULL;

drivers/net/ibmveth.c

@@ -60,6 +60,9 @@
 
 #include "ibmveth.h"
 
+#warning remove NO_TCE usage from ibmveth.c
+#define NO_TCE PCI_DMA_ERROR_CODE
+
 #define DEBUG 1
 
 #define ibmveth_printk(fmt, args...) \

include/asm-ppc64/iommu.h

@@ -33,8 +33,6 @@
  */
 #define IOMAP_MAX_ORDER 10
 
-#define NO_TCE ((dma_addr_t)-1)
-
 /*
  * Tces come in two formats, one for the virtual bus and a different
  * format for PCI

include/asm-ppc64/pci.h

@@ -169,6 +169,12 @@ static inline int pci_dac_dma_supported(struct pci_dev *hwdev,u64 mask)
 	return 0;
 }
 
+#define PCI_DMA_ERROR_CODE      (~(dma_addr_t)0x0)
+static inline int pci_dma_error(dma_addr_t dma_addr)
+{
+	return (dma_addr == PCI_DMA_ERROR_CODE);
+}
+
 extern int pci_domain_nr(struct pci_bus *bus);
 
 /* Set the name of the bus as it appears in /proc/bus/pci */