[PATCH] move consistent_dma_mask to the generic device

From: James Bottomley <James.Bottomley@SteelEye.com>

pci_dev.consistent_dma_mask was introduced to get around problems in the
IA64 Altix machine.

Now, we have a use for it in x86: the aacraid needs coherent memory in a
31 bit address range (2GB).  Unfortunately, x86 is converted to the dma
model, so it can't see the pci_dev by the time coherent memory is
allocated.

The solution to all of this is to move pci_dev.consistent_dma_mask to
dev.coherent_dma_mask and make x86 use it in the dma_alloc_coherent()
calls.

This should allow me to make the aacraid set the coherent mask instead
of using it's current dma_mask juggling.

arch/i386/kernel/pci-dma.c

@@ -20,8 +20,9 @@ void *dma_alloc_coherent(struct device *dev, size_t size,
 	/* ignore region specifiers */
 	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
 
-	if (dev == NULL || (*dev->dma_mask < 0xffffffff))
+	if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
 		gfp |= GFP_DMA;
+
 	ret = (void *)__get_free_pages(gfp, get_order(size));
 
 	if (ret != NULL) {

arch/ia64/sn/io/machvec/pci_dma.c

@@ -152,7 +152,7 @@ sn_pci_alloc_consistent(struct pci_dev *hwdev, size_t size, dma_addr_t *dma_hand
 	 *   pcibr_dmatrans_addr ignores a missing PCIIO_DMA_A64 flag on
 	 *   PCI-X buses.
 	 */
-	if (hwdev->consistent_dma_mask == ~0UL)
+	if (hwdev->dev.coherent_dma_mask == ~0UL)
 		*dma_handle = pcibr_dmatrans_addr(vhdl, NULL, phys_addr, size,
 					  PCIIO_DMA_CMD | PCIIO_DMA_A64);
 	else {
@@ -169,7 +169,7 @@ sn_pci_alloc_consistent(struct pci_dev *hwdev, size_t size, dma_addr_t *dma_hand
 		}
 	}
 
-	if (!*dma_handle || *dma_handle > hwdev->consistent_dma_mask) {
+	if (!*dma_handle || *dma_handle > hwdev->dev.coherent_dma_mask) {
 		if (dma_map) {
 			pcibr_dmamap_done(dma_map);
 			pcibr_dmamap_free(dma_map);

arch/parisc/kernel/drivers.c

@@ -618,6 +618,7 @@ static void parisc_generic_device_register_recursive( struct parisc_device *dev
 		 tmp1);
 	/* make the generic dma mask a pointer to the parisc one */
 	dev->dev.dma_mask = &dev->dma_mask;
+	dev->dev.coherent_dma_mask = dev->dma_mask;
 	pr_debug("device_register(%s)\n", dev->dev.bus_id);
 	device_register(&dev->dev);
 }

arch/parisc/kernel/pci-dma.c

@@ -372,7 +372,7 @@ static void * pa11_dma_alloc_consistent (struct device *dev, size_t size, dma_ad
 ** ISA cards will certainly only support 24-bit DMA addressing.
 ** Not clear if we can, want, or need to support ISA.
 */
-	if (!dev || *dev->dma_mask != 0xffffffff)
+	if (!dev || *dev->coherent_dma_mask < 0xffffffff)
 		gfp |= GFP_DMA;
 #endif
 	return (void *)vaddr;

arch/x86_64/kernel/pci-gart.c

@@ -183,7 +183,7 @@ void *pci_alloc_consistent(struct pci_dev *hwdev, size_t size,
 		gfp |= GFP_DMA; 
 		dma_mask = 0xffffffff; 
 	} else {
-		dma_mask = hwdev->consistent_dma_mask; 
+		dma_mask = hwdev->dev.coherent_dma_mask;
 	}
 
 	if (dma_mask == 0) 

drivers/eisa/eisa-bus.c

@@ -187,6 +187,7 @@ static int __init eisa_init_device (struct eisa_root_device *root,
 	edev->dev.parent = root->dev;
 	edev->dev.bus = &eisa_bus_type;
 	edev->dev.dma_mask = &edev->dma_mask;
+	edev->dev.coherent_dma_mask = edev->dma_mask;
 	sprintf (edev->dev.bus_id, "%02X:%02X", root->bus_nr, slot);
 
 	for (i = 0; i < EISA_MAX_RESOURCES; i++) {

drivers/mca/mca-bus.c

@@ -106,6 +106,7 @@ int __init mca_register_device(int bus, struct mca_device *mca_dev)
 	sprintf (mca_dev->dev.bus_id, "%02d:%02X", bus, mca_dev->slot);
 	mca_dev->dma_mask = mca_bus->default_dma_mask;
 	mca_dev->dev.dma_mask = &mca_dev->dma_mask;
+	mca_dev->dev.coherent_dma_mask = mca_dev->dma_mask;
 
 	if (device_register(&mca_dev->dev))
 		return 0;

drivers/pci/pci.c

@@ -686,7 +686,7 @@ pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
 	if (!pci_dma_supported(dev, mask))
 		return -EIO;
 
-	dev->consistent_dma_mask = mask;
+	dev->dev.coherent_dma_mask = mask;
 
 	return 0;
 }

drivers/pci/probe.c

@@ -570,7 +570,6 @@ pci_scan_device(struct pci_bus *bus, int devfn)
 	/* Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer)
 	   set this higher, assuming the system even supports it.  */
 	dev->dma_mask = 0xffffffff;
-	dev->consistent_dma_mask = 0xffffffff;
 	if (pci_setup_device(dev) < 0) {
 		kfree(dev);
 		return NULL;
@@ -582,6 +581,7 @@ pci_scan_device(struct pci_bus *bus, int devfn)
 	pci_name_device(dev);
 
 	dev->dev.dma_mask = &dev->dma_mask;
+	dev->dev.coherent_dma_mask = 0xffffffffull;
 
 	return dev;
 }

include/linux/device.h

@@ -285,6 +285,12 @@ struct device {
 					   detached from its driver. */
 
 	u64		*dma_mask;	/* dma mask (if dma'able device) */
+	u64		coherent_dma_mask;/* Like dma_mask, but for
+					     alloc_coherent mappings as
+					     not all hardware supports
+					     64 bit addresses for consistent
+					     allocations such descriptors. */
+
 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
 
 	void	(*release)(struct device * dev);

include/linux/pci.h

@@ -393,11 +393,6 @@ struct pci_dev {
 					   this if your device has broken DMA
 					   or supports 64-bit transfers.  */
 
-	u64		consistent_dma_mask;/* Like dma_mask, but for
-					       pci_alloc_consistent mappings as
-					       not all hardware supports
-					       64 bit addresses for consistent
-					       allocations such descriptors. */
 	u32             current_state;  /* Current operating state. In ACPI-speak,
 					   this is D0-D3, D0 being fully functional,
 					   and D3 being off. */