pci: give preference to non-PCI_REGION_SYS_MEMORY regions when matching

When we search for an address match in pci_hose_{phys_to_bus,bus_to_phys}
we should give preference to memory regions that aren't system memory.

Its possible that we have over mapped system memory in the regions and
we want to avoid depending on the order of the regions.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

drivers/pci/pci.c

@@ -218,67 +218,121 @@ pci_dev_t pci_find_device(unsigned int vendor, unsigned int device, int index)
  *
  */
 
-pci_addr_t pci_hose_phys_to_bus (struct pci_controller *hose,
+int __pci_hose_phys_to_bus (struct pci_controller *hose,
 				phys_addr_t phys_addr,
-				    unsigned long flags)
+				unsigned long flags,
+				unsigned long skip_mask,
+				pci_addr_t *ba)
 {
 	struct pci_region *res;
 	pci_addr_t bus_addr;
 	int i;
 
-	if (!hose) {
-		printf ("pci_hose_phys_to_bus: %s\n", "invalid hose");
-		goto Done;
-	}
-
 	for (i = 0; i < hose->region_count; i++) {
 		res = &hose->regions[i];
 
 		if (((res->flags ^ flags) & PCI_REGION_TYPE) != 0)
 			continue;
 
+		if (res->flags & skip_mask)
+			continue;
+
 		bus_addr = phys_addr - res->phys_start + res->bus_start;
 
 		if (bus_addr >= res->bus_start &&
 			bus_addr < res->bus_start + res->size) {
+			*ba = bus_addr;
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+pci_addr_t pci_hose_phys_to_bus (struct pci_controller *hose,
+				    phys_addr_t phys_addr,
+				    unsigned long flags)
+{
+	pci_addr_t bus_addr = 0;
+	int ret;
+
+	if (!hose) {
+		puts ("pci_hose_phys_to_bus: invalid hose\n");
 		return bus_addr;
 	}
+
+	/* if PCI_REGION_MEM is set we do a two pass search with preference
+	 * on matches that don't have PCI_REGION_SYS_MEMORY set */
+	if ((flags & PCI_REGION_MEM) == PCI_REGION_MEM) {
+		ret = __pci_hose_phys_to_bus(hose, phys_addr,
+				flags, PCI_REGION_SYS_MEMORY, &bus_addr);
+		if (!ret)
+			return bus_addr;
 	}
 
-	printf ("pci_hose_phys_to_bus: %s\n", "invalid physical address");
+	ret = __pci_hose_phys_to_bus(hose, phys_addr, flags, 0, &bus_addr);
 
-Done:
-	return 0;
+	if (ret)
+		puts ("pci_hose_phys_to_bus: invalid physical address\n");
+
+	return bus_addr;
 }
 
-phys_addr_t pci_hose_bus_to_phys(struct pci_controller* hose,
+int __pci_hose_bus_to_phys (struct pci_controller *hose,
 				pci_addr_t bus_addr,
-				 unsigned long flags)
+				unsigned long flags,
+				unsigned long skip_mask,
+				phys_addr_t *pa)
 {
 	struct pci_region *res;
 	int i;
 
-	if (!hose) {
-		printf ("pci_hose_bus_to_phys: %s\n", "invalid hose");
-		goto Done;
-	}
-
 	for (i = 0; i < hose->region_count; i++) {
 		res = &hose->regions[i];
 
 		if (((res->flags ^ flags) & PCI_REGION_TYPE) != 0)
 			continue;
 
+		if (res->flags & skip_mask)
+			continue;
+
 		if (bus_addr >= res->bus_start &&
 			bus_addr < res->bus_start + res->size) {
-			return bus_addr - res->bus_start + res->phys_start;
+			*pa = (bus_addr - res->bus_start + res->phys_start);
+			return 0;
 		}
 	}
 
-	printf ("pci_hose_bus_to_phys: %s\n", "invalid physical address");
+	return 1;
+}
 
-Done:
-	return 0;
+phys_addr_t pci_hose_bus_to_phys(struct pci_controller* hose,
+				 pci_addr_t bus_addr,
+				 unsigned long flags)
+{
+	phys_addr_t phys_addr = 0;
+	int ret;
+
+	if (!hose) {
+		puts ("pci_hose_bus_to_phys: invalid hose\n");
+		return phys_addr;
+	}
+
+	/* if PCI_REGION_MEM is set we do a two pass search with preference
+	 * on matches that don't have PCI_REGION_SYS_MEMORY set */
+	if ((flags & PCI_REGION_MEM) == PCI_REGION_MEM) {
+		ret = __pci_hose_bus_to_phys(hose, bus_addr,
+				flags, PCI_REGION_SYS_MEMORY, &phys_addr);
+		if (!ret)
+			return phys_addr;
+	}
+
+	ret = __pci_hose_bus_to_phys(hose, bus_addr, flags, 0, &phys_addr);
+
+	if (ret)
+		puts ("pci_hose_bus_to_phys: invalid physical address\n");
+
+	return phys_addr;
 }
 
 /*