Model Sparc64 pci_assign_resource more closely to the

implementation in drivers/pci/setup-res.c to make it
easier to track bugs.

Fix calculation of mem_space end on Sparc64 Schizo PCI controllers.
The decode register is set up for the whole 4GB even though the
top 2GB is reserved for DMA to/from main memory (ie. IOMMU translated)

arch/sparc64/kernel/pci.c

@@ -234,33 +234,63 @@ int pci_claim_resource(struct pci_dev *pdev, int resource)
 	return request_resource(root, res);
 }
 
+/*
+ * Given the PCI bus a device resides on, try to
+ * find an acceptable resource allocation for a
+ * specific device resource..
+ */
+static int pci_assign_bus_resource(const struct pci_bus *bus,
+	struct pci_dev *dev,
+	struct resource *res,
+	unsigned long size,
+	unsigned long min,
+	int resno)
+{
+	unsigned int type_mask;
+	int i;
+
+	type_mask = IORESOURCE_IO | IORESOURCE_MEM;
+	for (i = 0 ; i < 4; i++) {
+		struct resource *r = bus->resource[i];
+		if (!r)
+			continue;
+
+		/* type_mask must match */
+		if ((res->flags ^ r->flags) & type_mask)
+			continue;
+
+		/* Ok, try it out.. */
+		if (allocate_resource(r, res, size, min, -1, size, NULL, NULL) < 0)
+			continue;
+
+		/* PCI config space updated by caller.  */
+		return 0;
+	}
+	return -EBUSY;
+}
+
 int pci_assign_resource(struct pci_dev *pdev, int resource)
 {
 	struct pcidev_cookie *pcp = pdev->sysdata;
 	struct pci_pbm_info *pbm = pcp->pbm;
 	struct resource *res = &pdev->resource[resource];
-	struct resource *root;
-	unsigned long min, max, size, align;
+	unsigned long min, size;
 	int err;
 
-	if (res->flags & IORESOURCE_IO) {
-		root = &pbm->io_space;
-		min = root->start + 0x400UL;
-		max = root->end;
-	} else {
-		root = &pbm->mem_space;
-		min = root->start;
-		max = min + 0x80000000UL;
-	}
+	if (res->flags & IORESOURCE_IO)
+		min = pbm->io_space.start + 0x400UL;
+	else
+		min = pbm->mem_space.start;
+
+	size = res->end - res->start + 1;
 
-	size = res->end - res->start;
-	align = size + 1;
+	err = pci_assign_bus_resource(pdev->bus, pdev, res, size, min, resource);
 
-	err = allocate_resource(root, res, size + 1, min, max, align, NULL, NULL);
 	if (err < 0) {
 		printk("PCI: Failed to allocate resource %d for %s\n",
 		       resource, pdev->name);
 	} else {
+		/* Update PCI config space. */
 		pbm->parent->base_address_update(pdev, resource);
 	}
 

arch/sparc64/kernel/pci_schizo.c

@@ -1483,24 +1483,12 @@ static void __init schizo_resource_adjust(struct pci_dev *pdev,
 #define SCHIZO_PCI_B_IO_MATCH		0x00070UL
 #define SCHIZO_PCI_B_IO_MASK		0x00078UL
 
-/* VAL must be non-zero. */
-static unsigned long strip_to_lowest_bit_set(unsigned long val)
-{
-	unsigned long tmp;
-
-	tmp = 1UL;
-	while (!(tmp & val))
-		tmp <<= 1UL;
-
-	return tmp;
-}
-
 static void schizo_determine_mem_io_space(struct pci_pbm_info *pbm,
 					  int is_pbm_a, unsigned long reg_base)
 {
 	u64 mem_match, mem_mask;
 	u64 io_match;
-	u64 long a, b;
+	u64 a;
 
 	if (is_pbm_a) {
 		mem_match = reg_base + SCHIZO_PCI_A_MEM_MATCH;
@@ -1512,11 +1500,12 @@ static void schizo_determine_mem_io_space(struct pci_pbm_info *pbm,
 	mem_mask = mem_match + 0x8UL;
 
 	a = schizo_read(mem_match) & ~0x8000000000000000UL;
-	b = strip_to_lowest_bit_set(schizo_read(mem_mask));
 
-	/* It should be 2GB in size. */
+	/* It should be 2GB in size but the decode is set for the full
+	 * 4GB so we have to add the 2G by hand.
+	 */
 	pbm->mem_space.start = a;
-	pbm->mem_space.end = a + (b - 1UL);
+	pbm->mem_space.end = a + 0x80000000;
 	pbm->mem_space.flags = IORESOURCE_MEM;
 
 	/* This 32MB area is divided into two pieces.  The first