[SPARC64]: Handle PCI bridges without 'ranges' property.

This fixes the IDE controller not showing up on Netra-T1
systems.

Just like Simba bridges, some PCI bridges can lack the
'ranges' OBP property.  So we handle this similarly to
the existing Simba code:

1) In of_device register address resolving, we push the
   translation to the parent.

2) In PCI device scanning, we interrogate the PCI config
   space registers of the PCI bus device in order to resolve
   the resources, just like the generic Linux PCI probing
   code does.

With much help and testing from Fabio, who also reported
the initial problem.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Fabio Massimo Di Nitto <fabbione@ubuntu.com>

1 files changed, 89 insertions, 8 deletions

diff --git a/arch/sparc64/kernel/pci.c b/arch/sparc64/kernel/pci.c
index 38a32bc95d22..81f4a5ea05f7 100644
--- a/arch/sparc64/kernel/pci.c
+++ b/arch/sparc64/kernel/pci.c
@@ -522,6 +522,89 @@ static void pci_resource_adjust(struct resource *res,
 	res->end += root->start;
 }
 
+/* For PCI bus devices which lack a 'ranges' property we interrogate
+ * the config space values to set the resources, just like the generic
+ * Linux PCI probing code does.
+ */
+static void __devinit pci_cfg_fake_ranges(struct pci_dev *dev,
+					  struct pci_bus *bus,
+					  struct pci_pbm_info *pbm)
+{
+	struct resource *res;
+	u8 io_base_lo, io_limit_lo;
+	u16 mem_base_lo, mem_limit_lo;
+	unsigned long base, limit;
+
+	pci_read_config_byte(dev, PCI_IO_BASE, &io_base_lo);
+	pci_read_config_byte(dev, PCI_IO_LIMIT, &io_limit_lo);
+	base = (io_base_lo & PCI_IO_RANGE_MASK) << 8;
+	limit = (io_limit_lo & PCI_IO_RANGE_MASK) << 8;
+
+	if ((io_base_lo & PCI_IO_RANGE_TYPE_MASK) == PCI_IO_RANGE_TYPE_32) {
+		u16 io_base_hi, io_limit_hi;
+
+		pci_read_config_word(dev, PCI_IO_BASE_UPPER16, &io_base_hi);
+		pci_read_config_word(dev, PCI_IO_LIMIT_UPPER16, &io_limit_hi);
+		base |= (io_base_hi << 16);
+		limit |= (io_limit_hi << 16);
+	}
+
+	res = bus->resource[0];
+	if (base <= limit) {
+		res->flags = (io_base_lo & PCI_IO_RANGE_TYPE_MASK) | IORESOURCE_IO;
+		if (!res->start)
+			res->start = base;
+		if (!res->end)
+			res->end = limit + 0xfff;
+		pci_resource_adjust(res, &pbm->io_space);
+	}
+
+	pci_read_config_word(dev, PCI_MEMORY_BASE, &mem_base_lo);
+	pci_read_config_word(dev, PCI_MEMORY_LIMIT, &mem_limit_lo);
+	base = (mem_base_lo & PCI_MEMORY_RANGE_MASK) << 16;
+	limit = (mem_limit_lo & PCI_MEMORY_RANGE_MASK) << 16;
+
+	res = bus->resource[1];
+	if (base <= limit) {
+		res->flags = ((mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) |
+			      IORESOURCE_MEM);
+		res->start = base;
+		res->end = limit + 0xfffff;
+		pci_resource_adjust(res, &pbm->mem_space);
+	}
+
+	pci_read_config_word(dev, PCI_PREF_MEMORY_BASE, &mem_base_lo);
+	pci_read_config_word(dev, PCI_PREF_MEMORY_LIMIT, &mem_limit_lo);
+	base = (mem_base_lo & PCI_PREF_RANGE_MASK) << 16;
+	limit = (mem_limit_lo & PCI_PREF_RANGE_MASK) << 16;
+
+	if ((mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) {
+		u32 mem_base_hi, mem_limit_hi;
+
+		pci_read_config_dword(dev, PCI_PREF_BASE_UPPER32, &mem_base_hi);
+		pci_read_config_dword(dev, PCI_PREF_LIMIT_UPPER32, &mem_limit_hi);
+
+		/*
+		 * Some bridges set the base > limit by default, and some
+		 * (broken) BIOSes do not initialize them.  If we find
+		 * this, just assume they are not being used.
+		 */
+		if (mem_base_hi <= mem_limit_hi) {
+			base |= ((long) mem_base_hi) << 32;
+			limit |= ((long) mem_limit_hi) << 32;
+		}
+	}
+
+	res = bus->resource[2];
+	if (base <= limit) {
+		res->flags = ((mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) |
+			      IORESOURCE_MEM | IORESOURCE_PREFETCH);
+		res->start = base;
+		res->end = limit + 0xfffff;
+		pci_resource_adjust(res, &pbm->mem_space);
+	}
+}
+
 /* Cook up fake bus resources for SUNW,simba PCI bridges which lack
  * a proper 'ranges' property.
  */
@@ -581,13 +664,8 @@ static void __devinit of_scan_pci_bridge(struct pci_pbm_info *pbm,
 	simba = 0;
 	if (ranges == NULL) {
 		const char *model = of_get_property(node, "model", NULL);
-		if (model && !strcmp(model, "SUNW,simba")) {
+		if (model && !strcmp(model, "SUNW,simba"))
 			simba = 1;
-		} else {
-			printk(KERN_DEBUG "Can't get ranges for PCI-PCI bridge %s\n",
-			       node->full_name);
-			return;
-		}
 	}
 
 	bus = pci_add_new_bus(dev->bus, dev, busrange[0]);
@@ -611,7 +689,10 @@ static void __devinit of_scan_pci_bridge(struct pci_pbm_info *pbm,
 	}
 	if (simba) {
 		apb_fake_ranges(dev, bus, pbm);
-		goto simba_cont;
+		goto after_ranges;
+	} else if (ranges == NULL) {
+		pci_cfg_fake_ranges(dev, bus, pbm);
+		goto after_ranges;
 	}
 	i = 1;
 	for (; len >= 32; len -= 32, ranges += 8) {
@@ -650,7 +731,7 @@ static void __devinit of_scan_pci_bridge(struct pci_pbm_info *pbm,
 		 */
 		pci_resource_adjust(res, root);
 	}
-simba_cont:
+after_ranges:
 	sprintf(bus->name, "PCI Bus %04x:%02x", pci_domain_nr(bus),
 		bus->number);
 	if (ofpci_verbose)