powerpc/pci: Support per-aperture memory offset

The PCI core supports an offset per aperture nowadays but our arch
code still has a single offset per host bridge representing the
difference betwen CPU memory addresses and PCI MMIO addresses.

This is a problem as new machines and hypervisor versions are
coming out where the 64-bit windows will have a different offset
(basically mapped 1:1) from the 32-bit windows.

This fixes it by using separate offsets. In the long run, we probably
want to get rid of that intermediary struct pci_controller and have
those directly stored into the pci_host_bridge as they are parsed
but this will be a more invasive change.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index cf00588..f5c5c90 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -786,22 +786,8 @@
 				hose->isa_mem_size = size;
 			}
 
-			/* We get the PCI/Mem offset from the first range or
-			 * the, current one if the offset came from an ISA
-			 * hole. If they don't match, bugger.
-			 */
-			if (memno == 0 ||
-			    (isa_hole >= 0 && pci_addr != 0 &&
-			     hose->pci_mem_offset == isa_mb))
-				hose->pci_mem_offset = cpu_addr - pci_addr;
-			else if (pci_addr != 0 &&
-				 hose->pci_mem_offset != cpu_addr - pci_addr) {
-				printk(KERN_INFO
-				       " \\--> Skipped (offset mismatch) !\n");
-				continue;
-			}
-
 			/* Build resource */
+			hose->mem_offset[memno] = cpu_addr - pci_addr;
 			res = &hose->mem_resources[memno++];
 			res->flags = IORESOURCE_MEM;
 			if (pci_space & 0x40000000)
@@ -817,20 +803,6 @@
 			res->child = NULL;
 		}
 	}
-
-	/* If there's an ISA hole and the pci_mem_offset is -not- matching
-	 * the ISA hole offset, then we need to remove the ISA hole from
-	 * the resource list for that brige
-	 */
-	if (isa_hole >= 0 && hose->pci_mem_offset != isa_mb) {
-		unsigned int next = isa_hole + 1;
-		printk(KERN_INFO " Removing ISA hole at 0x%016llx\n", isa_mb);
-		if (next < memno)
-			memmove(&hose->mem_resources[isa_hole],
-				&hose->mem_resources[next],
-				sizeof(struct resource) * (memno - next));
-		hose->mem_resources[--memno].flags = 0;
-	}
 }
 
 /* Decide whether to display the domain number in /proc */
@@ -916,6 +888,7 @@
 	struct pci_controller *hose = pci_bus_to_host(bus);
 	struct pci_dev *dev = bus->self;
 	resource_size_t offset;
+	struct pci_bus_region region;
 	u16 command;
 	int i;
 
@@ -925,10 +898,10 @@
 
 	/* Job is a bit different between memory and IO */
 	if (res->flags & IORESOURCE_MEM) {
-		/* If the BAR is non-0 (res != pci_mem_offset) then it's probably been
-		 * initialized by somebody
-		 */
-		if (res->start != hose->pci_mem_offset)
+		pcibios_resource_to_bus(dev, &region, res);
+
+		/* If the BAR is non-0 then it's probably been initialized */
+		if (region.start != 0)
 			return 0;
 
 		/* The BAR is 0, let's check if memory decoding is enabled on
@@ -940,11 +913,11 @@
 
 		/* Memory decoding is enabled and the BAR is 0. If any of the bridge
 		 * resources covers that starting address (0 then it's good enough for
-		 * us for memory
+		 * us for memory space)
 		 */
 		for (i = 0; i < 3; i++) {
 			if ((hose->mem_resources[i].flags & IORESOURCE_MEM) &&
-			    hose->mem_resources[i].start == hose->pci_mem_offset)
+			    hose->mem_resources[i].start == hose->mem_offset[i])
 				return 0;
 		}
 
@@ -1381,10 +1354,9 @@
 
  no_io:
 	/* Check for memory */
-	offset = hose->pci_mem_offset;
-	pr_debug("hose mem offset: %016llx\n", (unsigned long long)offset);
 	for (i = 0; i < 3; i++) {
 		pres = &hose->mem_resources[i];
+		offset = hose->mem_offset[i];
 		if (!(pres->flags & IORESOURCE_MEM))
 			continue;
 		pr_debug("hose mem res: %pR\n", pres);
@@ -1524,6 +1496,7 @@
 					struct list_head *resources)
 {
 	struct resource *res;
+	resource_size_t offset;
 	int i;
 
 	/* Hookup PHB IO resource */
@@ -1533,51 +1506,37 @@
 		printk(KERN_WARNING "PCI: I/O resource not set for host"
 		       " bridge %s (domain %d)\n",
 		       hose->dn->full_name, hose->global_number);
-#ifdef CONFIG_PPC32
-		/* Workaround for lack of IO resource only on 32-bit */
-		res->start = (unsigned long)hose->io_base_virt - isa_io_base;
-		res->end = res->start + IO_SPACE_LIMIT;
-		res->flags = IORESOURCE_IO;
-#endif /* CONFIG_PPC32 */
-	}
-	if (res->flags) {
-		pr_debug("PCI: PHB IO resource    = %016llx-%016llx [%lx]\n",
+	} else {
+		offset = pcibios_io_space_offset(hose);
+
+		pr_debug("PCI: PHB IO resource    = %08llx-%08llx [%lx] off 0x%08llx\n",
 			 (unsigned long long)res->start,
 			 (unsigned long long)res->end,
-			 (unsigned long)res->flags);
-		pci_add_resource_offset(resources, res, pcibios_io_space_offset(hose));
-
-		pr_debug("PCI: PHB IO  offset     = %08lx\n",
-			 (unsigned long)hose->io_base_virt - _IO_BASE);
+			 (unsigned long)res->flags,
+			 (unsigned long long)offset);
+		pci_add_resource_offset(resources, res, offset);
 	}
 
 	/* Hookup PHB Memory resources */
 	for (i = 0; i < 3; ++i) {
 		res = &hose->mem_resources[i];
 		if (!res->flags) {
-			if (i > 0)
-				continue;
 			printk(KERN_ERR "PCI: Memory resource 0 not set for "
 			       "host bridge %s (domain %d)\n",
 			       hose->dn->full_name, hose->global_number);
-#ifdef CONFIG_PPC32
-			/* Workaround for lack of MEM resource only on 32-bit */
-			res->start = hose->pci_mem_offset;
-			res->end = (resource_size_t)-1LL;
-			res->flags = IORESOURCE_MEM;
-#endif /* CONFIG_PPC32 */
+			continue;
 		}
-		if (res->flags) {
-			pr_debug("PCI: PHB MEM resource %d = %016llx-%016llx [%lx]\n", i,
-				 (unsigned long long)res->start,
-				 (unsigned long long)res->end,
-				 (unsigned long)res->flags);
-			pci_add_resource_offset(resources, res, hose->pci_mem_offset);
-		}
-	}
+		offset = hose->mem_offset[i];
 
-	pr_debug("PCI: PHB MEM offset     = %016llx\n",
-		 (unsigned long long)hose->pci_mem_offset);
+
+		pr_debug("PCI: PHB MEM resource %d = %08llx-%08llx [%lx] off 0x%08llx\n", i,
+			 (unsigned long long)res->start,
+			 (unsigned long long)res->end,
+			 (unsigned long)res->flags,
+			 (unsigned long long)offset);
+
+		pci_add_resource_offset(resources, res, offset);
+	}
 }
 
 /*