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/sysdev/ppc4xx_pci.c b/arch/powerpc/sysdev/ppc4xx_pci.c
index 56e8b3c..64603a1 100644
--- a/arch/powerpc/sysdev/ppc4xx_pci.c
+++ b/arch/powerpc/sysdev/ppc4xx_pci.c
@@ -257,6 +257,7 @@
 	/* Setup outbound memory windows */
 	for (i = j = 0; i < 3; i++) {
 		struct resource *res = &hose->mem_resources[i];
+		resource_size_t offset = hose->mem_offset[i];
 
 		/* we only care about memory windows */
 		if (!(res->flags & IORESOURCE_MEM))
@@ -270,7 +271,7 @@
 		/* Configure the resource */
 		if (ppc4xx_setup_one_pci_PMM(hose, reg,
 					     res->start,
-					     res->start - hose->pci_mem_offset,
+					     res->start - offset,
 					     resource_size(res),
 					     res->flags,
 					     j) == 0) {
@@ -279,7 +280,7 @@
 			/* If the resource PCI address is 0 then we have our
 			 * ISA memory hole
 			 */
-			if (res->start == hose->pci_mem_offset)
+			if (res->start == offset)
 				found_isa_hole = 1;
 		}
 	}
@@ -457,6 +458,7 @@
 	/* Setup outbound memory windows */
 	for (i = j = 0; i < 3; i++) {
 		struct resource *res = &hose->mem_resources[i];
+		resource_size_t offset = hose->mem_offset[i];
 
 		/* we only care about memory windows */
 		if (!(res->flags & IORESOURCE_MEM))
@@ -470,7 +472,7 @@
 		/* Configure the resource */
 		if (ppc4xx_setup_one_pcix_POM(hose, reg,
 					      res->start,
-					      res->start - hose->pci_mem_offset,
+					      res->start - offset,
 					      resource_size(res),
 					      res->flags,
 					      j) == 0) {
@@ -479,7 +481,7 @@
 			/* If the resource PCI address is 0 then we have our
 			 * ISA memory hole
 			 */
-			if (res->start == hose->pci_mem_offset)
+			if (res->start == offset)
 				found_isa_hole = 1;
 		}
 	}
@@ -1792,6 +1794,7 @@
 	/* Setup outbound memory windows */
 	for (i = j = 0; i < 3; i++) {
 		struct resource *res = &hose->mem_resources[i];
+		resource_size_t offset = hose->mem_offset[i];
 
 		/* we only care about memory windows */
 		if (!(res->flags & IORESOURCE_MEM))
@@ -1805,7 +1808,7 @@
 		/* Configure the resource */
 		if (ppc4xx_setup_one_pciex_POM(port, hose, mbase,
 					       res->start,
-					       res->start - hose->pci_mem_offset,
+					       res->start - offset,
 					       resource_size(res),
 					       res->flags,
 					       j) == 0) {
@@ -1814,7 +1817,7 @@
 			/* If the resource PCI address is 0 then we have our
 			 * ISA memory hole
 			 */
-			if (res->start == hose->pci_mem_offset)
+			if (res->start == offset)
 				found_isa_hole = 1;
 		}
 	}