PCI: generic: Allow multiple hosts with different map_bus() methods

The generic driver kept a global struct pci_ops ("gen_pci_ops") which it
patched with the .map_bus() method appropriate for the bus device.  This is
a problem when we have two different types of bus devices: the .map_bus()
method for the last device probed clobbers the method for previous devices.
The result is that only the last bus device probed has the correct
.map_bus(), and the others fail.

Move the struct pci_ops into the bus-specific structure and initialize a
pointer to it when the bus device is probed.

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Will Deacon <will.deacon@arm.com>

drivers/pci/host/pci-host-generic.c

@@ -27,7 +27,7 @@
 
 struct gen_pci_cfg_bus_ops {
 	u32 bus_shift;
-	void __iomem *(*map_bus)(struct pci_bus *, unsigned int, int);
+	struct pci_ops ops;
 };
 
 struct gen_pci_cfg_windows {
@@ -35,7 +35,7 @@ struct gen_pci_cfg_windows {
 	struct resource				*bus_range;
 	void __iomem				**win;
 
-	const struct gen_pci_cfg_bus_ops	*ops;
+	struct gen_pci_cfg_bus_ops		*ops;
 };
 
 /*
@@ -65,7 +65,11 @@ static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
 
 static struct gen_pci_cfg_bus_ops gen_pci_cfg_cam_bus_ops = {
 	.bus_shift	= 16,
-	.map_bus	= gen_pci_map_cfg_bus_cam,
+	.ops		= {
+		.map_bus	= gen_pci_map_cfg_bus_cam,
+		.read		= pci_generic_config_read,
+		.write		= pci_generic_config_write,
+	}
 };
 
 static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
@@ -80,12 +84,11 @@ static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
 
 static struct gen_pci_cfg_bus_ops gen_pci_cfg_ecam_bus_ops = {
 	.bus_shift	= 20,
-	.map_bus	= gen_pci_map_cfg_bus_ecam,
-};
-
-static struct pci_ops gen_pci_ops = {
-	.read	= pci_generic_config_read,
-	.write	= pci_generic_config_write,
+	.ops		= {
+		.map_bus	= gen_pci_map_cfg_bus_ecam,
+		.read		= pci_generic_config_read,
+		.write		= pci_generic_config_write,
+	}
 };
 
 static const struct of_device_id gen_pci_of_match[] = {
@@ -227,8 +230,7 @@ static int gen_pci_probe(struct platform_device *pdev)
 	of_pci_check_probe_only();
 
 	of_id = of_match_node(gen_pci_of_match, np);
-	pci->cfg.ops = of_id->data;
-	gen_pci_ops.map_bus = pci->cfg.ops->map_bus;
+	pci->cfg.ops = (struct gen_pci_cfg_bus_ops *)of_id->data;
 	pci->host.dev.parent = dev;
 	INIT_LIST_HEAD(&pci->host.windows);
 	INIT_LIST_HEAD(&pci->resources);
@@ -249,7 +251,8 @@ static int gen_pci_probe(struct platform_device *pdev)
 	if (!pci_has_flag(PCI_PROBE_ONLY))
 		pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
 
-	bus = pci_scan_root_bus(dev, 0, &gen_pci_ops, pci, &pci->resources);
+	bus = pci_scan_root_bus(dev, 0,
+				&pci->cfg.ops->ops, pci, &pci->resources);
 	if (!bus) {
 		dev_err(dev, "Scanning rootbus failed");
 		return -ENODEV;