ARM/PCI: Convert PCI scan API to pci_scan_root_bus_bridge()

The introduction of pci_scan_root_bus_bridge() provides a PCI core API to
scan a PCI root bus backed by an already initialized struct pci_host_bridge
object, which simplifies the bus scan interface and makes the PCI scan root
bus interface easier to generalize as members are added to the struct
pci_host_bridge.

Convert ARM bios32 code to pci_scan_root_bus_bridge() to improve the PCI
root bus scanning interface.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
[bhelgaas: fold in warning fix from Arnd Bergmann <arnd@arndb.de>:
http://lkml.kernel.org/r/20170621215323.3921382-1-arnd@arndb.de]
[bhelgaas: set bridge->ops for mv78xx0]
[bhelgaas: fold in fixes from Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>:
http://lkml.kernel.org/r/20170701135457.GB8977@red-moon]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Andrew Lunn <andrew@lunn.ch>

2 files changed, 22 insertions, 12 deletions

diff --git a/arch/arm/mach-iop13xx/pci.c b/arch/arm/mach-iop13xx/pci.c
index 204eb4460271..070d92ae1b6f 100644
--- a/arch/arm/mach-iop13xx/pci.c
+++ b/arch/arm/mach-iop13xx/pci.c
@@ -504,10 +504,10 @@ iop13xx_pci_abort(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 
 /* Scan an IOP13XX PCI bus.  nr selects which ATU we use.
  */
-struct pci_bus *iop13xx_scan_bus(int nr, struct pci_sys_data *sys)
+int iop13xx_scan_bus(int nr, struct pci_host_bridge *bridge)
 {
-	int which_atu;
-	struct pci_bus *bus = NULL;
+	int which_atu, ret;
+	struct pci_sys_data *sys = pci_host_bridge_priv(bridge);
 
 	switch (init_atu) {
 	case IOP13XX_INIT_ATU_ATUX:
@@ -525,9 +525,14 @@ struct pci_bus *iop13xx_scan_bus(int nr, struct pci_sys_data *sys)
 
 	if (!which_atu) {
 		BUG();
-		return NULL;
+		return -ENODEV;
 	}
 
+	list_splice_init(&sys->resources, &bridge->windows);
+	bridge->dev.parent = NULL;
+	bridge->sysdata = sys;
+	bridge->busnr = sys->busnr;
+
 	switch (which_atu) {
 	case IOP13XX_INIT_ATU_ATUX:
 		if (time_after_eq(jiffies + msecs_to_jiffies(1000),
@@ -535,18 +540,22 @@ struct pci_bus *iop13xx_scan_bus(int nr, struct pci_sys_data *sys)
 			while(time_before(jiffies, atux_trhfa_timeout))
 				udelay(100);
 
-		bus = pci_bus_atux = pci_scan_root_bus(NULL, sys->busnr,
-						       &iop13xx_atux_ops,
-						       sys, &sys->resources);
+		bridge->ops = &iop13xx_atux_ops;
+		ret = pci_scan_root_bus_bridge(bridge);
+		if (!ret)
+			pci_bus_atux = bridge->bus;
 		break;
 	case IOP13XX_INIT_ATU_ATUE:
-		bus = pci_bus_atue = pci_scan_root_bus(NULL, sys->busnr,
-						       &iop13xx_atue_ops,
-						       sys, &sys->resources);
+		bridge->ops = &iop13xx_atue_ops;
+		ret = pci_scan_root_bus_bridge(bridge);
+		if (!ret)
+			pci_bus_atue = bridge->bus;
 		break;
+	default:
+		ret = -EINVAL;
 	}
 
-	return bus;
+	return ret;
 }
 
 /* This function is called from iop13xx_pci_init() after assigning valid
diff --git a/arch/arm/mach-iop13xx/pci.h b/arch/arm/mach-iop13xx/pci.h
index 71b9c57e1fde..8dc343cb887a 100644
--- a/arch/arm/mach-iop13xx/pci.h
+++ b/arch/arm/mach-iop13xx/pci.h
@@ -11,9 +11,10 @@ extern size_t iop13xx_atue_mem_size;
 extern size_t iop13xx_atux_mem_size;
 
 struct pci_sys_data;
+struct pci_host_bridge;
 struct hw_pci;
 int iop13xx_pci_setup(int nr, struct pci_sys_data *sys);
-struct pci_bus *iop13xx_scan_bus(int nr, struct pci_sys_data *);
+int iop13xx_scan_bus(int nr, struct pci_host_bridge *bridge);
 void iop13xx_atu_select(struct hw_pci *plat_pci);
 void iop13xx_pci_init(void);
 void iop13xx_map_pci_memory(void);