[RFC v2 1/7] PCI: Introduce pci_host_bridge::domain_nr

[Boqun Feng <boqun.feng@gmail.com>]

Currently we retrieve the PCI domain number of the host bridge from the
bus sysdata (or pci_config_window if PCI_DOMAINS_GENERIC=y). Actually
we have the information at PCI host bridge probing time, and it makes
sense that we store it into pci_host_bridge. One benefit of doing so is
the requirement for supporting PCI on Hyper-V for ARM64, because the
host bridge of Hyper-V doesnt' have pci_config_window, whereas ARM64 is
a PCI_DOMAINS_GENERIC=y arch, so we cannot retrieve the PCI domain
number from pci_config_window on ARM64 Hyper-V guest.

As the preparation for ARM64 Hyper-V PCI support, we introduce the
domain_nr in pci_host_bridge, and set it properly at probing time, then
for PCI_DOMAINS_GENERIC=y archs, bus domain numbers are set by the
bridge domain_nr.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
---
 arch/arm/kernel/bios32.c              |  2 ++
 arch/arm/mach-dove/pcie.c             |  2 ++
 arch/arm/mach-mv78xx0/pcie.c          |  2 ++
 arch/arm/mach-orion5x/pci.c           |  2 ++
 arch/arm64/kernel/pci.c               |  3 +--
 arch/mips/pci/pci-legacy.c            |  2 ++
 arch/mips/pci/pci-xtalk-bridge.c      |  2 ++
 drivers/pci/controller/pci-ftpci100.c |  2 ++
 drivers/pci/controller/pci-mvebu.c    |  2 ++
 drivers/pci/pci.c                     |  4 ++--
 drivers/pci/probe.c                   |  7 ++++++-
 include/linux/pci.h                   | 11 ++++++++---
 12 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index e7ef2b5bea9c..4942cd681e41 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -471,6 +471,8 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
 				bridge->sysdata = sys;
 				bridge->busnr = sys->busnr;
 				bridge->ops = hw->ops;
+				if (IS_ENABLED(CONFIG_PCI_DOMAINS_GENERIC))
+					bridge->domain_nr = pci_bus_find_domain_nr(sys, parent);
 
 				ret = pci_scan_root_bus_bridge(bridge);
 			}
diff --git a/arch/arm/mach-dove/pcie.c b/arch/arm/mach-dove/pcie.c
index ee91ac6b5ebf..92eb8484b49b 100644
--- a/arch/arm/mach-dove/pcie.c
+++ b/arch/arm/mach-dove/pcie.c
@@ -167,6 +167,8 @@ dove_pcie_scan_bus(int nr, struct pci_host_bridge *bridge)
 	bridge->sysdata = sys;
 	bridge->busnr = sys->busnr;
 	bridge->ops = &pcie_ops;
+	if (IS_ENABLED(CONFIG_PCI_DOMAINS_GENERIC))
+		bridge->domain_nr = pci_bus_find_domain_nr(sys, NULL);
 
 	return pci_scan_root_bus_bridge(bridge);
 }
diff --git a/arch/arm/mach-mv78xx0/pcie.c b/arch/arm/mach-mv78xx0/pcie.c
index 636d84b40466..6703d394bcde 100644
--- a/arch/arm/mach-mv78xx0/pcie.c
+++ b/arch/arm/mach-mv78xx0/pcie.c
@@ -208,6 +208,8 @@ static int __init mv78xx0_pcie_scan_bus(int nr, struct pci_host_bridge *bridge)
 	bridge->sysdata = sys;
 	bridge->busnr = sys->busnr;
 	bridge->ops = &pcie_ops;
+	if (IS_ENABLED(CONFIG_PCI_DOMAINS_GENERIC))
+		bridge->domain_nr = pci_bus_find_domain_nr(sys, NULL);
 
 	return pci_scan_root_bus_bridge(bridge);
 }
diff --git a/arch/arm/mach-orion5x/pci.c b/arch/arm/mach-orion5x/pci.c
index 76951bfbacf5..6257fbd4e705 100644
--- a/arch/arm/mach-orion5x/pci.c
+++ b/arch/arm/mach-orion5x/pci.c
@@ -563,6 +563,8 @@ int __init orion5x_pci_sys_scan_bus(int nr, struct pci_host_bridge *bridge)
 	bridge->dev.parent = NULL;
 	bridge->sysdata = sys;
 	bridge->busnr = sys->busnr;
+	if (IS_ENABLED(CONFIG_PCI_DOMAINS_GENERIC))
+		bridge->domain_nr = pci_bus_find_domain_nr(sys, NULL);
 
 	if (nr == 0) {
 		bridge->ops = &pcie_ops;
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index 1006ed2d7c60..e9a6eeb6a694 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -71,9 +71,8 @@ struct acpi_pci_generic_root_info {
 	struct pci_config_window	*cfg;	/* config space mapping */
 };
 
-int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
+int acpi_pci_bus_find_domain_nr(struct pci_config_window *cfg)
 {
-	struct pci_config_window *cfg = bus->sysdata;
 	struct acpi_device *adev = to_acpi_device(cfg->parent);
 	struct acpi_pci_root *root = acpi_driver_data(adev);
 
diff --git a/arch/mips/pci/pci-legacy.c b/arch/mips/pci/pci-legacy.c
index 39052de915f3..84ad482be22d 100644
--- a/arch/mips/pci/pci-legacy.c
+++ b/arch/mips/pci/pci-legacy.c
@@ -97,6 +97,8 @@ static void pcibios_scanbus(struct pci_controller *hose)
 	bridge->ops = hose->pci_ops;
 	bridge->swizzle_irq = pci_common_swizzle;
 	bridge->map_irq = pcibios_map_irq;
+	if (IS_ENABLED(CONFIG_PCI_DOMAINS_GENERIC))
+		bridge->domain_nr = pci_bus_find_domain_nr(hose, NULL);
 	ret = pci_scan_root_bus_bridge(bridge);
 	if (ret) {
 		pci_free_host_bridge(bridge);
diff --git a/arch/mips/pci/pci-xtalk-bridge.c b/arch/mips/pci/pci-xtalk-bridge.c
index 50f7d42cca5a..23355ab720be 100644
--- a/arch/mips/pci/pci-xtalk-bridge.c
+++ b/arch/mips/pci/pci-xtalk-bridge.c
@@ -712,6 +712,8 @@ static int bridge_probe(struct platform_device *pdev)
 	host->ops = &bridge_pci_ops;
 	host->map_irq = bridge_map_irq;
 	host->swizzle_irq = pci_common_swizzle;
+	if (IS_ENABLED(CONFIG_PCI_DOMAINS_GENERIC))
+		host->domain_nr = pci_bus_find_domain_nr(bc, dev);
 
 	err = pci_scan_root_bus_bridge(host);
 	if (err < 0)
diff --git a/drivers/pci/controller/pci-ftpci100.c b/drivers/pci/controller/pci-ftpci100.c
index da3cd216da00..cf6eec7f90e1 100644
--- a/drivers/pci/controller/pci-ftpci100.c
+++ b/drivers/pci/controller/pci-ftpci100.c
@@ -439,6 +439,8 @@ static int faraday_pci_probe(struct platform_device *pdev)
 	host->ops = &faraday_pci_ops;
 	p = pci_host_bridge_priv(host);
 	host->sysdata = p;
+	if (IS_ENABLED(CONFIG_PCI_DOMAINS_GENERIC))
+		host->domain_nr = pci_bus_find_domain_nr(p, dev);
 	p->dev = dev;
 
 	/* Retrieve and enable optional clocks */
diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c
index ed13e81cd691..b329ed2f0956 100644
--- a/drivers/pci/controller/pci-mvebu.c
+++ b/drivers/pci/controller/pci-mvebu.c
@@ -1122,6 +1122,8 @@ static int mvebu_pcie_probe(struct platform_device *pdev)
 	bridge->sysdata = pcie;
 	bridge->ops = &mvebu_pcie_ops;
 	bridge->align_resource = mvebu_pcie_align_resource;
+	if (IS_ENABLED(CONFIG_PCI_DOMAINS_GENERIC))
+		bridge->domain_nr = pci_bus_find_domain_nr(pcie, dev);
 
 	return mvebu_pci_host_probe(bridge);
 }
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 16a17215f633..a249dbf78c34 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -6505,10 +6505,10 @@ static int of_pci_bus_find_domain_nr(struct device *parent)
 	return domain;
 }
 
-int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent)
+int pci_bus_find_domain_nr(void *sysdata, struct device *parent)
 {
 	return acpi_disabled ? of_pci_bus_find_domain_nr(parent) :
-			       acpi_pci_bus_find_domain_nr(bus);
+			       acpi_pci_bus_find_domain_nr(sysdata);
 }
 #endif
 
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 953f15abc850..5e71cc5e1b6c 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -899,7 +899,7 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
 	bus->ops = bridge->ops;
 	bus->number = bus->busn_res.start = bridge->busnr;
 #ifdef CONFIG_PCI_DOMAINS_GENERIC
-	bus->domain_nr = pci_bus_find_domain_nr(bus, parent);
+	bus->domain_nr = bridge->domain_nr;
 #endif
 
 	b = pci_find_bus(pci_domain_nr(bus), bridge->busnr);
@@ -2974,6 +2974,8 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 	bridge->sysdata = sysdata;
 	bridge->busnr = bus;
 	bridge->ops = ops;
+	if (IS_ENABLED(CONFIG_PCI_DOMAINS_GENERIC))
+		bridge->domain_nr = pci_bus_find_domain_nr(sysdata, parent);
 
 	error = pci_register_host_bridge(bridge);
 	if (error < 0)
@@ -2992,6 +2994,9 @@ int pci_host_probe(struct pci_host_bridge *bridge)
 	struct pci_bus *bus, *child;
 	int ret;
 
+	if (IS_ENABLED(CONFIG_PCI_DOMAINS_GENERIC))
+		bridge->domain_nr = pci_bus_find_domain_nr(bridge->sysdata, bridge->dev.parent);
+
 	ret = pci_scan_root_bus_bridge(bridge);
 	if (ret < 0) {
 		dev_err(bridge->dev.parent, "Scanning root bridge failed");
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 86c799c97b77..5bbd8417d219 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -534,6 +534,7 @@ struct pci_host_bridge {
 	struct pci_ops	*child_ops;
 	void		*sysdata;
 	int		busnr;
+	int		domain_nr;
 	struct list_head windows;	/* resource_entry */
 	struct list_head dma_ranges;	/* dma ranges resource list */
 	u8 (*swizzle_irq)(struct pci_dev *, u8 *); /* Platform IRQ swizzler */
@@ -1637,13 +1638,17 @@ static inline int pci_domain_nr(struct pci_bus *bus)
 {
 	return bus->domain_nr;
 }
+struct pci_config_window;
 #ifdef CONFIG_ACPI
-int acpi_pci_bus_find_domain_nr(struct pci_bus *bus);
+int acpi_pci_bus_find_domain_nr(struct pci_config_window *cfg);
 #else
-static inline int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
+static inline int acpi_pci_bus_find_domain_nr(struct pci_config_window *cfg)
 { return 0; }
 #endif
-int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent);
+int pci_bus_find_domain_nr(void *sysdata, struct device *parent);
+#else
+static inline int pci_bus_find_domain_nr(void *sysdata, struct device *parent)
+{ return 0; }
 #endif
 
 /* Some architectures require additional setup to direct VGA traffic */
-- 
2.30.2