ARM/PCI: Move to generic PCI domains

Most if not all ARM PCI host controller device drivers either ignore the
domain field in the pci_sys_data structure or just increment it every time
a host controller is probed, using it as a domain counter.

Therefore, instead of relying on pci_sys_data to stash the domain number in
a standard location, ARM pcibios code can be moved to the newly introduced
generic PCI domains code, implemented in commits:

  41e5c0f81d3e ("of/pci: Add pci_get_new_domain_nr() and of_get_pci_domain_nr()")
  670ba0c8883b ("PCI: Add generic domain handling")

ARM code is made to select PCI_DOMAINS_GENERIC by default, which builds
core PCI code that assigns the domain number through the generic function:

  void pci_bus_assign_domain_nr(...)

that relies on a DT property to define the domain number or falls back to a
counter according to a predefined logic; its usage replaces the current
domain assignment code in PCI host controllers present in the kernel.

Tested-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Yijing Wang <wangyijing@huawei.com>
Reviewed-By: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> # mvebu
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Phil Edworthy <phil.edworthy@renesas.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
CC: Mohit Kumar <mohit.kumar@st.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 97d07ed..dcb2e0c 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1279,6 +1279,9 @@
 	bool
 	depends on PCI
 
+config PCI_DOMAINS_GENERIC
+	def_bool PCI_DOMAINS
+
 config PCI_NANOENGINE
 	bool "BSE nanoEngine PCI support"
 	depends on SA1100_NANOENGINE
diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h
index 8292b5f..28b9bb3 100644
--- a/arch/arm/include/asm/mach/pci.h
+++ b/arch/arm/include/asm/mach/pci.h
@@ -19,9 +19,6 @@
 struct device;
 
 struct hw_pci {
-#ifdef CONFIG_PCI_DOMAINS
-	int		domain;
-#endif
 #ifdef CONFIG_PCI_MSI
 	struct msi_controller *msi_ctrl;
 #endif
@@ -45,9 +42,6 @@
  * Per-controller structure
  */
 struct pci_sys_data {
-#ifdef CONFIG_PCI_DOMAINS
-	int		domain;
-#endif
 #ifdef CONFIG_PCI_MSI
 	struct msi_controller *msi_ctrl;
 #endif
diff --git a/arch/arm/include/asm/pci.h b/arch/arm/include/asm/pci.h
index 7e95d85..585dc33 100644
--- a/arch/arm/include/asm/pci.h
+++ b/arch/arm/include/asm/pci.h
@@ -18,13 +18,6 @@
 }
 
 #ifdef CONFIG_PCI_DOMAINS
-static inline int pci_domain_nr(struct pci_bus *bus)
-{
-	struct pci_sys_data *root = bus->sysdata;
-
-	return root->domain;
-}
-
 static inline int pci_proc_domain(struct pci_bus *bus)
 {
 	return pci_domain_nr(bus);
diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index a4effd6..ddd75c5 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -463,9 +463,6 @@
 		if (!sys)
 			panic("PCI: unable to allocate sys data!");
 
-#ifdef CONFIG_PCI_DOMAINS
-		sys->domain  = hw->domain;
-#endif
 #ifdef CONFIG_PCI_MSI
 		sys->msi_ctrl = hw->msi_ctrl;
 #endif