asm-generic: Add new pci.h and use it

The asm/pci.h used for many newer architectures share similar definitions.
Move the common parts to asm-generic/pci.h to allow for sharing code.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/lkml/CAK8P3a0JmPeczfmMBE__vn=Jbvf=nkbpVaZCycyv40pZNCJJXQ@mail.gmail.com/
Link: https://lore.kernel.org/r/20220722214944.831438-5-shorne@gmail.com
Signed-off-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

arch/arm64/include/asm/pci.h

@@ -9,7 +9,6 @@
 #include <asm/io.h>
 
 #define PCIBIOS_MIN_IO		0x1000
-#define PCIBIOS_MIN_MEM		0
 
 /*
  * Set to 1 if the kernel should re-assign all PCI bus numbers
@@ -18,13 +17,8 @@
 	(pci_has_flag(PCI_REASSIGN_ALL_BUS))
 
 #define arch_can_pci_mmap_wc() 1
-#define ARCH_GENERIC_PCI_MMAP_RESOURCE	1
 
-#ifdef CONFIG_PCI
-static inline int pci_proc_domain(struct pci_bus *bus)
-{
-	return 1;
-}
-#endif  /* CONFIG_PCI */
+/* Generic PCI */
+#include <asm-generic/pci.h>
 
 #endif  /* __ASM_PCI_H */

arch/csky/include/asm/pci.h

@@ -9,20 +9,7 @@
 
 #include <asm/io.h>
 
-#define PCIBIOS_MIN_IO		0
-#define PCIBIOS_MIN_MEM		0
-
-/* C-SKY shim does not initialize PCI bus */
-#define pcibios_assign_all_busses() 1
-
-#define ARCH_GENERIC_PCI_MMAP_RESOURCE	1
-
-#ifdef CONFIG_PCI
-static inline int pci_proc_domain(struct pci_bus *bus)
-{
-	/* always show the domain in /proc */
-	return 1;
-}
-#endif  /* CONFIG_PCI */
+/* Generic PCI */
+#include <asm-generic/pci.h>
 
 #endif  /* __ASM_CSKY_PCI_H */

arch/riscv/include/asm/pci.h

@@ -12,23 +12,7 @@
 
 #include <asm/io.h>
 
-#define PCIBIOS_MIN_IO		0
-#define PCIBIOS_MIN_MEM		0
-
-/* RISC-V shim does not initialize PCI bus */
-#define pcibios_assign_all_busses() 1
-
-#define ARCH_GENERIC_PCI_MMAP_RESOURCE 1
-
-#ifdef CONFIG_PCI
-static inline int pci_proc_domain(struct pci_bus *bus)
-{
-	/* always show the domain in /proc */
-	return 1;
-}
-
-#ifdef	CONFIG_NUMA
-
+#if defined(CONFIG_PCI) && defined(CONFIG_NUMA)
 static inline int pcibus_to_node(struct pci_bus *bus)
 {
 	return dev_to_node(&bus->dev);
@@ -38,8 +22,9 @@ static inline int pcibus_to_node(struct pci_bus *bus)
 				 cpu_all_mask :				\
 				 cpumask_of_node(pcibus_to_node(bus)))
 #endif
-#endif	/* CONFIG_NUMA */
+#endif /* defined(CONFIG_PCI) && defined(CONFIG_NUMA) */
 
-#endif  /* CONFIG_PCI */
+/* Generic PCI */
+#include <asm-generic/pci.h>
 
 #endif  /* _ASM_RISCV_PCI_H */

arch/um/include/asm/pci.h

@@ -4,18 +4,8 @@
 #include <linux/types.h>
 #include <asm/io.h>
 
-#define PCIBIOS_MIN_IO		0
-#define PCIBIOS_MIN_MEM		0
-
-#define pcibios_assign_all_busses() 1
-
-#ifdef CONFIG_PCI_DOMAINS
-static inline int pci_proc_domain(struct pci_bus *bus)
-{
-	/* always show the domain in /proc */
-	return 1;
-}
-#endif  /* CONFIG_PCI */
+/* Generic PCI */
+#include <asm-generic/pci.h>
 
 #ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
 /*

include/asm-generic/pci.h

@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ASM_GENERIC_PCI_H
+#define __ASM_GENERIC_PCI_H
+
+#ifndef PCIBIOS_MIN_IO
+#define PCIBIOS_MIN_IO		0
+#endif
+
+#ifndef PCIBIOS_MIN_MEM
+#define PCIBIOS_MIN_MEM		0
+#endif
+
+#ifndef pcibios_assign_all_busses
+/* For bootloaders that do not initialize the PCI bus */
+#define pcibios_assign_all_busses() 1
+#endif
+
+/* Enable generic resource mapping code in drivers/pci/ */
+#define ARCH_GENERIC_PCI_MMAP_RESOURCE
+
+#ifdef CONFIG_PCI_DOMAINS
+static inline int pci_proc_domain(struct pci_bus *bus)
+{
+	/* always show the domain in /proc */
+	return 1;
+}
+#endif /* CONFIG_PCI_DOMAINS */
+
+#endif /* __ASM_GENERIC_PCI_H */