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>

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 */