/* * Copyright (C) 2016 Imagination Technologies * Author: Paul Burton <paul.burton@mips.com> * * pcibios_align_resource taken from arch/arm/kernel/bios32.c. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. */ #include <linux/pci.h> /* * We need to avoid collisions with `mirrored' VGA ports * and other strange ISA hardware, so we always want the * addresses to be allocated in the 0x000-0x0ff region * modulo 0x400. * * Why? Because some silly external IO cards only decode * the low 10 bits of the IO address. The 0x00-0xff region * is reserved for motherboard devices that decode all 16 * bits, so it's ok to allocate at, say, 0x2800-0x28ff, * but we want to try to avoid allocating at 0x2900-0x2bff * which might have be mirrored at 0x0100-0x03ff.. */ resource_size_t pcibios_align_resource(void *data, const struct resource *res, resource_size_t size, resource_size_t align) { struct pci_dev *dev = data; resource_size_t start = res->start; struct pci_host_bridge *host_bridge; if (res->flags & IORESOURCE_IO && start & 0x300) start = (start + 0x3ff) & ~0x3ff; start = (start + align - 1) & ~(align - 1); host_bridge = pci_find_host_bridge(dev->bus); if (host_bridge->align_resource) return host_bridge->align_resource(dev, res, start, size, align); return start; } void pcibios_fixup_bus(struct pci_bus *bus) { pci_read_bridge_bases(bus); }