1/*
 2 * Copyright (C) 2016 Imagination Technologies
 3 * Author: Paul Burton <paul.burton@mips.com>
 4 *
 5 * pcibios_align_resource taken from arch/arm/kernel/bios32.c.
 6 *
 7 * This program is free software; you can redistribute it and/or modify it
 8 * under the terms of the GNU General Public License as published by the
 9 * Free Software Foundation;  either version 2 of the  License, or (at your
10 * option) any later version.
11 */
12
13#include <linux/pci.h>
14
15/*
16 * We need to avoid collisions with `mirrored' VGA ports
17 * and other strange ISA hardware, so we always want the
18 * addresses to be allocated in the 0x000-0x0ff region
19 * modulo 0x400.
20 *
21 * Why? Because some silly external IO cards only decode
22 * the low 10 bits of the IO address. The 0x00-0xff region
23 * is reserved for motherboard devices that decode all 16
24 * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
25 * but we want to try to avoid allocating at 0x2900-0x2bff
26 * which might have be mirrored at 0x0100-0x03ff..
27 */
28resource_size_t pcibios_align_resource(void *data, const struct resource *res,
29				resource_size_t size, resource_size_t align)
30{
31	struct pci_dev *dev = data;
32	resource_size_t start = res->start;
33	struct pci_host_bridge *host_bridge;
34
35	if (res->flags & IORESOURCE_IO && start & 0x300)
36		start = (start + 0x3ff) & ~0x3ff;
37
38	start = (start + align - 1) & ~(align - 1);
39
40	host_bridge = pci_find_host_bridge(dev->bus);
41
42	if (host_bridge->align_resource)
43		return host_bridge->align_resource(dev, res,
44				start, size, align);
45
46	return start;
47}
48
49void pcibios_fixup_bus(struct pci_bus *bus)
50{
51	pci_read_bridge_bases(bus);
52}