1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 * Copyright (C) 2016 Imagination Technologies
 4 * Author: Paul Burton <paul.burton@mips.com>
 5 *
 6 * pcibios_align_resource taken from arch/arm/kernel/bios32.c.
 7 */
 8
 9#include <linux/pci.h>
10
11/*
12 * We need to avoid collisions with `mirrored' VGA ports
13 * and other strange ISA hardware, so we always want the
14 * addresses to be allocated in the 0x000-0x0ff region
15 * modulo 0x400.
16 *
17 * Why? Because some silly external IO cards only decode
18 * the low 10 bits of the IO address. The 0x00-0xff region
19 * is reserved for motherboard devices that decode all 16
20 * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
21 * but we want to try to avoid allocating at 0x2900-0x2bff
22 * which might have be mirrored at 0x0100-0x03ff..
23 */
24resource_size_t pcibios_align_resource(void *data, const struct resource *res,
25				resource_size_t size, resource_size_t align)
26{
27	struct pci_dev *dev = data;
28	resource_size_t start = res->start;
29	struct pci_host_bridge *host_bridge;
30
31	if (res->flags & IORESOURCE_IO && start & 0x300)
32		start = (start + 0x3ff) & ~0x3ff;
33
34	start = (start + align - 1) & ~(align - 1);
35
36	host_bridge = pci_find_host_bridge(dev->bus);
37
38	if (host_bridge->align_resource)
39		return host_bridge->align_resource(dev, res,
40				start, size, align);
41
42	return start;
43}
44
45void pcibios_fixup_bus(struct pci_bus *bus)
46{
47	pci_read_bridge_bases(bus);
48}
49
50#ifdef pci_remap_iospace
51int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
52{
53	unsigned long vaddr;
54
55	if (res->start != 0) {
56		WARN_ONCE(1, "resource start address is not zero\n");
57		return -ENODEV;
58	}
59
60	vaddr = (unsigned long)ioremap(phys_addr, resource_size(res));
61	set_io_port_base(vaddr);
62	return 0;
63}
64#endif