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 | */ |
24 | resource_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(bus: 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 | |
45 | void pcibios_fixup_bus(struct pci_bus *bus) |
46 | { |
47 | pci_read_bridge_bases(child: bus); |
48 | } |
49 | |
50 | #ifdef pci_remap_iospace |
51 | int 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 |
65 | |