1 /* ASB2305 PCI resource stuff
2 *
3 * Copyright (C) 2001 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 * - Derived from arch/i386/pci-i386.c
6 * - Copyright 1997--2000 Martin Mares <mj@suse.cz>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public Licence
10 * as published by the Free Software Foundation; either version
11 * 2 of the Licence, or (at your option) any later version.
12 */
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/pci.h>
16 #include <linux/init.h>
17 #include <linux/ioport.h>
18 #include <linux/errno.h>
19 #include "pci-asb2305.h"
20
21 /*
22 * We need to avoid collisions with `mirrored' VGA ports
23 * and other strange ISA hardware, so we always want the
24 * addresses to be allocated in the 0x000-0x0ff region
25 * modulo 0x400.
26 *
27 * Why? Because some silly external IO cards only decode
28 * the low 10 bits of the IO address. The 0x00-0xff region
29 * is reserved for motherboard devices that decode all 16
30 * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
31 * but we want to try to avoid allocating at 0x2900-0x2bff
32 * which might have be mirrored at 0x0100-0x03ff..
33 */
pcibios_align_resource(void * data,const struct resource * res,resource_size_t size,resource_size_t align)34 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
35 resource_size_t size, resource_size_t align)
36 {
37 resource_size_t start = res->start;
38
39 #if 0
40 struct pci_dev *dev = data;
41
42 printk(KERN_DEBUG
43 "### PCIBIOS_ALIGN_RESOURCE(%s,,{%08lx-%08lx,%08lx},%lx)\n",
44 pci_name(dev),
45 res->start,
46 res->end,
47 res->flags,
48 size
49 );
50 #endif
51
52 if ((res->flags & IORESOURCE_IO) && (start & 0x300))
53 start = (start + 0x3ff) & ~0x3ff;
54
55 return start;
56 }
57
58
59 /*
60 * Handle resources of PCI devices. If the world were perfect, we could
61 * just allocate all the resource regions and do nothing more. It isn't.
62 * On the other hand, we cannot just re-allocate all devices, as it would
63 * require us to know lots of host bridge internals. So we attempt to
64 * keep as much of the original configuration as possible, but tweak it
65 * when it's found to be wrong.
66 *
67 * Known BIOS problems we have to work around:
68 * - I/O or memory regions not configured
69 * - regions configured, but not enabled in the command register
70 * - bogus I/O addresses above 64K used
71 * - expansion ROMs left enabled (this may sound harmless, but given
72 * the fact the PCI specs explicitly allow address decoders to be
73 * shared between expansion ROMs and other resource regions, it's
74 * at least dangerous)
75 *
76 * Our solution:
77 * (1) Allocate resources for all buses behind PCI-to-PCI bridges.
78 * This gives us fixed barriers on where we can allocate.
79 * (2) Allocate resources for all enabled devices. If there is
80 * a collision, just mark the resource as unallocated. Also
81 * disable expansion ROMs during this step.
82 * (3) Try to allocate resources for disabled devices. If the
83 * resources were assigned correctly, everything goes well,
84 * if they weren't, they won't disturb allocation of other
85 * resources.
86 * (4) Assign new addresses to resources which were either
87 * not configured at all or misconfigured. If explicitly
88 * requested by the user, configure expansion ROM address
89 * as well.
90 */
pcibios_allocate_bus_resources(struct list_head * bus_list)91 static void __init pcibios_allocate_bus_resources(struct list_head *bus_list)
92 {
93 struct pci_bus *bus;
94 struct pci_dev *dev;
95 int idx;
96 struct resource *r;
97
98 /* Depth-First Search on bus tree */
99 list_for_each_entry(bus, bus_list, node) {
100 dev = bus->self;
101 if (dev) {
102 for (idx = PCI_BRIDGE_RESOURCES;
103 idx < PCI_NUM_RESOURCES;
104 idx++) {
105 r = &dev->resource[idx];
106 if (!r->flags)
107 continue;
108 if (!r->start ||
109 pci_claim_bridge_resource(dev, idx) < 0) {
110 printk(KERN_ERR "PCI:"
111 " Cannot allocate resource"
112 " region %d of bridge %s\n",
113 idx, pci_name(dev));
114 /* Something is wrong with the region.
115 * Invalidate the resource to prevent
116 * child resource allocations in this
117 * range. */
118 r->start = r->end = 0;
119 r->flags = 0;
120 }
121 }
122 }
123 pcibios_allocate_bus_resources(&bus->children);
124 }
125 }
126
pcibios_allocate_resources(int pass)127 static void __init pcibios_allocate_resources(int pass)
128 {
129 struct pci_dev *dev = NULL;
130 int idx, disabled;
131 u16 command;
132 struct resource *r;
133
134 for_each_pci_dev(dev) {
135 pci_read_config_word(dev, PCI_COMMAND, &command);
136 for (idx = 0; idx < 6; idx++) {
137 r = &dev->resource[idx];
138 if (r->parent) /* Already allocated */
139 continue;
140 if (!r->start) /* Address not assigned */
141 continue;
142 if (r->flags & IORESOURCE_IO)
143 disabled = !(command & PCI_COMMAND_IO);
144 else
145 disabled = !(command & PCI_COMMAND_MEMORY);
146 if (pass == disabled) {
147 DBG("PCI[%s]: Resource %08lx-%08lx"
148 " (f=%lx, d=%d, p=%d)\n",
149 pci_name(dev), r->start, r->end, r->flags,
150 disabled, pass);
151 if (pci_claim_resource(dev, idx) < 0) {
152 printk(KERN_ERR "PCI:"
153 " Cannot allocate resource"
154 " region %d of device %s\n",
155 idx, pci_name(dev));
156 /* We'll assign a new address later */
157 r->end -= r->start;
158 r->start = 0;
159 }
160 }
161 }
162 if (!pass) {
163 r = &dev->resource[PCI_ROM_RESOURCE];
164 if (r->flags & IORESOURCE_ROM_ENABLE) {
165 /* Turn the ROM off, leave the resource region,
166 * but keep it unregistered. */
167 u32 reg;
168 DBG("PCI: Switching off ROM of %s\n",
169 pci_name(dev));
170 r->flags &= ~IORESOURCE_ROM_ENABLE;
171 pci_read_config_dword(
172 dev, dev->rom_base_reg, ®);
173 pci_write_config_dword(
174 dev, dev->rom_base_reg,
175 reg & ~PCI_ROM_ADDRESS_ENABLE);
176 }
177 }
178 }
179 }
180
pcibios_assign_resources(void)181 static int __init pcibios_assign_resources(void)
182 {
183 struct pci_dev *dev = NULL;
184 struct resource *r;
185
186 /* Try to use BIOS settings for ROMs, otherwise let
187 pci_assign_unassigned_resources() allocate the new
188 addresses. */
189 for_each_pci_dev(dev) {
190 r = &dev->resource[PCI_ROM_RESOURCE];
191 if (!r->flags || !r->start)
192 continue;
193 if (pci_claim_resource(dev, PCI_ROM_RESOURCE) < 0) {
194 r->end -= r->start;
195 r->start = 0;
196 }
197 }
198
199 pci_assign_unassigned_resources();
200
201 return 0;
202 }
203
204 fs_initcall(pcibios_assign_resources);
205
pcibios_resource_survey(void)206 void __init pcibios_resource_survey(void)
207 {
208 DBG("PCI: Allocating resources\n");
209 pcibios_allocate_bus_resources(&pci_root_buses);
210 pcibios_allocate_resources(0);
211 pcibios_allocate_resources(1);
212 }
213
pci_mmap_page_range(struct pci_dev * dev,struct vm_area_struct * vma,enum pci_mmap_state mmap_state,int write_combine)214 int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
215 enum pci_mmap_state mmap_state, int write_combine)
216 {
217 unsigned long prot;
218
219 /* Leave vm_pgoff as-is, the PCI space address is the physical
220 * address on this platform.
221 */
222 vma->vm_flags |= VM_LOCKED;
223
224 prot = pgprot_val(vma->vm_page_prot);
225 prot &= ~_PAGE_CACHE;
226 vma->vm_page_prot = __pgprot(prot);
227
228 /* Write-combine setting is ignored */
229 if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
230 vma->vm_end - vma->vm_start,
231 vma->vm_page_prot))
232 return -EAGAIN;
233
234 return 0;
235 }
236