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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/pci/i386.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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diff --git a/arch/i386/pci/i386.c b/arch/i386/pci/i386.c
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1/*
2 * Low-Level PCI Access for i386 machines
3 *
4 * Copyright 1993, 1994 Drew Eckhardt
5 * Visionary Computing
6 * (Unix and Linux consulting and custom programming)
7 * Drew@Colorado.EDU
8 * +1 (303) 786-7975
9 *
10 * Drew's work was sponsored by:
11 * iX Multiuser Multitasking Magazine
12 * Hannover, Germany
13 * hm@ix.de
14 *
15 * Copyright 1997--2000 Martin Mares <mj@ucw.cz>
16 *
17 * For more information, please consult the following manuals (look at
18 * http://www.pcisig.com/ for how to get them):
19 *
20 * PCI BIOS Specification
21 * PCI Local Bus Specification
22 * PCI to PCI Bridge Specification
23 * PCI System Design Guide
24 *
25 */
26
27#include <linux/types.h>
28#include <linux/kernel.h>
29#include <linux/pci.h>
30#include <linux/init.h>
31#include <linux/ioport.h>
32#include <linux/errno.h>
33
34#include "pci.h"
35
36/*
37 * We need to avoid collisions with `mirrored' VGA ports
38 * and other strange ISA hardware, so we always want the
39 * addresses to be allocated in the 0x000-0x0ff region
40 * modulo 0x400.
41 *
42 * Why? Because some silly external IO cards only decode
43 * the low 10 bits of the IO address. The 0x00-0xff region
44 * is reserved for motherboard devices that decode all 16
45 * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
46 * but we want to try to avoid allocating at 0x2900-0x2bff
47 * which might have be mirrored at 0x0100-0x03ff..
48 */
49void
50pcibios_align_resource(void *data, struct resource *res,
51 unsigned long size, unsigned long align)
52{
53 if (res->flags & IORESOURCE_IO) {
54 unsigned long start = res->start;
55
56 if (start & 0x300) {
57 start = (start + 0x3ff) & ~0x3ff;
58 res->start = start;
59 }
60 }
61}
62
63
64/*
65 * Handle resources of PCI devices. If the world were perfect, we could
66 * just allocate all the resource regions and do nothing more. It isn't.
67 * On the other hand, we cannot just re-allocate all devices, as it would
68 * require us to know lots of host bridge internals. So we attempt to
69 * keep as much of the original configuration as possible, but tweak it
70 * when it's found to be wrong.
71 *
72 * Known BIOS problems we have to work around:
73 * - I/O or memory regions not configured
74 * - regions configured, but not enabled in the command register
75 * - bogus I/O addresses above 64K used
76 * - expansion ROMs left enabled (this may sound harmless, but given
77 * the fact the PCI specs explicitly allow address decoders to be
78 * shared between expansion ROMs and other resource regions, it's
79 * at least dangerous)
80 *
81 * Our solution:
82 * (1) Allocate resources for all buses behind PCI-to-PCI bridges.
83 * This gives us fixed barriers on where we can allocate.
84 * (2) Allocate resources for all enabled devices. If there is
85 * a collision, just mark the resource as unallocated. Also
86 * disable expansion ROMs during this step.
87 * (3) Try to allocate resources for disabled devices. If the
88 * resources were assigned correctly, everything goes well,
89 * if they weren't, they won't disturb allocation of other
90 * resources.
91 * (4) Assign new addresses to resources which were either
92 * not configured at all or misconfigured. If explicitly
93 * requested by the user, configure expansion ROM address
94 * as well.
95 */
96
97static void __init pcibios_allocate_bus_resources(struct list_head *bus_list)
98{
99 struct pci_bus *bus;
100 struct pci_dev *dev;
101 int idx;
102 struct resource *r, *pr;
103
104 /* Depth-First Search on bus tree */
105 list_for_each_entry(bus, bus_list, node) {
106 if ((dev = bus->self)) {
107 for (idx = PCI_BRIDGE_RESOURCES; idx < PCI_NUM_RESOURCES; idx++) {
108 r = &dev->resource[idx];
109 if (!r->start)
110 continue;
111 pr = pci_find_parent_resource(dev, r);
112 if (!pr || request_resource(pr, r) < 0)
113 printk(KERN_ERR "PCI: Cannot allocate resource region %d of bridge %s\n", idx, pci_name(dev));
114 }
115 }
116 pcibios_allocate_bus_resources(&bus->children);
117 }
118}
119
120static void __init pcibios_allocate_resources(int pass)
121{
122 struct pci_dev *dev = NULL;
123 int idx, disabled;
124 u16 command;
125 struct resource *r, *pr;
126
127 for_each_pci_dev(dev) {
128 pci_read_config_word(dev, PCI_COMMAND, &command);
129 for(idx = 0; idx < 6; idx++) {
130 r = &dev->resource[idx];
131 if (r->parent) /* Already allocated */
132 continue;
133 if (!r->start) /* Address not assigned at all */
134 continue;
135 if (r->flags & IORESOURCE_IO)
136 disabled = !(command & PCI_COMMAND_IO);
137 else
138 disabled = !(command & PCI_COMMAND_MEMORY);
139 if (pass == disabled) {
140 DBG("PCI: Resource %08lx-%08lx (f=%lx, d=%d, p=%d)\n",
141 r->start, r->end, r->flags, disabled, pass);
142 pr = pci_find_parent_resource(dev, r);
143 if (!pr || request_resource(pr, r) < 0) {
144 printk(KERN_ERR "PCI: Cannot allocate resource region %d of device %s\n", idx, pci_name(dev));
145 /* We'll assign a new address later */
146 r->end -= r->start;
147 r->start = 0;
148 }
149 }
150 }
151 if (!pass) {
152 r = &dev->resource[PCI_ROM_RESOURCE];
153 if (r->flags & IORESOURCE_ROM_ENABLE) {
154 /* Turn the ROM off, leave the resource region, but keep it unregistered. */
155 u32 reg;
156 DBG("PCI: Switching off ROM of %s\n", pci_name(dev));
157 r->flags &= ~IORESOURCE_ROM_ENABLE;
158 pci_read_config_dword(dev, dev->rom_base_reg, &reg);
159 pci_write_config_dword(dev, dev->rom_base_reg, reg & ~PCI_ROM_ADDRESS_ENABLE);
160 }
161 }
162 }
163}
164
165static int __init pcibios_assign_resources(void)
166{
167 struct pci_dev *dev = NULL;
168 int idx;
169 struct resource *r;
170
171 for_each_pci_dev(dev) {
172 int class = dev->class >> 8;
173
174 /* Don't touch classless devices and host bridges */
175 if (!class || class == PCI_CLASS_BRIDGE_HOST)
176 continue;
177
178 for(idx=0; idx<6; idx++) {
179 r = &dev->resource[idx];
180
181 /*
182 * Don't touch IDE controllers and I/O ports of video cards!
183 */
184 if ((class == PCI_CLASS_STORAGE_IDE && idx < 4) ||
185 (class == PCI_CLASS_DISPLAY_VGA && (r->flags & IORESOURCE_IO)))
186 continue;
187
188 /*
189 * We shall assign a new address to this resource, either because
190 * the BIOS forgot to do so or because we have decided the old
191 * address was unusable for some reason.
192 */
193 if (!r->start && r->end)
194 pci_assign_resource(dev, idx);
195 }
196
197 if (pci_probe & PCI_ASSIGN_ROMS) {
198 r = &dev->resource[PCI_ROM_RESOURCE];
199 r->end -= r->start;
200 r->start = 0;
201 if (r->end)
202 pci_assign_resource(dev, PCI_ROM_RESOURCE);
203 }
204 }
205 return 0;
206}
207
208void __init pcibios_resource_survey(void)
209{
210 DBG("PCI: Allocating resources\n");
211 pcibios_allocate_bus_resources(&pci_root_buses);
212 pcibios_allocate_resources(0);
213 pcibios_allocate_resources(1);
214}
215
216/**
217 * called in fs_initcall (one below subsys_initcall),
218 * give a chance for motherboard reserve resources
219 */
220fs_initcall(pcibios_assign_resources);
221
222int pcibios_enable_resources(struct pci_dev *dev, int mask)
223{
224 u16 cmd, old_cmd;
225 int idx;
226 struct resource *r;
227
228 pci_read_config_word(dev, PCI_COMMAND, &cmd);
229 old_cmd = cmd;
230 for(idx=0; idx<6; idx++) {
231 /* Only set up the requested stuff */
232 if (!(mask & (1<<idx)))
233 continue;
234
235 r = &dev->resource[idx];
236 if (!r->start && r->end) {
237 printk(KERN_ERR "PCI: Device %s not available because of resource collisions\n", pci_name(dev));
238 return -EINVAL;
239 }
240 if (r->flags & IORESOURCE_IO)
241 cmd |= PCI_COMMAND_IO;
242 if (r->flags & IORESOURCE_MEM)
243 cmd |= PCI_COMMAND_MEMORY;
244 }
245 if (dev->resource[PCI_ROM_RESOURCE].start)
246 cmd |= PCI_COMMAND_MEMORY;
247 if (cmd != old_cmd) {
248 printk("PCI: Enabling device %s (%04x -> %04x)\n", pci_name(dev), old_cmd, cmd);
249 pci_write_config_word(dev, PCI_COMMAND, cmd);
250 }
251 return 0;
252}
253
254/*
255 * If we set up a device for bus mastering, we need to check the latency
256 * timer as certain crappy BIOSes forget to set it properly.
257 */
258unsigned int pcibios_max_latency = 255;
259
260void pcibios_set_master(struct pci_dev *dev)
261{
262 u8 lat;
263 pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
264 if (lat < 16)
265 lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
266 else if (lat > pcibios_max_latency)
267 lat = pcibios_max_latency;
268 else
269 return;
270 printk(KERN_DEBUG "PCI: Setting latency timer of device %s to %d\n", pci_name(dev), lat);
271 pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
272}
273
274int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
275 enum pci_mmap_state mmap_state, int write_combine)
276{
277 unsigned long prot;
278
279 /* I/O space cannot be accessed via normal processor loads and
280 * stores on this platform.
281 */
282 if (mmap_state == pci_mmap_io)
283 return -EINVAL;
284
285 /* Leave vm_pgoff as-is, the PCI space address is the physical
286 * address on this platform.
287 */
288 vma->vm_flags |= (VM_SHM | VM_LOCKED | VM_IO);
289
290 prot = pgprot_val(vma->vm_page_prot);
291 if (boot_cpu_data.x86 > 3)
292 prot |= _PAGE_PCD | _PAGE_PWT;
293 vma->vm_page_prot = __pgprot(prot);
294
295 /* Write-combine setting is ignored, it is changed via the mtrr
296 * interfaces on this platform.
297 */
298 if (remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
299 vma->vm_end - vma->vm_start,
300 vma->vm_page_prot))
301 return -EAGAIN;
302
303 return 0;
304}