diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /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!
Diffstat (limited to 'arch/i386/pci/i386.c')
-rw-r--r-- | arch/i386/pci/i386.c | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/arch/i386/pci/i386.c b/arch/i386/pci/i386.c new file mode 100644 index 000000000000..c205ea7e233b --- /dev/null +++ b/arch/i386/pci/i386.c | |||
@@ -0,0 +1,304 @@ | |||
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 | */ | ||
49 | void | ||
50 | pcibios_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 | |||
97 | static 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 | |||
120 | static 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, ®); | ||
159 | pci_write_config_dword(dev, dev->rom_base_reg, reg & ~PCI_ROM_ADDRESS_ENABLE); | ||
160 | } | ||
161 | } | ||
162 | } | ||
163 | } | ||
164 | |||
165 | static 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 | |||
208 | void __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 | */ | ||
220 | fs_initcall(pcibios_assign_resources); | ||
221 | |||
222 | int 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 | */ | ||
258 | unsigned int pcibios_max_latency = 255; | ||
259 | |||
260 | void 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 | |||
274 | int 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 | } | ||