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1da177e4 LT |
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> | |
03d72aa1 | 33 | #include <linux/bootmem.h> |
34 | ||
35 | #include <asm/pat.h> | |
58f7c988 | 36 | #include <asm/e820.h> |
82487711 | 37 | #include <asm/pci_x86.h> |
857fdc53 | 38 | #include <asm/io_apic.h> |
1da177e4 | 39 | |
1da177e4 | 40 | |
036fff4c GH |
41 | static int |
42 | skip_isa_ioresource_align(struct pci_dev *dev) { | |
43 | ||
44 | if ((pci_probe & PCI_CAN_SKIP_ISA_ALIGN) && | |
11949255 | 45 | !(dev->bus->bridge_ctl & PCI_BRIDGE_CTL_ISA)) |
036fff4c GH |
46 | return 1; |
47 | return 0; | |
48 | } | |
49 | ||
1da177e4 LT |
50 | /* |
51 | * We need to avoid collisions with `mirrored' VGA ports | |
52 | * and other strange ISA hardware, so we always want the | |
53 | * addresses to be allocated in the 0x000-0x0ff region | |
54 | * modulo 0x400. | |
55 | * | |
56 | * Why? Because some silly external IO cards only decode | |
57 | * the low 10 bits of the IO address. The 0x00-0xff region | |
58 | * is reserved for motherboard devices that decode all 16 | |
59 | * bits, so it's ok to allocate at, say, 0x2800-0x28ff, | |
60 | * but we want to try to avoid allocating at 0x2900-0x2bff | |
61 | * which might have be mirrored at 0x0100-0x03ff.. | |
62 | */ | |
63 | void | |
64 | pcibios_align_resource(void *data, struct resource *res, | |
e31dd6e4 | 65 | resource_size_t size, resource_size_t align) |
1da177e4 | 66 | { |
036fff4c GH |
67 | struct pci_dev *dev = data; |
68 | ||
1da177e4 | 69 | if (res->flags & IORESOURCE_IO) { |
e31dd6e4 | 70 | resource_size_t start = res->start; |
1da177e4 | 71 | |
036fff4c GH |
72 | if (skip_isa_ioresource_align(dev)) |
73 | return; | |
1da177e4 LT |
74 | if (start & 0x300) { |
75 | start = (start + 0x3ff) & ~0x3ff; | |
76 | res->start = start; | |
77 | } | |
78 | } | |
79 | } | |
6c00a61e | 80 | EXPORT_SYMBOL(pcibios_align_resource); |
1da177e4 LT |
81 | |
82 | /* | |
83 | * Handle resources of PCI devices. If the world were perfect, we could | |
84 | * just allocate all the resource regions and do nothing more. It isn't. | |
85 | * On the other hand, we cannot just re-allocate all devices, as it would | |
86 | * require us to know lots of host bridge internals. So we attempt to | |
87 | * keep as much of the original configuration as possible, but tweak it | |
88 | * when it's found to be wrong. | |
89 | * | |
90 | * Known BIOS problems we have to work around: | |
91 | * - I/O or memory regions not configured | |
92 | * - regions configured, but not enabled in the command register | |
93 | * - bogus I/O addresses above 64K used | |
94 | * - expansion ROMs left enabled (this may sound harmless, but given | |
95 | * the fact the PCI specs explicitly allow address decoders to be | |
96 | * shared between expansion ROMs and other resource regions, it's | |
97 | * at least dangerous) | |
98 | * | |
99 | * Our solution: | |
100 | * (1) Allocate resources for all buses behind PCI-to-PCI bridges. | |
101 | * This gives us fixed barriers on where we can allocate. | |
102 | * (2) Allocate resources for all enabled devices. If there is | |
103 | * a collision, just mark the resource as unallocated. Also | |
104 | * disable expansion ROMs during this step. | |
105 | * (3) Try to allocate resources for disabled devices. If the | |
106 | * resources were assigned correctly, everything goes well, | |
107 | * if they weren't, they won't disturb allocation of other | |
108 | * resources. | |
109 | * (4) Assign new addresses to resources which were either | |
110 | * not configured at all or misconfigured. If explicitly | |
111 | * requested by the user, configure expansion ROM address | |
112 | * as well. | |
113 | */ | |
114 | ||
115 | static void __init pcibios_allocate_bus_resources(struct list_head *bus_list) | |
116 | { | |
117 | struct pci_bus *bus; | |
118 | struct pci_dev *dev; | |
119 | int idx; | |
a76117df | 120 | struct resource *r; |
1da177e4 LT |
121 | |
122 | /* Depth-First Search on bus tree */ | |
123 | list_for_each_entry(bus, bus_list, node) { | |
124 | if ((dev = bus->self)) { | |
7edab2f0 RD |
125 | for (idx = PCI_BRIDGE_RESOURCES; |
126 | idx < PCI_NUM_RESOURCES; idx++) { | |
1da177e4 | 127 | r = &dev->resource[idx]; |
299de034 | 128 | if (!r->flags) |
1da177e4 | 129 | continue; |
a76117df MW |
130 | if (!r->start || |
131 | pci_claim_resource(dev, idx) < 0) { | |
42887b29 | 132 | dev_info(&dev->dev, "BAR %d: can't allocate %pRt\n", idx, r); |
7edab2f0 RD |
133 | /* |
134 | * Something is wrong with the region. | |
135 | * Invalidate the resource to prevent | |
136 | * child resource allocations in this | |
137 | * range. | |
138 | */ | |
299de034 IK |
139 | r->flags = 0; |
140 | } | |
1da177e4 LT |
141 | } |
142 | } | |
143 | pcibios_allocate_bus_resources(&bus->children); | |
144 | } | |
145 | } | |
146 | ||
147 | static void __init pcibios_allocate_resources(int pass) | |
148 | { | |
149 | struct pci_dev *dev = NULL; | |
150 | int idx, disabled; | |
151 | u16 command; | |
a76117df | 152 | struct resource *r; |
1da177e4 LT |
153 | |
154 | for_each_pci_dev(dev) { | |
155 | pci_read_config_word(dev, PCI_COMMAND, &command); | |
7edab2f0 | 156 | for (idx = 0; idx < PCI_ROM_RESOURCE; idx++) { |
1da177e4 LT |
157 | r = &dev->resource[idx]; |
158 | if (r->parent) /* Already allocated */ | |
159 | continue; | |
160 | if (!r->start) /* Address not assigned at all */ | |
161 | continue; | |
162 | if (r->flags & IORESOURCE_IO) | |
163 | disabled = !(command & PCI_COMMAND_IO); | |
164 | else | |
165 | disabled = !(command & PCI_COMMAND_MEMORY); | |
166 | if (pass == disabled) { | |
42887b29 BH |
167 | dev_dbg(&dev->dev, "%pRf (d=%d, p=%d)\n", r, |
168 | disabled, pass); | |
a76117df | 169 | if (pci_claim_resource(dev, idx) < 0) { |
42887b29 | 170 | dev_info(&dev->dev, "BAR %d: can't allocate %pRt\n", idx, r); |
1da177e4 LT |
171 | /* We'll assign a new address later */ |
172 | r->end -= r->start; | |
173 | r->start = 0; | |
174 | } | |
175 | } | |
176 | } | |
177 | if (!pass) { | |
178 | r = &dev->resource[PCI_ROM_RESOURCE]; | |
179 | if (r->flags & IORESOURCE_ROM_ENABLE) { | |
7edab2f0 RD |
180 | /* Turn the ROM off, leave the resource region, |
181 | * but keep it unregistered. */ | |
1da177e4 | 182 | u32 reg; |
42887b29 | 183 | dev_dbg(&dev->dev, "disabling ROM %pRt\n", r); |
1da177e4 | 184 | r->flags &= ~IORESOURCE_ROM_ENABLE; |
7edab2f0 RD |
185 | pci_read_config_dword(dev, |
186 | dev->rom_base_reg, ®); | |
187 | pci_write_config_dword(dev, dev->rom_base_reg, | |
188 | reg & ~PCI_ROM_ADDRESS_ENABLE); | |
1da177e4 LT |
189 | } |
190 | } | |
191 | } | |
192 | } | |
193 | ||
194 | static int __init pcibios_assign_resources(void) | |
195 | { | |
196 | struct pci_dev *dev = NULL; | |
a76117df | 197 | struct resource *r; |
1da177e4 | 198 | |
81d4af13 | 199 | if (!(pci_probe & PCI_ASSIGN_ROMS)) { |
7edab2f0 RD |
200 | /* |
201 | * Try to use BIOS settings for ROMs, otherwise let | |
202 | * pci_assign_unassigned_resources() allocate the new | |
203 | * addresses. | |
204 | */ | |
81d4af13 | 205 | for_each_pci_dev(dev) { |
1da177e4 | 206 | r = &dev->resource[PCI_ROM_RESOURCE]; |
81d4af13 IK |
207 | if (!r->flags || !r->start) |
208 | continue; | |
a76117df | 209 | if (pci_claim_resource(dev, PCI_ROM_RESOURCE) < 0) { |
81d4af13 IK |
210 | r->end -= r->start; |
211 | r->start = 0; | |
212 | } | |
1da177e4 LT |
213 | } |
214 | } | |
81d4af13 IK |
215 | |
216 | pci_assign_unassigned_resources(); | |
217 | ||
1da177e4 LT |
218 | return 0; |
219 | } | |
220 | ||
221 | void __init pcibios_resource_survey(void) | |
222 | { | |
223 | DBG("PCI: Allocating resources\n"); | |
224 | pcibios_allocate_bus_resources(&pci_root_buses); | |
225 | pcibios_allocate_resources(0); | |
226 | pcibios_allocate_resources(1); | |
a5444d15 IM |
227 | |
228 | e820_reserve_resources_late(); | |
857fdc53 YL |
229 | /* |
230 | * Insert the IO APIC resources after PCI initialization has | |
231 | * occured to handle IO APICS that are mapped in on a BAR in | |
232 | * PCI space, but before trying to assign unassigned pci res. | |
233 | */ | |
234 | ioapic_insert_resources(); | |
1da177e4 LT |
235 | } |
236 | ||
237 | /** | |
238 | * called in fs_initcall (one below subsys_initcall), | |
239 | * give a chance for motherboard reserve resources | |
240 | */ | |
241 | fs_initcall(pcibios_assign_resources); | |
242 | ||
0e94ecd0 YL |
243 | void __weak x86_pci_root_bus_res_quirks(struct pci_bus *b) |
244 | { | |
245 | } | |
246 | ||
1da177e4 LT |
247 | /* |
248 | * If we set up a device for bus mastering, we need to check the latency | |
249 | * timer as certain crappy BIOSes forget to set it properly. | |
250 | */ | |
251 | unsigned int pcibios_max_latency = 255; | |
252 | ||
253 | void pcibios_set_master(struct pci_dev *dev) | |
254 | { | |
255 | u8 lat; | |
256 | pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat); | |
257 | if (lat < 16) | |
258 | lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency; | |
259 | else if (lat > pcibios_max_latency) | |
260 | lat = pcibios_max_latency; | |
261 | else | |
262 | return; | |
12c0b20f | 263 | dev_printk(KERN_DEBUG, &dev->dev, "setting latency timer to %d\n", lat); |
1da177e4 LT |
264 | pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat); |
265 | } | |
266 | ||
f0f37e2f | 267 | static const struct vm_operations_struct pci_mmap_ops = { |
7ae8ed50 | 268 | .access = generic_access_phys, |
03d72aa1 | 269 | }; |
270 | ||
1da177e4 LT |
271 | int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, |
272 | enum pci_mmap_state mmap_state, int write_combine) | |
273 | { | |
274 | unsigned long prot; | |
275 | ||
276 | /* I/O space cannot be accessed via normal processor loads and | |
277 | * stores on this platform. | |
278 | */ | |
279 | if (mmap_state == pci_mmap_io) | |
280 | return -EINVAL; | |
281 | ||
1da177e4 | 282 | prot = pgprot_val(vma->vm_page_prot); |
2992e545 SS |
283 | |
284 | /* | |
285 | * Return error if pat is not enabled and write_combine is requested. | |
286 | * Caller can followup with UC MINUS request and add a WC mtrr if there | |
287 | * is a free mtrr slot. | |
288 | */ | |
289 | if (!pat_enabled && write_combine) | |
290 | return -EINVAL; | |
291 | ||
499f8f84 | 292 | if (pat_enabled && write_combine) |
03d72aa1 | 293 | prot |= _PAGE_CACHE_WC; |
499f8f84 | 294 | else if (pat_enabled || boot_cpu_data.x86 > 3) |
de33c442 SS |
295 | /* |
296 | * ioremap() and ioremap_nocache() defaults to UC MINUS for now. | |
297 | * To avoid attribute conflicts, request UC MINUS here | |
298 | * aswell. | |
299 | */ | |
300 | prot |= _PAGE_CACHE_UC_MINUS; | |
03d72aa1 | 301 | |
1da177e4 LT |
302 | vma->vm_page_prot = __pgprot(prot); |
303 | ||
346d3882 MT |
304 | if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, |
305 | vma->vm_end - vma->vm_start, | |
306 | vma->vm_page_prot)) | |
1da177e4 LT |
307 | return -EAGAIN; |
308 | ||
03d72aa1 | 309 | vma->vm_ops = &pci_mmap_ops; |
310 | ||
1da177e4 LT |
311 | return 0; |
312 | } |