Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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]; |
Ivan Kokshaysky | 299de03 | 2005-06-15 18:59:27 +0400 | [diff] [blame] | 109 | if (!r->flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | continue; |
| 111 | pr = pci_find_parent_resource(dev, r); |
Ivan Kokshaysky | 299de03 | 2005-06-15 18:59:27 +0400 | [diff] [blame] | 112 | if (!r->start || !pr || request_resource(pr, r) < 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | printk(KERN_ERR "PCI: Cannot allocate resource region %d of bridge %s\n", idx, pci_name(dev)); |
Ivan Kokshaysky | 299de03 | 2005-06-15 18:59:27 +0400 | [diff] [blame] | 114 | /* Something is wrong with the region. |
| 115 | Invalidate the resource to prevent child |
| 116 | resource allocations in this range. */ |
| 117 | r->flags = 0; |
| 118 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | } |
| 120 | } |
| 121 | pcibios_allocate_bus_resources(&bus->children); |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | static void __init pcibios_allocate_resources(int pass) |
| 126 | { |
| 127 | struct pci_dev *dev = NULL; |
| 128 | int idx, disabled; |
| 129 | u16 command; |
| 130 | struct resource *r, *pr; |
| 131 | |
| 132 | for_each_pci_dev(dev) { |
| 133 | pci_read_config_word(dev, PCI_COMMAND, &command); |
| 134 | for(idx = 0; idx < 6; idx++) { |
| 135 | r = &dev->resource[idx]; |
| 136 | if (r->parent) /* Already allocated */ |
| 137 | continue; |
| 138 | if (!r->start) /* Address not assigned at all */ |
| 139 | continue; |
| 140 | if (r->flags & IORESOURCE_IO) |
| 141 | disabled = !(command & PCI_COMMAND_IO); |
| 142 | else |
| 143 | disabled = !(command & PCI_COMMAND_MEMORY); |
| 144 | if (pass == disabled) { |
| 145 | DBG("PCI: Resource %08lx-%08lx (f=%lx, d=%d, p=%d)\n", |
| 146 | r->start, r->end, r->flags, disabled, pass); |
| 147 | pr = pci_find_parent_resource(dev, r); |
| 148 | if (!pr || request_resource(pr, r) < 0) { |
| 149 | printk(KERN_ERR "PCI: Cannot allocate resource region %d of device %s\n", idx, pci_name(dev)); |
| 150 | /* We'll assign a new address later */ |
| 151 | r->end -= r->start; |
| 152 | r->start = 0; |
| 153 | } |
| 154 | } |
| 155 | } |
| 156 | if (!pass) { |
| 157 | r = &dev->resource[PCI_ROM_RESOURCE]; |
| 158 | if (r->flags & IORESOURCE_ROM_ENABLE) { |
| 159 | /* Turn the ROM off, leave the resource region, but keep it unregistered. */ |
| 160 | u32 reg; |
| 161 | DBG("PCI: Switching off ROM of %s\n", pci_name(dev)); |
| 162 | r->flags &= ~IORESOURCE_ROM_ENABLE; |
| 163 | pci_read_config_dword(dev, dev->rom_base_reg, ®); |
| 164 | pci_write_config_dword(dev, dev->rom_base_reg, reg & ~PCI_ROM_ADDRESS_ENABLE); |
| 165 | } |
| 166 | } |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | static int __init pcibios_assign_resources(void) |
| 171 | { |
| 172 | struct pci_dev *dev = NULL; |
Ivan Kokshaysky | 81d4af1 | 2005-08-30 18:48:52 +0400 | [diff] [blame] | 173 | struct resource *r, *pr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | |
Ivan Kokshaysky | 81d4af1 | 2005-08-30 18:48:52 +0400 | [diff] [blame] | 175 | if (!(pci_probe & PCI_ASSIGN_ROMS)) { |
| 176 | /* Try to use BIOS settings for ROMs, otherwise let |
| 177 | pci_assign_unassigned_resources() allocate the new |
| 178 | addresses. */ |
| 179 | for_each_pci_dev(dev) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | r = &dev->resource[PCI_ROM_RESOURCE]; |
Ivan Kokshaysky | 81d4af1 | 2005-08-30 18:48:52 +0400 | [diff] [blame] | 181 | if (!r->flags || !r->start) |
| 182 | continue; |
| 183 | pr = pci_find_parent_resource(dev, r); |
| 184 | if (!pr || request_resource(pr, r) < 0) { |
| 185 | r->end -= r->start; |
| 186 | r->start = 0; |
| 187 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | } |
| 189 | } |
Ivan Kokshaysky | 81d4af1 | 2005-08-30 18:48:52 +0400 | [diff] [blame] | 190 | |
| 191 | pci_assign_unassigned_resources(); |
| 192 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | return 0; |
| 194 | } |
| 195 | |
| 196 | void __init pcibios_resource_survey(void) |
| 197 | { |
| 198 | DBG("PCI: Allocating resources\n"); |
| 199 | pcibios_allocate_bus_resources(&pci_root_buses); |
| 200 | pcibios_allocate_resources(0); |
| 201 | pcibios_allocate_resources(1); |
| 202 | } |
| 203 | |
| 204 | /** |
| 205 | * called in fs_initcall (one below subsys_initcall), |
| 206 | * give a chance for motherboard reserve resources |
| 207 | */ |
| 208 | fs_initcall(pcibios_assign_resources); |
| 209 | |
| 210 | int pcibios_enable_resources(struct pci_dev *dev, int mask) |
| 211 | { |
| 212 | u16 cmd, old_cmd; |
| 213 | int idx; |
| 214 | struct resource *r; |
| 215 | |
| 216 | pci_read_config_word(dev, PCI_COMMAND, &cmd); |
| 217 | old_cmd = cmd; |
Ivan Kokshaysky | 299de03 | 2005-06-15 18:59:27 +0400 | [diff] [blame] | 218 | for(idx = 0; idx < PCI_NUM_RESOURCES; idx++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | /* Only set up the requested stuff */ |
| 220 | if (!(mask & (1<<idx))) |
| 221 | continue; |
| 222 | |
| 223 | r = &dev->resource[idx]; |
Rajesh Shah | ed6d14f | 2005-11-23 15:44:59 -0800 | [diff] [blame] | 224 | if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM))) |
| 225 | continue; |
| 226 | if ((idx == PCI_ROM_RESOURCE) && |
| 227 | (!(r->flags & IORESOURCE_ROM_ENABLE))) |
| 228 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | if (!r->start && r->end) { |
| 230 | printk(KERN_ERR "PCI: Device %s not available because of resource collisions\n", pci_name(dev)); |
| 231 | return -EINVAL; |
| 232 | } |
| 233 | if (r->flags & IORESOURCE_IO) |
| 234 | cmd |= PCI_COMMAND_IO; |
| 235 | if (r->flags & IORESOURCE_MEM) |
| 236 | cmd |= PCI_COMMAND_MEMORY; |
| 237 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | if (cmd != old_cmd) { |
| 239 | printk("PCI: Enabling device %s (%04x -> %04x)\n", pci_name(dev), old_cmd, cmd); |
| 240 | pci_write_config_word(dev, PCI_COMMAND, cmd); |
| 241 | } |
| 242 | return 0; |
| 243 | } |
| 244 | |
Rajesh Shah | 53e4d30 | 2006-05-03 15:27:47 -0700 | [diff] [blame] | 245 | void pcibios_disable_resources(struct pci_dev *dev) |
| 246 | { |
| 247 | u16 cmd; |
| 248 | |
| 249 | pci_read_config_word(dev, PCI_COMMAND, &cmd); |
| 250 | cmd &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY); |
| 251 | pci_write_config_word(dev, PCI_COMMAND, cmd); |
| 252 | } |
| 253 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | prot = pgprot_val(vma->vm_page_prot); |
| 289 | if (boot_cpu_data.x86 > 3) |
| 290 | prot |= _PAGE_PCD | _PAGE_PWT; |
| 291 | vma->vm_page_prot = __pgprot(prot); |
| 292 | |
| 293 | /* Write-combine setting is ignored, it is changed via the mtrr |
| 294 | * interfaces on this platform. |
| 295 | */ |
Michael S. Tsirkin | 346d388 | 2005-07-31 11:51:45 +0300 | [diff] [blame] | 296 | if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, |
| 297 | vma->vm_end - vma->vm_start, |
| 298 | vma->vm_page_prot)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | return -EAGAIN; |
| 300 | |
| 301 | return 0; |
| 302 | } |