1 /* 2 * This program is free software; you can redistribute it and/or modify it 3 * under the terms of the GNU General Public License as published by the 4 * Free Software Foundation; either version 2 of the License, or (at your 5 * option) any later version. 6 * 7 * Copyright (C) 2003, 04 Ralf Baechle (ralf@linux-mips.org) 8 */ 9 #include <linux/kernel.h> 10 #include <linux/mm.h> 11 #include <linux/bootmem.h> 12 #include <linux/init.h> 13 #include <linux/types.h> 14 #include <linux/pci.h> 15 16 /* 17 * Indicate whether we respect the PCI setup left by the firmware. 18 * 19 * Make this long-lived so that we know when shutting down 20 * whether we probed only or not. 21 */ 22 int pci_probe_only; 23 24 #define PCI_ASSIGN_ALL_BUSSES 1 25 26 unsigned int pci_probe = PCI_ASSIGN_ALL_BUSSES; 27 28 /* 29 * The PCI controller list. 30 */ 31 32 struct pci_controller *hose_head, **hose_tail = &hose_head; 33 struct pci_controller *pci_isa_hose; 34 35 unsigned long PCIBIOS_MIN_IO = 0x0000; 36 unsigned long PCIBIOS_MIN_MEM = 0; 37 38 /* 39 * We need to avoid collisions with `mirrored' VGA ports 40 * and other strange ISA hardware, so we always want the 41 * addresses to be allocated in the 0x000-0x0ff region 42 * modulo 0x400. 43 * 44 * Why? Because some silly external IO cards only decode 45 * the low 10 bits of the IO address. The 0x00-0xff region 46 * is reserved for motherboard devices that decode all 16 47 * bits, so it's ok to allocate at, say, 0x2800-0x28ff, 48 * but we want to try to avoid allocating at 0x2900-0x2bff 49 * which might have be mirrored at 0x0100-0x03ff.. 50 */ 51 void 52 pcibios_align_resource(void *data, struct resource *res, 53 resource_size_t size, resource_size_t align) 54 { 55 struct pci_dev *dev = data; 56 struct pci_controller *hose = dev->sysdata; 57 resource_size_t start = res->start; 58 59 if (res->flags & IORESOURCE_IO) { 60 /* Make sure we start at our min on all hoses */ 61 if (start < PCIBIOS_MIN_IO + hose->io_resource->start) 62 start = PCIBIOS_MIN_IO + hose->io_resource->start; 63 64 /* 65 * Put everything into 0x00-0xff region modulo 0x400 66 */ 67 if (start & 0x300) 68 start = (start + 0x3ff) & ~0x3ff; 69 } else if (res->flags & IORESOURCE_MEM) { 70 /* Make sure we start at our min on all hoses */ 71 if (start < PCIBIOS_MIN_MEM + hose->mem_resource->start) 72 start = PCIBIOS_MIN_MEM + hose->mem_resource->start; 73 } 74 75 res->start = start; 76 } 77 78 void __init register_pci_controller(struct pci_controller *hose) 79 { 80 if (request_resource(&iomem_resource, hose->mem_resource) < 0) 81 goto out; 82 if (request_resource(&ioport_resource, hose->io_resource) < 0) { 83 release_resource(hose->mem_resource); 84 goto out; 85 } 86 87 *hose_tail = hose; 88 hose_tail = &hose->next; 89 90 /* 91 * Do not panic here but later - this might hapen before console init. 92 */ 93 if (!hose->io_map_base) { 94 printk(KERN_WARNING 95 "registering PCI controller with io_map_base unset\n"); 96 } 97 return; 98 99 out: 100 printk(KERN_WARNING 101 "Skipping PCI bus scan due to resource conflict\n"); 102 } 103 104 /* Most MIPS systems have straight-forward swizzling needs. */ 105 106 static inline u8 bridge_swizzle(u8 pin, u8 slot) 107 { 108 return (((pin - 1) + slot) % 4) + 1; 109 } 110 111 static u8 __init common_swizzle(struct pci_dev *dev, u8 *pinp) 112 { 113 u8 pin = *pinp; 114 115 while (dev->bus->parent) { 116 pin = bridge_swizzle(pin, PCI_SLOT(dev->devfn)); 117 /* Move up the chain of bridges. */ 118 dev = dev->bus->self; 119 } 120 *pinp = pin; 121 122 /* The slot is the slot of the last bridge. */ 123 return PCI_SLOT(dev->devfn); 124 } 125 126 static int __init pcibios_init(void) 127 { 128 struct pci_controller *hose; 129 struct pci_bus *bus; 130 int next_busno; 131 int need_domain_info = 0; 132 133 /* Scan all of the recorded PCI controllers. */ 134 for (next_busno = 0, hose = hose_head; hose; hose = hose->next) { 135 136 if (!hose->iommu) 137 PCI_DMA_BUS_IS_PHYS = 1; 138 139 if (hose->get_busno && pci_probe_only) 140 next_busno = (*hose->get_busno)(); 141 142 bus = pci_scan_bus(next_busno, hose->pci_ops, hose); 143 hose->bus = bus; 144 hose->need_domain_info = need_domain_info; 145 if (bus) { 146 next_busno = bus->subordinate + 1; 147 /* Don't allow 8-bit bus number overflow inside the hose - 148 reserve some space for bridges. */ 149 if (next_busno > 224) { 150 next_busno = 0; 151 need_domain_info = 1; 152 } 153 } 154 } 155 156 if (!pci_probe_only) 157 pci_assign_unassigned_resources(); 158 pci_fixup_irqs(common_swizzle, pcibios_map_irq); 159 160 return 0; 161 } 162 163 subsys_initcall(pcibios_init); 164 165 static int pcibios_enable_resources(struct pci_dev *dev, int mask) 166 { 167 u16 cmd, old_cmd; 168 int idx; 169 struct resource *r; 170 171 pci_read_config_word(dev, PCI_COMMAND, &cmd); 172 old_cmd = cmd; 173 for (idx=0; idx < PCI_NUM_RESOURCES; idx++) { 174 /* Only set up the requested stuff */ 175 if (!(mask & (1<<idx))) 176 continue; 177 178 r = &dev->resource[idx]; 179 if (!r->start && r->end) { 180 printk(KERN_ERR "PCI: Device %s not available because of resource collisions\n", pci_name(dev)); 181 return -EINVAL; 182 } 183 if (r->flags & IORESOURCE_IO) 184 cmd |= PCI_COMMAND_IO; 185 if (r->flags & IORESOURCE_MEM) 186 cmd |= PCI_COMMAND_MEMORY; 187 } 188 if (dev->resource[PCI_ROM_RESOURCE].start) 189 cmd |= PCI_COMMAND_MEMORY; 190 if (cmd != old_cmd) { 191 printk("PCI: Enabling device %s (%04x -> %04x)\n", pci_name(dev), old_cmd, cmd); 192 pci_write_config_word(dev, PCI_COMMAND, cmd); 193 } 194 return 0; 195 } 196 197 /* 198 * If we set up a device for bus mastering, we need to check the latency 199 * timer as certain crappy BIOSes forget to set it properly. 200 */ 201 unsigned int pcibios_max_latency = 255; 202 203 void pcibios_set_master(struct pci_dev *dev) 204 { 205 u8 lat; 206 pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat); 207 if (lat < 16) 208 lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency; 209 else if (lat > pcibios_max_latency) 210 lat = pcibios_max_latency; 211 else 212 return; 213 printk(KERN_DEBUG "PCI: Setting latency timer of device %s to %d\n", 214 pci_name(dev), lat); 215 pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat); 216 } 217 218 unsigned int pcibios_assign_all_busses(void) 219 { 220 return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0; 221 } 222 223 int pcibios_enable_device(struct pci_dev *dev, int mask) 224 { 225 int err; 226 227 if ((err = pcibios_enable_resources(dev, mask)) < 0) 228 return err; 229 230 return pcibios_plat_dev_init(dev); 231 } 232 233 static void __devinit pcibios_fixup_device_resources(struct pci_dev *dev, 234 struct pci_bus *bus) 235 { 236 /* Update device resources. */ 237 struct pci_controller *hose = (struct pci_controller *)bus->sysdata; 238 unsigned long offset = 0; 239 int i; 240 241 for (i = 0; i < PCI_NUM_RESOURCES; i++) { 242 if (!dev->resource[i].start) 243 continue; 244 if (dev->resource[i].flags & IORESOURCE_IO) 245 offset = hose->io_offset; 246 else if (dev->resource[i].flags & IORESOURCE_MEM) 247 offset = hose->mem_offset; 248 249 dev->resource[i].start += offset; 250 dev->resource[i].end += offset; 251 } 252 } 253 254 void __devinit pcibios_fixup_bus(struct pci_bus *bus) 255 { 256 /* Propagate hose info into the subordinate devices. */ 257 258 struct pci_controller *hose = bus->sysdata; 259 struct list_head *ln; 260 struct pci_dev *dev = bus->self; 261 262 if (!dev) { 263 bus->resource[0] = hose->io_resource; 264 bus->resource[1] = hose->mem_resource; 265 } else if (pci_probe_only && 266 (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) { 267 pci_read_bridge_bases(bus); 268 pcibios_fixup_device_resources(dev, bus); 269 } 270 271 for (ln = bus->devices.next; ln != &bus->devices; ln = ln->next) { 272 struct pci_dev *dev = pci_dev_b(ln); 273 274 if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI) 275 pcibios_fixup_device_resources(dev, bus); 276 } 277 } 278 279 void __init 280 pcibios_update_irq(struct pci_dev *dev, int irq) 281 { 282 pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq); 283 } 284 285 void __devinit 286 pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region, 287 struct resource *res) 288 { 289 struct pci_controller *hose = (struct pci_controller *)dev->sysdata; 290 unsigned long offset = 0; 291 292 if (res->flags & IORESOURCE_IO) 293 offset = hose->io_offset; 294 else if (res->flags & IORESOURCE_MEM) 295 offset = hose->mem_offset; 296 297 region->start = res->start - offset; 298 region->end = res->end - offset; 299 } 300 301 void __devinit 302 pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res, 303 struct pci_bus_region *region) 304 { 305 struct pci_controller *hose = (struct pci_controller *)dev->sysdata; 306 unsigned long offset = 0; 307 308 if (res->flags & IORESOURCE_IO) 309 offset = hose->io_offset; 310 else if (res->flags & IORESOURCE_MEM) 311 offset = hose->mem_offset; 312 313 res->start = region->start + offset; 314 res->end = region->end + offset; 315 } 316 317 #ifdef CONFIG_HOTPLUG 318 EXPORT_SYMBOL(pcibios_resource_to_bus); 319 EXPORT_SYMBOL(pcibios_bus_to_resource); 320 EXPORT_SYMBOL(PCIBIOS_MIN_IO); 321 EXPORT_SYMBOL(PCIBIOS_MIN_MEM); 322 #endif 323 324 char *pcibios_setup(char *str) 325 { 326 return str; 327 } 328