1 /* 2 * arch/xtensa/kernel/pci.c 3 * 4 * PCI bios-type initialisation for PCI machines 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License as published by the 8 * Free Software Foundation; either version 2 of the License, or (at your 9 * option) any later version. 10 * 11 * Copyright (C) 2001-2005 Tensilica Inc. 12 * 13 * Based largely on work from Cort (ppc/kernel/pci.c) 14 * IO functions copied from sparc. 15 * 16 * Chris Zankel <chris@zankel.net> 17 * 18 */ 19 20 #include <linux/kernel.h> 21 #include <linux/pci.h> 22 #include <linux/delay.h> 23 #include <linux/string.h> 24 #include <linux/init.h> 25 #include <linux/sched.h> 26 #include <linux/errno.h> 27 #include <linux/bootmem.h> 28 29 #include <asm/pci-bridge.h> 30 #include <asm/platform.h> 31 32 #undef DEBUG 33 34 #ifdef DEBUG 35 #define DBG(x...) printk(x) 36 #else 37 #define DBG(x...) 38 #endif 39 40 /* PCI Controller */ 41 42 43 /* 44 * pcibios_alloc_controller 45 * pcibios_enable_device 46 * pcibios_fixups 47 * pcibios_align_resource 48 * pcibios_fixup_bus 49 * pcibios_setup 50 * pci_bus_add_device 51 * pci_mmap_page_range 52 */ 53 54 struct pci_controller* pci_ctrl_head; 55 struct pci_controller** pci_ctrl_tail = &pci_ctrl_head; 56 57 static int pci_bus_count; 58 59 /* 60 * We need to avoid collisions with `mirrored' VGA ports 61 * and other strange ISA hardware, so we always want the 62 * addresses to be allocated in the 0x000-0x0ff region 63 * modulo 0x400. 64 * 65 * Why? Because some silly external IO cards only decode 66 * the low 10 bits of the IO address. The 0x00-0xff region 67 * is reserved for motherboard devices that decode all 16 68 * bits, so it's ok to allocate at, say, 0x2800-0x28ff, 69 * but we want to try to avoid allocating at 0x2900-0x2bff 70 * which might have be mirrored at 0x0100-0x03ff.. 71 */ 72 resource_size_t 73 pcibios_align_resource(void *data, const struct resource *res, 74 resource_size_t size, resource_size_t align) 75 { 76 struct pci_dev *dev = data; 77 resource_size_t start = res->start; 78 79 if (res->flags & IORESOURCE_IO) { 80 if (size > 0x100) { 81 printk(KERN_ERR "PCI: I/O Region %s/%d too large" 82 " (%ld bytes)\n", pci_name(dev), 83 dev->resource - res, size); 84 } 85 86 if (start & 0x300) 87 start = (start + 0x3ff) & ~0x3ff; 88 } 89 90 return start; 91 } 92 93 int 94 pcibios_enable_resources(struct pci_dev *dev, int mask) 95 { 96 u16 cmd, old_cmd; 97 int idx; 98 struct resource *r; 99 100 pci_read_config_word(dev, PCI_COMMAND, &cmd); 101 old_cmd = cmd; 102 for(idx=0; idx<6; idx++) { 103 r = &dev->resource[idx]; 104 if (!r->start && r->end) { 105 printk (KERN_ERR "PCI: Device %s not available because " 106 "of resource collisions\n", pci_name(dev)); 107 return -EINVAL; 108 } 109 if (r->flags & IORESOURCE_IO) 110 cmd |= PCI_COMMAND_IO; 111 if (r->flags & IORESOURCE_MEM) 112 cmd |= PCI_COMMAND_MEMORY; 113 } 114 if (dev->resource[PCI_ROM_RESOURCE].start) 115 cmd |= PCI_COMMAND_MEMORY; 116 if (cmd != old_cmd) { 117 printk("PCI: Enabling device %s (%04x -> %04x)\n", 118 pci_name(dev), old_cmd, cmd); 119 pci_write_config_word(dev, PCI_COMMAND, cmd); 120 } 121 return 0; 122 } 123 124 struct pci_controller * __init pcibios_alloc_controller(void) 125 { 126 struct pci_controller *pci_ctrl; 127 128 pci_ctrl = (struct pci_controller *)alloc_bootmem(sizeof(*pci_ctrl)); 129 memset(pci_ctrl, 0, sizeof(struct pci_controller)); 130 131 *pci_ctrl_tail = pci_ctrl; 132 pci_ctrl_tail = &pci_ctrl->next; 133 134 return pci_ctrl; 135 } 136 137 static void __init pci_controller_apertures(struct pci_controller *pci_ctrl, 138 struct list_head *resources) 139 { 140 struct resource *res; 141 unsigned long io_offset; 142 int i; 143 144 io_offset = (unsigned long)pci_ctrl->io_space.base; 145 res = &pci_ctrl->io_resource; 146 if (!res->flags) { 147 if (io_offset) 148 printk (KERN_ERR "I/O resource not set for host" 149 " bridge %d\n", pci_ctrl->index); 150 res->start = 0; 151 res->end = IO_SPACE_LIMIT; 152 res->flags = IORESOURCE_IO; 153 } 154 res->start += io_offset; 155 res->end += io_offset; 156 pci_add_resource_offset(resources, res, io_offset); 157 158 for (i = 0; i < 3; i++) { 159 res = &pci_ctrl->mem_resources[i]; 160 if (!res->flags) { 161 if (i > 0) 162 continue; 163 printk(KERN_ERR "Memory resource not set for " 164 "host bridge %d\n", pci_ctrl->index); 165 res->start = 0; 166 res->end = ~0U; 167 res->flags = IORESOURCE_MEM; 168 } 169 pci_add_resource(resources, res); 170 } 171 } 172 173 static int __init pcibios_init(void) 174 { 175 struct pci_controller *pci_ctrl; 176 struct list_head resources; 177 struct pci_bus *bus; 178 int next_busno = 0, i; 179 180 printk("PCI: Probing PCI hardware\n"); 181 182 /* Scan all of the recorded PCI controllers. */ 183 for (pci_ctrl = pci_ctrl_head; pci_ctrl; pci_ctrl = pci_ctrl->next) { 184 pci_ctrl->last_busno = 0xff; 185 INIT_LIST_HEAD(&resources); 186 pci_controller_apertures(pci_ctrl, &resources); 187 bus = pci_scan_root_bus(NULL, pci_ctrl->first_busno, 188 pci_ctrl->ops, pci_ctrl, &resources); 189 pci_ctrl->bus = bus; 190 pci_ctrl->last_busno = bus->subordinate; 191 if (next_busno <= pci_ctrl->last_busno) 192 next_busno = pci_ctrl->last_busno+1; 193 } 194 pci_bus_count = next_busno; 195 196 return platform_pcibios_fixup(); 197 } 198 199 subsys_initcall(pcibios_init); 200 201 void __init pcibios_fixup_bus(struct pci_bus *bus) 202 { 203 if (bus->parent) { 204 /* This is a subordinate bridge */ 205 pci_read_bridge_bases(bus); 206 } 207 } 208 209 char __init *pcibios_setup(char *str) 210 { 211 return str; 212 } 213 214 void pcibios_set_master(struct pci_dev *dev) 215 { 216 /* No special bus mastering setup handling */ 217 } 218 219 /* the next one is stolen from the alpha port... */ 220 221 void __init 222 pcibios_update_irq(struct pci_dev *dev, int irq) 223 { 224 pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq); 225 } 226 227 int pcibios_enable_device(struct pci_dev *dev, int mask) 228 { 229 u16 cmd, old_cmd; 230 int idx; 231 struct resource *r; 232 233 pci_read_config_word(dev, PCI_COMMAND, &cmd); 234 old_cmd = cmd; 235 for (idx=0; idx<6; idx++) { 236 r = &dev->resource[idx]; 237 if (!r->start && r->end) { 238 printk(KERN_ERR "PCI: Device %s not available because " 239 "of resource collisions\n", pci_name(dev)); 240 return -EINVAL; 241 } 242 if (r->flags & IORESOURCE_IO) 243 cmd |= PCI_COMMAND_IO; 244 if (r->flags & IORESOURCE_MEM) 245 cmd |= PCI_COMMAND_MEMORY; 246 } 247 if (cmd != old_cmd) { 248 printk("PCI: Enabling device %s (%04x -> %04x)\n", 249 pci_name(dev), old_cmd, cmd); 250 pci_write_config_word(dev, PCI_COMMAND, cmd); 251 } 252 253 return 0; 254 } 255 256 #ifdef CONFIG_PROC_FS 257 258 /* 259 * Return the index of the PCI controller for device pdev. 260 */ 261 262 int 263 pci_controller_num(struct pci_dev *dev) 264 { 265 struct pci_controller *pci_ctrl = (struct pci_controller*) dev->sysdata; 266 return pci_ctrl->index; 267 } 268 269 #endif /* CONFIG_PROC_FS */ 270 271 /* 272 * Platform support for /proc/bus/pci/X/Y mmap()s, 273 * modelled on the sparc64 implementation by Dave Miller. 274 * -- paulus. 275 */ 276 277 /* 278 * Adjust vm_pgoff of VMA such that it is the physical page offset 279 * corresponding to the 32-bit pci bus offset for DEV requested by the user. 280 * 281 * Basically, the user finds the base address for his device which he wishes 282 * to mmap. They read the 32-bit value from the config space base register, 283 * add whatever PAGE_SIZE multiple offset they wish, and feed this into the 284 * offset parameter of mmap on /proc/bus/pci/XXX for that device. 285 * 286 * Returns negative error code on failure, zero on success. 287 */ 288 static __inline__ int 289 __pci_mmap_make_offset(struct pci_dev *dev, struct vm_area_struct *vma, 290 enum pci_mmap_state mmap_state) 291 { 292 struct pci_controller *pci_ctrl = (struct pci_controller*) dev->sysdata; 293 unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; 294 unsigned long io_offset = 0; 295 int i, res_bit; 296 297 if (pci_ctrl == 0) 298 return -EINVAL; /* should never happen */ 299 300 /* If memory, add on the PCI bridge address offset */ 301 if (mmap_state == pci_mmap_mem) { 302 res_bit = IORESOURCE_MEM; 303 } else { 304 io_offset = (unsigned long)pci_ctrl->io_space.base; 305 offset += io_offset; 306 res_bit = IORESOURCE_IO; 307 } 308 309 /* 310 * Check that the offset requested corresponds to one of the 311 * resources of the device. 312 */ 313 for (i = 0; i <= PCI_ROM_RESOURCE; i++) { 314 struct resource *rp = &dev->resource[i]; 315 int flags = rp->flags; 316 317 /* treat ROM as memory (should be already) */ 318 if (i == PCI_ROM_RESOURCE) 319 flags |= IORESOURCE_MEM; 320 321 /* Active and same type? */ 322 if ((flags & res_bit) == 0) 323 continue; 324 325 /* In the range of this resource? */ 326 if (offset < (rp->start & PAGE_MASK) || offset > rp->end) 327 continue; 328 329 /* found it! construct the final physical address */ 330 if (mmap_state == pci_mmap_io) 331 offset += pci_ctrl->io_space.start - io_offset; 332 vma->vm_pgoff = offset >> PAGE_SHIFT; 333 return 0; 334 } 335 336 return -EINVAL; 337 } 338 339 /* 340 * Set vm_page_prot of VMA, as appropriate for this architecture, for a pci 341 * device mapping. 342 */ 343 static __inline__ void 344 __pci_mmap_set_pgprot(struct pci_dev *dev, struct vm_area_struct *vma, 345 enum pci_mmap_state mmap_state, int write_combine) 346 { 347 int prot = pgprot_val(vma->vm_page_prot); 348 349 /* Set to write-through */ 350 prot &= ~_PAGE_NO_CACHE; 351 #if 0 352 if (!write_combine) 353 prot |= _PAGE_WRITETHRU; 354 #endif 355 vma->vm_page_prot = __pgprot(prot); 356 } 357 358 /* 359 * Perform the actual remap of the pages for a PCI device mapping, as 360 * appropriate for this architecture. The region in the process to map 361 * is described by vm_start and vm_end members of VMA, the base physical 362 * address is found in vm_pgoff. 363 * The pci device structure is provided so that architectures may make mapping 364 * decisions on a per-device or per-bus basis. 365 * 366 * Returns a negative error code on failure, zero on success. 367 */ 368 int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, 369 enum pci_mmap_state mmap_state, 370 int write_combine) 371 { 372 int ret; 373 374 ret = __pci_mmap_make_offset(dev, vma, mmap_state); 375 if (ret < 0) 376 return ret; 377 378 __pci_mmap_set_pgprot(dev, vma, mmap_state, write_combine); 379 380 ret = io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, 381 vma->vm_end - vma->vm_start,vma->vm_page_prot); 382 383 return ret; 384 } 385