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