1/* 2 * arch/xtensa/lib/pci-auto.c 3 * 4 * PCI autoconfiguration library 5 * 6 * Copyright (C) 2001 - 2005 Tensilica Inc. 7 * 8 * Chris Zankel <zankel@tensilica.com, cez@zankel.net> 9 * 10 * Based on work from Matt Porter <mporter@mvista.com> 11 * 12 * This program is free software; you can redistribute it and/or modify it 13 * under the terms of the GNU General Public License as published by the 14 * Free Software Foundation; either version 2 of the License, or (at your 15 * option) any later version. 16 */ 17 18#include <linux/kernel.h> 19#include <linux/init.h> 20#include <linux/pci.h> 21 22#include <asm/pci-bridge.h> 23 24 25/* 26 * 27 * Setting up a PCI 28 * 29 * pci_ctrl->first_busno = <first bus number (0)> 30 * pci_ctrl->last_busno = <last bus number (0xff)> 31 * pci_ctrl->ops = <PCI config operations> 32 * pci_ctrl->map_irq = <function to return the interrupt number for a device> 33 * 34 * pci_ctrl->io_space.start = <IO space start address (PCI view)> 35 * pci_ctrl->io_space.end = <IO space end address (PCI view)> 36 * pci_ctrl->io_space.base = <IO space offset: address 0 from CPU space> 37 * pci_ctrl->mem_space.start = <MEM space start address (PCI view)> 38 * pci_ctrl->mem_space.end = <MEM space end address (PCI view)> 39 * pci_ctrl->mem_space.base = <MEM space offset: address 0 from CPU space> 40 * 41 * pcibios_init_resource(&pci_ctrl->io_resource, <IO space start>, 42 * <IO space end>, IORESOURCE_IO, "PCI host bridge"); 43 * pcibios_init_resource(&pci_ctrl->mem_resources[0], <MEM space start>, 44 * <MEM space end>, IORESOURCE_MEM, "PCI host bridge"); 45 * 46 * pci_ctrl->last_busno = pciauto_bus_scan(pci_ctrl,pci_ctrl->first_busno); 47 * 48 * int __init pciauto_bus_scan(struct pci_controller *pci_ctrl, int current_bus) 49 * 50 */ 51 52 53/* define DEBUG to print some debugging messages. */ 54 55#undef DEBUG 56 57#ifdef DEBUG 58# define DBG(x...) printk(x) 59#else 60# define DBG(x...) 61#endif 62 63static int pciauto_upper_iospc; 64static int pciauto_upper_memspc; 65 66static struct pci_dev pciauto_dev; 67static struct pci_bus pciauto_bus; 68 69/* 70 * Helper functions 71 */ 72 73/* Initialize the bars of a PCI device. */ 74 75static void __init 76pciauto_setup_bars(struct pci_dev *dev, int bar_limit) 77{ 78 int bar_size; 79 int bar, bar_nr; 80 int *upper_limit; 81 int found_mem64 = 0; 82 83 for (bar = PCI_BASE_ADDRESS_0, bar_nr = 0; 84 bar <= bar_limit; 85 bar+=4, bar_nr++) 86 { 87 /* Tickle the BAR and get the size */ 88 pci_write_config_dword(dev, bar, 0xffffffff); 89 pci_read_config_dword(dev, bar, &bar_size); 90 91 /* If BAR is not implemented go to the next BAR */ 92 if (!bar_size) 93 continue; 94 95 /* Check the BAR type and set our address mask */ 96 if (bar_size & PCI_BASE_ADDRESS_SPACE_IO) 97 { 98 bar_size &= PCI_BASE_ADDRESS_IO_MASK; 99 upper_limit = &pciauto_upper_iospc; 100 DBG("PCI Autoconfig: BAR %d, I/O, ", bar_nr); 101 } 102 else 103 { 104 if ((bar_size & PCI_BASE_ADDRESS_MEM_TYPE_MASK) == 105 PCI_BASE_ADDRESS_MEM_TYPE_64) 106 found_mem64 = 1; 107 108 bar_size &= PCI_BASE_ADDRESS_MEM_MASK; 109 upper_limit = &pciauto_upper_memspc; 110 DBG("PCI Autoconfig: BAR %d, Mem, ", bar_nr); 111 } 112 113 /* Allocate a base address (bar_size is negative!) */ 114 *upper_limit = (*upper_limit + bar_size) & bar_size; 115 116 /* Write it out and update our limit */ 117 pci_write_config_dword(dev, bar, *upper_limit); 118 119 /* 120 * If we are a 64-bit decoder then increment to the 121 * upper 32 bits of the bar and force it to locate 122 * in the lower 4GB of memory. 123 */ 124 125 if (found_mem64) 126 pci_write_config_dword(dev, (bar+=4), 0x00000000); 127 128 DBG("size=0x%x, address=0x%x\n", ~bar_size + 1, *upper_limit); 129 } 130} 131 132/* Initialize the interrupt number. */ 133 134static void __init 135pciauto_setup_irq(struct pci_controller* pci_ctrl,struct pci_dev *dev,int devfn) 136{ 137 u8 pin; 138 int irq = 0; 139 140 pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin); 141 142 /* Fix illegal pin numbers. */ 143 144 if (pin == 0 || pin > 4) 145 pin = 1; 146 147 if (pci_ctrl->map_irq) 148 irq = pci_ctrl->map_irq(dev, PCI_SLOT(devfn), pin); 149 150 if (irq == -1) 151 irq = 0; 152 153 DBG("PCI Autoconfig: Interrupt %d, pin %d\n", irq, pin); 154 155 pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq); 156} 157 158 159static void __init 160pciauto_prescan_setup_bridge(struct pci_dev *dev, int current_bus, 161 int sub_bus, int *iosave, int *memsave) 162{ 163 /* Configure bus number registers */ 164 pci_write_config_byte(dev, PCI_PRIMARY_BUS, current_bus); 165 pci_write_config_byte(dev, PCI_SECONDARY_BUS, sub_bus + 1); 166 pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, 0xff); 167 168 /* Round memory allocator to 1MB boundary */ 169 pciauto_upper_memspc &= ~(0x100000 - 1); 170 *memsave = pciauto_upper_memspc; 171 172 /* Round I/O allocator to 4KB boundary */ 173 pciauto_upper_iospc &= ~(0x1000 - 1); 174 *iosave = pciauto_upper_iospc; 175 176 /* Set up memory and I/O filter limits, assume 32-bit I/O space */ 177 pci_write_config_word(dev, PCI_MEMORY_LIMIT, 178 ((pciauto_upper_memspc - 1) & 0xfff00000) >> 16); 179 pci_write_config_byte(dev, PCI_IO_LIMIT, 180 ((pciauto_upper_iospc - 1) & 0x0000f000) >> 8); 181 pci_write_config_word(dev, PCI_IO_LIMIT_UPPER16, 182 ((pciauto_upper_iospc - 1) & 0xffff0000) >> 16); 183} 184 185static void __init 186pciauto_postscan_setup_bridge(struct pci_dev *dev, int current_bus, int sub_bus, 187 int *iosave, int *memsave) 188{ 189 int cmdstat; 190 191 /* Configure bus number registers */ 192 pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, sub_bus); 193 194 /* 195 * Round memory allocator to 1MB boundary. 196 * If no space used, allocate minimum. 197 */ 198 pciauto_upper_memspc &= ~(0x100000 - 1); 199 if (*memsave == pciauto_upper_memspc) 200 pciauto_upper_memspc -= 0x00100000; 201 202 pci_write_config_word(dev, PCI_MEMORY_BASE, pciauto_upper_memspc >> 16); 203 204 /* Allocate 1MB for pre-fretch */ 205 pci_write_config_word(dev, PCI_PREF_MEMORY_LIMIT, 206 ((pciauto_upper_memspc - 1) & 0xfff00000) >> 16); 207 208 pciauto_upper_memspc -= 0x100000; 209 210 pci_write_config_word(dev, PCI_PREF_MEMORY_BASE, 211 pciauto_upper_memspc >> 16); 212 213 /* Round I/O allocator to 4KB boundary */ 214 pciauto_upper_iospc &= ~(0x1000 - 1); 215 if (*iosave == pciauto_upper_iospc) 216 pciauto_upper_iospc -= 0x1000; 217 218 pci_write_config_byte(dev, PCI_IO_BASE, 219 (pciauto_upper_iospc & 0x0000f000) >> 8); 220 pci_write_config_word(dev, PCI_IO_BASE_UPPER16, 221 pciauto_upper_iospc >> 16); 222 223 /* Enable memory and I/O accesses, enable bus master */ 224 pci_read_config_dword(dev, PCI_COMMAND, &cmdstat); 225 pci_write_config_dword(dev, PCI_COMMAND, 226 cmdstat | 227 PCI_COMMAND_IO | 228 PCI_COMMAND_MEMORY | 229 PCI_COMMAND_MASTER); 230} 231 232/* 233 * Scan the current PCI bus. 234 */ 235 236 237int __init pciauto_bus_scan(struct pci_controller *pci_ctrl, int current_bus) 238{ 239 int sub_bus, pci_devfn, pci_class, cmdstat, found_multi=0; 240 unsigned short vid; 241 unsigned char header_type; 242 struct pci_dev *dev = &pciauto_dev; 243 244 pciauto_dev.bus = &pciauto_bus; 245 pciauto_dev.sysdata = pci_ctrl; 246 pciauto_bus.ops = pci_ctrl->ops; 247 248 /* 249 * Fetch our I/O and memory space upper boundaries used 250 * to allocated base addresses on this pci_controller. 251 */ 252 253 if (current_bus == pci_ctrl->first_busno) 254 { 255 pciauto_upper_iospc = pci_ctrl->io_resource.end + 1; 256 pciauto_upper_memspc = pci_ctrl->mem_resources[0].end + 1; 257 } 258 259 sub_bus = current_bus; 260 261 for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) 262 { 263 /* Skip our host bridge */ 264 if ((current_bus == pci_ctrl->first_busno) && (pci_devfn == 0)) 265 continue; 266 267 if (PCI_FUNC(pci_devfn) && !found_multi) 268 continue; 269 270 pciauto_bus.number = current_bus; 271 pciauto_dev.devfn = pci_devfn; 272 273 /* If config space read fails from this device, move on */ 274 if (pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type)) 275 continue; 276 277 if (!PCI_FUNC(pci_devfn)) 278 found_multi = header_type & 0x80; 279 pci_read_config_word(dev, PCI_VENDOR_ID, &vid); 280 281 if (vid == 0xffff || vid == 0x0000) { 282 found_multi = 0; 283 continue; 284 } 285 286 pci_read_config_dword(dev, PCI_CLASS_REVISION, &pci_class); 287 288 if ((pci_class >> 16) == PCI_CLASS_BRIDGE_PCI) { 289 290 int iosave, memsave; 291 292 DBG("PCI Autoconfig: Found P2P bridge, device %d\n", 293 PCI_SLOT(pci_devfn)); 294 295 /* Allocate PCI I/O and/or memory space */ 296 pciauto_setup_bars(dev, PCI_BASE_ADDRESS_1); 297 298 pciauto_prescan_setup_bridge(dev, current_bus, sub_bus, 299 &iosave, &memsave); 300 sub_bus = pciauto_bus_scan(pci_ctrl, sub_bus+1); 301 pciauto_postscan_setup_bridge(dev, current_bus, sub_bus, 302 &iosave, &memsave); 303 pciauto_bus.number = current_bus; 304 305 continue; 306 307 } 308 309 310 311 /* 312 * Found a peripheral, enable some standard 313 * settings 314 */ 315 316 pci_read_config_dword(dev, PCI_COMMAND, &cmdstat); 317 pci_write_config_dword(dev, PCI_COMMAND, 318 cmdstat | 319 PCI_COMMAND_IO | 320 PCI_COMMAND_MEMORY | 321 PCI_COMMAND_MASTER); 322 pci_write_config_byte(dev, PCI_LATENCY_TIMER, 0x80); 323 324 /* Allocate PCI I/O and/or memory space */ 325 DBG("PCI Autoconfig: Found Bus %d, Device %d, Function %d\n", 326 current_bus, PCI_SLOT(pci_devfn), PCI_FUNC(pci_devfn) ); 327 328 pciauto_setup_bars(dev, PCI_BASE_ADDRESS_5); 329 pciauto_setup_irq(pci_ctrl, dev, pci_devfn); 330 } 331 return sub_bus; 332} 333