arch/xtensa/lib/pci-auto.c

   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
  63 static int pciauto_upper_iospc;
  64 static int pciauto_upper_memspc;
  65
  66 static struct pci_dev pciauto_dev;
  67 static struct pci_bus pciauto_bus;
  68
  69 /*
  70  * Helper functions
  71  */
  72
  73 /* Initialize the bars of a PCI device.  */
  74
  75 static void __init
  76 pciauto_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
 134 static void __init
 135 pciauto_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
 159 static void __init
 160 pciauto_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
 185 static void __init
 186 pciauto_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
 237 int __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 #if 0
 311                 /* Skip legacy mode IDE controller */
 312
 313                 if ((pci_class >> 16) == PCI_CLASS_STORAGE_IDE) {
 314
 315                         unsigned char prg_iface;
 316                         pci_read_config_byte(dev, PCI_CLASS_PROG, &prg_iface);
 317
 318                         if (!(prg_iface & PCIAUTO_IDE_MODE_MASK)) {
 319                                 DBG("PCI Autoconfig: Skipping legacy mode "
 320                                     "IDE controller\n");
 321                                 continue;
 322                         }
 323                 }
 324 #endif
 325
 326                 /*
 327                  * Found a peripheral, enable some standard
 328                  * settings
 329                  */
 330
 331                 pci_read_config_dword(dev, PCI_COMMAND, &cmdstat);
 332                 pci_write_config_dword(dev, PCI_COMMAND,
 333                                 cmdstat |
 334                                         PCI_COMMAND_IO |
 335                                         PCI_COMMAND_MEMORY |
 336                                         PCI_COMMAND_MASTER);
 337                 pci_write_config_byte(dev, PCI_LATENCY_TIMER, 0x80);
 338
 339                 /* Allocate PCI I/O and/or memory space */
 340                 DBG("PCI Autoconfig: Found Bus %d, Device %d, Function %d\n",
 341                     current_bus, PCI_SLOT(pci_devfn), PCI_FUNC(pci_devfn) );
 342
 343                 pciauto_setup_bars(dev, PCI_BASE_ADDRESS_5);
 344                 pciauto_setup_irq(pci_ctrl, dev, pci_devfn);
 345         }
 346         return sub_bus;
 347 }