src/drivers/bus/pci.c

   1 /*
   2  * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
   3  *
   4  * Based in part on pci.c from Etherboot 5.4, by Ken Yap and David
   5  * Munro, in turn based on the Linux kernel's PCI implementation.
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 of the
  10  * License, or any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 FILE_LICENCE ( GPL2_OR_LATER );
  23
  24 #include <stdint.h>
  25 #include <stdlib.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <errno.h>
  29 #include <gpxe/tables.h>
  30 #include <gpxe/device.h>
  31 #include <gpxe/pci.h>
  32
  33 /** @file
  34  *
  35  * PCI bus
  36  *
  37  */
  38
  39 static void pcibus_remove ( struct root_device *rootdev );
  40
  41 /**
  42  * Read PCI BAR
  43  *
  44  * @v pci               PCI device
  45  * @v reg               PCI register number
  46  * @ret bar             Base address register
  47  *
  48  * Reads the specified PCI base address register, including the flags
  49  * portion.  64-bit BARs will be handled automatically.  If the value
  50  * of the 64-bit BAR exceeds the size of an unsigned long (i.e. if the
  51  * high dword is non-zero on a 32-bit platform), then the value
  52  * returned will be zero plus the flags for a 64-bit BAR.  Unreachable
  53  * 64-bit BARs are therefore returned as uninitialised 64-bit BARs.
  54  */
  55 static unsigned long pci_bar ( struct pci_device *pci, unsigned int reg ) {
  56         uint32_t low;
  57         uint32_t high;
  58
  59         pci_read_config_dword ( pci, reg, &low );
  60         if ( ( low & (PCI_BASE_ADDRESS_SPACE|PCI_BASE_ADDRESS_MEM_TYPE_MASK) )
  61              == (PCI_BASE_ADDRESS_SPACE_MEMORY|PCI_BASE_ADDRESS_MEM_TYPE_64) ){
  62                 pci_read_config_dword ( pci, reg + 4, &high );
  63                 if ( high ) {
  64                         if ( sizeof ( unsigned long ) > sizeof ( uint32_t ) ) {
  65                                 return ( ( ( uint64_t ) high << 32 ) | low );
  66                         } else {
  67                                 DBG ( "Unhandled 64-bit BAR %08x%08x\n",
  68                                       high, low );
  69                                 return PCI_BASE_ADDRESS_MEM_TYPE_64;
  70                         }
  71                 }
  72         }
  73         return low;
  74 }
  75
  76 /**
  77  * Find the start of a PCI BAR
  78  *
  79  * @v pci               PCI device
  80  * @v reg               PCI register number
  81  * @ret start           BAR start address
  82  *
  83  * Reads the specified PCI base address register, and returns the
  84  * address portion of the BAR (i.e. without the flags).
  85  *
  86  * If the address exceeds the size of an unsigned long (i.e. if a
  87  * 64-bit BAR has a non-zero high dword on a 32-bit machine), the
  88  * return value will be zero.
  89  */
  90 unsigned long pci_bar_start ( struct pci_device *pci, unsigned int reg ) {
  91         unsigned long bar;
  92
  93         bar = pci_bar ( pci, reg );
  94         if ( (bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_MEMORY ){
  95                 return ( bar & PCI_BASE_ADDRESS_MEM_MASK );
  96         } else {
  97                 return ( bar & PCI_BASE_ADDRESS_IO_MASK );
  98         }
  99 }
 100
 101 /**
 102  * Read membase and ioaddr for a PCI device
 103  *
 104  * @v pci               PCI device
 105  *
 106  * This scans through all PCI BARs on the specified device.  The first
 107  * valid memory BAR is recorded as pci_device::membase, and the first
 108  * valid IO BAR is recorded as pci_device::ioaddr.
 109  *
 110  * 64-bit BARs are handled automatically.  On a 32-bit platform, if a
 111  * 64-bit BAR has a non-zero high dword, it will be regarded as
 112  * invalid.
 113  */
 114 static void pci_read_bases ( struct pci_device *pci ) {
 115         unsigned long bar;
 116         int reg;
 117
 118         for ( reg = PCI_BASE_ADDRESS_0; reg <= PCI_BASE_ADDRESS_5; reg += 4 ) {
 119                 bar = pci_bar ( pci, reg );
 120                 if ( bar & PCI_BASE_ADDRESS_SPACE_IO ) {
 121                         if ( ! pci->ioaddr )
 122                                 pci->ioaddr =
 123                                         ( bar & PCI_BASE_ADDRESS_IO_MASK );
 124                 } else {
 125                         if ( ! pci->membase )
 126                                 pci->membase =
 127                                         ( bar & PCI_BASE_ADDRESS_MEM_MASK );
 128                         /* Skip next BAR if 64-bit */
 129                         if ( bar & PCI_BASE_ADDRESS_MEM_TYPE_64 )
 130                                 reg += 4;
 131                 }
 132         }
 133 }
 134
 135 /**
 136  * Enable PCI device
 137  *
 138  * @v pci               PCI device
 139  *
 140  * Set device to be a busmaster in case BIOS neglected to do so.  Also
 141  * adjust PCI latency timer to a reasonable value, 32.
 142  */
 143 void adjust_pci_device ( struct pci_device *pci ) {
 144         unsigned short new_command, pci_command;
 145         unsigned char pci_latency;
 146
 147         pci_read_config_word ( pci, PCI_COMMAND, &pci_command );
 148         new_command = ( pci_command | PCI_COMMAND_MASTER |
 149                         PCI_COMMAND_MEM | PCI_COMMAND_IO );
 150         if ( pci_command != new_command ) {
 151                 DBG ( "PCI BIOS has not enabled device %02x:%02x.%x! "
 152                       "Updating PCI command %04x->%04x\n", pci->bus,
 153                       PCI_SLOT ( pci->devfn ), PCI_FUNC ( pci->devfn ),
 154                       pci_command, new_command );
 155                 pci_write_config_word ( pci, PCI_COMMAND, new_command );
 156         }
 157
 158         pci_read_config_byte ( pci, PCI_LATENCY_TIMER, &pci_latency);
 159         if ( pci_latency < 32 ) {
 160                 DBG ( "PCI device %02x:%02x.%x latency timer is unreasonably "
 161                       "low at %d. Setting to 32.\n", pci->bus,
 162                       PCI_SLOT ( pci->devfn ), PCI_FUNC ( pci->devfn ),
 163                       pci_latency );
 164                 pci_write_config_byte ( pci, PCI_LATENCY_TIMER, 32);
 165         }
 166 }
 167
 168 /**
 169  * Probe a PCI device
 170  *
 171  * @v pci               PCI device
 172  * @ret rc              Return status code
 173  *
 174  * Searches for a driver for the PCI device.  If a driver is found,
 175  * its probe() routine is called.
 176  */
 177 static int pci_probe ( struct pci_device *pci ) {
 178         struct pci_driver *driver;
 179         struct pci_device_id *id;
 180         unsigned int i;
 181         int rc;
 182
 183         DBG ( "Adding PCI device %02x:%02x.%x (%04x:%04x mem %lx io %lx "
 184               "irq %d)\n", pci->bus, PCI_SLOT ( pci->devfn ),
 185               PCI_FUNC ( pci->devfn ), pci->vendor, pci->device,
 186               pci->membase, pci->ioaddr, pci->irq );
 187
 188         for_each_table_entry ( driver, PCI_DRIVERS ) {
 189                 for ( i = 0 ; i < driver->id_count ; i++ ) {
 190                         id = &driver->ids[i];
 191                         if ( ( id->vendor != PCI_ANY_ID ) &&
 192                              ( id->vendor != pci->vendor ) )
 193                                 continue;
 194                         if ( ( id->device != PCI_ANY_ID ) &&
 195                              ( id->device != pci->device ) )
 196                                 continue;
 197                         pci->driver = driver;
 198                         pci->driver_name = id->name;
 199                         DBG ( "...using driver %s\n", pci->driver_name );
 200                         if ( ( rc = driver->probe ( pci, id ) ) != 0 ) {
 201                                 DBG ( "......probe failed\n" );
 202                                 continue;
 203                         }
 204                         return 0;
 205                 }
 206         }
 207
 208         DBG ( "...no driver found\n" );
 209         return -ENOTTY;
 210 }
 211
 212 /**
 213  * Remove a PCI device
 214  *
 215  * @v pci               PCI device
 216  */
 217 static void pci_remove ( struct pci_device *pci ) {
 218         pci->driver->remove ( pci );
 219         DBG ( "Removed PCI device %02x:%02x.%x\n", pci->bus,
 220               PCI_SLOT ( pci->devfn ), PCI_FUNC ( pci->devfn ) );
 221 }
 222
 223 /**
 224  * Probe PCI root bus
 225  *
 226  * @v rootdev           PCI bus root device
 227  *
 228  * Scans the PCI bus for devices and registers all devices it can
 229  * find.
 230  */
 231 static int pcibus_probe ( struct root_device *rootdev ) {
 232         struct pci_device *pci = NULL;
 233         unsigned int max_bus;
 234         unsigned int bus;
 235         unsigned int devfn;
 236         uint8_t hdrtype = 0;
 237         uint32_t tmp;
 238         int rc;
 239
 240         max_bus = pci_max_bus();
 241         for ( bus = 0 ; bus <= max_bus ; bus++ ) {
 242                 for ( devfn = 0 ; devfn <= 0xff ; devfn++ ) {
 243
 244                         /* Allocate struct pci_device */
 245                         if ( ! pci )
 246                                 pci = malloc ( sizeof ( *pci ) );
 247                         if ( ! pci ) {
 248                                 rc = -ENOMEM;
 249                                 goto err;
 250                         }
 251                         memset ( pci, 0, sizeof ( *pci ) );
 252                         pci->bus = bus;
 253                         pci->devfn = devfn;
 254
 255                         /* Skip all but the first function on
 256                          * non-multifunction cards
 257                          */
 258                         if ( PCI_FUNC ( devfn ) == 0 ) {
 259                                 pci_read_config_byte ( pci, PCI_HEADER_TYPE,
 260                                                        &hdrtype );
 261                         } else if ( ! ( hdrtype & 0x80 ) ) {
 262                                         continue;
 263                         }
 264
 265                         /* Check for physical device presence */
 266                         pci_read_config_dword ( pci, PCI_VENDOR_ID, &tmp );
 267                         if ( ( tmp == 0xffffffff ) || ( tmp == 0 ) )
 268                                 continue;
 269
 270                         /* Populate struct pci_device */
 271                         pci->vendor = ( tmp & 0xffff );
 272                         pci->device = ( tmp >> 16 );
 273                         pci_read_config_dword ( pci, PCI_REVISION, &tmp );
 274                         pci->class = ( tmp >> 8 );
 275                         pci_read_config_byte ( pci, PCI_INTERRUPT_LINE,
 276                                                &pci->irq );
 277                         pci_read_bases ( pci );
 278
 279                         /* Add to device hierarchy */
 280                         snprintf ( pci->dev.name, sizeof ( pci->dev.name ),
 281                                    "PCI%02x:%02x.%x", bus,
 282                                    PCI_SLOT ( devfn ), PCI_FUNC ( devfn ) );
 283                         pci->dev.desc.bus_type = BUS_TYPE_PCI;
 284                         pci->dev.desc.location = PCI_BUSDEVFN (bus, devfn);
 285                         pci->dev.desc.vendor = pci->vendor;
 286                         pci->dev.desc.device = pci->device;
 287                         pci->dev.desc.class = pci->class;
 288                         pci->dev.desc.ioaddr = pci->ioaddr;
 289                         pci->dev.desc.irq = pci->irq;
 290                         pci->dev.parent = &rootdev->dev;
 291                         list_add ( &pci->dev.siblings, &rootdev->dev.children);
 292                         INIT_LIST_HEAD ( &pci->dev.children );
 293
 294                         /* Look for a driver */
 295                         if ( pci_probe ( pci ) == 0 ) {
 296                                 /* pcidev registered, we can drop our ref */
 297                                 pci = NULL;
 298                         } else {
 299                                 /* Not registered; re-use struct pci_device */
 300                                 list_del ( &pci->dev.siblings );
 301                         }
 302                 }
 303         }
 304
 305         free ( pci );
 306         return 0;
 307
 308  err:
 309         free ( pci );
 310         pcibus_remove ( rootdev );
 311         return rc;
 312 }
 313
 314 /**
 315  * Remove PCI root bus
 316  *
 317  * @v rootdev           PCI bus root device
 318  */
 319 static void pcibus_remove ( struct root_device *rootdev ) {
 320         struct pci_device *pci;
 321         struct pci_device *tmp;
 322
 323         list_for_each_entry_safe ( pci, tmp, &rootdev->dev.children,
 324                                    dev.siblings ) {
 325                 pci_remove ( pci );
 326                 list_del ( &pci->dev.siblings );
 327                 free ( pci );
 328         }
 329 }
 330
 331 /** PCI bus root device driver */
 332 static struct root_driver pci_root_driver = {
 333         .probe = pcibus_probe,
 334         .remove = pcibus_remove,
 335 };
 336
 337 /** PCI bus root device */
 338 struct root_device pci_root_device __root_device = {
 339         .dev = { .name = "PCI" },
 340         .driver = &pci_root_driver,
 341 };