arch/tile/kernel/pci.c

   1 /*
   2  * Copyright 2011 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/pci.h>
  17 #include <linux/delay.h>
  18 #include <linux/string.h>
  19 #include <linux/init.h>
  20 #include <linux/capability.h>
  21 #include <linux/sched.h>
  22 #include <linux/errno.h>
  23 #include <linux/irq.h>
  24 #include <linux/io.h>
  25 #include <linux/uaccess.h>
  26 #include <linux/export.h>
  27
  28 #include <asm/processor.h>
  29 #include <asm/sections.h>
  30 #include <asm/byteorder.h>
  31 #include <asm/hv_driver.h>
  32 #include <hv/drv_pcie_rc_intf.h>
  33
  34
  35 /*
  36  * Initialization flow and process
  37  * -------------------------------
  38  *
  39  * This files contains the routines to search for PCI buses,
  40  * enumerate the buses, and configure any attached devices.
  41  *
  42  * There are two entry points here:
  43  * 1) tile_pci_init
  44  *    This sets up the pci_controller structs, and opens the
  45  *    FDs to the hypervisor.  This is called from setup_arch() early
  46  *    in the boot process.
  47  * 2) pcibios_init
  48  *    This probes the PCI bus(es) for any attached hardware.  It's
  49  *    called by subsys_initcall.  All of the real work is done by the
  50  *    generic Linux PCI layer.
  51  *
  52  */
  53
  54 static int pci_probe = 1;
  55
  56 /*
  57  * This flag tells if the platform is TILEmpower that needs
  58  * special configuration for the PLX switch chip.
  59  */
  60 int __write_once tile_plx_gen1;
  61
  62 static struct pci_controller controllers[TILE_NUM_PCIE];
  63 static int num_controllers;
  64 static int pci_scan_flags[TILE_NUM_PCIE];
  65
  66 static struct pci_ops tile_cfg_ops;
  67
  68
  69 /*
  70  * We don't need to worry about the alignment of resources.
  71  */
  72 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
  73                             resource_size_t size, resource_size_t align)
  74 {
  75         return res->start;
  76 }
  77 EXPORT_SYMBOL(pcibios_align_resource);
  78
  79 /*
  80  * Open a FD to the hypervisor PCI device.
  81  *
  82  * controller_id is the controller number, config type is 0 or 1 for
  83  * config0 or config1 operations.
  84  */
  85 static int tile_pcie_open(int controller_id, int config_type)
  86 {
  87         char filename[32];
  88         int fd;
  89
  90         sprintf(filename, "pcie/%d/config%d", controller_id, config_type);
  91
  92         fd = hv_dev_open((HV_VirtAddr)filename, 0);
  93
  94         return fd;
  95 }
  96
  97
  98 /*
  99  * Get the IRQ numbers from the HV and set up the handlers for them.
 100  */
 101 static int tile_init_irqs(int controller_id, struct pci_controller *controller)
 102 {
 103         char filename[32];
 104         int fd;
 105         int ret;
 106         int x;
 107         struct pcie_rc_config rc_config;
 108
 109         sprintf(filename, "pcie/%d/ctl", controller_id);
 110         fd = hv_dev_open((HV_VirtAddr)filename, 0);
 111         if (fd < 0) {
 112                 pr_err("PCI: hv_dev_open(%s) failed\n", filename);
 113                 return -1;
 114         }
 115         ret = hv_dev_pread(fd, 0, (HV_VirtAddr)(&rc_config),
 116                            sizeof(rc_config), PCIE_RC_CONFIG_MASK_OFF);
 117         hv_dev_close(fd);
 118         if (ret != sizeof(rc_config)) {
 119                 pr_err("PCI: wanted %zd bytes, got %d\n",
 120                        sizeof(rc_config), ret);
 121                 return -1;
 122         }
 123         /* Record irq_base so that we can map INTx to IRQ # later. */
 124         controller->irq_base = rc_config.intr;
 125
 126         for (x = 0; x < 4; x++)
 127                 tile_irq_activate(rc_config.intr + x,
 128                                   TILE_IRQ_HW_CLEAR);
 129
 130         if (rc_config.plx_gen1)
 131                 controller->plx_gen1 = 1;
 132
 133         return 0;
 134 }
 135
 136 /*
 137  * First initialization entry point, called from setup_arch().
 138  *
 139  * Find valid controllers and fill in pci_controller structs for each
 140  * of them.
 141  *
 142  * Returns the number of controllers discovered.
 143  */
 144 int __init tile_pci_init(void)
 145 {
 146         int i;
 147
 148         if (!pci_probe) {
 149                 pr_info("PCI: disabled by boot argument\n");
 150                 return 0;
 151         }
 152
 153         pr_info("PCI: Searching for controllers...\n");
 154
 155         /* Re-init number of PCIe controllers to support hot-plug feature. */
 156         num_controllers = 0;
 157
 158         /* Do any configuration we need before using the PCIe */
 159
 160         for (i = 0; i < TILE_NUM_PCIE; i++) {
 161                 /*
 162                  * To see whether we need a real config op based on
 163                  * the results of pcibios_init(), to support PCIe hot-plug.
 164                  */
 165                 if (pci_scan_flags[i] == 0) {
 166                         int hv_cfg_fd0 = -1;
 167                         int hv_cfg_fd1 = -1;
 168                         int hv_mem_fd = -1;
 169                         char name[32];
 170                         struct pci_controller *controller;
 171
 172                         /*
 173                          * Open the fd to the HV.  If it fails then this
 174                          * device doesn't exist.
 175                          */
 176                         hv_cfg_fd0 = tile_pcie_open(i, 0);
 177                         if (hv_cfg_fd0 < 0)
 178                                 continue;
 179                         hv_cfg_fd1 = tile_pcie_open(i, 1);
 180                         if (hv_cfg_fd1 < 0) {
 181                                 pr_err("PCI: Couldn't open config fd to HV "
 182                                     "for controller %d\n", i);
 183                                 goto err_cont;
 184                         }
 185
 186                         sprintf(name, "pcie/%d/mem", i);
 187                         hv_mem_fd = hv_dev_open((HV_VirtAddr)name, 0);
 188                         if (hv_mem_fd < 0) {
 189                                 pr_err("PCI: Could not open mem fd to HV!\n");
 190                                 goto err_cont;
 191                         }
 192
 193                         pr_info("PCI: Found PCI controller #%d\n", i);
 194
 195                         controller = &controllers[i];
 196
 197                         controller->index = i;
 198                         controller->hv_cfg_fd[0] = hv_cfg_fd0;
 199                         controller->hv_cfg_fd[1] = hv_cfg_fd1;
 200                         controller->hv_mem_fd = hv_mem_fd;
 201                         controller->last_busno = 0xff;
 202                         controller->ops = &tile_cfg_ops;
 203
 204                         num_controllers++;
 205                         continue;
 206
 207 err_cont:
 208                         if (hv_cfg_fd0 >= 0)
 209                                 hv_dev_close(hv_cfg_fd0);
 210                         if (hv_cfg_fd1 >= 0)
 211                                 hv_dev_close(hv_cfg_fd1);
 212                         if (hv_mem_fd >= 0)
 213                                 hv_dev_close(hv_mem_fd);
 214                         continue;
 215                 }
 216         }
 217
 218         /*
 219          * Before using the PCIe, see if we need to do any platform-specific
 220          * configuration, such as the PLX switch Gen 1 issue on TILEmpower.
 221          */
 222         for (i = 0; i < num_controllers; i++) {
 223                 struct pci_controller *controller = &controllers[i];
 224
 225                 if (controller->plx_gen1)
 226                         tile_plx_gen1 = 1;
 227         }
 228
 229         return num_controllers;
 230 }
 231
 232 /*
 233  * (pin - 1) converts from the PCI standard's [1:4] convention to
 234  * a normal [0:3] range.
 235  */
 236 static int tile_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
 237 {
 238         struct pci_controller *controller =
 239                 (struct pci_controller *)dev->sysdata;
 240         return (pin - 1) + controller->irq_base;
 241 }
 242
 243
 244 static void fixup_read_and_payload_sizes(void)
 245 {
 246         struct pci_dev *dev = NULL;
 247         int smallest_max_payload = 0x1; /* Tile maxes out at 256 bytes. */
 248         int max_read_size = 0x2; /* Limit to 512 byte reads. */
 249         u16 new_values;
 250
 251         /* Scan for the smallest maximum payload size. */
 252         for_each_pci_dev(dev) {
 253                 if (!pci_is_pcie(dev))
 254                         continue;
 255
 256                 if (dev->pcie_mpss < smallest_max_payload)
 257                         smallest_max_payload = dev->pcie_mpss;
 258         }
 259
 260         /* Now, set the max_payload_size for all devices to that value. */
 261         new_values = (max_read_size << 12) | (smallest_max_payload << 5);
 262         for_each_pci_dev(dev)
 263                 pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
 264                                 PCI_EXP_DEVCTL_PAYLOAD | PCI_EXP_DEVCTL_READRQ,
 265                                 new_values);
 266 }
 267
 268
 269 /*
 270  * Second PCI initialization entry point, called by subsys_initcall.
 271  *
 272  * The controllers have been set up by the time we get here, by a call to
 273  * tile_pci_init.
 274  */
 275 int __init pcibios_init(void)
 276 {
 277         int i;
 278
 279         pr_info("PCI: Probing PCI hardware\n");
 280
 281         /*
 282          * Delay a bit in case devices aren't ready.  Some devices are
 283          * known to require at least 20ms here, but we use a more
 284          * conservative value.
 285          */
 286         msleep(250);
 287
 288         /* Scan all of the recorded PCI controllers.  */
 289         for (i = 0; i < TILE_NUM_PCIE; i++) {
 290                 /*
 291                  * Do real pcibios init ops if the controller is initialized
 292                  * by tile_pci_init() successfully and not initialized by
 293                  * pcibios_init() yet to support PCIe hot-plug.
 294                  */
 295                 if (pci_scan_flags[i] == 0 && controllers[i].ops != NULL) {
 296                         struct pci_controller *controller = &controllers[i];
 297                         struct pci_bus *bus;
 298                         LIST_HEAD(resources);
 299
 300                         if (tile_init_irqs(i, controller)) {
 301                                 pr_err("PCI: Could not initialize IRQs\n");
 302                                 continue;
 303                         }
 304
 305                         pr_info("PCI: initializing controller #%d\n", i);
 306
 307                         pci_add_resource(&resources, &ioport_resource);
 308                         pci_add_resource(&resources, &iomem_resource);
 309                         bus = pci_scan_root_bus(NULL, 0, controller->ops,
 310                                                 controller, &resources);
 311                         controller->root_bus = bus;
 312                         controller->last_busno = bus->busn_res.end;
 313                 }
 314         }
 315
 316         /* Do machine dependent PCI interrupt routing */
 317         pci_fixup_irqs(pci_common_swizzle, tile_map_irq);
 318
 319         /*
 320          * This comes from the generic Linux PCI driver.
 321          *
 322          * It allocates all of the resources (I/O memory, etc)
 323          * associated with the devices read in above.
 324          */
 325         pci_assign_unassigned_resources();
 326
 327         /* Configure the max_read_size and max_payload_size values. */
 328         fixup_read_and_payload_sizes();
 329
 330         /* Record the I/O resources in the PCI controller structure. */
 331         for (i = 0; i < TILE_NUM_PCIE; i++) {
 332                 /*
 333                  * Do real pcibios init ops if the controller is initialized
 334                  * by tile_pci_init() successfully and not initialized by
 335                  * pcibios_init() yet to support PCIe hot-plug.
 336                  */
 337                 if (pci_scan_flags[i] == 0 && controllers[i].ops != NULL) {
 338                         struct pci_bus *root_bus = controllers[i].root_bus;
 339                         struct pci_bus *next_bus;
 340                         struct pci_dev *dev;
 341
 342                         list_for_each_entry(dev, &root_bus->devices, bus_list) {
 343                                 /*
 344                                  * Find the PCI host controller, ie. the 1st
 345                                  * bridge.
 346                                  */
 347                                 if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI &&
 348                                         (PCI_SLOT(dev->devfn) == 0)) {
 349                                         next_bus = dev->subordinate;
 350                                         controllers[i].mem_resources[0] =
 351                                                 *next_bus->resource[0];
 352                                         controllers[i].mem_resources[1] =
 353                                                  *next_bus->resource[1];
 354                                         controllers[i].mem_resources[2] =
 355                                                  *next_bus->resource[2];
 356
 357                                         /* Setup flags. */
 358                                         pci_scan_flags[i] = 1;
 359
 360                                         break;
 361                                 }
 362                         }
 363                 }
 364         }
 365
 366         return 0;
 367 }
 368 subsys_initcall(pcibios_init);
 369
 370 /*
 371  * No bus fixups needed.
 372  */
 373 void pcibios_fixup_bus(struct pci_bus *bus)
 374 {
 375         /* Nothing needs to be done. */
 376 }
 377
 378 void pcibios_set_master(struct pci_dev *dev)
 379 {
 380         /* No special bus mastering setup handling. */
 381 }
 382
 383 /* Process any "pci=" kernel boot arguments. */
 384 char *__init pcibios_setup(char *str)
 385 {
 386         if (!strcmp(str, "off")) {
 387                 pci_probe = 0;
 388                 return NULL;
 389         }
 390         return str;
 391 }
 392
 393 /*
 394  * Enable memory and/or address decoding, as appropriate, for the
 395  * device described by the 'dev' struct.
 396  *
 397  * This is called from the generic PCI layer, and can be called
 398  * for bridges or endpoints.
 399  */
 400 int pcibios_enable_device(struct pci_dev *dev, int mask)
 401 {
 402         u16 cmd, old_cmd;
 403         u8 header_type;
 404         int i;
 405         struct resource *r;
 406
 407         pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type);
 408
 409         pci_read_config_word(dev, PCI_COMMAND, &cmd);
 410         old_cmd = cmd;
 411         if ((header_type & 0x7F) == PCI_HEADER_TYPE_BRIDGE) {
 412                 /*
 413                  * For bridges, we enable both memory and I/O decoding
 414                  * in call cases.
 415                  */
 416                 cmd |= PCI_COMMAND_IO;
 417                 cmd |= PCI_COMMAND_MEMORY;
 418         } else {
 419                 /*
 420                  * For endpoints, we enable memory and/or I/O decoding
 421                  * only if they have a memory resource of that type.
 422                  */
 423                 for (i = 0; i < 6; i++) {
 424                         r = &dev->resource[i];
 425                         if (r->flags & IORESOURCE_UNSET) {
 426                                 pr_err("PCI: Device %s not available "
 427                                        "because of resource collisions\n",
 428                                        pci_name(dev));
 429                                 return -EINVAL;
 430                         }
 431                         if (r->flags & IORESOURCE_IO)
 432                                 cmd |= PCI_COMMAND_IO;
 433                         if (r->flags & IORESOURCE_MEM)
 434                                 cmd |= PCI_COMMAND_MEMORY;
 435                 }
 436         }
 437
 438         /*
 439          * We only write the command if it changed.
 440          */
 441         if (cmd != old_cmd)
 442                 pci_write_config_word(dev, PCI_COMMAND, cmd);
 443         return 0;
 444 }
 445
 446 /****************************************************************
 447  *
 448  * Tile PCI config space read/write routines
 449  *
 450  ****************************************************************/
 451
 452 /*
 453  * These are the normal read and write ops
 454  * These are expanded with macros from  pci_bus_read_config_byte() etc.
 455  *
 456  * devfn is the combined PCI slot & function.
 457  *
 458  * offset is in bytes, from the start of config space for the
 459  * specified bus & slot.
 460  */
 461
 462 static int tile_cfg_read(struct pci_bus *bus, unsigned int devfn, int offset,
 463                          int size, u32 *val)
 464 {
 465         struct pci_controller *controller = bus->sysdata;
 466         int busnum = bus->number & 0xff;
 467         int slot = (devfn >> 3) & 0x1f;
 468         int function = devfn & 0x7;
 469         u32 addr;
 470         int config_mode = 1;
 471
 472         /*
 473          * There is no bridge between the Tile and bus 0, so we
 474          * use config0 to talk to bus 0.
 475          *
 476          * If we're talking to a bus other than zero then we
 477          * must have found a bridge.
 478          */
 479         if (busnum == 0) {
 480                 /*
 481                  * We fake an empty slot for (busnum == 0) && (slot > 0),
 482                  * since there is only one slot on bus 0.
 483                  */
 484                 if (slot) {
 485                         *val = 0xFFFFFFFF;
 486                         return 0;
 487                 }
 488                 config_mode = 0;
 489         }
 490
 491         addr = busnum << 20;            /* Bus in 27:20 */
 492         addr |= slot << 15;             /* Slot (device) in 19:15 */
 493         addr |= function << 12;         /* Function is in 14:12 */
 494         addr |= (offset & 0xFFF);       /* byte address in 0:11 */
 495
 496         return hv_dev_pread(controller->hv_cfg_fd[config_mode], 0,
 497                             (HV_VirtAddr)(val), size, addr);
 498 }
 499
 500
 501 /*
 502  * See tile_cfg_read() for relevant comments.
 503  * Note that "val" is the value to write, not a pointer to that value.
 504  */
 505 static int tile_cfg_write(struct pci_bus *bus, unsigned int devfn, int offset,
 506                           int size, u32 val)
 507 {
 508         struct pci_controller *controller = bus->sysdata;
 509         int busnum = bus->number & 0xff;
 510         int slot = (devfn >> 3) & 0x1f;
 511         int function = devfn & 0x7;
 512         u32 addr;
 513         int config_mode = 1;
 514         HV_VirtAddr valp = (HV_VirtAddr)&val;
 515
 516         /*
 517          * For bus 0 slot 0 we use config 0 accesses.
 518          */
 519         if (busnum == 0) {
 520                 /*
 521                  * We fake an empty slot for (busnum == 0) && (slot > 0),
 522                  * since there is only one slot on bus 0.
 523                  */
 524                 if (slot)
 525                         return 0;
 526                 config_mode = 0;
 527         }
 528
 529         addr = busnum << 20;            /* Bus in 27:20 */
 530         addr |= slot << 15;             /* Slot (device) in 19:15 */
 531         addr |= function << 12;         /* Function is in 14:12 */
 532         addr |= (offset & 0xFFF);       /* byte address in 0:11 */
 533
 534 #ifdef __BIG_ENDIAN
 535         /* Point to the correct part of the 32-bit "val". */
 536         valp += 4 - size;
 537 #endif
 538
 539         return hv_dev_pwrite(controller->hv_cfg_fd[config_mode], 0,
 540                              valp, size, addr);
 541 }
 542
 543
 544 static struct pci_ops tile_cfg_ops = {
 545         .read =         tile_cfg_read,
 546         .write =        tile_cfg_write,
 547 };
 548
 549
 550 /*
 551  * In the following, each PCI controller's mem_resources[1]
 552  * represents its (non-prefetchable) PCI memory resource.
 553  * mem_resources[0] and mem_resources[2] refer to its PCI I/O and
 554  * prefetchable PCI memory resources, respectively.
 555  * For more details, see pci_setup_bridge() in setup-bus.c.
 556  * By comparing the target PCI memory address against the
 557  * end address of controller 0, we can determine the controller
 558  * that should accept the PCI memory access.
 559  */
 560 #define TILE_READ(size, type)                                           \
 561 type _tile_read##size(unsigned long addr)                               \
 562 {                                                                       \
 563         type val;                                                       \
 564         int idx = 0;                                                    \
 565         if (addr > controllers[0].mem_resources[1].end &&               \
 566             addr > controllers[0].mem_resources[2].end)                 \
 567                 idx = 1;                                                \
 568         if (hv_dev_pread(controllers[idx].hv_mem_fd, 0,                 \
 569                          (HV_VirtAddr)(&val), sizeof(type), addr))      \
 570                 pr_err("PCI: read %zd bytes at 0x%lX failed\n",         \
 571                        sizeof(type), addr);                             \
 572         return val;                                                     \
 573 }                                                                       \
 574 EXPORT_SYMBOL(_tile_read##size)
 575
 576 TILE_READ(b, u8);
 577 TILE_READ(w, u16);
 578 TILE_READ(l, u32);
 579 TILE_READ(q, u64);
 580
 581 #define TILE_WRITE(size, type)                                          \
 582 void _tile_write##size(type val, unsigned long addr)                    \
 583 {                                                                       \
 584         int idx = 0;                                                    \
 585         if (addr > controllers[0].mem_resources[1].end &&               \
 586             addr > controllers[0].mem_resources[2].end)                 \
 587                 idx = 1;                                                \
 588         if (hv_dev_pwrite(controllers[idx].hv_mem_fd, 0,                \
 589                           (HV_VirtAddr)(&val), sizeof(type), addr))     \
 590                 pr_err("PCI: write %zd bytes at 0x%lX failed\n",        \
 591                        sizeof(type), addr);                             \
 592 }                                                                       \
 593 EXPORT_SYMBOL(_tile_write##size)
 594
 595 TILE_WRITE(b, u8);
 596 TILE_WRITE(w, u16);
 597 TILE_WRITE(l, u32);
 598 TILE_WRITE(q, u64);