arch/powerpc/kernel/pci_dn.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * pci_dn.c
   4  *
   5  * Copyright (C) 2001 Todd Inglett, IBM Corporation
   6  *
   7  * PCI manipulation via device_nodes.
   8  */
   9 #include <linux/kernel.h>
  10 #include <linux/pci.h>
  11 #include <linux/string.h>
  12 #include <linux/export.h>
  13 #include <linux/init.h>
  14 #include <linux/gfp.h>
  15
  16 #include <asm/io.h>
  17 #include <asm/prom.h>
  18 #include <asm/pci-bridge.h>
  19 #include <asm/ppc-pci.h>
  20 #include <asm/firmware.h>
  21 #include <asm/eeh.h>
  22
  23 /*
  24  * The function is used to find the firmware data of one
  25  * specific PCI device, which is attached to the indicated
  26  * PCI bus. For VFs, their firmware data is linked to that
  27  * one of PF's bridge. For other devices, their firmware
  28  * data is linked to that of their bridge.
  29  */
  30 static struct pci_dn *pci_bus_to_pdn(struct pci_bus *bus)
  31 {
  32         struct pci_bus *pbus;
  33         struct device_node *dn;
  34         struct pci_dn *pdn;
  35
  36         /*
  37          * We probably have virtual bus which doesn't
  38          * have associated bridge.
  39          */
  40         pbus = bus;
  41         while (pbus) {
  42                 if (pci_is_root_bus(pbus) || pbus->self)
  43                         break;
  44
  45                 pbus = pbus->parent;
  46         }
  47
  48         /*
  49          * Except virtual bus, all PCI buses should
  50          * have device nodes.
  51          */
  52         dn = pci_bus_to_OF_node(pbus);
  53         pdn = dn ? PCI_DN(dn) : NULL;
  54
  55         return pdn;
  56 }
  57
  58 struct pci_dn *pci_get_pdn_by_devfn(struct pci_bus *bus,
  59                                     int devfn)
  60 {
  61         struct device_node *dn = NULL;
  62         struct pci_dn *parent, *pdn;
  63         struct pci_dev *pdev = NULL;
  64
  65         /* Fast path: fetch from PCI device */
  66         list_for_each_entry(pdev, &bus->devices, bus_list) {
  67                 if (pdev->devfn == devfn) {
  68                         if (pdev->dev.archdata.pci_data)
  69                                 return pdev->dev.archdata.pci_data;
  70
  71                         dn = pci_device_to_OF_node(pdev);
  72                         break;
  73                 }
  74         }
  75
  76         /* Fast path: fetch from device node */
  77         pdn = dn ? PCI_DN(dn) : NULL;
  78         if (pdn)
  79                 return pdn;
  80
  81         /* Slow path: fetch from firmware data hierarchy */
  82         parent = pci_bus_to_pdn(bus);
  83         if (!parent)
  84                 return NULL;
  85
  86         list_for_each_entry(pdn, &parent->child_list, list) {
  87                 if (pdn->busno == bus->number &&
  88                     pdn->devfn == devfn)
  89                         return pdn;
  90         }
  91
  92         return NULL;
  93 }
  94
  95 struct pci_dn *pci_get_pdn(struct pci_dev *pdev)
  96 {
  97         struct device_node *dn;
  98         struct pci_dn *parent, *pdn;
  99
 100         /* Search device directly */
 101         if (pdev->dev.archdata.pci_data)
 102                 return pdev->dev.archdata.pci_data;
 103
 104         /* Check device node */
 105         dn = pci_device_to_OF_node(pdev);
 106         pdn = dn ? PCI_DN(dn) : NULL;
 107         if (pdn)
 108                 return pdn;
 109
 110         /*
 111          * VFs don't have device nodes. We hook their
 112          * firmware data to PF's bridge.
 113          */
 114         parent = pci_bus_to_pdn(pdev->bus);
 115         if (!parent)
 116                 return NULL;
 117
 118         list_for_each_entry(pdn, &parent->child_list, list) {
 119                 if (pdn->busno == pdev->bus->number &&
 120                     pdn->devfn == pdev->devfn)
 121                         return pdn;
 122         }
 123
 124         return NULL;
 125 }
 126
 127 #ifdef CONFIG_EEH
 128 static struct eeh_dev *eeh_dev_init(struct pci_dn *pdn)
 129 {
 130         struct eeh_dev *edev;
 131
 132         /* Allocate EEH device */
 133         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
 134         if (!edev)
 135                 return NULL;
 136
 137         /* Associate EEH device with OF node */
 138         pdn->edev = edev;
 139         edev->pdn = pdn;
 140         edev->bdfn = (pdn->busno << 8) | pdn->devfn;
 141         edev->controller = pdn->phb;
 142
 143         return edev;
 144 }
 145 #endif /* CONFIG_EEH */
 146
 147 #ifdef CONFIG_PCI_IOV
 148 static struct pci_dn *add_one_sriov_vf_pdn(struct pci_dn *parent,
 149                                            int busno, int devfn)
 150 {
 151         struct pci_dn *pdn;
 152
 153         /* Except PHB, we always have the parent */
 154         if (!parent)
 155                 return NULL;
 156
 157         pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
 158         if (!pdn)
 159                 return NULL;
 160
 161         pdn->phb = parent->phb;
 162         pdn->parent = parent;
 163         pdn->busno = busno;
 164         pdn->devfn = devfn;
 165         pdn->pe_number = IODA_INVALID_PE;
 166         INIT_LIST_HEAD(&pdn->child_list);
 167         INIT_LIST_HEAD(&pdn->list);
 168         list_add_tail(&pdn->list, &parent->child_list);
 169
 170         return pdn;
 171 }
 172
 173 struct pci_dn *add_sriov_vf_pdns(struct pci_dev *pdev)
 174 {
 175         struct pci_dn *parent, *pdn;
 176         int i;
 177
 178         /* Only support IOV for now */
 179         if (WARN_ON(!pdev->is_physfn))
 180                 return NULL;
 181
 182         /* Check if VFs have been populated */
 183         pdn = pci_get_pdn(pdev);
 184         if (!pdn || (pdn->flags & PCI_DN_FLAG_IOV_VF))
 185                 return NULL;
 186
 187         pdn->flags |= PCI_DN_FLAG_IOV_VF;
 188         parent = pci_bus_to_pdn(pdev->bus);
 189         if (!parent)
 190                 return NULL;
 191
 192         for (i = 0; i < pci_sriov_get_totalvfs(pdev); i++) {
 193                 struct eeh_dev *edev __maybe_unused;
 194
 195                 pdn = add_one_sriov_vf_pdn(parent,
 196                                            pci_iov_virtfn_bus(pdev, i),
 197                                            pci_iov_virtfn_devfn(pdev, i));
 198                 if (!pdn) {
 199                         dev_warn(&pdev->dev, "%s: Cannot create firmware data for VF#%d\n",
 200                                  __func__, i);
 201                         return NULL;
 202                 }
 203
 204 #ifdef CONFIG_EEH
 205                 /* Create the EEH device for the VF */
 206                 edev = eeh_dev_init(pdn);
 207                 BUG_ON(!edev);
 208
 209                 /* FIXME: these should probably be populated by the EEH probe */
 210                 edev->physfn = pdev;
 211                 edev->vf_index = i;
 212 #endif /* CONFIG_EEH */
 213         }
 214         return pci_get_pdn(pdev);
 215 }
 216
 217 void remove_sriov_vf_pdns(struct pci_dev *pdev)
 218 {
 219         struct pci_dn *parent;
 220         struct pci_dn *pdn, *tmp;
 221         int i;
 222
 223         /* Only support IOV PF for now */
 224         if (WARN_ON(!pdev->is_physfn))
 225                 return;
 226
 227         /* Check if VFs have been populated */
 228         pdn = pci_get_pdn(pdev);
 229         if (!pdn || !(pdn->flags & PCI_DN_FLAG_IOV_VF))
 230                 return;
 231
 232         pdn->flags &= ~PCI_DN_FLAG_IOV_VF;
 233         parent = pci_bus_to_pdn(pdev->bus);
 234         if (!parent)
 235                 return;
 236
 237         /*
 238          * We might introduce flag to pci_dn in future
 239          * so that we can release VF's firmware data in
 240          * a batch mode.
 241          */
 242         for (i = 0; i < pci_sriov_get_totalvfs(pdev); i++) {
 243                 struct eeh_dev *edev __maybe_unused;
 244
 245                 list_for_each_entry_safe(pdn, tmp,
 246                         &parent->child_list, list) {
 247                         if (pdn->busno != pci_iov_virtfn_bus(pdev, i) ||
 248                             pdn->devfn != pci_iov_virtfn_devfn(pdev, i))
 249                                 continue;
 250
 251 #ifdef CONFIG_EEH
 252                         /*
 253                          * Release EEH state for this VF. The PCI core
 254                          * has already torn down the pci_dev for this VF, but
 255                          * we're responsible to removing the eeh_dev since it
 256                          * has the same lifetime as the pci_dn that spawned it.
 257                          */
 258                         edev = pdn_to_eeh_dev(pdn);
 259                         if (edev) {
 260                                 /*
 261                                  * We allocate pci_dn's for the totalvfs count,
 262                                  * but only only the vfs that were activated
 263                                  * have a configured PE.
 264                                  */
 265                                 if (edev->pe)
 266                                         eeh_pe_tree_remove(edev);
 267
 268                                 pdn->edev = NULL;
 269                                 kfree(edev);
 270                         }
 271 #endif /* CONFIG_EEH */
 272
 273                         if (!list_empty(&pdn->list))
 274                                 list_del(&pdn->list);
 275
 276                         kfree(pdn);
 277                 }
 278         }
 279 }
 280 #endif /* CONFIG_PCI_IOV */
 281
 282 struct pci_dn *pci_add_device_node_info(struct pci_controller *hose,
 283                                         struct device_node *dn)
 284 {
 285         const __be32 *type = of_get_property(dn, "ibm,pci-config-space-type", NULL);
 286         const __be32 *regs;
 287         struct device_node *parent;
 288         struct pci_dn *pdn;
 289 #ifdef CONFIG_EEH
 290         struct eeh_dev *edev;
 291 #endif
 292
 293         pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
 294         if (pdn == NULL)
 295                 return NULL;
 296         dn->data = pdn;
 297         pdn->phb = hose;
 298         pdn->pe_number = IODA_INVALID_PE;
 299         regs = of_get_property(dn, "reg", NULL);
 300         if (regs) {
 301                 u32 addr = of_read_number(regs, 1);
 302
 303                 /* First register entry is addr (00BBSS00)  */
 304                 pdn->busno = (addr >> 16) & 0xff;
 305                 pdn->devfn = (addr >> 8) & 0xff;
 306         }
 307
 308         /* vendor/device IDs and class code */
 309         regs = of_get_property(dn, "vendor-id", NULL);
 310         pdn->vendor_id = regs ? of_read_number(regs, 1) : 0;
 311         regs = of_get_property(dn, "device-id", NULL);
 312         pdn->device_id = regs ? of_read_number(regs, 1) : 0;
 313         regs = of_get_property(dn, "class-code", NULL);
 314         pdn->class_code = regs ? of_read_number(regs, 1) : 0;
 315
 316         /* Extended config space */
 317         pdn->pci_ext_config_space = (type && of_read_number(type, 1) == 1);
 318
 319         /* Create EEH device */
 320 #ifdef CONFIG_EEH
 321         edev = eeh_dev_init(pdn);
 322         if (!edev) {
 323                 kfree(pdn);
 324                 return NULL;
 325         }
 326 #endif
 327
 328         /* Attach to parent node */
 329         INIT_LIST_HEAD(&pdn->child_list);
 330         INIT_LIST_HEAD(&pdn->list);
 331         parent = of_get_parent(dn);
 332         pdn->parent = parent ? PCI_DN(parent) : NULL;
 333         if (pdn->parent)
 334                 list_add_tail(&pdn->list, &pdn->parent->child_list);
 335
 336         return pdn;
 337 }
 338 EXPORT_SYMBOL_GPL(pci_add_device_node_info);
 339
 340 void pci_remove_device_node_info(struct device_node *dn)
 341 {
 342         struct pci_dn *pdn = dn ? PCI_DN(dn) : NULL;
 343         struct device_node *parent;
 344         struct pci_dev *pdev;
 345 #ifdef CONFIG_EEH
 346         struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
 347
 348         if (edev)
 349                 edev->pdn = NULL;
 350 #endif
 351
 352         if (!pdn)
 353                 return;
 354
 355         WARN_ON(!list_empty(&pdn->child_list));
 356         list_del(&pdn->list);
 357
 358         /* Drop the parent pci_dn's ref to our backing dt node */
 359         parent = of_get_parent(dn);
 360         if (parent)
 361                 of_node_put(parent);
 362
 363         /*
 364          * At this point we *might* still have a pci_dev that was
 365          * instantiated from this pci_dn. So defer free()ing it until
 366          * the pci_dev's release function is called.
 367          */
 368         pdev = pci_get_domain_bus_and_slot(pdn->phb->global_number,
 369                         pdn->busno, pdn->devfn);
 370         if (pdev) {
 371                 /* NB: pdev has a ref to dn */
 372                 pci_dbg(pdev, "marked pdn (from %pOF) as dead\n", dn);
 373                 pdn->flags |= PCI_DN_FLAG_DEAD;
 374         } else {
 375                 dn->data = NULL;
 376                 kfree(pdn);
 377         }
 378
 379         pci_dev_put(pdev);
 380 }
 381 EXPORT_SYMBOL_GPL(pci_remove_device_node_info);
 382
 383 /*
 384  * Traverse a device tree stopping each PCI device in the tree.
 385  * This is done depth first.  As each node is processed, a "pre"
 386  * function is called and the children are processed recursively.
 387  *
 388  * The "pre" func returns a value.  If non-zero is returned from
 389  * the "pre" func, the traversal stops and this value is returned.
 390  * This return value is useful when using traverse as a method of
 391  * finding a device.
 392  *
 393  * NOTE: we do not run the func for devices that do not appear to
 394  * be PCI except for the start node which we assume (this is good
 395  * because the start node is often a phb which may be missing PCI
 396  * properties).
 397  * We use the class-code as an indicator. If we run into
 398  * one of these nodes we also assume its siblings are non-pci for
 399  * performance.
 400  */
 401 void *pci_traverse_device_nodes(struct device_node *start,
 402                                 void *(*fn)(struct device_node *, void *),
 403                                 void *data)
 404 {
 405         struct device_node *dn, *nextdn;
 406         void *ret;
 407
 408         /* We started with a phb, iterate all childs */
 409         for (dn = start->child; dn; dn = nextdn) {
 410                 const __be32 *classp;
 411                 u32 class = 0;
 412
 413                 nextdn = NULL;
 414                 classp = of_get_property(dn, "class-code", NULL);
 415                 if (classp)
 416                         class = of_read_number(classp, 1);
 417
 418                 if (fn) {
 419                         ret = fn(dn, data);
 420                         if (ret)
 421                                 return ret;
 422                 }
 423
 424                 /* If we are a PCI bridge, go down */
 425                 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
 426                                   (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
 427                         /* Depth first...do children */
 428                         nextdn = dn->child;
 429                 else if (dn->sibling)
 430                         /* ok, try next sibling instead. */
 431                         nextdn = dn->sibling;
 432                 if (!nextdn) {
 433                         /* Walk up to next valid sibling. */
 434                         do {
 435                                 dn = dn->parent;
 436                                 if (dn == start)
 437                                         return NULL;
 438                         } while (dn->sibling == NULL);
 439                         nextdn = dn->sibling;
 440                 }
 441         }
 442         return NULL;
 443 }
 444 EXPORT_SYMBOL_GPL(pci_traverse_device_nodes);
 445
 446 static struct pci_dn *pci_dn_next_one(struct pci_dn *root,
 447                                       struct pci_dn *pdn)
 448 {
 449         struct list_head *next = pdn->child_list.next;
 450
 451         if (next != &pdn->child_list)
 452                 return list_entry(next, struct pci_dn, list);
 453
 454         while (1) {
 455                 if (pdn == root)
 456                         return NULL;
 457
 458                 next = pdn->list.next;
 459                 if (next != &pdn->parent->child_list)
 460                         break;
 461
 462                 pdn = pdn->parent;
 463         }
 464
 465         return list_entry(next, struct pci_dn, list);
 466 }
 467
 468 void *traverse_pci_dn(struct pci_dn *root,
 469                       void *(*fn)(struct pci_dn *, void *),
 470                       void *data)
 471 {
 472         struct pci_dn *pdn = root;
 473         void *ret;
 474
 475         /* Only scan the child nodes */
 476         for (pdn = pci_dn_next_one(root, pdn); pdn;
 477              pdn = pci_dn_next_one(root, pdn)) {
 478                 ret = fn(pdn, data);
 479                 if (ret)
 480                         return ret;
 481         }
 482
 483         return NULL;
 484 }
 485
 486 static void *add_pdn(struct device_node *dn, void *data)
 487 {
 488         struct pci_controller *hose = data;
 489         struct pci_dn *pdn;
 490
 491         pdn = pci_add_device_node_info(hose, dn);
 492         if (!pdn)
 493                 return ERR_PTR(-ENOMEM);
 494
 495         return NULL;
 496 }
 497
 498 /**
 499  * pci_devs_phb_init_dynamic - setup pci devices under this PHB
 500  * phb: pci-to-host bridge (top-level bridge connecting to cpu)
 501  *
 502  * This routine is called both during boot, (before the memory
 503  * subsystem is set up, before kmalloc is valid) and during the
 504  * dynamic lpar operation of adding a PHB to a running system.
 505  */
 506 void pci_devs_phb_init_dynamic(struct pci_controller *phb)
 507 {
 508         struct device_node *dn = phb->dn;
 509         struct pci_dn *pdn;
 510
 511         /* PHB nodes themselves must not match */
 512         pdn = pci_add_device_node_info(phb, dn);
 513         if (pdn) {
 514                 pdn->devfn = pdn->busno = -1;
 515                 pdn->vendor_id = pdn->device_id = pdn->class_code = 0;
 516                 pdn->phb = phb;
 517                 phb->pci_data = pdn;
 518         }
 519
 520         /* Update dn->phb ptrs for new phb and children devices */
 521         pci_traverse_device_nodes(dn, add_pdn, phb);
 522 }
 523
 524 /**
 525  * pci_devs_phb_init - Initialize phbs and pci devs under them.
 526  *
 527  * This routine walks over all phb's (pci-host bridges) on the
 528  * system, and sets up assorted pci-related structures
 529  * (including pci info in the device node structs) for each
 530  * pci device found underneath.  This routine runs once,
 531  * early in the boot sequence.
 532  */
 533 static int __init pci_devs_phb_init(void)
 534 {
 535         struct pci_controller *phb, *tmp;
 536
 537         /* This must be done first so the device nodes have valid pci info! */
 538         list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
 539                 pci_devs_phb_init_dynamic(phb);
 540
 541         return 0;
 542 }
 543
 544 core_initcall(pci_devs_phb_init);
 545
 546 static void pci_dev_pdn_setup(struct pci_dev *pdev)
 547 {
 548         struct pci_dn *pdn;
 549
 550         if (pdev->dev.archdata.pci_data)
 551                 return;
 552
 553         /* Setup the fast path */
 554         pdn = pci_get_pdn(pdev);
 555         pdev->dev.archdata.pci_data = pdn;
 556 }
 557 DECLARE_PCI_FIXUP_EARLY(PCI_ANY_ID, PCI_ANY_ID, pci_dev_pdn_setup);