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_PCI_IOV
 128 static struct pci_dn *add_one_sriov_vf_pdn(struct pci_dn *parent,
 129                                            int vf_index,
 130                                            int busno, int devfn)
 131 {
 132         struct pci_dn *pdn;
 133
 134         /* Except PHB, we always have the parent */
 135         if (!parent)
 136                 return NULL;
 137
 138         pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
 139         if (!pdn)
 140                 return NULL;
 141
 142         pdn->phb = parent->phb;
 143         pdn->parent = parent;
 144         pdn->busno = busno;
 145         pdn->devfn = devfn;
 146         pdn->vf_index = vf_index;
 147         pdn->pe_number = IODA_INVALID_PE;
 148         INIT_LIST_HEAD(&pdn->child_list);
 149         INIT_LIST_HEAD(&pdn->list);
 150         list_add_tail(&pdn->list, &parent->child_list);
 151
 152         return pdn;
 153 }
 154
 155 struct pci_dn *add_sriov_vf_pdns(struct pci_dev *pdev)
 156 {
 157         struct pci_dn *parent, *pdn;
 158         int i;
 159
 160         /* Only support IOV for now */
 161         if (WARN_ON(!pdev->is_physfn))
 162                 return NULL;
 163
 164         /* Check if VFs have been populated */
 165         pdn = pci_get_pdn(pdev);
 166         if (!pdn || (pdn->flags & PCI_DN_FLAG_IOV_VF))
 167                 return NULL;
 168
 169         pdn->flags |= PCI_DN_FLAG_IOV_VF;
 170         parent = pci_bus_to_pdn(pdev->bus);
 171         if (!parent)
 172                 return NULL;
 173
 174         for (i = 0; i < pci_sriov_get_totalvfs(pdev); i++) {
 175                 struct eeh_dev *edev __maybe_unused;
 176
 177                 pdn = add_one_sriov_vf_pdn(parent, i,
 178                                            pci_iov_virtfn_bus(pdev, i),
 179                                            pci_iov_virtfn_devfn(pdev, i));
 180                 if (!pdn) {
 181                         dev_warn(&pdev->dev, "%s: Cannot create firmware data for VF#%d\n",
 182                                  __func__, i);
 183                         return NULL;
 184                 }
 185
 186 #ifdef CONFIG_EEH
 187                 /* Create the EEH device for the VF */
 188                 edev = eeh_dev_init(pdn);
 189                 BUG_ON(!edev);
 190                 edev->physfn = pdev;
 191 #endif /* CONFIG_EEH */
 192         }
 193         return pci_get_pdn(pdev);
 194 }
 195
 196 void remove_sriov_vf_pdns(struct pci_dev *pdev)
 197 {
 198         struct pci_dn *parent;
 199         struct pci_dn *pdn, *tmp;
 200         int i;
 201
 202         /* Only support IOV PF for now */
 203         if (WARN_ON(!pdev->is_physfn))
 204                 return;
 205
 206         /* Check if VFs have been populated */
 207         pdn = pci_get_pdn(pdev);
 208         if (!pdn || !(pdn->flags & PCI_DN_FLAG_IOV_VF))
 209                 return;
 210
 211         pdn->flags &= ~PCI_DN_FLAG_IOV_VF;
 212         parent = pci_bus_to_pdn(pdev->bus);
 213         if (!parent)
 214                 return;
 215
 216         /*
 217          * We might introduce flag to pci_dn in future
 218          * so that we can release VF's firmware data in
 219          * a batch mode.
 220          */
 221         for (i = 0; i < pci_sriov_get_totalvfs(pdev); i++) {
 222                 struct eeh_dev *edev __maybe_unused;
 223
 224                 list_for_each_entry_safe(pdn, tmp,
 225                         &parent->child_list, list) {
 226                         if (pdn->busno != pci_iov_virtfn_bus(pdev, i) ||
 227                             pdn->devfn != pci_iov_virtfn_devfn(pdev, i))
 228                                 continue;
 229
 230 #ifdef CONFIG_EEH
 231                         /*
 232                          * Release EEH state for this VF. The PCI core
 233                          * has already torn down the pci_dev for this VF, but
 234                          * we're responsible to removing the eeh_dev since it
 235                          * has the same lifetime as the pci_dn that spawned it.
 236                          */
 237                         edev = pdn_to_eeh_dev(pdn);
 238                         if (edev) {
 239                                 /*
 240                                  * We allocate pci_dn's for the totalvfs count,
 241                                  * but only only the vfs that were activated
 242                                  * have a configured PE.
 243                                  */
 244                                 if (edev->pe)
 245                                         eeh_rmv_from_parent_pe(edev);
 246
 247                                 pdn->edev = NULL;
 248                                 kfree(edev);
 249                         }
 250 #endif /* CONFIG_EEH */
 251
 252                         if (!list_empty(&pdn->list))
 253                                 list_del(&pdn->list);
 254
 255                         kfree(pdn);
 256                 }
 257         }
 258 }
 259 #endif /* CONFIG_PCI_IOV */
 260
 261 struct pci_dn *pci_add_device_node_info(struct pci_controller *hose,
 262                                         struct device_node *dn)
 263 {
 264         const __be32 *type = of_get_property(dn, "ibm,pci-config-space-type", NULL);
 265         const __be32 *regs;
 266         struct device_node *parent;
 267         struct pci_dn *pdn;
 268 #ifdef CONFIG_EEH
 269         struct eeh_dev *edev;
 270 #endif
 271
 272         pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
 273         if (pdn == NULL)
 274                 return NULL;
 275         dn->data = pdn;
 276         pdn->phb = hose;
 277         pdn->pe_number = IODA_INVALID_PE;
 278         regs = of_get_property(dn, "reg", NULL);
 279         if (regs) {
 280                 u32 addr = of_read_number(regs, 1);
 281
 282                 /* First register entry is addr (00BBSS00)  */
 283                 pdn->busno = (addr >> 16) & 0xff;
 284                 pdn->devfn = (addr >> 8) & 0xff;
 285         }
 286
 287         /* vendor/device IDs and class code */
 288         regs = of_get_property(dn, "vendor-id", NULL);
 289         pdn->vendor_id = regs ? of_read_number(regs, 1) : 0;
 290         regs = of_get_property(dn, "device-id", NULL);
 291         pdn->device_id = regs ? of_read_number(regs, 1) : 0;
 292         regs = of_get_property(dn, "class-code", NULL);
 293         pdn->class_code = regs ? of_read_number(regs, 1) : 0;
 294
 295         /* Extended config space */
 296         pdn->pci_ext_config_space = (type && of_read_number(type, 1) == 1);
 297
 298         /* Create EEH device */
 299 #ifdef CONFIG_EEH
 300         edev = eeh_dev_init(pdn);
 301         if (!edev) {
 302                 kfree(pdn);
 303                 return NULL;
 304         }
 305 #endif
 306
 307         /* Attach to parent node */
 308         INIT_LIST_HEAD(&pdn->child_list);
 309         INIT_LIST_HEAD(&pdn->list);
 310         parent = of_get_parent(dn);
 311         pdn->parent = parent ? PCI_DN(parent) : NULL;
 312         if (pdn->parent)
 313                 list_add_tail(&pdn->list, &pdn->parent->child_list);
 314
 315         return pdn;
 316 }
 317 EXPORT_SYMBOL_GPL(pci_add_device_node_info);
 318
 319 void pci_remove_device_node_info(struct device_node *dn)
 320 {
 321         struct pci_dn *pdn = dn ? PCI_DN(dn) : NULL;
 322         struct device_node *parent;
 323         struct pci_dev *pdev;
 324 #ifdef CONFIG_EEH
 325         struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
 326
 327         if (edev)
 328                 edev->pdn = NULL;
 329 #endif
 330
 331         if (!pdn)
 332                 return;
 333
 334         WARN_ON(!list_empty(&pdn->child_list));
 335         list_del(&pdn->list);
 336
 337         /* Drop the parent pci_dn's ref to our backing dt node */
 338         parent = of_get_parent(dn);
 339         if (parent)
 340                 of_node_put(parent);
 341
 342         /*
 343          * At this point we *might* still have a pci_dev that was
 344          * instantiated from this pci_dn. So defer free()ing it until
 345          * the pci_dev's release function is called.
 346          */
 347         pdev = pci_get_domain_bus_and_slot(pdn->phb->global_number,
 348                         pdn->busno, pdn->devfn);
 349         if (pdev) {
 350                 /* NB: pdev has a ref to dn */
 351                 pci_dbg(pdev, "marked pdn (from %pOF) as dead\n", dn);
 352                 pdn->flags |= PCI_DN_FLAG_DEAD;
 353         } else {
 354                 dn->data = NULL;
 355                 kfree(pdn);
 356         }
 357
 358         pci_dev_put(pdev);
 359 }
 360 EXPORT_SYMBOL_GPL(pci_remove_device_node_info);
 361
 362 /*
 363  * Traverse a device tree stopping each PCI device in the tree.
 364  * This is done depth first.  As each node is processed, a "pre"
 365  * function is called and the children are processed recursively.
 366  *
 367  * The "pre" func returns a value.  If non-zero is returned from
 368  * the "pre" func, the traversal stops and this value is returned.
 369  * This return value is useful when using traverse as a method of
 370  * finding a device.
 371  *
 372  * NOTE: we do not run the func for devices that do not appear to
 373  * be PCI except for the start node which we assume (this is good
 374  * because the start node is often a phb which may be missing PCI
 375  * properties).
 376  * We use the class-code as an indicator. If we run into
 377  * one of these nodes we also assume its siblings are non-pci for
 378  * performance.
 379  */
 380 void *pci_traverse_device_nodes(struct device_node *start,
 381                                 void *(*fn)(struct device_node *, void *),
 382                                 void *data)
 383 {
 384         struct device_node *dn, *nextdn;
 385         void *ret;
 386
 387         /* We started with a phb, iterate all childs */
 388         for (dn = start->child; dn; dn = nextdn) {
 389                 const __be32 *classp;
 390                 u32 class = 0;
 391
 392                 nextdn = NULL;
 393                 classp = of_get_property(dn, "class-code", NULL);
 394                 if (classp)
 395                         class = of_read_number(classp, 1);
 396
 397                 if (fn) {
 398                         ret = fn(dn, data);
 399                         if (ret)
 400                                 return ret;
 401                 }
 402
 403                 /* If we are a PCI bridge, go down */
 404                 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
 405                                   (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
 406                         /* Depth first...do children */
 407                         nextdn = dn->child;
 408                 else if (dn->sibling)
 409                         /* ok, try next sibling instead. */
 410                         nextdn = dn->sibling;
 411                 if (!nextdn) {
 412                         /* Walk up to next valid sibling. */
 413                         do {
 414                                 dn = dn->parent;
 415                                 if (dn == start)
 416                                         return NULL;
 417                         } while (dn->sibling == NULL);
 418                         nextdn = dn->sibling;
 419                 }
 420         }
 421         return NULL;
 422 }
 423 EXPORT_SYMBOL_GPL(pci_traverse_device_nodes);
 424
 425 static struct pci_dn *pci_dn_next_one(struct pci_dn *root,
 426                                       struct pci_dn *pdn)
 427 {
 428         struct list_head *next = pdn->child_list.next;
 429
 430         if (next != &pdn->child_list)
 431                 return list_entry(next, struct pci_dn, list);
 432
 433         while (1) {
 434                 if (pdn == root)
 435                         return NULL;
 436
 437                 next = pdn->list.next;
 438                 if (next != &pdn->parent->child_list)
 439                         break;
 440
 441                 pdn = pdn->parent;
 442         }
 443
 444         return list_entry(next, struct pci_dn, list);
 445 }
 446
 447 void *traverse_pci_dn(struct pci_dn *root,
 448                       void *(*fn)(struct pci_dn *, void *),
 449                       void *data)
 450 {
 451         struct pci_dn *pdn = root;
 452         void *ret;
 453
 454         /* Only scan the child nodes */
 455         for (pdn = pci_dn_next_one(root, pdn); pdn;
 456              pdn = pci_dn_next_one(root, pdn)) {
 457                 ret = fn(pdn, data);
 458                 if (ret)
 459                         return ret;
 460         }
 461
 462         return NULL;
 463 }
 464
 465 static void *add_pdn(struct device_node *dn, void *data)
 466 {
 467         struct pci_controller *hose = data;
 468         struct pci_dn *pdn;
 469
 470         pdn = pci_add_device_node_info(hose, dn);
 471         if (!pdn)
 472                 return ERR_PTR(-ENOMEM);
 473
 474         return NULL;
 475 }
 476
 477 /**
 478  * pci_devs_phb_init_dynamic - setup pci devices under this PHB
 479  * phb: pci-to-host bridge (top-level bridge connecting to cpu)
 480  *
 481  * This routine is called both during boot, (before the memory
 482  * subsystem is set up, before kmalloc is valid) and during the
 483  * dynamic lpar operation of adding a PHB to a running system.
 484  */
 485 void pci_devs_phb_init_dynamic(struct pci_controller *phb)
 486 {
 487         struct device_node *dn = phb->dn;
 488         struct pci_dn *pdn;
 489
 490         /* PHB nodes themselves must not match */
 491         pdn = pci_add_device_node_info(phb, dn);
 492         if (pdn) {
 493                 pdn->devfn = pdn->busno = -1;
 494                 pdn->vendor_id = pdn->device_id = pdn->class_code = 0;
 495                 pdn->phb = phb;
 496                 phb->pci_data = pdn;
 497         }
 498
 499         /* Update dn->phb ptrs for new phb and children devices */
 500         pci_traverse_device_nodes(dn, add_pdn, phb);
 501 }
 502
 503 /**
 504  * pci_devs_phb_init - Initialize phbs and pci devs under them.
 505  *
 506  * This routine walks over all phb's (pci-host bridges) on the
 507  * system, and sets up assorted pci-related structures
 508  * (including pci info in the device node structs) for each
 509  * pci device found underneath.  This routine runs once,
 510  * early in the boot sequence.
 511  */
 512 static int __init pci_devs_phb_init(void)
 513 {
 514         struct pci_controller *phb, *tmp;
 515
 516         /* This must be done first so the device nodes have valid pci info! */
 517         list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
 518                 pci_devs_phb_init_dynamic(phb);
 519
 520         return 0;
 521 }
 522
 523 core_initcall(pci_devs_phb_init);
 524
 525 static void pci_dev_pdn_setup(struct pci_dev *pdev)
 526 {
 527         struct pci_dn *pdn;
 528
 529         if (pdev->dev.archdata.pci_data)
 530                 return;
 531
 532         /* Setup the fast path */
 533         pdn = pci_get_pdn(pdev);
 534         pdev->dev.archdata.pci_data = pdn;
 535 }
 536 DECLARE_PCI_FIXUP_EARLY(PCI_ANY_ID, PCI_ANY_ID, pci_dev_pdn_setup);