drivers/pci/hotplug/rpadlpar_core.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Interface for Dynamic Logical Partitioning of I/O Slots on
   4  * RPA-compliant PPC64 platform.
   5  *
   6  * John Rose <johnrose@austin.ibm.com>
   7  * Linda Xie <lxie@us.ibm.com>
   8  *
   9  * October 2003
  10  *
  11  * Copyright (C) 2003 IBM.
  12  */
  13
  14 #undef DEBUG
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/pci.h>
  19 #include <linux/string.h>
  20 #include <linux/vmalloc.h>
  21
  22 #include <asm/pci-bridge.h>
  23 #include <linux/mutex.h>
  24 #include <asm/rtas.h>
  25 #include <asm/vio.h>
  26 #include <linux/firmware.h>
  27
  28 #include "../pci.h"
  29 #include "rpaphp.h"
  30 #include "rpadlpar.h"
  31
  32 static DEFINE_MUTEX(rpadlpar_mutex);
  33
  34 #define DLPAR_MODULE_NAME "rpadlpar_io"
  35
  36 #define NODE_TYPE_VIO  1
  37 #define NODE_TYPE_SLOT 2
  38 #define NODE_TYPE_PHB  3
  39
  40 static struct device_node *find_vio_slot_node(char *drc_name)
  41 {
  42         struct device_node *parent = of_find_node_by_name(NULL, "vdevice");
  43         struct device_node *dn = NULL;
  44         int rc;
  45
  46         if (!parent)
  47                 return NULL;
  48
  49         while ((dn = of_get_next_child(parent, dn))) {
  50                 rc = rpaphp_check_drc_props(dn, drc_name, NULL);
  51                 if (rc == 0)
  52                         break;
  53         }
  54
  55         return dn;
  56 }
  57
  58 /* Find dlpar-capable pci node that contains the specified name and type */
  59 static struct device_node *find_php_slot_pci_node(char *drc_name,
  60                                                   char *drc_type)
  61 {
  62         struct device_node *np = NULL;
  63         int rc;
  64
  65         while ((np = of_find_node_by_name(np, "pci"))) {
  66                 rc = rpaphp_check_drc_props(np, drc_name, drc_type);
  67                 if (rc == 0)
  68                         break;
  69         }
  70
  71         return np;
  72 }
  73
  74 static struct device_node *find_dlpar_node(char *drc_name, int *node_type)
  75 {
  76         struct device_node *dn;
  77
  78         dn = find_php_slot_pci_node(drc_name, "SLOT");
  79         if (dn) {
  80                 *node_type = NODE_TYPE_SLOT;
  81                 return dn;
  82         }
  83
  84         dn = find_php_slot_pci_node(drc_name, "PHB");
  85         if (dn) {
  86                 *node_type = NODE_TYPE_PHB;
  87                 return dn;
  88         }
  89
  90         dn = find_vio_slot_node(drc_name);
  91         if (dn) {
  92                 *node_type = NODE_TYPE_VIO;
  93                 return dn;
  94         }
  95
  96         return NULL;
  97 }
  98
  99 /**
 100  * find_php_slot - return hotplug slot structure for device node
 101  * @dn: target &device_node
 102  *
 103  * This routine will return the hotplug slot structure
 104  * for a given device node. Note that built-in PCI slots
 105  * may be dlpar-able, but not hot-pluggable, so this routine
 106  * will return NULL for built-in PCI slots.
 107  */
 108 static struct slot *find_php_slot(struct device_node *dn)
 109 {
 110         struct slot *slot, *next;
 111
 112         list_for_each_entry_safe(slot, next, &rpaphp_slot_head,
 113                                  rpaphp_slot_list) {
 114                 if (slot->dn == dn)
 115                         return slot;
 116         }
 117
 118         return NULL;
 119 }
 120
 121 static struct pci_dev *dlpar_find_new_dev(struct pci_bus *parent,
 122                                         struct device_node *dev_dn)
 123 {
 124         struct pci_dev *tmp = NULL;
 125         struct device_node *child_dn;
 126
 127         list_for_each_entry(tmp, &parent->devices, bus_list) {
 128                 child_dn = pci_device_to_OF_node(tmp);
 129                 if (child_dn == dev_dn)
 130                         return tmp;
 131         }
 132         return NULL;
 133 }
 134
 135 static void dlpar_pci_add_bus(struct device_node *dn)
 136 {
 137         struct pci_dn *pdn = PCI_DN(dn);
 138         struct pci_controller *phb = pdn->phb;
 139         struct pci_dev *dev = NULL;
 140
 141         eeh_add_device_tree_early(pdn);
 142
 143         /* Add EADS device to PHB bus, adding new entry to bus->devices */
 144         dev = of_create_pci_dev(dn, phb->bus, pdn->devfn);
 145         if (!dev) {
 146                 printk(KERN_ERR "%s: failed to create pci dev for %pOF\n",
 147                                 __func__, dn);
 148                 return;
 149         }
 150
 151         /* Scan below the new bridge */
 152         if (pci_is_bridge(dev))
 153                 of_scan_pci_bridge(dev);
 154
 155         /* Map IO space for child bus, which may or may not succeed */
 156         pcibios_map_io_space(dev->subordinate);
 157
 158         /* Finish adding it : resource allocation, adding devices, etc...
 159          * Note that we need to perform the finish pass on the -parent-
 160          * bus of the EADS bridge so the bridge device itself gets
 161          * properly added
 162          */
 163         pcibios_finish_adding_to_bus(phb->bus);
 164 }
 165
 166 static int dlpar_add_pci_slot(char *drc_name, struct device_node *dn)
 167 {
 168         struct pci_dev *dev;
 169         struct pci_controller *phb;
 170
 171         if (pci_find_bus_by_node(dn))
 172                 return -EINVAL;
 173
 174         /* Add pci bus */
 175         dlpar_pci_add_bus(dn);
 176
 177         /* Confirm new bridge dev was created */
 178         phb = PCI_DN(dn)->phb;
 179         dev = dlpar_find_new_dev(phb->bus, dn);
 180
 181         if (!dev) {
 182                 printk(KERN_ERR "%s: unable to add bus %s\n", __func__,
 183                         drc_name);
 184                 return -EIO;
 185         }
 186
 187         if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
 188                 printk(KERN_ERR "%s: unexpected header type %d, unable to add bus %s\n",
 189                         __func__, dev->hdr_type, drc_name);
 190                 return -EIO;
 191         }
 192
 193         /* Add hotplug slot */
 194         if (rpaphp_add_slot(dn)) {
 195                 printk(KERN_ERR "%s: unable to add hotplug slot %s\n",
 196                         __func__, drc_name);
 197                 return -EIO;
 198         }
 199         return 0;
 200 }
 201
 202 static int dlpar_remove_phb(char *drc_name, struct device_node *dn)
 203 {
 204         struct slot *slot;
 205         struct pci_dn *pdn;
 206         int rc = 0;
 207
 208         if (!pci_find_bus_by_node(dn))
 209                 return -EINVAL;
 210
 211         /* If pci slot is hotpluggable, use hotplug to remove it */
 212         slot = find_php_slot(dn);
 213         if (slot && rpaphp_deregister_slot(slot)) {
 214                 printk(KERN_ERR "%s: unable to remove hotplug slot %s\n",
 215                        __func__, drc_name);
 216                 return -EIO;
 217         }
 218
 219         pdn = dn->data;
 220         BUG_ON(!pdn || !pdn->phb);
 221         rc = remove_phb_dynamic(pdn->phb);
 222         if (rc < 0)
 223                 return rc;
 224
 225         pdn->phb = NULL;
 226
 227         return 0;
 228 }
 229
 230 static int dlpar_add_phb(char *drc_name, struct device_node *dn)
 231 {
 232         struct pci_controller *phb;
 233
 234         if (PCI_DN(dn) && PCI_DN(dn)->phb) {
 235                 /* PHB already exists */
 236                 return -EINVAL;
 237         }
 238
 239         phb = init_phb_dynamic(dn);
 240         if (!phb)
 241                 return -EIO;
 242
 243         if (rpaphp_add_slot(dn)) {
 244                 printk(KERN_ERR "%s: unable to add hotplug slot %s\n",
 245                         __func__, drc_name);
 246                 return -EIO;
 247         }
 248         return 0;
 249 }
 250
 251 static int dlpar_add_vio_slot(char *drc_name, struct device_node *dn)
 252 {
 253         struct vio_dev *vio_dev;
 254
 255         vio_dev = vio_find_node(dn);
 256         if (vio_dev) {
 257                 put_device(&vio_dev->dev);
 258                 return -EINVAL;
 259         }
 260
 261         if (!vio_register_device_node(dn)) {
 262                 printk(KERN_ERR
 263                         "%s: failed to register vio node %s\n",
 264                         __func__, drc_name);
 265                 return -EIO;
 266         }
 267         return 0;
 268 }
 269
 270 /**
 271  * dlpar_add_slot - DLPAR add an I/O Slot
 272  * @drc_name: drc-name of newly added slot
 273  *
 274  * Make the hotplug module and the kernel aware of a newly added I/O Slot.
 275  * Return Codes:
 276  * 0                    Success
 277  * -ENODEV              Not a valid drc_name
 278  * -EINVAL              Slot already added
 279  * -ERESTARTSYS         Signalled before obtaining lock
 280  * -EIO                 Internal PCI Error
 281  */
 282 int dlpar_add_slot(char *drc_name)
 283 {
 284         struct device_node *dn = NULL;
 285         int node_type;
 286         int rc = -EIO;
 287
 288         if (mutex_lock_interruptible(&rpadlpar_mutex))
 289                 return -ERESTARTSYS;
 290
 291         /* Find newly added node */
 292         dn = find_dlpar_node(drc_name, &node_type);
 293         if (!dn) {
 294                 rc = -ENODEV;
 295                 goto exit;
 296         }
 297
 298         switch (node_type) {
 299                 case NODE_TYPE_VIO:
 300                         rc = dlpar_add_vio_slot(drc_name, dn);
 301                         break;
 302                 case NODE_TYPE_SLOT:
 303                         rc = dlpar_add_pci_slot(drc_name, dn);
 304                         break;
 305                 case NODE_TYPE_PHB:
 306                         rc = dlpar_add_phb(drc_name, dn);
 307                         break;
 308         }
 309
 310         printk(KERN_INFO "%s: slot %s added\n", DLPAR_MODULE_NAME, drc_name);
 311 exit:
 312         mutex_unlock(&rpadlpar_mutex);
 313         return rc;
 314 }
 315
 316 /**
 317  * dlpar_remove_vio_slot - DLPAR remove a virtual I/O Slot
 318  * @drc_name: drc-name of newly added slot
 319  * @dn: &device_node
 320  *
 321  * Remove the kernel and hotplug representations of an I/O Slot.
 322  * Return Codes:
 323  * 0                    Success
 324  * -EINVAL              Vio dev doesn't exist
 325  */
 326 static int dlpar_remove_vio_slot(char *drc_name, struct device_node *dn)
 327 {
 328         struct vio_dev *vio_dev;
 329
 330         vio_dev = vio_find_node(dn);
 331         if (!vio_dev)
 332                 return -EINVAL;
 333
 334         vio_unregister_device(vio_dev);
 335
 336         put_device(&vio_dev->dev);
 337
 338         return 0;
 339 }
 340
 341 /**
 342  * dlpar_remove_pci_slot - DLPAR remove a PCI I/O Slot
 343  * @drc_name: drc-name of newly added slot
 344  * @dn: &device_node
 345  *
 346  * Remove the kernel and hotplug representations of a PCI I/O Slot.
 347  * Return Codes:
 348  * 0                    Success
 349  * -ENODEV              Not a valid drc_name
 350  * -EIO                 Internal PCI Error
 351  */
 352 int dlpar_remove_pci_slot(char *drc_name, struct device_node *dn)
 353 {
 354         struct pci_bus *bus;
 355         struct slot *slot;
 356         int ret = 0;
 357
 358         pci_lock_rescan_remove();
 359
 360         bus = pci_find_bus_by_node(dn);
 361         if (!bus) {
 362                 ret = -EINVAL;
 363                 goto out;
 364         }
 365
 366         pr_debug("PCI: Removing PCI slot below EADS bridge %s\n",
 367                  bus->self ? pci_name(bus->self) : "<!PHB!>");
 368
 369         slot = find_php_slot(dn);
 370         if (slot) {
 371                 pr_debug("PCI: Removing hotplug slot for %04x:%02x...\n",
 372                          pci_domain_nr(bus), bus->number);
 373
 374                 if (rpaphp_deregister_slot(slot)) {
 375                         printk(KERN_ERR
 376                                 "%s: unable to remove hotplug slot %s\n",
 377                                 __func__, drc_name);
 378                         ret = -EIO;
 379                         goto out;
 380                 }
 381         }
 382
 383         /* Remove all devices below slot */
 384         pci_hp_remove_devices(bus);
 385
 386         /* Unmap PCI IO space */
 387         if (pcibios_unmap_io_space(bus)) {
 388                 printk(KERN_ERR "%s: failed to unmap bus range\n",
 389                         __func__);
 390                 ret = -ERANGE;
 391                 goto out;
 392         }
 393
 394         /* Remove the EADS bridge device itself */
 395         BUG_ON(!bus->self);
 396         pr_debug("PCI: Now removing bridge device %s\n", pci_name(bus->self));
 397         pci_stop_and_remove_bus_device(bus->self);
 398
 399  out:
 400         pci_unlock_rescan_remove();
 401         return ret;
 402 }
 403
 404 /**
 405  * dlpar_remove_slot - DLPAR remove an I/O Slot
 406  * @drc_name: drc-name of newly added slot
 407  *
 408  * Remove the kernel and hotplug representations of an I/O Slot.
 409  * Return Codes:
 410  * 0                    Success
 411  * -ENODEV              Not a valid drc_name
 412  * -EINVAL              Slot already removed
 413  * -ERESTARTSYS         Signalled before obtaining lock
 414  * -EIO                 Internal Error
 415  */
 416 int dlpar_remove_slot(char *drc_name)
 417 {
 418         struct device_node *dn;
 419         int node_type;
 420         int rc = 0;
 421
 422         if (mutex_lock_interruptible(&rpadlpar_mutex))
 423                 return -ERESTARTSYS;
 424
 425         dn = find_dlpar_node(drc_name, &node_type);
 426         if (!dn) {
 427                 rc = -ENODEV;
 428                 goto exit;
 429         }
 430
 431         switch (node_type) {
 432                 case NODE_TYPE_VIO:
 433                         rc = dlpar_remove_vio_slot(drc_name, dn);
 434                         break;
 435                 case NODE_TYPE_PHB:
 436                         rc = dlpar_remove_phb(drc_name, dn);
 437                         break;
 438                 case NODE_TYPE_SLOT:
 439                         rc = dlpar_remove_pci_slot(drc_name, dn);
 440                         break;
 441         }
 442         vm_unmap_aliases();
 443
 444         printk(KERN_INFO "%s: slot %s removed\n", DLPAR_MODULE_NAME, drc_name);
 445 exit:
 446         mutex_unlock(&rpadlpar_mutex);
 447         return rc;
 448 }
 449
 450 static inline int is_dlpar_capable(void)
 451 {
 452         int rc = rtas_token("ibm,configure-connector");
 453
 454         return (int) (rc != RTAS_UNKNOWN_SERVICE);
 455 }
 456
 457 int __init rpadlpar_io_init(void)
 458 {
 459
 460         if (!is_dlpar_capable()) {
 461                 printk(KERN_WARNING "%s: partition not DLPAR capable\n",
 462                         __func__);
 463                 return -EPERM;
 464         }
 465
 466         return dlpar_sysfs_init();
 467 }
 468
 469 void rpadlpar_io_exit(void)
 470 {
 471         dlpar_sysfs_exit();
 472         return;
 473 }
 474
 475 module_init(rpadlpar_io_init);
 476 module_exit(rpadlpar_io_exit);
 477 MODULE_LICENSE("GPL");