1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright IBM Corp. 2020 4 * 5 * Author(s): 6 * Pierre Morel <pmorel@linux.ibm.com> 7 * 8 */ 9 10 #define KMSG_COMPONENT "zpci" 11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 12 13 #include <linux/kernel.h> 14 #include <linux/slab.h> 15 #include <linux/err.h> 16 #include <linux/export.h> 17 #include <linux/delay.h> 18 #include <linux/seq_file.h> 19 #include <linux/jump_label.h> 20 #include <linux/pci.h> 21 #include <linux/printk.h> 22 23 #include <asm/pci_clp.h> 24 #include <asm/pci_dma.h> 25 26 #include "pci_bus.h" 27 #include "pci_iov.h" 28 29 static LIST_HEAD(zbus_list); 30 static DEFINE_MUTEX(zbus_list_lock); 31 static int zpci_nb_devices; 32 33 /* zpci_bus_prepare_device - Prepare a zPCI function for scanning 34 * @zdev: the zPCI function to be prepared 35 * 36 * The PCI resources for the function are set up and added to its zbus and the 37 * function is enabled. The function must be added to a zbus which must have 38 * a PCI bus created. If an error occurs the zPCI function is not enabled. 39 * 40 * Return: 0 on success, an error code otherwise 41 */ 42 static int zpci_bus_prepare_device(struct zpci_dev *zdev) 43 { 44 struct resource_entry *window, *n; 45 struct resource *res; 46 int rc; 47 48 if (!zdev_enabled(zdev)) { 49 rc = zpci_enable_device(zdev); 50 if (rc) 51 return rc; 52 rc = zpci_dma_init_device(zdev); 53 if (rc) { 54 zpci_disable_device(zdev); 55 return rc; 56 } 57 } 58 59 if (!zdev->has_resources) { 60 zpci_setup_bus_resources(zdev, &zdev->zbus->resources); 61 resource_list_for_each_entry_safe(window, n, &zdev->zbus->resources) { 62 res = window->res; 63 pci_bus_add_resource(zdev->zbus->bus, res, 0); 64 } 65 } 66 67 return 0; 68 } 69 70 /* zpci_bus_scan_device - Scan a single device adding it to the PCI core 71 * @zdev: the zdev to be scanned 72 * 73 * Scans the PCI function making it available to the common PCI code. 74 * 75 * Return: 0 on success, an error value otherwise 76 */ 77 int zpci_bus_scan_device(struct zpci_dev *zdev) 78 { 79 struct pci_dev *pdev; 80 int rc; 81 82 rc = zpci_bus_prepare_device(zdev); 83 if (rc) 84 return rc; 85 86 pdev = pci_scan_single_device(zdev->zbus->bus, zdev->devfn); 87 if (!pdev) 88 return -ENODEV; 89 90 pci_bus_add_device(pdev); 91 pci_lock_rescan_remove(); 92 pci_bus_add_devices(zdev->zbus->bus); 93 pci_unlock_rescan_remove(); 94 95 return 0; 96 } 97 98 /* zpci_bus_remove_device - Removes the given zdev from the PCI core 99 * @zdev: the zdev to be removed from the PCI core 100 * @set_error: if true the device's error state is set to permanent failure 101 * 102 * Sets a zPCI device to a configured but offline state; the zPCI 103 * device is still accessible through its hotplug slot and the zPCI 104 * API but is removed from the common code PCI bus, making it 105 * no longer available to drivers. 106 */ 107 void zpci_bus_remove_device(struct zpci_dev *zdev, bool set_error) 108 { 109 struct zpci_bus *zbus = zdev->zbus; 110 struct pci_dev *pdev; 111 112 if (!zdev->zbus->bus) 113 return; 114 115 pdev = pci_get_slot(zbus->bus, zdev->devfn); 116 if (pdev) { 117 if (set_error) 118 pdev->error_state = pci_channel_io_perm_failure; 119 if (pdev->is_virtfn) { 120 zpci_iov_remove_virtfn(pdev, zdev->vfn); 121 /* balance pci_get_slot */ 122 pci_dev_put(pdev); 123 return; 124 } 125 pci_stop_and_remove_bus_device_locked(pdev); 126 /* balance pci_get_slot */ 127 pci_dev_put(pdev); 128 } 129 } 130 131 /* zpci_bus_scan_bus - Scan all configured zPCI functions on the bus 132 * @zbus: the zbus to be scanned 133 * 134 * Enables and scans all PCI functions on the bus making them available to the 135 * common PCI code. If there is no function 0 on the zbus nothing is scanned. If 136 * a function does not have a slot yet because it was added to the zbus before 137 * function 0 the slot is created. If a PCI function fails to be initialized 138 * an error will be returned but attempts will still be made for all other 139 * functions on the bus. 140 * 141 * Return: 0 on success, an error value otherwise 142 */ 143 int zpci_bus_scan_bus(struct zpci_bus *zbus) 144 { 145 struct zpci_dev *zdev; 146 int devfn, rc, ret = 0; 147 148 if (!zbus->function[0]) 149 return 0; 150 151 for (devfn = 0; devfn < ZPCI_FUNCTIONS_PER_BUS; devfn++) { 152 zdev = zbus->function[devfn]; 153 if (zdev && zdev->state == ZPCI_FN_STATE_CONFIGURED) { 154 rc = zpci_bus_prepare_device(zdev); 155 if (rc) 156 ret = -EIO; 157 } 158 } 159 160 pci_lock_rescan_remove(); 161 pci_scan_child_bus(zbus->bus); 162 pci_bus_add_devices(zbus->bus); 163 pci_unlock_rescan_remove(); 164 165 return ret; 166 } 167 168 /* zpci_bus_scan_busses - Scan all registered busses 169 * 170 * Scan all available zbusses 171 * 172 */ 173 void zpci_bus_scan_busses(void) 174 { 175 struct zpci_bus *zbus = NULL; 176 177 mutex_lock(&zbus_list_lock); 178 list_for_each_entry(zbus, &zbus_list, bus_next) { 179 zpci_bus_scan_bus(zbus); 180 cond_resched(); 181 } 182 mutex_unlock(&zbus_list_lock); 183 } 184 185 /* zpci_bus_create_pci_bus - Create the PCI bus associated with this zbus 186 * @zbus: the zbus holding the zdevices 187 * @f0: function 0 of the bus 188 * @ops: the pci operations 189 * 190 * Function zero is taken as a parameter as this is used to determine the 191 * domain, multifunction property and maximum bus speed of the entire bus. 192 * 193 * Return: 0 on success, an error code otherwise 194 */ 195 static int zpci_bus_create_pci_bus(struct zpci_bus *zbus, struct zpci_dev *f0, struct pci_ops *ops) 196 { 197 struct pci_bus *bus; 198 int domain; 199 200 domain = zpci_alloc_domain((u16)f0->uid); 201 if (domain < 0) 202 return domain; 203 204 zbus->domain_nr = domain; 205 zbus->multifunction = f0->rid_available; 206 zbus->max_bus_speed = f0->max_bus_speed; 207 208 /* 209 * Note that the zbus->resources are taken over and zbus->resources 210 * is empty after a successful call 211 */ 212 bus = pci_create_root_bus(NULL, ZPCI_BUS_NR, ops, zbus, &zbus->resources); 213 if (!bus) { 214 zpci_free_domain(zbus->domain_nr); 215 return -EFAULT; 216 } 217 218 zbus->bus = bus; 219 pci_bus_add_devices(bus); 220 221 return 0; 222 } 223 224 static void zpci_bus_release(struct kref *kref) 225 { 226 struct zpci_bus *zbus = container_of(kref, struct zpci_bus, kref); 227 228 if (zbus->bus) { 229 pci_lock_rescan_remove(); 230 pci_stop_root_bus(zbus->bus); 231 232 zpci_free_domain(zbus->domain_nr); 233 pci_free_resource_list(&zbus->resources); 234 235 pci_remove_root_bus(zbus->bus); 236 pci_unlock_rescan_remove(); 237 } 238 239 mutex_lock(&zbus_list_lock); 240 list_del(&zbus->bus_next); 241 mutex_unlock(&zbus_list_lock); 242 kfree(zbus); 243 } 244 245 static void zpci_bus_put(struct zpci_bus *zbus) 246 { 247 kref_put(&zbus->kref, zpci_bus_release); 248 } 249 250 static struct zpci_bus *zpci_bus_get(int pchid) 251 { 252 struct zpci_bus *zbus; 253 254 mutex_lock(&zbus_list_lock); 255 list_for_each_entry(zbus, &zbus_list, bus_next) { 256 if (pchid == zbus->pchid) { 257 kref_get(&zbus->kref); 258 goto out_unlock; 259 } 260 } 261 zbus = NULL; 262 out_unlock: 263 mutex_unlock(&zbus_list_lock); 264 return zbus; 265 } 266 267 static struct zpci_bus *zpci_bus_alloc(int pchid) 268 { 269 struct zpci_bus *zbus; 270 271 zbus = kzalloc(sizeof(*zbus), GFP_KERNEL); 272 if (!zbus) 273 return NULL; 274 275 zbus->pchid = pchid; 276 INIT_LIST_HEAD(&zbus->bus_next); 277 mutex_lock(&zbus_list_lock); 278 list_add_tail(&zbus->bus_next, &zbus_list); 279 mutex_unlock(&zbus_list_lock); 280 281 kref_init(&zbus->kref); 282 INIT_LIST_HEAD(&zbus->resources); 283 284 zbus->bus_resource.start = 0; 285 zbus->bus_resource.end = ZPCI_BUS_NR; 286 zbus->bus_resource.flags = IORESOURCE_BUS; 287 pci_add_resource(&zbus->resources, &zbus->bus_resource); 288 289 return zbus; 290 } 291 292 void pcibios_bus_add_device(struct pci_dev *pdev) 293 { 294 struct zpci_dev *zdev = to_zpci(pdev); 295 296 /* 297 * With pdev->no_vf_scan the common PCI probing code does not 298 * perform PF/VF linking. 299 */ 300 if (zdev->vfn) { 301 zpci_iov_setup_virtfn(zdev->zbus, pdev, zdev->vfn); 302 pdev->no_command_memory = 1; 303 } 304 } 305 306 /* zpci_bus_create_hotplug_slots - Add hotplug slot(s) for device added to bus 307 * @zdev: the zPCI device that was newly added 308 * 309 * Add the hotplug slot(s) for the newly added PCI function. Normally this is 310 * simply the slot for the function itself. If however we are adding the 311 * function 0 on a zbus, it might be that we already registered functions on 312 * that zbus but could not create their hotplug slots yet so add those now too. 313 * 314 * Return: 0 on success, an error code otherwise 315 */ 316 static int zpci_bus_create_hotplug_slots(struct zpci_dev *zdev) 317 { 318 struct zpci_bus *zbus = zdev->zbus; 319 int devfn, rc = 0; 320 321 rc = zpci_init_slot(zdev); 322 if (rc) 323 return rc; 324 zdev->has_hp_slot = 1; 325 326 if (zdev->devfn == 0 && zbus->multifunction) { 327 /* Now that function 0 is there we can finally create the 328 * hotplug slots for those functions with devfn != 0 that have 329 * been parked in zbus->function[] waiting for us to be able to 330 * create the PCI bus. 331 */ 332 for (devfn = 1; devfn < ZPCI_FUNCTIONS_PER_BUS; devfn++) { 333 zdev = zbus->function[devfn]; 334 if (zdev && !zdev->has_hp_slot) { 335 rc = zpci_init_slot(zdev); 336 if (rc) 337 return rc; 338 zdev->has_hp_slot = 1; 339 } 340 } 341 342 } 343 344 return rc; 345 } 346 347 static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev) 348 { 349 int rc = -EINVAL; 350 351 if (zbus->function[zdev->devfn]) { 352 pr_err("devfn %04x is already assigned\n", zdev->devfn); 353 return rc; 354 } 355 zdev->zbus = zbus; 356 zbus->function[zdev->devfn] = zdev; 357 zpci_nb_devices++; 358 359 if (zbus->bus) { 360 if (zbus->multifunction && !zdev->rid_available) { 361 WARN_ONCE(1, "rid_available not set for multifunction\n"); 362 goto error; 363 } 364 365 zpci_bus_create_hotplug_slots(zdev); 366 } else { 367 /* Hotplug slot will be created once function 0 appears */ 368 zbus->multifunction = 1; 369 } 370 371 return 0; 372 373 error: 374 zbus->function[zdev->devfn] = NULL; 375 zdev->zbus = NULL; 376 zpci_nb_devices--; 377 return rc; 378 } 379 380 int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops) 381 { 382 struct zpci_bus *zbus = NULL; 383 int rc = -EBADF; 384 385 if (zpci_nb_devices == ZPCI_NR_DEVICES) { 386 pr_warn("Adding PCI function %08x failed because the configured limit of %d is reached\n", 387 zdev->fid, ZPCI_NR_DEVICES); 388 return -ENOSPC; 389 } 390 391 if (zdev->devfn >= ZPCI_FUNCTIONS_PER_BUS) 392 return -EINVAL; 393 394 if (!s390_pci_no_rid && zdev->rid_available) 395 zbus = zpci_bus_get(zdev->pchid); 396 397 if (!zbus) { 398 zbus = zpci_bus_alloc(zdev->pchid); 399 if (!zbus) 400 return -ENOMEM; 401 } 402 403 if (zdev->devfn == 0) { 404 rc = zpci_bus_create_pci_bus(zbus, zdev, ops); 405 if (rc) 406 goto error; 407 } 408 409 rc = zpci_bus_add_device(zbus, zdev); 410 if (rc) 411 goto error; 412 413 return 0; 414 415 error: 416 pr_err("Adding PCI function %08x failed\n", zdev->fid); 417 zpci_bus_put(zbus); 418 return rc; 419 } 420 421 void zpci_bus_device_unregister(struct zpci_dev *zdev) 422 { 423 struct zpci_bus *zbus = zdev->zbus; 424 425 zpci_nb_devices--; 426 zbus->function[zdev->devfn] = NULL; 427 zpci_bus_put(zbus); 428 } 429