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 int rc, i; 45 46 if (!zdev_enabled(zdev)) { 47 rc = zpci_enable_device(zdev); 48 if (rc) 49 return rc; 50 rc = zpci_dma_init_device(zdev); 51 if (rc) { 52 zpci_disable_device(zdev); 53 return rc; 54 } 55 } 56 57 if (!zdev->has_resources) { 58 zpci_setup_bus_resources(zdev); 59 for (i = 0; i < PCI_STD_NUM_BARS; i++) { 60 if (zdev->bars[i].res) 61 pci_bus_add_resource(zdev->zbus->bus, zdev->bars[i].res, 0); 62 } 63 } 64 65 return 0; 66 } 67 68 /* zpci_bus_scan_device - Scan a single device adding it to the PCI core 69 * @zdev: the zdev to be scanned 70 * 71 * Scans the PCI function making it available to the common PCI code. 72 * 73 * Return: 0 on success, an error value otherwise 74 */ 75 int zpci_bus_scan_device(struct zpci_dev *zdev) 76 { 77 struct pci_dev *pdev; 78 int rc; 79 80 rc = zpci_bus_prepare_device(zdev); 81 if (rc) 82 return rc; 83 84 pdev = pci_scan_single_device(zdev->zbus->bus, zdev->devfn); 85 if (!pdev) 86 return -ENODEV; 87 88 pci_bus_add_device(pdev); 89 pci_lock_rescan_remove(); 90 pci_bus_add_devices(zdev->zbus->bus); 91 pci_unlock_rescan_remove(); 92 93 return 0; 94 } 95 96 /* zpci_bus_remove_device - Removes the given zdev from the PCI core 97 * @zdev: the zdev to be removed from the PCI core 98 * @set_error: if true the device's error state is set to permanent failure 99 * 100 * Sets a zPCI device to a configured but offline state; the zPCI 101 * device is still accessible through its hotplug slot and the zPCI 102 * API but is removed from the common code PCI bus, making it 103 * no longer available to drivers. 104 */ 105 void zpci_bus_remove_device(struct zpci_dev *zdev, bool set_error) 106 { 107 struct zpci_bus *zbus = zdev->zbus; 108 struct pci_dev *pdev; 109 110 if (!zdev->zbus->bus) 111 return; 112 113 pdev = pci_get_slot(zbus->bus, zdev->devfn); 114 if (pdev) { 115 if (set_error) 116 pdev->error_state = pci_channel_io_perm_failure; 117 if (pdev->is_virtfn) { 118 zpci_iov_remove_virtfn(pdev, zdev->vfn); 119 /* balance pci_get_slot */ 120 pci_dev_put(pdev); 121 return; 122 } 123 pci_stop_and_remove_bus_device_locked(pdev); 124 /* balance pci_get_slot */ 125 pci_dev_put(pdev); 126 } 127 } 128 129 /* zpci_bus_scan_bus - Scan all configured zPCI functions on the bus 130 * @zbus: the zbus to be scanned 131 * 132 * Enables and scans all PCI functions on the bus making them available to the 133 * common PCI code. If there is no function 0 on the zbus nothing is scanned. If 134 * a function does not have a slot yet because it was added to the zbus before 135 * function 0 the slot is created. If a PCI function fails to be initialized 136 * an error will be returned but attempts will still be made for all other 137 * functions on the bus. 138 * 139 * Return: 0 on success, an error value otherwise 140 */ 141 int zpci_bus_scan_bus(struct zpci_bus *zbus) 142 { 143 struct zpci_dev *zdev; 144 int devfn, rc, ret = 0; 145 146 for (devfn = 0; devfn < ZPCI_FUNCTIONS_PER_BUS; devfn++) { 147 zdev = zbus->function[devfn]; 148 if (zdev && zdev->state == ZPCI_FN_STATE_CONFIGURED) { 149 rc = zpci_bus_prepare_device(zdev); 150 if (rc) 151 ret = -EIO; 152 } 153 } 154 155 pci_lock_rescan_remove(); 156 pci_scan_child_bus(zbus->bus); 157 pci_bus_add_devices(zbus->bus); 158 pci_unlock_rescan_remove(); 159 160 return ret; 161 } 162 163 /* zpci_bus_scan_busses - Scan all registered busses 164 * 165 * Scan all available zbusses 166 * 167 */ 168 void zpci_bus_scan_busses(void) 169 { 170 struct zpci_bus *zbus = NULL; 171 172 mutex_lock(&zbus_list_lock); 173 list_for_each_entry(zbus, &zbus_list, bus_next) { 174 zpci_bus_scan_bus(zbus); 175 cond_resched(); 176 } 177 mutex_unlock(&zbus_list_lock); 178 } 179 180 /* zpci_bus_create_pci_bus - Create the PCI bus associated with this zbus 181 * @zbus: the zbus holding the zdevices 182 * @fr: PCI root function that will determine the bus's domain, and bus speeed 183 * @ops: the pci operations 184 * 185 * The PCI function @fr determines the domain (its UID), multifunction property 186 * and maximum bus speed of the entire bus. 187 * 188 * Return: 0 on success, an error code otherwise 189 */ 190 static int zpci_bus_create_pci_bus(struct zpci_bus *zbus, struct zpci_dev *fr, struct pci_ops *ops) 191 { 192 struct pci_bus *bus; 193 int domain; 194 195 domain = zpci_alloc_domain((u16)fr->uid); 196 if (domain < 0) 197 return domain; 198 199 zbus->domain_nr = domain; 200 zbus->multifunction = fr->rid_available; 201 zbus->max_bus_speed = fr->max_bus_speed; 202 203 /* 204 * Note that the zbus->resources are taken over and zbus->resources 205 * is empty after a successful call 206 */ 207 bus = pci_create_root_bus(NULL, ZPCI_BUS_NR, ops, zbus, &zbus->resources); 208 if (!bus) { 209 zpci_free_domain(zbus->domain_nr); 210 return -EFAULT; 211 } 212 213 zbus->bus = bus; 214 pci_bus_add_devices(bus); 215 216 return 0; 217 } 218 219 static void zpci_bus_release(struct kref *kref) 220 { 221 struct zpci_bus *zbus = container_of(kref, struct zpci_bus, kref); 222 223 if (zbus->bus) { 224 pci_lock_rescan_remove(); 225 pci_stop_root_bus(zbus->bus); 226 227 zpci_free_domain(zbus->domain_nr); 228 pci_free_resource_list(&zbus->resources); 229 230 pci_remove_root_bus(zbus->bus); 231 pci_unlock_rescan_remove(); 232 } 233 234 mutex_lock(&zbus_list_lock); 235 list_del(&zbus->bus_next); 236 mutex_unlock(&zbus_list_lock); 237 kfree(zbus); 238 } 239 240 static void zpci_bus_put(struct zpci_bus *zbus) 241 { 242 kref_put(&zbus->kref, zpci_bus_release); 243 } 244 245 static struct zpci_bus *zpci_bus_get(int pchid) 246 { 247 struct zpci_bus *zbus; 248 249 mutex_lock(&zbus_list_lock); 250 list_for_each_entry(zbus, &zbus_list, bus_next) { 251 if (pchid == zbus->pchid) { 252 kref_get(&zbus->kref); 253 goto out_unlock; 254 } 255 } 256 zbus = NULL; 257 out_unlock: 258 mutex_unlock(&zbus_list_lock); 259 return zbus; 260 } 261 262 static struct zpci_bus *zpci_bus_alloc(int pchid) 263 { 264 struct zpci_bus *zbus; 265 266 zbus = kzalloc(sizeof(*zbus), GFP_KERNEL); 267 if (!zbus) 268 return NULL; 269 270 zbus->pchid = pchid; 271 INIT_LIST_HEAD(&zbus->bus_next); 272 mutex_lock(&zbus_list_lock); 273 list_add_tail(&zbus->bus_next, &zbus_list); 274 mutex_unlock(&zbus_list_lock); 275 276 kref_init(&zbus->kref); 277 INIT_LIST_HEAD(&zbus->resources); 278 279 zbus->bus_resource.start = 0; 280 zbus->bus_resource.end = ZPCI_BUS_NR; 281 zbus->bus_resource.flags = IORESOURCE_BUS; 282 pci_add_resource(&zbus->resources, &zbus->bus_resource); 283 284 return zbus; 285 } 286 287 void pcibios_bus_add_device(struct pci_dev *pdev) 288 { 289 struct zpci_dev *zdev = to_zpci(pdev); 290 291 /* 292 * With pdev->no_vf_scan the common PCI probing code does not 293 * perform PF/VF linking. 294 */ 295 if (zdev->vfn) { 296 zpci_iov_setup_virtfn(zdev->zbus, pdev, zdev->vfn); 297 pdev->no_command_memory = 1; 298 } 299 } 300 301 static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev) 302 { 303 int rc = -EINVAL; 304 305 if (zbus->function[zdev->devfn]) { 306 pr_err("devfn %04x is already assigned\n", zdev->devfn); 307 return rc; 308 } 309 310 zdev->zbus = zbus; 311 zbus->function[zdev->devfn] = zdev; 312 zpci_nb_devices++; 313 314 if (zbus->multifunction && !zdev->rid_available) { 315 WARN_ONCE(1, "rid_available not set for multifunction\n"); 316 goto error; 317 } 318 rc = zpci_init_slot(zdev); 319 if (rc) 320 goto error; 321 zdev->has_hp_slot = 1; 322 323 return 0; 324 325 error: 326 zbus->function[zdev->devfn] = NULL; 327 zdev->zbus = NULL; 328 zpci_nb_devices--; 329 return rc; 330 } 331 332 int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops) 333 { 334 struct zpci_bus *zbus = NULL; 335 int rc = -EBADF; 336 337 if (zpci_nb_devices == ZPCI_NR_DEVICES) { 338 pr_warn("Adding PCI function %08x failed because the configured limit of %d is reached\n", 339 zdev->fid, ZPCI_NR_DEVICES); 340 return -ENOSPC; 341 } 342 343 if (zdev->devfn >= ZPCI_FUNCTIONS_PER_BUS) 344 return -EINVAL; 345 346 if (!s390_pci_no_rid && zdev->rid_available) 347 zbus = zpci_bus_get(zdev->pchid); 348 349 if (!zbus) { 350 zbus = zpci_bus_alloc(zdev->pchid); 351 if (!zbus) 352 return -ENOMEM; 353 } 354 355 if (!zbus->bus) { 356 /* The UID of the first PCI function registered with a zpci_bus 357 * is used as the domain number for that bus. Currently there 358 * is exactly one zpci_bus per domain. 359 */ 360 rc = zpci_bus_create_pci_bus(zbus, zdev, ops); 361 if (rc) 362 goto error; 363 } 364 365 rc = zpci_bus_add_device(zbus, zdev); 366 if (rc) 367 goto error; 368 369 return 0; 370 371 error: 372 pr_err("Adding PCI function %08x failed\n", zdev->fid); 373 zpci_bus_put(zbus); 374 return rc; 375 } 376 377 void zpci_bus_device_unregister(struct zpci_dev *zdev) 378 { 379 struct zpci_bus *zbus = zdev->zbus; 380 381 zpci_nb_devices--; 382 zbus->function[zdev->devfn] = NULL; 383 zpci_bus_put(zbus); 384 } 385