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 } 51 52 if (!zdev->has_resources) { 53 zpci_setup_bus_resources(zdev); 54 for (i = 0; i < PCI_STD_NUM_BARS; i++) { 55 if (zdev->bars[i].res) 56 pci_bus_add_resource(zdev->zbus->bus, zdev->bars[i].res, 0); 57 } 58 } 59 60 return 0; 61 } 62 63 /* zpci_bus_scan_device - Scan a single device adding it to the PCI core 64 * @zdev: the zdev to be scanned 65 * 66 * Scans the PCI function making it available to the common PCI code. 67 * 68 * Return: 0 on success, an error value otherwise 69 */ 70 int zpci_bus_scan_device(struct zpci_dev *zdev) 71 { 72 struct pci_dev *pdev; 73 int rc; 74 75 rc = zpci_bus_prepare_device(zdev); 76 if (rc) 77 return rc; 78 79 pdev = pci_scan_single_device(zdev->zbus->bus, zdev->devfn); 80 if (!pdev) 81 return -ENODEV; 82 83 pci_lock_rescan_remove(); 84 pci_bus_add_device(pdev); 85 pci_unlock_rescan_remove(); 86 87 return 0; 88 } 89 90 /* zpci_bus_remove_device - Removes the given zdev from the PCI core 91 * @zdev: the zdev to be removed from the PCI core 92 * @set_error: if true the device's error state is set to permanent failure 93 * 94 * Sets a zPCI device to a configured but offline state; the zPCI 95 * device is still accessible through its hotplug slot and the zPCI 96 * API but is removed from the common code PCI bus, making it 97 * no longer available to drivers. 98 */ 99 void zpci_bus_remove_device(struct zpci_dev *zdev, bool set_error) 100 { 101 struct zpci_bus *zbus = zdev->zbus; 102 struct pci_dev *pdev; 103 104 if (!zdev->zbus->bus) 105 return; 106 107 pdev = pci_get_slot(zbus->bus, zdev->devfn); 108 if (pdev) { 109 if (set_error) 110 pdev->error_state = pci_channel_io_perm_failure; 111 if (pdev->is_virtfn) { 112 zpci_iov_remove_virtfn(pdev, zdev->vfn); 113 /* balance pci_get_slot */ 114 pci_dev_put(pdev); 115 return; 116 } 117 pci_stop_and_remove_bus_device_locked(pdev); 118 /* balance pci_get_slot */ 119 pci_dev_put(pdev); 120 } 121 } 122 123 /* zpci_bus_scan_bus - Scan all configured zPCI functions on the bus 124 * @zbus: the zbus to be scanned 125 * 126 * Enables and scans all PCI functions on the bus making them available to the 127 * common PCI code. If a PCI function fails to be initialized an error will be 128 * returned but attempts will still be made for all other functions on the bus. 129 * 130 * Return: 0 on success, an error value otherwise 131 */ 132 int zpci_bus_scan_bus(struct zpci_bus *zbus) 133 { 134 struct zpci_dev *zdev; 135 int devfn, rc, ret = 0; 136 137 for (devfn = 0; devfn < ZPCI_FUNCTIONS_PER_BUS; devfn++) { 138 zdev = zbus->function[devfn]; 139 if (zdev && zdev->state == ZPCI_FN_STATE_CONFIGURED) { 140 rc = zpci_bus_prepare_device(zdev); 141 if (rc) 142 ret = -EIO; 143 } 144 } 145 146 pci_lock_rescan_remove(); 147 pci_scan_child_bus(zbus->bus); 148 pci_bus_add_devices(zbus->bus); 149 pci_unlock_rescan_remove(); 150 151 return ret; 152 } 153 154 /* zpci_bus_scan_busses - Scan all registered busses 155 * 156 * Scan all available zbusses 157 * 158 */ 159 void zpci_bus_scan_busses(void) 160 { 161 struct zpci_bus *zbus = NULL; 162 163 mutex_lock(&zbus_list_lock); 164 list_for_each_entry(zbus, &zbus_list, bus_next) { 165 zpci_bus_scan_bus(zbus); 166 cond_resched(); 167 } 168 mutex_unlock(&zbus_list_lock); 169 } 170 171 /* zpci_bus_create_pci_bus - Create the PCI bus associated with this zbus 172 * @zbus: the zbus holding the zdevices 173 * @fr: PCI root function that will determine the bus's domain, and bus speeed 174 * @ops: the pci operations 175 * 176 * The PCI function @fr determines the domain (its UID), multifunction property 177 * and maximum bus speed of the entire bus. 178 * 179 * Return: 0 on success, an error code otherwise 180 */ 181 static int zpci_bus_create_pci_bus(struct zpci_bus *zbus, struct zpci_dev *fr, struct pci_ops *ops) 182 { 183 struct pci_bus *bus; 184 int domain; 185 186 domain = zpci_alloc_domain((u16)fr->uid); 187 if (domain < 0) 188 return domain; 189 190 zbus->domain_nr = domain; 191 zbus->multifunction = fr->rid_available; 192 zbus->max_bus_speed = fr->max_bus_speed; 193 194 /* 195 * Note that the zbus->resources are taken over and zbus->resources 196 * is empty after a successful call 197 */ 198 bus = pci_create_root_bus(NULL, ZPCI_BUS_NR, ops, zbus, &zbus->resources); 199 if (!bus) { 200 zpci_free_domain(zbus->domain_nr); 201 return -EFAULT; 202 } 203 204 zbus->bus = bus; 205 206 return 0; 207 } 208 209 static void zpci_bus_release(struct kref *kref) 210 { 211 struct zpci_bus *zbus = container_of(kref, struct zpci_bus, kref); 212 213 if (zbus->bus) { 214 pci_lock_rescan_remove(); 215 pci_stop_root_bus(zbus->bus); 216 217 zpci_free_domain(zbus->domain_nr); 218 pci_free_resource_list(&zbus->resources); 219 220 pci_remove_root_bus(zbus->bus); 221 pci_unlock_rescan_remove(); 222 } 223 224 mutex_lock(&zbus_list_lock); 225 list_del(&zbus->bus_next); 226 mutex_unlock(&zbus_list_lock); 227 kfree(zbus); 228 } 229 230 static void zpci_bus_put(struct zpci_bus *zbus) 231 { 232 kref_put(&zbus->kref, zpci_bus_release); 233 } 234 235 static struct zpci_bus *zpci_bus_get(int pchid) 236 { 237 struct zpci_bus *zbus; 238 239 mutex_lock(&zbus_list_lock); 240 list_for_each_entry(zbus, &zbus_list, bus_next) { 241 if (pchid == zbus->pchid) { 242 kref_get(&zbus->kref); 243 goto out_unlock; 244 } 245 } 246 zbus = NULL; 247 out_unlock: 248 mutex_unlock(&zbus_list_lock); 249 return zbus; 250 } 251 252 static struct zpci_bus *zpci_bus_alloc(int pchid) 253 { 254 struct zpci_bus *zbus; 255 256 zbus = kzalloc(sizeof(*zbus), GFP_KERNEL); 257 if (!zbus) 258 return NULL; 259 260 zbus->pchid = pchid; 261 INIT_LIST_HEAD(&zbus->bus_next); 262 mutex_lock(&zbus_list_lock); 263 list_add_tail(&zbus->bus_next, &zbus_list); 264 mutex_unlock(&zbus_list_lock); 265 266 kref_init(&zbus->kref); 267 INIT_LIST_HEAD(&zbus->resources); 268 269 zbus->bus_resource.start = 0; 270 zbus->bus_resource.end = ZPCI_BUS_NR; 271 zbus->bus_resource.flags = IORESOURCE_BUS; 272 pci_add_resource(&zbus->resources, &zbus->bus_resource); 273 274 return zbus; 275 } 276 277 void pcibios_bus_add_device(struct pci_dev *pdev) 278 { 279 struct zpci_dev *zdev = to_zpci(pdev); 280 281 /* 282 * With pdev->no_vf_scan the common PCI probing code does not 283 * perform PF/VF linking. 284 */ 285 if (zdev->vfn) { 286 zpci_iov_setup_virtfn(zdev->zbus, pdev, zdev->vfn); 287 pdev->no_command_memory = 1; 288 } 289 } 290 291 static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev) 292 { 293 int rc = -EINVAL; 294 295 if (zbus->function[zdev->devfn]) { 296 pr_err("devfn %04x is already assigned\n", zdev->devfn); 297 return rc; 298 } 299 300 zdev->zbus = zbus; 301 zbus->function[zdev->devfn] = zdev; 302 zpci_nb_devices++; 303 304 if (zbus->multifunction && !zdev->rid_available) { 305 WARN_ONCE(1, "rid_available not set for multifunction\n"); 306 goto error; 307 } 308 rc = zpci_init_slot(zdev); 309 if (rc) 310 goto error; 311 zdev->has_hp_slot = 1; 312 313 return 0; 314 315 error: 316 zbus->function[zdev->devfn] = NULL; 317 zdev->zbus = NULL; 318 zpci_nb_devices--; 319 return rc; 320 } 321 322 int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops) 323 { 324 struct zpci_bus *zbus = NULL; 325 int rc = -EBADF; 326 327 if (zpci_nb_devices == ZPCI_NR_DEVICES) { 328 pr_warn("Adding PCI function %08x failed because the configured limit of %d is reached\n", 329 zdev->fid, ZPCI_NR_DEVICES); 330 return -ENOSPC; 331 } 332 333 if (zdev->devfn >= ZPCI_FUNCTIONS_PER_BUS) 334 return -EINVAL; 335 336 if (!s390_pci_no_rid && zdev->rid_available) 337 zbus = zpci_bus_get(zdev->pchid); 338 339 if (!zbus) { 340 zbus = zpci_bus_alloc(zdev->pchid); 341 if (!zbus) 342 return -ENOMEM; 343 } 344 345 if (!zbus->bus) { 346 /* The UID of the first PCI function registered with a zpci_bus 347 * is used as the domain number for that bus. Currently there 348 * is exactly one zpci_bus per domain. 349 */ 350 rc = zpci_bus_create_pci_bus(zbus, zdev, ops); 351 if (rc) 352 goto error; 353 } 354 355 rc = zpci_bus_add_device(zbus, zdev); 356 if (rc) 357 goto error; 358 359 return 0; 360 361 error: 362 pr_err("Adding PCI function %08x failed\n", zdev->fid); 363 zpci_bus_put(zbus); 364 return rc; 365 } 366 367 void zpci_bus_device_unregister(struct zpci_dev *zdev) 368 { 369 struct zpci_bus *zbus = zdev->zbus; 370 371 zpci_nb_devices--; 372 zbus->function[zdev->devfn] = NULL; 373 zpci_bus_put(zbus); 374 } 375