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 29static LIST_HEAD(zbus_list); 30static DEFINE_MUTEX(zbus_list_lock); 31static 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 */ 42static 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 */ 75int 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_lock_rescan_remove(); 89 pci_bus_add_device(pdev); 90 pci_unlock_rescan_remove(); 91 92 return 0; 93} 94 95/* zpci_bus_remove_device - Removes the given zdev from the PCI core 96 * @zdev: the zdev to be removed from the PCI core 97 * @set_error: if true the device's error state is set to permanent failure 98 * 99 * Sets a zPCI device to a configured but offline state; the zPCI 100 * device is still accessible through its hotplug slot and the zPCI 101 * API but is removed from the common code PCI bus, making it 102 * no longer available to drivers. 103 */ 104void zpci_bus_remove_device(struct zpci_dev *zdev, bool set_error) 105{ 106 struct zpci_bus *zbus = zdev->zbus; 107 struct pci_dev *pdev; 108 109 if (!zdev->zbus->bus) 110 return; 111 112 pdev = pci_get_slot(zbus->bus, zdev->devfn); 113 if (pdev) { 114 if (set_error) 115 pdev->error_state = pci_channel_io_perm_failure; 116 if (pdev->is_virtfn) { 117 zpci_iov_remove_virtfn(pdev, zdev->vfn); 118 /* balance pci_get_slot */ 119 pci_dev_put(pdev); 120 return; 121 } 122 pci_stop_and_remove_bus_device_locked(pdev); 123 /* balance pci_get_slot */ 124 pci_dev_put(pdev); 125 } 126} 127 128/* zpci_bus_scan_bus - Scan all configured zPCI functions on the bus 129 * @zbus: the zbus to be scanned 130 * 131 * Enables and scans all PCI functions on the bus making them available to the 132 * common PCI code. If a PCI function fails to be initialized an error will be 133 * returned but attempts will still be made for all other functions on the bus. 134 * 135 * Return: 0 on success, an error value otherwise 136 */ 137int zpci_bus_scan_bus(struct zpci_bus *zbus) 138{ 139 struct zpci_dev *zdev; 140 int devfn, rc, ret = 0; 141 142 for (devfn = 0; devfn < ZPCI_FUNCTIONS_PER_BUS; devfn++) { 143 zdev = zbus->function[devfn]; 144 if (zdev && zdev->state == ZPCI_FN_STATE_CONFIGURED) { 145 rc = zpci_bus_prepare_device(zdev); 146 if (rc) 147 ret = -EIO; 148 } 149 } 150 151 pci_lock_rescan_remove(); 152 pci_scan_child_bus(zbus->bus); 153 pci_bus_add_devices(zbus->bus); 154 pci_unlock_rescan_remove(); 155 156 return ret; 157} 158 159/* zpci_bus_scan_busses - Scan all registered busses 160 * 161 * Scan all available zbusses 162 * 163 */ 164void zpci_bus_scan_busses(void) 165{ 166 struct zpci_bus *zbus = NULL; 167 168 mutex_lock(&zbus_list_lock); 169 list_for_each_entry(zbus, &zbus_list, bus_next) { 170 zpci_bus_scan_bus(zbus); 171 cond_resched(); 172 } 173 mutex_unlock(&zbus_list_lock); 174} 175 176/* zpci_bus_create_pci_bus - Create the PCI bus associated with this zbus 177 * @zbus: the zbus holding the zdevices 178 * @fr: PCI root function that will determine the bus's domain, and bus speeed 179 * @ops: the pci operations 180 * 181 * The PCI function @fr determines the domain (its UID), multifunction property 182 * and maximum bus speed of the entire bus. 183 * 184 * Return: 0 on success, an error code otherwise 185 */ 186static int zpci_bus_create_pci_bus(struct zpci_bus *zbus, struct zpci_dev *fr, struct pci_ops *ops) 187{ 188 struct pci_bus *bus; 189 int domain; 190 191 domain = zpci_alloc_domain((u16)fr->uid); 192 if (domain < 0) 193 return domain; 194 195 zbus->domain_nr = domain; 196 zbus->multifunction = fr->rid_available; 197 zbus->max_bus_speed = fr->max_bus_speed; 198 199 /* 200 * Note that the zbus->resources are taken over and zbus->resources 201 * is empty after a successful call 202 */ 203 bus = pci_create_root_bus(NULL, ZPCI_BUS_NR, ops, zbus, &zbus->resources); 204 if (!bus) { 205 zpci_free_domain(zbus->domain_nr); 206 return -EFAULT; 207 } 208 209 zbus->bus = bus; 210 211 return 0; 212} 213 214static void zpci_bus_release(struct kref *kref) 215{ 216 struct zpci_bus *zbus = container_of(kref, struct zpci_bus, kref); 217 218 if (zbus->bus) { 219 pci_lock_rescan_remove(); 220 pci_stop_root_bus(zbus->bus); 221 222 zpci_free_domain(zbus->domain_nr); 223 pci_free_resource_list(&zbus->resources); 224 225 pci_remove_root_bus(zbus->bus); 226 pci_unlock_rescan_remove(); 227 } 228 229 mutex_lock(&zbus_list_lock); 230 list_del(&zbus->bus_next); 231 mutex_unlock(&zbus_list_lock); 232 kfree(zbus); 233} 234 235static void zpci_bus_put(struct zpci_bus *zbus) 236{ 237 kref_put(&zbus->kref, zpci_bus_release); 238} 239 240static struct zpci_bus *zpci_bus_get(int pchid) 241{ 242 struct zpci_bus *zbus; 243 244 mutex_lock(&zbus_list_lock); 245 list_for_each_entry(zbus, &zbus_list, bus_next) { 246 if (pchid == zbus->pchid) { 247 kref_get(&zbus->kref); 248 goto out_unlock; 249 } 250 } 251 zbus = NULL; 252out_unlock: 253 mutex_unlock(&zbus_list_lock); 254 return zbus; 255} 256 257static struct zpci_bus *zpci_bus_alloc(int pchid) 258{ 259 struct zpci_bus *zbus; 260 261 zbus = kzalloc(sizeof(*zbus), GFP_KERNEL); 262 if (!zbus) 263 return NULL; 264 265 zbus->pchid = pchid; 266 INIT_LIST_HEAD(&zbus->bus_next); 267 mutex_lock(&zbus_list_lock); 268 list_add_tail(&zbus->bus_next, &zbus_list); 269 mutex_unlock(&zbus_list_lock); 270 271 kref_init(&zbus->kref); 272 INIT_LIST_HEAD(&zbus->resources); 273 274 zbus->bus_resource.start = 0; 275 zbus->bus_resource.end = ZPCI_BUS_NR; 276 zbus->bus_resource.flags = IORESOURCE_BUS; 277 pci_add_resource(&zbus->resources, &zbus->bus_resource); 278 279 return zbus; 280} 281 282void pcibios_bus_add_device(struct pci_dev *pdev) 283{ 284 struct zpci_dev *zdev = to_zpci(pdev); 285 286 /* 287 * With pdev->no_vf_scan the common PCI probing code does not 288 * perform PF/VF linking. 289 */ 290 if (zdev->vfn) { 291 zpci_iov_setup_virtfn(zdev->zbus, pdev, zdev->vfn); 292 pdev->no_command_memory = 1; 293 } 294} 295 296static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev) 297{ 298 int rc = -EINVAL; 299 300 if (zbus->function[zdev->devfn]) { 301 pr_err("devfn %04x is already assigned\n", zdev->devfn); 302 return rc; 303 } 304 305 zdev->zbus = zbus; 306 zbus->function[zdev->devfn] = zdev; 307 zpci_nb_devices++; 308 309 if (zbus->multifunction && !zdev->rid_available) { 310 WARN_ONCE(1, "rid_available not set for multifunction\n"); 311 goto error; 312 } 313 rc = zpci_init_slot(zdev); 314 if (rc) 315 goto error; 316 zdev->has_hp_slot = 1; 317 318 return 0; 319 320error: 321 zbus->function[zdev->devfn] = NULL; 322 zdev->zbus = NULL; 323 zpci_nb_devices--; 324 return rc; 325} 326 327int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops) 328{ 329 struct zpci_bus *zbus = NULL; 330 int rc = -EBADF; 331 332 if (zpci_nb_devices == ZPCI_NR_DEVICES) { 333 pr_warn("Adding PCI function %08x failed because the configured limit of %d is reached\n", 334 zdev->fid, ZPCI_NR_DEVICES); 335 return -ENOSPC; 336 } 337 338 if (zdev->devfn >= ZPCI_FUNCTIONS_PER_BUS) 339 return -EINVAL; 340 341 if (!s390_pci_no_rid && zdev->rid_available) 342 zbus = zpci_bus_get(zdev->pchid); 343 344 if (!zbus) { 345 zbus = zpci_bus_alloc(zdev->pchid); 346 if (!zbus) 347 return -ENOMEM; 348 } 349 350 if (!zbus->bus) { 351 /* The UID of the first PCI function registered with a zpci_bus 352 * is used as the domain number for that bus. Currently there 353 * is exactly one zpci_bus per domain. 354 */ 355 rc = zpci_bus_create_pci_bus(zbus, zdev, ops); 356 if (rc) 357 goto error; 358 } 359 360 rc = zpci_bus_add_device(zbus, zdev); 361 if (rc) 362 goto error; 363 364 return 0; 365 366error: 367 pr_err("Adding PCI function %08x failed\n", zdev->fid); 368 zpci_bus_put(zbus); 369 return rc; 370} 371 372void zpci_bus_device_unregister(struct zpci_dev *zdev) 373{ 374 struct zpci_bus *zbus = zdev->zbus; 375 376 zpci_nb_devices--; 377 zbus->function[zdev->devfn] = NULL; 378 zpci_bus_put(zbus); 379} 380