1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Thunderbolt Cactus Ridge driver - bus logic (NHI independent) 4 * 5 * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com> 6 */ 7 8 #include <linux/slab.h> 9 #include <linux/errno.h> 10 #include <linux/delay.h> 11 #include <linux/platform_data/x86/apple.h> 12 13 #include "tb.h" 14 #include "tb_regs.h" 15 #include "tunnel_pci.h" 16 17 /** 18 * struct tb_cm - Simple Thunderbolt connection manager 19 * @tunnel_list: List of active tunnels 20 * @hotplug_active: tb_handle_hotplug will stop progressing plug 21 * events and exit if this is not set (it needs to 22 * acquire the lock one more time). Used to drain wq 23 * after cfg has been paused. 24 */ 25 struct tb_cm { 26 struct list_head tunnel_list; 27 bool hotplug_active; 28 }; 29 30 /* enumeration & hot plug handling */ 31 32 33 static void tb_scan_port(struct tb_port *port); 34 35 /** 36 * tb_scan_switch() - scan for and initialize downstream switches 37 */ 38 static void tb_scan_switch(struct tb_switch *sw) 39 { 40 int i; 41 for (i = 1; i <= sw->config.max_port_number; i++) 42 tb_scan_port(&sw->ports[i]); 43 } 44 45 /** 46 * tb_scan_port() - check for and initialize switches below port 47 */ 48 static void tb_scan_port(struct tb_port *port) 49 { 50 struct tb_switch *sw; 51 if (tb_is_upstream_port(port)) 52 return; 53 if (port->config.type != TB_TYPE_PORT) 54 return; 55 if (port->dual_link_port && port->link_nr) 56 return; /* 57 * Downstream switch is reachable through two ports. 58 * Only scan on the primary port (link_nr == 0). 59 */ 60 if (tb_wait_for_port(port, false) <= 0) 61 return; 62 if (port->remote) { 63 tb_port_WARN(port, "port already has a remote!\n"); 64 return; 65 } 66 sw = tb_switch_alloc(port->sw->tb, &port->sw->dev, 67 tb_downstream_route(port)); 68 if (!sw) 69 return; 70 71 if (tb_switch_configure(sw)) { 72 tb_switch_put(sw); 73 return; 74 } 75 76 sw->authorized = true; 77 78 if (tb_switch_add(sw)) { 79 tb_switch_put(sw); 80 return; 81 } 82 83 port->remote = tb_upstream_port(sw); 84 tb_upstream_port(sw)->remote = port; 85 tb_scan_switch(sw); 86 } 87 88 /** 89 * tb_free_invalid_tunnels() - destroy tunnels of devices that have gone away 90 */ 91 static void tb_free_invalid_tunnels(struct tb *tb) 92 { 93 struct tb_cm *tcm = tb_priv(tb); 94 struct tb_pci_tunnel *tunnel; 95 struct tb_pci_tunnel *n; 96 97 list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) { 98 if (tb_pci_is_invalid(tunnel)) { 99 tb_pci_deactivate(tunnel); 100 list_del(&tunnel->list); 101 tb_pci_free(tunnel); 102 } 103 } 104 } 105 106 /** 107 * tb_free_unplugged_children() - traverse hierarchy and free unplugged switches 108 */ 109 static void tb_free_unplugged_children(struct tb_switch *sw) 110 { 111 int i; 112 for (i = 1; i <= sw->config.max_port_number; i++) { 113 struct tb_port *port = &sw->ports[i]; 114 if (tb_is_upstream_port(port)) 115 continue; 116 if (!port->remote) 117 continue; 118 if (port->remote->sw->is_unplugged) { 119 tb_switch_remove(port->remote->sw); 120 port->remote = NULL; 121 } else { 122 tb_free_unplugged_children(port->remote->sw); 123 } 124 } 125 } 126 127 128 /** 129 * find_pci_up_port() - return the first PCIe up port on @sw or NULL 130 */ 131 static struct tb_port *tb_find_pci_up_port(struct tb_switch *sw) 132 { 133 int i; 134 for (i = 1; i <= sw->config.max_port_number; i++) 135 if (sw->ports[i].config.type == TB_TYPE_PCIE_UP) 136 return &sw->ports[i]; 137 return NULL; 138 } 139 140 /** 141 * find_unused_down_port() - return the first inactive PCIe down port on @sw 142 */ 143 static struct tb_port *tb_find_unused_down_port(struct tb_switch *sw) 144 { 145 int i; 146 int cap; 147 int res; 148 int data; 149 for (i = 1; i <= sw->config.max_port_number; i++) { 150 if (tb_is_upstream_port(&sw->ports[i])) 151 continue; 152 if (sw->ports[i].config.type != TB_TYPE_PCIE_DOWN) 153 continue; 154 cap = tb_port_find_cap(&sw->ports[i], TB_PORT_CAP_ADAP); 155 if (cap < 0) 156 continue; 157 res = tb_port_read(&sw->ports[i], &data, TB_CFG_PORT, cap, 1); 158 if (res < 0) 159 continue; 160 if (data & 0x80000000) 161 continue; 162 return &sw->ports[i]; 163 } 164 return NULL; 165 } 166 167 /** 168 * tb_activate_pcie_devices() - scan for and activate PCIe devices 169 * 170 * This method is somewhat ad hoc. For now it only supports one device 171 * per port and only devices at depth 1. 172 */ 173 static void tb_activate_pcie_devices(struct tb *tb) 174 { 175 int i; 176 int cap; 177 u32 data; 178 struct tb_switch *sw; 179 struct tb_port *up_port; 180 struct tb_port *down_port; 181 struct tb_pci_tunnel *tunnel; 182 struct tb_cm *tcm = tb_priv(tb); 183 184 /* scan for pcie devices at depth 1*/ 185 for (i = 1; i <= tb->root_switch->config.max_port_number; i++) { 186 if (tb_is_upstream_port(&tb->root_switch->ports[i])) 187 continue; 188 if (tb->root_switch->ports[i].config.type != TB_TYPE_PORT) 189 continue; 190 if (!tb->root_switch->ports[i].remote) 191 continue; 192 sw = tb->root_switch->ports[i].remote->sw; 193 up_port = tb_find_pci_up_port(sw); 194 if (!up_port) { 195 tb_sw_info(sw, "no PCIe devices found, aborting\n"); 196 continue; 197 } 198 199 /* check whether port is already activated */ 200 cap = tb_port_find_cap(up_port, TB_PORT_CAP_ADAP); 201 if (cap < 0) 202 continue; 203 if (tb_port_read(up_port, &data, TB_CFG_PORT, cap, 1)) 204 continue; 205 if (data & 0x80000000) { 206 tb_port_info(up_port, 207 "PCIe port already activated, aborting\n"); 208 continue; 209 } 210 211 down_port = tb_find_unused_down_port(tb->root_switch); 212 if (!down_port) { 213 tb_port_info(up_port, 214 "All PCIe down ports are occupied, aborting\n"); 215 continue; 216 } 217 tunnel = tb_pci_alloc(tb, up_port, down_port); 218 if (!tunnel) { 219 tb_port_info(up_port, 220 "PCIe tunnel allocation failed, aborting\n"); 221 continue; 222 } 223 224 if (tb_pci_activate(tunnel)) { 225 tb_port_info(up_port, 226 "PCIe tunnel activation failed, aborting\n"); 227 tb_pci_free(tunnel); 228 } 229 230 list_add(&tunnel->list, &tcm->tunnel_list); 231 } 232 } 233 234 /* hotplug handling */ 235 236 struct tb_hotplug_event { 237 struct work_struct work; 238 struct tb *tb; 239 u64 route; 240 u8 port; 241 bool unplug; 242 }; 243 244 /** 245 * tb_handle_hotplug() - handle hotplug event 246 * 247 * Executes on tb->wq. 248 */ 249 static void tb_handle_hotplug(struct work_struct *work) 250 { 251 struct tb_hotplug_event *ev = container_of(work, typeof(*ev), work); 252 struct tb *tb = ev->tb; 253 struct tb_cm *tcm = tb_priv(tb); 254 struct tb_switch *sw; 255 struct tb_port *port; 256 mutex_lock(&tb->lock); 257 if (!tcm->hotplug_active) 258 goto out; /* during init, suspend or shutdown */ 259 260 sw = get_switch_at_route(tb->root_switch, ev->route); 261 if (!sw) { 262 tb_warn(tb, 263 "hotplug event from non existent switch %llx:%x (unplug: %d)\n", 264 ev->route, ev->port, ev->unplug); 265 goto out; 266 } 267 if (ev->port > sw->config.max_port_number) { 268 tb_warn(tb, 269 "hotplug event from non existent port %llx:%x (unplug: %d)\n", 270 ev->route, ev->port, ev->unplug); 271 goto out; 272 } 273 port = &sw->ports[ev->port]; 274 if (tb_is_upstream_port(port)) { 275 tb_warn(tb, 276 "hotplug event for upstream port %llx:%x (unplug: %d)\n", 277 ev->route, ev->port, ev->unplug); 278 goto out; 279 } 280 if (ev->unplug) { 281 if (port->remote) { 282 tb_port_info(port, "unplugged\n"); 283 tb_sw_set_unplugged(port->remote->sw); 284 tb_free_invalid_tunnels(tb); 285 tb_switch_remove(port->remote->sw); 286 port->remote = NULL; 287 } else { 288 tb_port_info(port, 289 "got unplug event for disconnected port, ignoring\n"); 290 } 291 } else if (port->remote) { 292 tb_port_info(port, 293 "got plug event for connected port, ignoring\n"); 294 } else { 295 tb_port_info(port, "hotplug: scanning\n"); 296 tb_scan_port(port); 297 if (!port->remote) { 298 tb_port_info(port, "hotplug: no switch found\n"); 299 } else if (port->remote->sw->config.depth > 1) { 300 tb_sw_warn(port->remote->sw, 301 "hotplug: chaining not supported\n"); 302 } else { 303 tb_sw_info(port->remote->sw, 304 "hotplug: activating pcie devices\n"); 305 tb_activate_pcie_devices(tb); 306 } 307 } 308 out: 309 mutex_unlock(&tb->lock); 310 kfree(ev); 311 } 312 313 /** 314 * tb_schedule_hotplug_handler() - callback function for the control channel 315 * 316 * Delegates to tb_handle_hotplug. 317 */ 318 static void tb_handle_event(struct tb *tb, enum tb_cfg_pkg_type type, 319 const void *buf, size_t size) 320 { 321 const struct cfg_event_pkg *pkg = buf; 322 struct tb_hotplug_event *ev; 323 u64 route; 324 325 if (type != TB_CFG_PKG_EVENT) { 326 tb_warn(tb, "unexpected event %#x, ignoring\n", type); 327 return; 328 } 329 330 route = tb_cfg_get_route(&pkg->header); 331 332 if (tb_cfg_error(tb->ctl, route, pkg->port, 333 TB_CFG_ERROR_ACK_PLUG_EVENT)) { 334 tb_warn(tb, "could not ack plug event on %llx:%x\n", route, 335 pkg->port); 336 } 337 338 ev = kmalloc(sizeof(*ev), GFP_KERNEL); 339 if (!ev) 340 return; 341 INIT_WORK(&ev->work, tb_handle_hotplug); 342 ev->tb = tb; 343 ev->route = route; 344 ev->port = pkg->port; 345 ev->unplug = pkg->unplug; 346 queue_work(tb->wq, &ev->work); 347 } 348 349 static void tb_stop(struct tb *tb) 350 { 351 struct tb_cm *tcm = tb_priv(tb); 352 struct tb_pci_tunnel *tunnel; 353 struct tb_pci_tunnel *n; 354 355 /* tunnels are only present after everything has been initialized */ 356 list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) { 357 tb_pci_deactivate(tunnel); 358 tb_pci_free(tunnel); 359 } 360 tb_switch_remove(tb->root_switch); 361 tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */ 362 } 363 364 static int tb_start(struct tb *tb) 365 { 366 struct tb_cm *tcm = tb_priv(tb); 367 int ret; 368 369 tb->root_switch = tb_switch_alloc(tb, &tb->dev, 0); 370 if (!tb->root_switch) 371 return -ENOMEM; 372 373 /* 374 * ICM firmware upgrade needs running firmware and in native 375 * mode that is not available so disable firmware upgrade of the 376 * root switch. 377 */ 378 tb->root_switch->no_nvm_upgrade = true; 379 380 ret = tb_switch_configure(tb->root_switch); 381 if (ret) { 382 tb_switch_put(tb->root_switch); 383 return ret; 384 } 385 386 /* Announce the switch to the world */ 387 ret = tb_switch_add(tb->root_switch); 388 if (ret) { 389 tb_switch_put(tb->root_switch); 390 return ret; 391 } 392 393 /* Full scan to discover devices added before the driver was loaded. */ 394 tb_scan_switch(tb->root_switch); 395 tb_activate_pcie_devices(tb); 396 397 /* Allow tb_handle_hotplug to progress events */ 398 tcm->hotplug_active = true; 399 return 0; 400 } 401 402 static int tb_suspend_noirq(struct tb *tb) 403 { 404 struct tb_cm *tcm = tb_priv(tb); 405 406 tb_info(tb, "suspending...\n"); 407 tb_switch_suspend(tb->root_switch); 408 tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */ 409 tb_info(tb, "suspend finished\n"); 410 411 return 0; 412 } 413 414 static int tb_resume_noirq(struct tb *tb) 415 { 416 struct tb_cm *tcm = tb_priv(tb); 417 struct tb_pci_tunnel *tunnel, *n; 418 419 tb_info(tb, "resuming...\n"); 420 421 /* remove any pci devices the firmware might have setup */ 422 tb_switch_reset(tb, 0); 423 424 tb_switch_resume(tb->root_switch); 425 tb_free_invalid_tunnels(tb); 426 tb_free_unplugged_children(tb->root_switch); 427 list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) 428 tb_pci_restart(tunnel); 429 if (!list_empty(&tcm->tunnel_list)) { 430 /* 431 * the pcie links need some time to get going. 432 * 100ms works for me... 433 */ 434 tb_info(tb, "tunnels restarted, sleeping for 100ms\n"); 435 msleep(100); 436 } 437 /* Allow tb_handle_hotplug to progress events */ 438 tcm->hotplug_active = true; 439 tb_info(tb, "resume finished\n"); 440 441 return 0; 442 } 443 444 static const struct tb_cm_ops tb_cm_ops = { 445 .start = tb_start, 446 .stop = tb_stop, 447 .suspend_noirq = tb_suspend_noirq, 448 .resume_noirq = tb_resume_noirq, 449 .handle_event = tb_handle_event, 450 }; 451 452 struct tb *tb_probe(struct tb_nhi *nhi) 453 { 454 struct tb_cm *tcm; 455 struct tb *tb; 456 457 if (!x86_apple_machine) 458 return NULL; 459 460 tb = tb_domain_alloc(nhi, sizeof(*tcm)); 461 if (!tb) 462 return NULL; 463 464 tb->security_level = TB_SECURITY_NONE; 465 tb->cm_ops = &tb_cm_ops; 466 467 tcm = tb_priv(tb); 468 INIT_LIST_HEAD(&tcm->tunnel_list); 469 470 return tb; 471 } 472