drivers/thunderbolt/tb.c

   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                         continue;
 229                 }
 230
 231                 list_add(&tunnel->list, &tcm->tunnel_list);
 232         }
 233 }
 234
 235 /* hotplug handling */
 236
 237 struct tb_hotplug_event {
 238         struct work_struct work;
 239         struct tb *tb;
 240         u64 route;
 241         u8 port;
 242         bool unplug;
 243 };
 244
 245 /**
 246  * tb_handle_hotplug() - handle hotplug event
 247  *
 248  * Executes on tb->wq.
 249  */
 250 static void tb_handle_hotplug(struct work_struct *work)
 251 {
 252         struct tb_hotplug_event *ev = container_of(work, typeof(*ev), work);
 253         struct tb *tb = ev->tb;
 254         struct tb_cm *tcm = tb_priv(tb);
 255         struct tb_switch *sw;
 256         struct tb_port *port;
 257         mutex_lock(&tb->lock);
 258         if (!tcm->hotplug_active)
 259                 goto out; /* during init, suspend or shutdown */
 260
 261         sw = tb_switch_find_by_route(tb, ev->route);
 262         if (!sw) {
 263                 tb_warn(tb,
 264                         "hotplug event from non existent switch %llx:%x (unplug: %d)\n",
 265                         ev->route, ev->port, ev->unplug);
 266                 goto out;
 267         }
 268         if (ev->port > sw->config.max_port_number) {
 269                 tb_warn(tb,
 270                         "hotplug event from non existent port %llx:%x (unplug: %d)\n",
 271                         ev->route, ev->port, ev->unplug);
 272                 goto put_sw;
 273         }
 274         port = &sw->ports[ev->port];
 275         if (tb_is_upstream_port(port)) {
 276                 tb_warn(tb,
 277                         "hotplug event for upstream port %llx:%x (unplug: %d)\n",
 278                         ev->route, ev->port, ev->unplug);
 279                 goto put_sw;
 280         }
 281         if (ev->unplug) {
 282                 if (port->remote) {
 283                         tb_port_info(port, "unplugged\n");
 284                         tb_sw_set_unplugged(port->remote->sw);
 285                         tb_free_invalid_tunnels(tb);
 286                         tb_switch_remove(port->remote->sw);
 287                         port->remote = NULL;
 288                 } else {
 289                         tb_port_info(port,
 290                                      "got unplug event for disconnected port, ignoring\n");
 291                 }
 292         } else if (port->remote) {
 293                 tb_port_info(port,
 294                              "got plug event for connected port, ignoring\n");
 295         } else {
 296                 tb_port_info(port, "hotplug: scanning\n");
 297                 tb_scan_port(port);
 298                 if (!port->remote) {
 299                         tb_port_info(port, "hotplug: no switch found\n");
 300                 } else if (port->remote->sw->config.depth > 1) {
 301                         tb_sw_warn(port->remote->sw,
 302                                    "hotplug: chaining not supported\n");
 303                 } else {
 304                         tb_sw_info(port->remote->sw,
 305                                    "hotplug: activating pcie devices\n");
 306                         tb_activate_pcie_devices(tb);
 307                 }
 308         }
 309
 310 put_sw:
 311         tb_switch_put(sw);
 312 out:
 313         mutex_unlock(&tb->lock);
 314         kfree(ev);
 315 }
 316
 317 /**
 318  * tb_schedule_hotplug_handler() - callback function for the control channel
 319  *
 320  * Delegates to tb_handle_hotplug.
 321  */
 322 static void tb_handle_event(struct tb *tb, enum tb_cfg_pkg_type type,
 323                             const void *buf, size_t size)
 324 {
 325         const struct cfg_event_pkg *pkg = buf;
 326         struct tb_hotplug_event *ev;
 327         u64 route;
 328
 329         if (type != TB_CFG_PKG_EVENT) {
 330                 tb_warn(tb, "unexpected event %#x, ignoring\n", type);
 331                 return;
 332         }
 333
 334         route = tb_cfg_get_route(&pkg->header);
 335
 336         if (tb_cfg_error(tb->ctl, route, pkg->port,
 337                          TB_CFG_ERROR_ACK_PLUG_EVENT)) {
 338                 tb_warn(tb, "could not ack plug event on %llx:%x\n", route,
 339                         pkg->port);
 340         }
 341
 342         ev = kmalloc(sizeof(*ev), GFP_KERNEL);
 343         if (!ev)
 344                 return;
 345         INIT_WORK(&ev->work, tb_handle_hotplug);
 346         ev->tb = tb;
 347         ev->route = route;
 348         ev->port = pkg->port;
 349         ev->unplug = pkg->unplug;
 350         queue_work(tb->wq, &ev->work);
 351 }
 352
 353 static void tb_stop(struct tb *tb)
 354 {
 355         struct tb_cm *tcm = tb_priv(tb);
 356         struct tb_pci_tunnel *tunnel;
 357         struct tb_pci_tunnel *n;
 358
 359         /* tunnels are only present after everything has been initialized */
 360         list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
 361                 tb_pci_deactivate(tunnel);
 362                 tb_pci_free(tunnel);
 363         }
 364         tb_switch_remove(tb->root_switch);
 365         tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
 366 }
 367
 368 static int tb_start(struct tb *tb)
 369 {
 370         struct tb_cm *tcm = tb_priv(tb);
 371         int ret;
 372
 373         tb->root_switch = tb_switch_alloc(tb, &tb->dev, 0);
 374         if (!tb->root_switch)
 375                 return -ENOMEM;
 376
 377         /*
 378          * ICM firmware upgrade needs running firmware and in native
 379          * mode that is not available so disable firmware upgrade of the
 380          * root switch.
 381          */
 382         tb->root_switch->no_nvm_upgrade = true;
 383
 384         ret = tb_switch_configure(tb->root_switch);
 385         if (ret) {
 386                 tb_switch_put(tb->root_switch);
 387                 return ret;
 388         }
 389
 390         /* Announce the switch to the world */
 391         ret = tb_switch_add(tb->root_switch);
 392         if (ret) {
 393                 tb_switch_put(tb->root_switch);
 394                 return ret;
 395         }
 396
 397         /* Full scan to discover devices added before the driver was loaded. */
 398         tb_scan_switch(tb->root_switch);
 399         tb_activate_pcie_devices(tb);
 400
 401         /* Allow tb_handle_hotplug to progress events */
 402         tcm->hotplug_active = true;
 403         return 0;
 404 }
 405
 406 static int tb_suspend_noirq(struct tb *tb)
 407 {
 408         struct tb_cm *tcm = tb_priv(tb);
 409
 410         tb_info(tb, "suspending...\n");
 411         tb_switch_suspend(tb->root_switch);
 412         tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
 413         tb_info(tb, "suspend finished\n");
 414
 415         return 0;
 416 }
 417
 418 static int tb_resume_noirq(struct tb *tb)
 419 {
 420         struct tb_cm *tcm = tb_priv(tb);
 421         struct tb_pci_tunnel *tunnel, *n;
 422
 423         tb_info(tb, "resuming...\n");
 424
 425         /* remove any pci devices the firmware might have setup */
 426         tb_switch_reset(tb, 0);
 427
 428         tb_switch_resume(tb->root_switch);
 429         tb_free_invalid_tunnels(tb);
 430         tb_free_unplugged_children(tb->root_switch);
 431         list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list)
 432                 tb_pci_restart(tunnel);
 433         if (!list_empty(&tcm->tunnel_list)) {
 434                 /*
 435                  * the pcie links need some time to get going.
 436                  * 100ms works for me...
 437                  */
 438                 tb_info(tb, "tunnels restarted, sleeping for 100ms\n");
 439                 msleep(100);
 440         }
 441          /* Allow tb_handle_hotplug to progress events */
 442         tcm->hotplug_active = true;
 443         tb_info(tb, "resume finished\n");
 444
 445         return 0;
 446 }
 447
 448 static const struct tb_cm_ops tb_cm_ops = {
 449         .start = tb_start,
 450         .stop = tb_stop,
 451         .suspend_noirq = tb_suspend_noirq,
 452         .resume_noirq = tb_resume_noirq,
 453         .handle_event = tb_handle_event,
 454 };
 455
 456 struct tb *tb_probe(struct tb_nhi *nhi)
 457 {
 458         struct tb_cm *tcm;
 459         struct tb *tb;
 460
 461         if (!x86_apple_machine)
 462                 return NULL;
 463
 464         tb = tb_domain_alloc(nhi, sizeof(*tcm));
 465         if (!tb)
 466                 return NULL;
 467
 468         tb->security_level = TB_SECURITY_NONE;
 469         tb->cm_ops = &tb_cm_ops;
 470
 471         tcm = tb_priv(tb);
 472         INIT_LIST_HEAD(&tcm->tunnel_list);
 473
 474         return tb;
 475 }