drivers/pci/hotplug/pciehp_ctrl.c

   1 /*
   2  * PCI Express Hot Plug Controller Driver
   3  *
   4  * Copyright (C) 1995,2001 Compaq Computer Corporation
   5  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
   6  * Copyright (C) 2001 IBM Corp.
   7  * Copyright (C) 2003-2004 Intel Corporation
   8  *
   9  * All rights reserved.
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or (at
  14  * your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  19  * NON INFRINGEMENT.  See the GNU General Public License for more
  20  * details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25  *
  26  * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
  27  *
  28  */
  29
  30 #include <linux/module.h>
  31 #include <linux/kernel.h>
  32 #include <linux/types.h>
  33 #include <linux/slab.h>
  34 #include <linux/pm_runtime.h>
  35 #include <linux/pci.h>
  36 #include "../pci.h"
  37 #include "pciehp.h"
  38
  39 static void interrupt_event_handler(struct work_struct *work);
  40
  41 void pciehp_queue_interrupt_event(struct slot *p_slot, u32 event_type)
  42 {
  43         struct event_info *info;
  44
  45         info = kmalloc(sizeof(*info), GFP_ATOMIC);
  46         if (!info) {
  47                 ctrl_err(p_slot->ctrl, "dropped event %d (ENOMEM)\n", event_type);
  48                 return;
  49         }
  50
  51         INIT_WORK(&info->work, interrupt_event_handler);
  52         info->event_type = event_type;
  53         info->p_slot = p_slot;
  54         queue_work(p_slot->wq, &info->work);
  55 }
  56
  57 /* The following routines constitute the bulk of the
  58    hotplug controller logic
  59  */
  60
  61 static void set_slot_off(struct controller *ctrl, struct slot *pslot)
  62 {
  63         /* turn off slot, turn on Amber LED, turn off Green LED if supported*/
  64         if (POWER_CTRL(ctrl)) {
  65                 pciehp_power_off_slot(pslot);
  66
  67                 /*
  68                  * After turning power off, we must wait for at least 1 second
  69                  * before taking any action that relies on power having been
  70                  * removed from the slot/adapter.
  71                  */
  72                 msleep(1000);
  73         }
  74
  75         pciehp_green_led_off(pslot);
  76         pciehp_set_attention_status(pslot, 1);
  77 }
  78
  79 /**
  80  * board_added - Called after a board has been added to the system.
  81  * @p_slot: &slot where board is added
  82  *
  83  * Turns power on for the board.
  84  * Configures board.
  85  */
  86 static int board_added(struct slot *p_slot)
  87 {
  88         int retval = 0;
  89         struct controller *ctrl = p_slot->ctrl;
  90         struct pci_bus *parent = ctrl->pcie->port->subordinate;
  91
  92         if (POWER_CTRL(ctrl)) {
  93                 /* Power on slot */
  94                 retval = pciehp_power_on_slot(p_slot);
  95                 if (retval)
  96                         return retval;
  97         }
  98
  99         pciehp_green_led_blink(p_slot);
 100
 101         /* Check link training status */
 102         pm_runtime_get_sync(&ctrl->pcie->port->dev);
 103         retval = pciehp_check_link_status(ctrl);
 104         if (retval) {
 105                 ctrl_err(ctrl, "Failed to check link status\n");
 106                 goto err_exit;
 107         }
 108
 109         /* Check for a power fault */
 110         if (ctrl->power_fault_detected || pciehp_query_power_fault(p_slot)) {
 111                 ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(p_slot));
 112                 retval = -EIO;
 113                 goto err_exit;
 114         }
 115
 116         retval = pciehp_configure_device(p_slot);
 117         if (retval) {
 118                 ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
 119                          pci_domain_nr(parent), parent->number);
 120                 if (retval != -EEXIST)
 121                         goto err_exit;
 122         }
 123         pm_runtime_put(&ctrl->pcie->port->dev);
 124
 125         pciehp_green_led_on(p_slot);
 126         pciehp_set_attention_status(p_slot, 0);
 127         return 0;
 128
 129 err_exit:
 130         pm_runtime_put(&ctrl->pcie->port->dev);
 131         set_slot_off(ctrl, p_slot);
 132         return retval;
 133 }
 134
 135 /**
 136  * remove_board - Turns off slot and LEDs
 137  * @p_slot: slot where board is being removed
 138  */
 139 static int remove_board(struct slot *p_slot)
 140 {
 141         int retval;
 142         struct controller *ctrl = p_slot->ctrl;
 143
 144         pm_runtime_get_sync(&ctrl->pcie->port->dev);
 145         retval = pciehp_unconfigure_device(p_slot);
 146         pm_runtime_put(&ctrl->pcie->port->dev);
 147         if (retval)
 148                 return retval;
 149
 150         if (POWER_CTRL(ctrl)) {
 151                 pciehp_power_off_slot(p_slot);
 152
 153                 /*
 154                  * After turning power off, we must wait for at least 1 second
 155                  * before taking any action that relies on power having been
 156                  * removed from the slot/adapter.
 157                  */
 158                 msleep(1000);
 159         }
 160
 161         /* turn off Green LED */
 162         pciehp_green_led_off(p_slot);
 163         return 0;
 164 }
 165
 166 struct power_work_info {
 167         struct slot *p_slot;
 168         struct work_struct work;
 169         unsigned int req;
 170 #define DISABLE_REQ 0
 171 #define ENABLE_REQ  1
 172 };
 173
 174 /**
 175  * pciehp_power_thread - handle pushbutton events
 176  * @work: &struct work_struct describing work to be done
 177  *
 178  * Scheduled procedure to handle blocking stuff for the pushbuttons.
 179  * Handles all pending events and exits.
 180  */
 181 static void pciehp_power_thread(struct work_struct *work)
 182 {
 183         struct power_work_info *info =
 184                 container_of(work, struct power_work_info, work);
 185         struct slot *p_slot = info->p_slot;
 186         int ret;
 187
 188         switch (info->req) {
 189         case DISABLE_REQ:
 190                 mutex_lock(&p_slot->hotplug_lock);
 191                 pciehp_disable_slot(p_slot);
 192                 mutex_unlock(&p_slot->hotplug_lock);
 193                 mutex_lock(&p_slot->lock);
 194                 p_slot->state = STATIC_STATE;
 195                 mutex_unlock(&p_slot->lock);
 196                 break;
 197         case ENABLE_REQ:
 198                 mutex_lock(&p_slot->hotplug_lock);
 199                 ret = pciehp_enable_slot(p_slot);
 200                 mutex_unlock(&p_slot->hotplug_lock);
 201                 if (ret)
 202                         pciehp_green_led_off(p_slot);
 203                 mutex_lock(&p_slot->lock);
 204                 p_slot->state = STATIC_STATE;
 205                 mutex_unlock(&p_slot->lock);
 206                 break;
 207         default:
 208                 break;
 209         }
 210
 211         kfree(info);
 212 }
 213
 214 static void pciehp_queue_power_work(struct slot *p_slot, int req)
 215 {
 216         struct power_work_info *info;
 217
 218         p_slot->state = (req == ENABLE_REQ) ? POWERON_STATE : POWEROFF_STATE;
 219
 220         info = kmalloc(sizeof(*info), GFP_KERNEL);
 221         if (!info) {
 222                 ctrl_err(p_slot->ctrl, "no memory to queue %s request\n",
 223                          (req == ENABLE_REQ) ? "poweron" : "poweroff");
 224                 return;
 225         }
 226         info->p_slot = p_slot;
 227         INIT_WORK(&info->work, pciehp_power_thread);
 228         info->req = req;
 229         queue_work(p_slot->wq, &info->work);
 230 }
 231
 232 void pciehp_queue_pushbutton_work(struct work_struct *work)
 233 {
 234         struct slot *p_slot = container_of(work, struct slot, work.work);
 235
 236         mutex_lock(&p_slot->lock);
 237         switch (p_slot->state) {
 238         case BLINKINGOFF_STATE:
 239                 pciehp_queue_power_work(p_slot, DISABLE_REQ);
 240                 break;
 241         case BLINKINGON_STATE:
 242                 pciehp_queue_power_work(p_slot, ENABLE_REQ);
 243                 break;
 244         default:
 245                 break;
 246         }
 247         mutex_unlock(&p_slot->lock);
 248 }
 249
 250 /*
 251  * Note: This function must be called with slot->lock held
 252  */
 253 static void handle_button_press_event(struct slot *p_slot)
 254 {
 255         struct controller *ctrl = p_slot->ctrl;
 256         u8 getstatus;
 257
 258         switch (p_slot->state) {
 259         case STATIC_STATE:
 260                 pciehp_get_power_status(p_slot, &getstatus);
 261                 if (getstatus) {
 262                         p_slot->state = BLINKINGOFF_STATE;
 263                         ctrl_info(ctrl, "Slot(%s): Powering off due to button press\n",
 264                                   slot_name(p_slot));
 265                 } else {
 266                         p_slot->state = BLINKINGON_STATE;
 267                         ctrl_info(ctrl, "Slot(%s) Powering on due to button press\n",
 268                                   slot_name(p_slot));
 269                 }
 270                 /* blink green LED and turn off amber */
 271                 pciehp_green_led_blink(p_slot);
 272                 pciehp_set_attention_status(p_slot, 0);
 273                 queue_delayed_work(p_slot->wq, &p_slot->work, 5*HZ);
 274                 break;
 275         case BLINKINGOFF_STATE:
 276         case BLINKINGON_STATE:
 277                 /*
 278                  * Cancel if we are still blinking; this means that we
 279                  * press the attention again before the 5 sec. limit
 280                  * expires to cancel hot-add or hot-remove
 281                  */
 282                 ctrl_info(ctrl, "Slot(%s): Button cancel\n", slot_name(p_slot));
 283                 cancel_delayed_work(&p_slot->work);
 284                 if (p_slot->state == BLINKINGOFF_STATE)
 285                         pciehp_green_led_on(p_slot);
 286                 else
 287                         pciehp_green_led_off(p_slot);
 288                 pciehp_set_attention_status(p_slot, 0);
 289                 ctrl_info(ctrl, "Slot(%s): Action canceled due to button press\n",
 290                           slot_name(p_slot));
 291                 p_slot->state = STATIC_STATE;
 292                 break;
 293         case POWEROFF_STATE:
 294         case POWERON_STATE:
 295                 /*
 296                  * Ignore if the slot is on power-on or power-off state;
 297                  * this means that the previous attention button action
 298                  * to hot-add or hot-remove is undergoing
 299                  */
 300                 ctrl_info(ctrl, "Slot(%s): Button ignored\n",
 301                           slot_name(p_slot));
 302                 break;
 303         default:
 304                 ctrl_err(ctrl, "Slot(%s): Ignoring invalid state %#x\n",
 305                          slot_name(p_slot), p_slot->state);
 306                 break;
 307         }
 308 }
 309
 310 /*
 311  * Note: This function must be called with slot->lock held
 312  */
 313 static void handle_link_event(struct slot *p_slot, u32 event)
 314 {
 315         struct controller *ctrl = p_slot->ctrl;
 316
 317         switch (p_slot->state) {
 318         case BLINKINGON_STATE:
 319         case BLINKINGOFF_STATE:
 320                 cancel_delayed_work(&p_slot->work);
 321                 /* Fall through */
 322         case STATIC_STATE:
 323                 pciehp_queue_power_work(p_slot, event == INT_LINK_UP ?
 324                                         ENABLE_REQ : DISABLE_REQ);
 325                 break;
 326         case POWERON_STATE:
 327                 if (event == INT_LINK_UP) {
 328                         ctrl_info(ctrl, "Slot(%s): Link Up event ignored; already powering on\n",
 329                                   slot_name(p_slot));
 330                 } else {
 331                         ctrl_info(ctrl, "Slot(%s): Link Down event queued; currently getting powered on\n",
 332                                   slot_name(p_slot));
 333                         pciehp_queue_power_work(p_slot, DISABLE_REQ);
 334                 }
 335                 break;
 336         case POWEROFF_STATE:
 337                 if (event == INT_LINK_UP) {
 338                         ctrl_info(ctrl, "Slot(%s): Link Up event queued; currently getting powered off\n",
 339                                   slot_name(p_slot));
 340                         pciehp_queue_power_work(p_slot, ENABLE_REQ);
 341                 } else {
 342                         ctrl_info(ctrl, "Slot(%s): Link Down event ignored; already powering off\n",
 343                                   slot_name(p_slot));
 344                 }
 345                 break;
 346         default:
 347                 ctrl_err(ctrl, "Slot(%s): Ignoring invalid state %#x\n",
 348                          slot_name(p_slot), p_slot->state);
 349                 break;
 350         }
 351 }
 352
 353 static void interrupt_event_handler(struct work_struct *work)
 354 {
 355         struct event_info *info = container_of(work, struct event_info, work);
 356         struct slot *p_slot = info->p_slot;
 357         struct controller *ctrl = p_slot->ctrl;
 358
 359         mutex_lock(&p_slot->lock);
 360         switch (info->event_type) {
 361         case INT_BUTTON_PRESS:
 362                 handle_button_press_event(p_slot);
 363                 break;
 364         case INT_POWER_FAULT:
 365                 if (!POWER_CTRL(ctrl))
 366                         break;
 367                 pciehp_set_attention_status(p_slot, 1);
 368                 pciehp_green_led_off(p_slot);
 369                 break;
 370         case INT_PRESENCE_ON:
 371                 pciehp_queue_power_work(p_slot, ENABLE_REQ);
 372                 break;
 373         case INT_PRESENCE_OFF:
 374                 /*
 375                  * Regardless of surprise capability, we need to
 376                  * definitely remove a card that has been pulled out!
 377                  */
 378                 pciehp_queue_power_work(p_slot, DISABLE_REQ);
 379                 break;
 380         case INT_LINK_UP:
 381         case INT_LINK_DOWN:
 382                 handle_link_event(p_slot, info->event_type);
 383                 break;
 384         default:
 385                 break;
 386         }
 387         mutex_unlock(&p_slot->lock);
 388
 389         kfree(info);
 390 }
 391
 392 /*
 393  * Note: This function must be called with slot->hotplug_lock held
 394  */
 395 int pciehp_enable_slot(struct slot *p_slot)
 396 {
 397         u8 getstatus = 0;
 398         struct controller *ctrl = p_slot->ctrl;
 399
 400         pciehp_get_adapter_status(p_slot, &getstatus);
 401         if (!getstatus) {
 402                 ctrl_info(ctrl, "Slot(%s): No adapter\n", slot_name(p_slot));
 403                 return -ENODEV;
 404         }
 405         if (MRL_SENS(p_slot->ctrl)) {
 406                 pciehp_get_latch_status(p_slot, &getstatus);
 407                 if (getstatus) {
 408                         ctrl_info(ctrl, "Slot(%s): Latch open\n",
 409                                   slot_name(p_slot));
 410                         return -ENODEV;
 411                 }
 412         }
 413
 414         if (POWER_CTRL(p_slot->ctrl)) {
 415                 pciehp_get_power_status(p_slot, &getstatus);
 416                 if (getstatus) {
 417                         ctrl_info(ctrl, "Slot(%s): Already enabled\n",
 418                                   slot_name(p_slot));
 419                         return 0;
 420                 }
 421         }
 422
 423         return board_added(p_slot);
 424 }
 425
 426 /*
 427  * Note: This function must be called with slot->hotplug_lock held
 428  */
 429 int pciehp_disable_slot(struct slot *p_slot)
 430 {
 431         u8 getstatus = 0;
 432         struct controller *ctrl = p_slot->ctrl;
 433
 434         if (!p_slot->ctrl)
 435                 return 1;
 436
 437         if (POWER_CTRL(p_slot->ctrl)) {
 438                 pciehp_get_power_status(p_slot, &getstatus);
 439                 if (!getstatus) {
 440                         ctrl_info(ctrl, "Slot(%s): Already disabled\n",
 441                                   slot_name(p_slot));
 442                         return -EINVAL;
 443                 }
 444         }
 445
 446         return remove_board(p_slot);
 447 }
 448
 449 int pciehp_sysfs_enable_slot(struct slot *p_slot)
 450 {
 451         int retval = -ENODEV;
 452         struct controller *ctrl = p_slot->ctrl;
 453
 454         mutex_lock(&p_slot->lock);
 455         switch (p_slot->state) {
 456         case BLINKINGON_STATE:
 457                 cancel_delayed_work(&p_slot->work);
 458         case STATIC_STATE:
 459                 p_slot->state = POWERON_STATE;
 460                 mutex_unlock(&p_slot->lock);
 461                 mutex_lock(&p_slot->hotplug_lock);
 462                 retval = pciehp_enable_slot(p_slot);
 463                 mutex_unlock(&p_slot->hotplug_lock);
 464                 mutex_lock(&p_slot->lock);
 465                 p_slot->state = STATIC_STATE;
 466                 break;
 467         case POWERON_STATE:
 468                 ctrl_info(ctrl, "Slot(%s): Already in powering on state\n",
 469                           slot_name(p_slot));
 470                 break;
 471         case BLINKINGOFF_STATE:
 472         case POWEROFF_STATE:
 473                 ctrl_info(ctrl, "Slot(%s): Already enabled\n",
 474                           slot_name(p_slot));
 475                 break;
 476         default:
 477                 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
 478                          slot_name(p_slot), p_slot->state);
 479                 break;
 480         }
 481         mutex_unlock(&p_slot->lock);
 482
 483         return retval;
 484 }
 485
 486 int pciehp_sysfs_disable_slot(struct slot *p_slot)
 487 {
 488         int retval = -ENODEV;
 489         struct controller *ctrl = p_slot->ctrl;
 490
 491         mutex_lock(&p_slot->lock);
 492         switch (p_slot->state) {
 493         case BLINKINGOFF_STATE:
 494                 cancel_delayed_work(&p_slot->work);
 495         case STATIC_STATE:
 496                 p_slot->state = POWEROFF_STATE;
 497                 mutex_unlock(&p_slot->lock);
 498                 mutex_lock(&p_slot->hotplug_lock);
 499                 retval = pciehp_disable_slot(p_slot);
 500                 mutex_unlock(&p_slot->hotplug_lock);
 501                 mutex_lock(&p_slot->lock);
 502                 p_slot->state = STATIC_STATE;
 503                 break;
 504         case POWEROFF_STATE:
 505                 ctrl_info(ctrl, "Slot(%s): Already in powering off state\n",
 506                           slot_name(p_slot));
 507                 break;
 508         case BLINKINGON_STATE:
 509         case POWERON_STATE:
 510                 ctrl_info(ctrl, "Slot(%s): Already disabled\n",
 511                           slot_name(p_slot));
 512                 break;
 513         default:
 514                 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
 515                          slot_name(p_slot), p_slot->state);
 516                 break;
 517         }
 518         mutex_unlock(&p_slot->lock);
 519
 520         return retval;
 521 }