drivers/pci/hotplug/pciehp_ctrl.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * PCI Express Hot Plug Controller Driver
   4  *
   5  * Copyright (C) 1995,2001 Compaq Computer Corporation
   6  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
   7  * Copyright (C) 2001 IBM Corp.
   8  * Copyright (C) 2003-2004 Intel Corporation
   9  *
  10  * All rights reserved.
  11  *
  12  * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
  13  *
  14  */
  15
  16 #define dev_fmt(fmt) "pciehp: " fmt
  17
  18 #include <linux/kernel.h>
  19 #include <linux/types.h>
  20 #include <linux/pm_runtime.h>
  21 #include <linux/pci.h>
  22 #include "pciehp.h"
  23
  24 /* The following routines constitute the bulk of the
  25    hotplug controller logic
  26  */
  27
  28 #define SAFE_REMOVAL     true
  29 #define SURPRISE_REMOVAL false
  30
  31 static void set_slot_off(struct controller *ctrl)
  32 {
  33         /*
  34          * Turn off slot, turn on attention indicator, turn off power
  35          * indicator
  36          */
  37         if (POWER_CTRL(ctrl)) {
  38                 pciehp_power_off_slot(ctrl);
  39
  40                 /*
  41                  * After turning power off, we must wait for at least 1 second
  42                  * before taking any action that relies on power having been
  43                  * removed from the slot/adapter.
  44                  */
  45                 msleep(1000);
  46         }
  47
  48         pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
  49                               PCI_EXP_SLTCTL_ATTN_IND_ON);
  50 }
  51
  52 /**
  53  * board_added - Called after a board has been added to the system.
  54  * @ctrl: PCIe hotplug controller where board is added
  55  *
  56  * Turns power on for the board.
  57  * Configures board.
  58  */
  59 static int board_added(struct controller *ctrl)
  60 {
  61         int retval = 0;
  62         struct pci_bus *parent = ctrl->pcie->port->subordinate;
  63
  64         if (POWER_CTRL(ctrl)) {
  65                 /* Power on slot */
  66                 retval = pciehp_power_on_slot(ctrl);
  67                 if (retval)
  68                         return retval;
  69         }
  70
  71         pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_BLINK,
  72                               INDICATOR_NOOP);
  73
  74         /* Check link training status */
  75         retval = pciehp_check_link_status(ctrl);
  76         if (retval)
  77                 goto err_exit;
  78
  79         /* Check for a power fault */
  80         if (ctrl->power_fault_detected || pciehp_query_power_fault(ctrl)) {
  81                 ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(ctrl));
  82                 retval = -EIO;
  83                 goto err_exit;
  84         }
  85
  86         retval = pciehp_configure_device(ctrl);
  87         if (retval) {
  88                 if (retval != -EEXIST) {
  89                         ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
  90                                  pci_domain_nr(parent), parent->number);
  91                         goto err_exit;
  92                 }
  93         }
  94
  95         pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_ON,
  96                               PCI_EXP_SLTCTL_ATTN_IND_OFF);
  97         return 0;
  98
  99 err_exit:
 100         set_slot_off(ctrl);
 101         return retval;
 102 }
 103
 104 /**
 105  * remove_board - Turn off slot and Power Indicator
 106  * @ctrl: PCIe hotplug controller where board is being removed
 107  * @safe_removal: whether the board is safely removed (versus surprise removed)
 108  */
 109 static void remove_board(struct controller *ctrl, bool safe_removal)
 110 {
 111         pciehp_unconfigure_device(ctrl, safe_removal);
 112
 113         if (POWER_CTRL(ctrl)) {
 114                 pciehp_power_off_slot(ctrl);
 115
 116                 /*
 117                  * After turning power off, we must wait for at least 1 second
 118                  * before taking any action that relies on power having been
 119                  * removed from the slot/adapter.
 120                  */
 121                 msleep(1000);
 122
 123                 /* Ignore link or presence changes caused by power off */
 124                 atomic_and(~(PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_PDC),
 125                            &ctrl->pending_events);
 126         }
 127
 128         pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
 129                               INDICATOR_NOOP);
 130 }
 131
 132 static int pciehp_enable_slot(struct controller *ctrl);
 133 static int pciehp_disable_slot(struct controller *ctrl, bool safe_removal);
 134
 135 void pciehp_request(struct controller *ctrl, int action)
 136 {
 137         atomic_or(action, &ctrl->pending_events);
 138         if (!pciehp_poll_mode)
 139                 irq_wake_thread(ctrl->pcie->irq, ctrl);
 140 }
 141
 142 void pciehp_queue_pushbutton_work(struct work_struct *work)
 143 {
 144         struct controller *ctrl = container_of(work, struct controller,
 145                                                button_work.work);
 146
 147         mutex_lock(&ctrl->state_lock);
 148         switch (ctrl->state) {
 149         case BLINKINGOFF_STATE:
 150                 pciehp_request(ctrl, DISABLE_SLOT);
 151                 break;
 152         case BLINKINGON_STATE:
 153                 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
 154                 break;
 155         default:
 156                 break;
 157         }
 158         mutex_unlock(&ctrl->state_lock);
 159 }
 160
 161 void pciehp_handle_button_press(struct controller *ctrl)
 162 {
 163         mutex_lock(&ctrl->state_lock);
 164         switch (ctrl->state) {
 165         case OFF_STATE:
 166         case ON_STATE:
 167                 if (ctrl->state == ON_STATE) {
 168                         ctrl->state = BLINKINGOFF_STATE;
 169                         ctrl_info(ctrl, "Slot(%s): Powering off due to button press\n",
 170                                   slot_name(ctrl));
 171                 } else {
 172                         ctrl->state = BLINKINGON_STATE;
 173                         ctrl_info(ctrl, "Slot(%s) Powering on due to button press\n",
 174                                   slot_name(ctrl));
 175                 }
 176                 /* blink power indicator and turn off attention */
 177                 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_BLINK,
 178                                       PCI_EXP_SLTCTL_ATTN_IND_OFF);
 179                 schedule_delayed_work(&ctrl->button_work, 5 * HZ);
 180                 break;
 181         case BLINKINGOFF_STATE:
 182         case BLINKINGON_STATE:
 183                 /*
 184                  * Cancel if we are still blinking; this means that we
 185                  * press the attention again before the 5 sec. limit
 186                  * expires to cancel hot-add or hot-remove
 187                  */
 188                 ctrl_info(ctrl, "Slot(%s): Button cancel\n", slot_name(ctrl));
 189                 cancel_delayed_work(&ctrl->button_work);
 190                 if (ctrl->state == BLINKINGOFF_STATE) {
 191                         ctrl->state = ON_STATE;
 192                         pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_ON,
 193                                               PCI_EXP_SLTCTL_ATTN_IND_OFF);
 194                 } else {
 195                         ctrl->state = OFF_STATE;
 196                         pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
 197                                               PCI_EXP_SLTCTL_ATTN_IND_OFF);
 198                 }
 199                 ctrl_info(ctrl, "Slot(%s): Action canceled due to button press\n",
 200                           slot_name(ctrl));
 201                 break;
 202         default:
 203                 ctrl_err(ctrl, "Slot(%s): Ignoring invalid state %#x\n",
 204                          slot_name(ctrl), ctrl->state);
 205                 break;
 206         }
 207         mutex_unlock(&ctrl->state_lock);
 208 }
 209
 210 void pciehp_handle_disable_request(struct controller *ctrl)
 211 {
 212         mutex_lock(&ctrl->state_lock);
 213         switch (ctrl->state) {
 214         case BLINKINGON_STATE:
 215         case BLINKINGOFF_STATE:
 216                 cancel_delayed_work(&ctrl->button_work);
 217                 break;
 218         }
 219         ctrl->state = POWEROFF_STATE;
 220         mutex_unlock(&ctrl->state_lock);
 221
 222         ctrl->request_result = pciehp_disable_slot(ctrl, SAFE_REMOVAL);
 223 }
 224
 225 void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events)
 226 {
 227         int present, link_active;
 228
 229         /*
 230          * If the slot is on and presence or link has changed, turn it off.
 231          * Even if it's occupied again, we cannot assume the card is the same.
 232          */
 233         mutex_lock(&ctrl->state_lock);
 234         switch (ctrl->state) {
 235         case BLINKINGOFF_STATE:
 236                 cancel_delayed_work(&ctrl->button_work);
 237                 fallthrough;
 238         case ON_STATE:
 239                 ctrl->state = POWEROFF_STATE;
 240                 mutex_unlock(&ctrl->state_lock);
 241                 if (events & PCI_EXP_SLTSTA_DLLSC)
 242                         ctrl_info(ctrl, "Slot(%s): Link Down\n",
 243                                   slot_name(ctrl));
 244                 if (events & PCI_EXP_SLTSTA_PDC)
 245                         ctrl_info(ctrl, "Slot(%s): Card not present\n",
 246                                   slot_name(ctrl));
 247                 pciehp_disable_slot(ctrl, SURPRISE_REMOVAL);
 248                 break;
 249         default:
 250                 mutex_unlock(&ctrl->state_lock);
 251                 break;
 252         }
 253
 254         /* Turn the slot on if it's occupied or link is up */
 255         mutex_lock(&ctrl->state_lock);
 256         present = pciehp_card_present(ctrl);
 257         link_active = pciehp_check_link_active(ctrl);
 258         if (present <= 0 && link_active <= 0) {
 259                 if (ctrl->state == BLINKINGON_STATE) {
 260                         ctrl->state = OFF_STATE;
 261                         cancel_delayed_work(&ctrl->button_work);
 262                         pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
 263                                               INDICATOR_NOOP);
 264                         ctrl_info(ctrl, "Slot(%s): Card not present\n",
 265                                   slot_name(ctrl));
 266                 }
 267                 mutex_unlock(&ctrl->state_lock);
 268                 return;
 269         }
 270
 271         switch (ctrl->state) {
 272         case BLINKINGON_STATE:
 273                 cancel_delayed_work(&ctrl->button_work);
 274                 fallthrough;
 275         case OFF_STATE:
 276                 ctrl->state = POWERON_STATE;
 277                 mutex_unlock(&ctrl->state_lock);
 278                 if (present)
 279                         ctrl_info(ctrl, "Slot(%s): Card present\n",
 280                                   slot_name(ctrl));
 281                 if (link_active)
 282                         ctrl_info(ctrl, "Slot(%s): Link Up\n",
 283                                   slot_name(ctrl));
 284                 ctrl->request_result = pciehp_enable_slot(ctrl);
 285                 break;
 286         default:
 287                 mutex_unlock(&ctrl->state_lock);
 288                 break;
 289         }
 290 }
 291
 292 static int __pciehp_enable_slot(struct controller *ctrl)
 293 {
 294         u8 getstatus = 0;
 295
 296         if (MRL_SENS(ctrl)) {
 297                 pciehp_get_latch_status(ctrl, &getstatus);
 298                 if (getstatus) {
 299                         ctrl_info(ctrl, "Slot(%s): Latch open\n",
 300                                   slot_name(ctrl));
 301                         return -ENODEV;
 302                 }
 303         }
 304
 305         if (POWER_CTRL(ctrl)) {
 306                 pciehp_get_power_status(ctrl, &getstatus);
 307                 if (getstatus) {
 308                         ctrl_info(ctrl, "Slot(%s): Already enabled\n",
 309                                   slot_name(ctrl));
 310                         return 0;
 311                 }
 312         }
 313
 314         return board_added(ctrl);
 315 }
 316
 317 static int pciehp_enable_slot(struct controller *ctrl)
 318 {
 319         int ret;
 320
 321         pm_runtime_get_sync(&ctrl->pcie->port->dev);
 322         ret = __pciehp_enable_slot(ctrl);
 323         if (ret && ATTN_BUTTN(ctrl))
 324                 /* may be blinking */
 325                 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
 326                                       INDICATOR_NOOP);
 327         pm_runtime_put(&ctrl->pcie->port->dev);
 328
 329         mutex_lock(&ctrl->state_lock);
 330         ctrl->state = ret ? OFF_STATE : ON_STATE;
 331         mutex_unlock(&ctrl->state_lock);
 332
 333         return ret;
 334 }
 335
 336 static int __pciehp_disable_slot(struct controller *ctrl, bool safe_removal)
 337 {
 338         u8 getstatus = 0;
 339
 340         if (POWER_CTRL(ctrl)) {
 341                 pciehp_get_power_status(ctrl, &getstatus);
 342                 if (!getstatus) {
 343                         ctrl_info(ctrl, "Slot(%s): Already disabled\n",
 344                                   slot_name(ctrl));
 345                         return -EINVAL;
 346                 }
 347         }
 348
 349         remove_board(ctrl, safe_removal);
 350         return 0;
 351 }
 352
 353 static int pciehp_disable_slot(struct controller *ctrl, bool safe_removal)
 354 {
 355         int ret;
 356
 357         pm_runtime_get_sync(&ctrl->pcie->port->dev);
 358         ret = __pciehp_disable_slot(ctrl, safe_removal);
 359         pm_runtime_put(&ctrl->pcie->port->dev);
 360
 361         mutex_lock(&ctrl->state_lock);
 362         ctrl->state = OFF_STATE;
 363         mutex_unlock(&ctrl->state_lock);
 364
 365         return ret;
 366 }
 367
 368 int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot)
 369 {
 370         struct controller *ctrl = to_ctrl(hotplug_slot);
 371
 372         mutex_lock(&ctrl->state_lock);
 373         switch (ctrl->state) {
 374         case BLINKINGON_STATE:
 375         case OFF_STATE:
 376                 mutex_unlock(&ctrl->state_lock);
 377                 /*
 378                  * The IRQ thread becomes a no-op if the user pulls out the
 379                  * card before the thread wakes up, so initialize to -ENODEV.
 380                  */
 381                 ctrl->request_result = -ENODEV;
 382                 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
 383                 wait_event(ctrl->requester,
 384                            !atomic_read(&ctrl->pending_events) &&
 385                            !ctrl->ist_running);
 386                 return ctrl->request_result;
 387         case POWERON_STATE:
 388                 ctrl_info(ctrl, "Slot(%s): Already in powering on state\n",
 389                           slot_name(ctrl));
 390                 break;
 391         case BLINKINGOFF_STATE:
 392         case ON_STATE:
 393         case POWEROFF_STATE:
 394                 ctrl_info(ctrl, "Slot(%s): Already enabled\n",
 395                           slot_name(ctrl));
 396                 break;
 397         default:
 398                 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
 399                          slot_name(ctrl), ctrl->state);
 400                 break;
 401         }
 402         mutex_unlock(&ctrl->state_lock);
 403
 404         return -ENODEV;
 405 }
 406
 407 int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot)
 408 {
 409         struct controller *ctrl = to_ctrl(hotplug_slot);
 410
 411         mutex_lock(&ctrl->state_lock);
 412         switch (ctrl->state) {
 413         case BLINKINGOFF_STATE:
 414         case ON_STATE:
 415                 mutex_unlock(&ctrl->state_lock);
 416                 pciehp_request(ctrl, DISABLE_SLOT);
 417                 wait_event(ctrl->requester,
 418                            !atomic_read(&ctrl->pending_events) &&
 419                            !ctrl->ist_running);
 420                 return ctrl->request_result;
 421         case POWEROFF_STATE:
 422                 ctrl_info(ctrl, "Slot(%s): Already in powering off state\n",
 423                           slot_name(ctrl));
 424                 break;
 425         case BLINKINGON_STATE:
 426         case OFF_STATE:
 427         case POWERON_STATE:
 428                 ctrl_info(ctrl, "Slot(%s): Already disabled\n",
 429                           slot_name(ctrl));
 430                 break;
 431         default:
 432                 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
 433                          slot_name(ctrl), ctrl->state);
 434                 break;
 435         }
 436         mutex_unlock(&ctrl->state_lock);
 437
 438         return -ENODEV;
 439 }