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 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/types.h>
  19 #include <linux/slab.h>
  20 #include <linux/pm_runtime.h>
  21 #include <linux/pci.h>
  22 #include "../pci.h"
  23 #include "pciehp.h"
  24
  25 /* The following routines constitute the bulk of the
  26    hotplug controller logic
  27  */
  28
  29 static void set_slot_off(struct controller *ctrl, struct slot *pslot)
  30 {
  31         /* turn off slot, turn on Amber LED, turn off Green LED if supported*/
  32         if (POWER_CTRL(ctrl)) {
  33                 pciehp_power_off_slot(pslot);
  34
  35                 /*
  36                  * After turning power off, we must wait for at least 1 second
  37                  * before taking any action that relies on power having been
  38                  * removed from the slot/adapter.
  39                  */
  40                 msleep(1000);
  41         }
  42
  43         pciehp_green_led_off(pslot);
  44         pciehp_set_attention_status(pslot, 1);
  45 }
  46
  47 /**
  48  * board_added - Called after a board has been added to the system.
  49  * @p_slot: &slot where board is added
  50  *
  51  * Turns power on for the board.
  52  * Configures board.
  53  */
  54 static int board_added(struct slot *p_slot)
  55 {
  56         int retval = 0;
  57         struct controller *ctrl = p_slot->ctrl;
  58         struct pci_bus *parent = ctrl->pcie->port->subordinate;
  59
  60         if (POWER_CTRL(ctrl)) {
  61                 /* Power on slot */
  62                 retval = pciehp_power_on_slot(p_slot);
  63                 if (retval)
  64                         return retval;
  65         }
  66
  67         pciehp_green_led_blink(p_slot);
  68
  69         /* Check link training status */
  70         retval = pciehp_check_link_status(ctrl);
  71         if (retval) {
  72                 ctrl_err(ctrl, "Failed to check link status\n");
  73                 goto err_exit;
  74         }
  75
  76         /* Check for a power fault */
  77         if (ctrl->power_fault_detected || pciehp_query_power_fault(p_slot)) {
  78                 ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(p_slot));
  79                 retval = -EIO;
  80                 goto err_exit;
  81         }
  82
  83         retval = pciehp_configure_device(p_slot);
  84         if (retval) {
  85                 if (retval != -EEXIST) {
  86                         ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
  87                                  pci_domain_nr(parent), parent->number);
  88                         goto err_exit;
  89                 }
  90         }
  91
  92         pciehp_green_led_on(p_slot);
  93         pciehp_set_attention_status(p_slot, 0);
  94         return 0;
  95
  96 err_exit:
  97         set_slot_off(ctrl, p_slot);
  98         return retval;
  99 }
 100
 101 /**
 102  * remove_board - Turns off slot and LEDs
 103  * @p_slot: slot where board is being removed
 104  */
 105 static void remove_board(struct slot *p_slot)
 106 {
 107         struct controller *ctrl = p_slot->ctrl;
 108
 109         pciehp_unconfigure_device(p_slot);
 110
 111         if (POWER_CTRL(ctrl)) {
 112                 pciehp_power_off_slot(p_slot);
 113
 114                 /*
 115                  * After turning power off, we must wait for at least 1 second
 116                  * before taking any action that relies on power having been
 117                  * removed from the slot/adapter.
 118                  */
 119                 msleep(1000);
 120
 121                 /* Ignore link or presence changes caused by power off */
 122                 atomic_and(~(PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_PDC),
 123                            &ctrl->pending_events);
 124         }
 125
 126         /* turn off Green LED */
 127         pciehp_green_led_off(p_slot);
 128 }
 129
 130 static int pciehp_enable_slot(struct slot *slot);
 131 static int pciehp_disable_slot(struct slot *slot);
 132
 133 void pciehp_request(struct controller *ctrl, int action)
 134 {
 135         atomic_or(action, &ctrl->pending_events);
 136         if (!pciehp_poll_mode)
 137                 irq_wake_thread(ctrl->pcie->irq, ctrl);
 138 }
 139
 140 void pciehp_queue_pushbutton_work(struct work_struct *work)
 141 {
 142         struct slot *p_slot = container_of(work, struct slot, work.work);
 143         struct controller *ctrl = p_slot->ctrl;
 144
 145         mutex_lock(&p_slot->lock);
 146         switch (p_slot->state) {
 147         case BLINKINGOFF_STATE:
 148                 pciehp_request(ctrl, DISABLE_SLOT);
 149                 break;
 150         case BLINKINGON_STATE:
 151                 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
 152                 break;
 153         default:
 154                 break;
 155         }
 156         mutex_unlock(&p_slot->lock);
 157 }
 158
 159 void pciehp_handle_button_press(struct slot *p_slot)
 160 {
 161         struct controller *ctrl = p_slot->ctrl;
 162
 163         mutex_lock(&p_slot->lock);
 164         switch (p_slot->state) {
 165         case OFF_STATE:
 166         case ON_STATE:
 167                 if (p_slot->state == ON_STATE) {
 168                         p_slot->state = BLINKINGOFF_STATE;
 169                         ctrl_info(ctrl, "Slot(%s): Powering off due to button press\n",
 170                                   slot_name(p_slot));
 171                 } else {
 172                         p_slot->state = BLINKINGON_STATE;
 173                         ctrl_info(ctrl, "Slot(%s) Powering on due to button press\n",
 174                                   slot_name(p_slot));
 175                 }
 176                 /* blink green LED and turn off amber */
 177                 pciehp_green_led_blink(p_slot);
 178                 pciehp_set_attention_status(p_slot, 0);
 179                 schedule_delayed_work(&p_slot->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(p_slot));
 189                 cancel_delayed_work(&p_slot->work);
 190                 if (p_slot->state == BLINKINGOFF_STATE) {
 191                         p_slot->state = ON_STATE;
 192                         pciehp_green_led_on(p_slot);
 193                 } else {
 194                         p_slot->state = OFF_STATE;
 195                         pciehp_green_led_off(p_slot);
 196                 }
 197                 pciehp_set_attention_status(p_slot, 0);
 198                 ctrl_info(ctrl, "Slot(%s): Action canceled due to button press\n",
 199                           slot_name(p_slot));
 200                 break;
 201         default:
 202                 ctrl_err(ctrl, "Slot(%s): Ignoring invalid state %#x\n",
 203                          slot_name(p_slot), p_slot->state);
 204                 break;
 205         }
 206         mutex_unlock(&p_slot->lock);
 207 }
 208
 209 void pciehp_handle_disable_request(struct slot *slot)
 210 {
 211         struct controller *ctrl = slot->ctrl;
 212
 213         mutex_lock(&slot->lock);
 214         switch (slot->state) {
 215         case BLINKINGON_STATE:
 216         case BLINKINGOFF_STATE:
 217                 cancel_delayed_work(&slot->work);
 218                 break;
 219         }
 220         slot->state = POWEROFF_STATE;
 221         mutex_unlock(&slot->lock);
 222
 223         ctrl->request_result = pciehp_disable_slot(slot);
 224 }
 225
 226 void pciehp_handle_presence_or_link_change(struct slot *slot, u32 events)
 227 {
 228         struct controller *ctrl = slot->ctrl;
 229         bool link_active;
 230         u8 present;
 231
 232         /*
 233          * If the slot is on and presence or link has changed, turn it off.
 234          * Even if it's occupied again, we cannot assume the card is the same.
 235          */
 236         mutex_lock(&slot->lock);
 237         switch (slot->state) {
 238         case BLINKINGOFF_STATE:
 239                 cancel_delayed_work(&slot->work);
 240                 /* fall through */
 241         case ON_STATE:
 242                 slot->state = POWEROFF_STATE;
 243                 mutex_unlock(&slot->lock);
 244                 if (events & PCI_EXP_SLTSTA_DLLSC)
 245                         ctrl_info(ctrl, "Slot(%s): Link Down\n",
 246                                   slot_name(slot));
 247                 if (events & PCI_EXP_SLTSTA_PDC)
 248                         ctrl_info(ctrl, "Slot(%s): Card not present\n",
 249                                   slot_name(slot));
 250                 pciehp_disable_slot(slot);
 251                 break;
 252         default:
 253                 mutex_unlock(&slot->lock);
 254                 break;
 255         }
 256
 257         /* Turn the slot on if it's occupied or link is up */
 258         mutex_lock(&slot->lock);
 259         pciehp_get_adapter_status(slot, &present);
 260         link_active = pciehp_check_link_active(ctrl);
 261         if (!present && !link_active) {
 262                 mutex_unlock(&slot->lock);
 263                 return;
 264         }
 265
 266         switch (slot->state) {
 267         case BLINKINGON_STATE:
 268                 cancel_delayed_work(&slot->work);
 269                 /* fall through */
 270         case OFF_STATE:
 271                 slot->state = POWERON_STATE;
 272                 mutex_unlock(&slot->lock);
 273                 if (present)
 274                         ctrl_info(ctrl, "Slot(%s): Card present\n",
 275                                   slot_name(slot));
 276                 if (link_active)
 277                         ctrl_info(ctrl, "Slot(%s): Link Up\n",
 278                                   slot_name(slot));
 279                 ctrl->request_result = pciehp_enable_slot(slot);
 280                 break;
 281         default:
 282                 mutex_unlock(&slot->lock);
 283                 break;
 284         }
 285 }
 286
 287 static int __pciehp_enable_slot(struct slot *p_slot)
 288 {
 289         u8 getstatus = 0;
 290         struct controller *ctrl = p_slot->ctrl;
 291
 292         pciehp_get_adapter_status(p_slot, &getstatus);
 293         if (!getstatus) {
 294                 ctrl_info(ctrl, "Slot(%s): No adapter\n", slot_name(p_slot));
 295                 return -ENODEV;
 296         }
 297         if (MRL_SENS(p_slot->ctrl)) {
 298                 pciehp_get_latch_status(p_slot, &getstatus);
 299                 if (getstatus) {
 300                         ctrl_info(ctrl, "Slot(%s): Latch open\n",
 301                                   slot_name(p_slot));
 302                         return -ENODEV;
 303                 }
 304         }
 305
 306         if (POWER_CTRL(p_slot->ctrl)) {
 307                 pciehp_get_power_status(p_slot, &getstatus);
 308                 if (getstatus) {
 309                         ctrl_info(ctrl, "Slot(%s): Already enabled\n",
 310                                   slot_name(p_slot));
 311                         return 0;
 312                 }
 313         }
 314
 315         return board_added(p_slot);
 316 }
 317
 318 static int pciehp_enable_slot(struct slot *slot)
 319 {
 320         struct controller *ctrl = slot->ctrl;
 321         int ret;
 322
 323         pm_runtime_get_sync(&ctrl->pcie->port->dev);
 324         ret = __pciehp_enable_slot(slot);
 325         if (ret && ATTN_BUTTN(ctrl))
 326                 pciehp_green_led_off(slot); /* may be blinking */
 327         pm_runtime_put(&ctrl->pcie->port->dev);
 328
 329         mutex_lock(&slot->lock);
 330         slot->state = ret ? OFF_STATE : ON_STATE;
 331         mutex_unlock(&slot->lock);
 332
 333         return ret;
 334 }
 335
 336 static int __pciehp_disable_slot(struct slot *p_slot)
 337 {
 338         u8 getstatus = 0;
 339         struct controller *ctrl = p_slot->ctrl;
 340
 341         if (POWER_CTRL(p_slot->ctrl)) {
 342                 pciehp_get_power_status(p_slot, &getstatus);
 343                 if (!getstatus) {
 344                         ctrl_info(ctrl, "Slot(%s): Already disabled\n",
 345                                   slot_name(p_slot));
 346                         return -EINVAL;
 347                 }
 348         }
 349
 350         remove_board(p_slot);
 351         return 0;
 352 }
 353
 354 static int pciehp_disable_slot(struct slot *slot)
 355 {
 356         struct controller *ctrl = slot->ctrl;
 357         int ret;
 358
 359         pm_runtime_get_sync(&ctrl->pcie->port->dev);
 360         ret = __pciehp_disable_slot(slot);
 361         pm_runtime_put(&ctrl->pcie->port->dev);
 362
 363         mutex_lock(&slot->lock);
 364         slot->state = OFF_STATE;
 365         mutex_unlock(&slot->lock);
 366
 367         return ret;
 368 }
 369
 370 int pciehp_sysfs_enable_slot(struct slot *p_slot)
 371 {
 372         struct controller *ctrl = p_slot->ctrl;
 373
 374         mutex_lock(&p_slot->lock);
 375         switch (p_slot->state) {
 376         case BLINKINGON_STATE:
 377         case OFF_STATE:
 378                 mutex_unlock(&p_slot->lock);
 379                 /*
 380                  * The IRQ thread becomes a no-op if the user pulls out the
 381                  * card before the thread wakes up, so initialize to -ENODEV.
 382                  */
 383                 ctrl->request_result = -ENODEV;
 384                 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
 385                 wait_event(ctrl->requester,
 386                            !atomic_read(&ctrl->pending_events) &&
 387                            !ctrl->ist_running);
 388                 return ctrl->request_result;
 389         case POWERON_STATE:
 390                 ctrl_info(ctrl, "Slot(%s): Already in powering on state\n",
 391                           slot_name(p_slot));
 392                 break;
 393         case BLINKINGOFF_STATE:
 394         case ON_STATE:
 395         case POWEROFF_STATE:
 396                 ctrl_info(ctrl, "Slot(%s): Already enabled\n",
 397                           slot_name(p_slot));
 398                 break;
 399         default:
 400                 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
 401                          slot_name(p_slot), p_slot->state);
 402                 break;
 403         }
 404         mutex_unlock(&p_slot->lock);
 405
 406         return -ENODEV;
 407 }
 408
 409 int pciehp_sysfs_disable_slot(struct slot *p_slot)
 410 {
 411         struct controller *ctrl = p_slot->ctrl;
 412
 413         mutex_lock(&p_slot->lock);
 414         switch (p_slot->state) {
 415         case BLINKINGOFF_STATE:
 416         case ON_STATE:
 417                 mutex_unlock(&p_slot->lock);
 418                 pciehp_request(ctrl, DISABLE_SLOT);
 419                 wait_event(ctrl->requester,
 420                            !atomic_read(&ctrl->pending_events) &&
 421                            !ctrl->ist_running);
 422                 return ctrl->request_result;
 423         case POWEROFF_STATE:
 424                 ctrl_info(ctrl, "Slot(%s): Already in powering off state\n",
 425                           slot_name(p_slot));
 426                 break;
 427         case BLINKINGON_STATE:
 428         case OFF_STATE:
 429         case POWERON_STATE:
 430                 ctrl_info(ctrl, "Slot(%s): Already disabled\n",
 431                           slot_name(p_slot));
 432                 break;
 433         default:
 434                 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
 435                          slot_name(p_slot), p_slot->state);
 436                 break;
 437         }
 438         mutex_unlock(&p_slot->lock);
 439
 440         return -ENODEV;
 441 }