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