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1// SPDX-License-Identifier: GPL-2.0+2/*3 * PCI Express Hot Plug Controller Driver4 *5 * Copyright (C) 1995,2001 Compaq Computer Corporation6 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)7 * Copyright (C) 2001 IBM Corp.8 * Copyright (C) 2003-2004 Intel Corporation9 *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: " fmt17 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 the25 hotplug controller logic26 */27 28#define SAFE_REMOVAL true29#define SURPRISE_REMOVAL false30 31static void set_slot_off(struct controller *ctrl)32{33 /*34 * Turn off slot, turn on attention indicator, turn off power35 * indicator36 */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 second42 * before taking any action that relies on power having been43 * 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 added55 *56 * Turns power on for the board.57 * Configures board.58 */59static 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 99err_exit:100 set_slot_off(ctrl);101 return retval;102}103 104/**105 * remove_board - Turn off slot and Power Indicator106 * @ctrl: PCIe hotplug controller where board is being removed107 * @safe_removal: whether the board is safely removed (versus surprise removed)108 */109static 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 second118 * before taking any action that relies on power having been119 * 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 132static int pciehp_enable_slot(struct controller *ctrl);133static int pciehp_disable_slot(struct controller *ctrl, bool safe_removal);134 135void 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 142void 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 161void 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): Button press: will power off in 5 sec\n",170 slot_name(ctrl));171 } else {172 ctrl->state = BLINKINGON_STATE;173 ctrl_info(ctrl, "Slot(%s): Button press: will power on in 5 sec\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 we185 * press the attention again before the 5 sec. limit186 * expires to cancel hot-add or hot-remove187 */188 cancel_delayed_work(&ctrl->button_work);189 if (ctrl->state == BLINKINGOFF_STATE) {190 ctrl->state = ON_STATE;191 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_ON,192 PCI_EXP_SLTCTL_ATTN_IND_OFF);193 ctrl_info(ctrl, "Slot(%s): Button press: canceling request to power off\n",194 slot_name(ctrl));195 } else {196 ctrl->state = OFF_STATE;197 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,198 PCI_EXP_SLTCTL_ATTN_IND_OFF);199 ctrl_info(ctrl, "Slot(%s): Button press: canceling request to power on\n",200 slot_name(ctrl));201 }202 break;203 default:204 ctrl_err(ctrl, "Slot(%s): Button press: ignoring invalid state %#x\n",205 slot_name(ctrl), ctrl->state);206 break;207 }208 mutex_unlock(&ctrl->state_lock);209}210 211void pciehp_handle_disable_request(struct controller *ctrl)212{213 mutex_lock(&ctrl->state_lock);214 switch (ctrl->state) {215 case BLINKINGON_STATE:216 case BLINKINGOFF_STATE:217 cancel_delayed_work(&ctrl->button_work);218 break;219 }220 ctrl->state = POWEROFF_STATE;221 mutex_unlock(&ctrl->state_lock);222 223 ctrl->request_result = pciehp_disable_slot(ctrl, SAFE_REMOVAL);224}225 226void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events)227{228 int present, link_active;229 230 /*231 * If the slot is on and presence or link has changed, turn it off.232 * Even if it's occupied again, we cannot assume the card is the same.233 */234 mutex_lock(&ctrl->state_lock);235 switch (ctrl->state) {236 case BLINKINGOFF_STATE:237 cancel_delayed_work(&ctrl->button_work);238 fallthrough;239 case ON_STATE:240 ctrl->state = POWEROFF_STATE;241 mutex_unlock(&ctrl->state_lock);242 if (events & PCI_EXP_SLTSTA_DLLSC)243 ctrl_info(ctrl, "Slot(%s): Link Down\n",244 slot_name(ctrl));245 if (events & PCI_EXP_SLTSTA_PDC)246 ctrl_info(ctrl, "Slot(%s): Card not present\n",247 slot_name(ctrl));248 pciehp_disable_slot(ctrl, SURPRISE_REMOVAL);249 break;250 default:251 mutex_unlock(&ctrl->state_lock);252 break;253 }254 255 /* Turn the slot on if it's occupied or link is up */256 mutex_lock(&ctrl->state_lock);257 present = pciehp_card_present(ctrl);258 link_active = pciehp_check_link_active(ctrl);259 if (present <= 0 && link_active <= 0) {260 if (ctrl->state == BLINKINGON_STATE) {261 ctrl->state = OFF_STATE;262 cancel_delayed_work(&ctrl->button_work);263 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,264 INDICATOR_NOOP);265 ctrl_info(ctrl, "Slot(%s): Card not present\n",266 slot_name(ctrl));267 }268 mutex_unlock(&ctrl->state_lock);269 return;270 }271 272 switch (ctrl->state) {273 case BLINKINGON_STATE:274 cancel_delayed_work(&ctrl->button_work);275 fallthrough;276 case OFF_STATE:277 ctrl->state = POWERON_STATE;278 mutex_unlock(&ctrl->state_lock);279 if (present)280 ctrl_info(ctrl, "Slot(%s): Card present\n",281 slot_name(ctrl));282 if (link_active)283 ctrl_info(ctrl, "Slot(%s): Link Up\n",284 slot_name(ctrl));285 ctrl->request_result = pciehp_enable_slot(ctrl);286 break;287 default:288 mutex_unlock(&ctrl->state_lock);289 break;290 }291}292 293static int __pciehp_enable_slot(struct controller *ctrl)294{295 u8 getstatus = 0;296 297 if (MRL_SENS(ctrl)) {298 pciehp_get_latch_status(ctrl, &getstatus);299 if (getstatus) {300 ctrl_info(ctrl, "Slot(%s): Latch open\n",301 slot_name(ctrl));302 return -ENODEV;303 }304 }305 306 if (POWER_CTRL(ctrl)) {307 pciehp_get_power_status(ctrl, &getstatus);308 if (getstatus) {309 ctrl_info(ctrl, "Slot(%s): Already enabled\n",310 slot_name(ctrl));311 return 0;312 }313 }314 315 return board_added(ctrl);316}317 318static int pciehp_enable_slot(struct controller *ctrl)319{320 int ret;321 322 pm_runtime_get_sync(&ctrl->pcie->port->dev);323 ret = __pciehp_enable_slot(ctrl);324 if (ret && ATTN_BUTTN(ctrl))325 /* may be blinking */326 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,327 INDICATOR_NOOP);328 pm_runtime_put(&ctrl->pcie->port->dev);329 330 mutex_lock(&ctrl->state_lock);331 ctrl->state = ret ? OFF_STATE : ON_STATE;332 mutex_unlock(&ctrl->state_lock);333 334 return ret;335}336 337static int __pciehp_disable_slot(struct controller *ctrl, bool safe_removal)338{339 u8 getstatus = 0;340 341 if (POWER_CTRL(ctrl)) {342 pciehp_get_power_status(ctrl, &getstatus);343 if (!getstatus) {344 ctrl_info(ctrl, "Slot(%s): Already disabled\n",345 slot_name(ctrl));346 return -EINVAL;347 }348 }349 350 remove_board(ctrl, safe_removal);351 return 0;352}353 354static int pciehp_disable_slot(struct controller *ctrl, bool safe_removal)355{356 int ret;357 358 pm_runtime_get_sync(&ctrl->pcie->port->dev);359 ret = __pciehp_disable_slot(ctrl, safe_removal);360 pm_runtime_put(&ctrl->pcie->port->dev);361 362 mutex_lock(&ctrl->state_lock);363 ctrl->state = OFF_STATE;364 mutex_unlock(&ctrl->state_lock);365 366 return ret;367}368 369int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot)370{371 struct controller *ctrl = to_ctrl(hotplug_slot);372 373 mutex_lock(&ctrl->state_lock);374 switch (ctrl->state) {375 case BLINKINGON_STATE:376 case OFF_STATE:377 mutex_unlock(&ctrl->state_lock);378 /*379 * The IRQ thread becomes a no-op if the user pulls out the380 * card before the thread wakes up, so initialize to -ENODEV.381 */382 ctrl->request_result = -ENODEV;383 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);384 wait_event(ctrl->requester,385 !atomic_read(&ctrl->pending_events) &&386 !ctrl->ist_running);387 return ctrl->request_result;388 case POWERON_STATE:389 ctrl_info(ctrl, "Slot(%s): Already in powering on state\n",390 slot_name(ctrl));391 break;392 case BLINKINGOFF_STATE:393 case ON_STATE:394 case POWEROFF_STATE:395 ctrl_info(ctrl, "Slot(%s): Already enabled\n",396 slot_name(ctrl));397 break;398 default:399 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",400 slot_name(ctrl), ctrl->state);401 break;402 }403 mutex_unlock(&ctrl->state_lock);404 405 return -ENODEV;406}407 408int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot)409{410 struct controller *ctrl = to_ctrl(hotplug_slot);411 412 mutex_lock(&ctrl->state_lock);413 switch (ctrl->state) {414 case BLINKINGOFF_STATE:415 case ON_STATE:416 mutex_unlock(&ctrl->state_lock);417 pciehp_request(ctrl, DISABLE_SLOT);418 wait_event(ctrl->requester,419 !atomic_read(&ctrl->pending_events) &&420 !ctrl->ist_running);421 return ctrl->request_result;422 case POWEROFF_STATE:423 ctrl_info(ctrl, "Slot(%s): Already in powering off state\n",424 slot_name(ctrl));425 break;426 case BLINKINGON_STATE:427 case OFF_STATE:428 case POWERON_STATE:429 ctrl_info(ctrl, "Slot(%s): Already disabled\n",430 slot_name(ctrl));431 break;432 default:433 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",434 slot_name(ctrl), ctrl->state);435 break;436 }437 mutex_unlock(&ctrl->state_lock);438 439 return -ENODEV;440}441