1 // SPDX-License-Identifier: GPL-2.0+
3 * PCI Express Hot Plug Controller Driver
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
10 * All rights reserved.
12 * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
16 #define dev_fmt(fmt) "pciehp: " fmt
18 #include <linux/kernel.h>
19 #include <linux/types.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/pci.h>
24 /* The following routines constitute the bulk of the
25 hotplug controller logic
28 #define SAFE_REMOVAL true
29 #define SURPRISE_REMOVAL false
31 static void set_slot_off(struct controller *ctrl)
34 * Turn off slot, turn on attention indicator, turn off power
37 if (POWER_CTRL(ctrl)) {
38 pciehp_power_off_slot(ctrl);
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.
48 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
49 PCI_EXP_SLTCTL_ATTN_IND_ON);
53 * board_added - Called after a board has been added to the system.
54 * @ctrl: PCIe hotplug controller where board is added
56 * Turns power on for the board.
59 static int board_added(struct controller *ctrl)
62 struct pci_bus *parent = ctrl->pcie->port->subordinate;
64 if (POWER_CTRL(ctrl)) {
66 retval = pciehp_power_on_slot(ctrl);
71 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_BLINK,
74 /* Check link training status */
75 retval = pciehp_check_link_status(ctrl);
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));
86 retval = pciehp_configure_device(ctrl);
88 if (retval != -EEXIST) {
89 ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
90 pci_domain_nr(parent), parent->number);
95 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_ON,
96 PCI_EXP_SLTCTL_ATTN_IND_OFF);
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)
109 static void remove_board(struct controller *ctrl, bool safe_removal)
111 pciehp_unconfigure_device(ctrl, safe_removal);
113 if (POWER_CTRL(ctrl)) {
114 pciehp_power_off_slot(ctrl);
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.
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);
128 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
132 static int pciehp_enable_slot(struct controller *ctrl);
133 static int pciehp_disable_slot(struct controller *ctrl, bool safe_removal);
135 void pciehp_request(struct controller *ctrl, int action)
137 atomic_or(action, &ctrl->pending_events);
138 if (!pciehp_poll_mode)
139 irq_wake_thread(ctrl->pcie->irq, ctrl);
142 void pciehp_queue_pushbutton_work(struct work_struct *work)
144 struct controller *ctrl = container_of(work, struct controller,
147 mutex_lock(&ctrl->state_lock);
148 switch (ctrl->state) {
149 case BLINKINGOFF_STATE:
150 pciehp_request(ctrl, DISABLE_SLOT);
152 case BLINKINGON_STATE:
153 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
158 mutex_unlock(&ctrl->state_lock);
161 void pciehp_handle_button_press(struct controller *ctrl)
163 mutex_lock(&ctrl->state_lock);
164 switch (ctrl->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",
172 ctrl->state = BLINKINGON_STATE;
173 ctrl_info(ctrl, "Slot(%s): Button press: will power on in 5 sec\n",
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);
181 case BLINKINGOFF_STATE:
182 case BLINKINGON_STATE:
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
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",
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",
204 ctrl_err(ctrl, "Slot(%s): Button press: ignoring invalid state %#x\n",
205 slot_name(ctrl), ctrl->state);
208 mutex_unlock(&ctrl->state_lock);
211 void pciehp_handle_disable_request(struct controller *ctrl)
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);
220 ctrl->state = POWEROFF_STATE;
221 mutex_unlock(&ctrl->state_lock);
223 ctrl->request_result = pciehp_disable_slot(ctrl, SAFE_REMOVAL);
226 void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events)
228 int present, link_active;
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.
234 mutex_lock(&ctrl->state_lock);
235 switch (ctrl->state) {
236 case BLINKINGOFF_STATE:
237 cancel_delayed_work(&ctrl->button_work);
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",
245 if (events & PCI_EXP_SLTSTA_PDC)
246 ctrl_info(ctrl, "Slot(%s): Card not present\n",
248 pciehp_disable_slot(ctrl, SURPRISE_REMOVAL);
251 mutex_unlock(&ctrl->state_lock);
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,
265 ctrl_info(ctrl, "Slot(%s): Card not present\n",
268 mutex_unlock(&ctrl->state_lock);
272 switch (ctrl->state) {
273 case BLINKINGON_STATE:
274 cancel_delayed_work(&ctrl->button_work);
277 ctrl->state = POWERON_STATE;
278 mutex_unlock(&ctrl->state_lock);
280 ctrl_info(ctrl, "Slot(%s): Card present\n",
283 ctrl_info(ctrl, "Slot(%s): Link Up\n",
285 ctrl->request_result = pciehp_enable_slot(ctrl);
288 mutex_unlock(&ctrl->state_lock);
293 static int __pciehp_enable_slot(struct controller *ctrl)
297 if (MRL_SENS(ctrl)) {
298 pciehp_get_latch_status(ctrl, &getstatus);
300 ctrl_info(ctrl, "Slot(%s): Latch open\n",
306 if (POWER_CTRL(ctrl)) {
307 pciehp_get_power_status(ctrl, &getstatus);
309 ctrl_info(ctrl, "Slot(%s): Already enabled\n",
315 return board_added(ctrl);
318 static int pciehp_enable_slot(struct controller *ctrl)
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,
328 pm_runtime_put(&ctrl->pcie->port->dev);
330 mutex_lock(&ctrl->state_lock);
331 ctrl->state = ret ? OFF_STATE : ON_STATE;
332 mutex_unlock(&ctrl->state_lock);
337 static int __pciehp_disable_slot(struct controller *ctrl, bool safe_removal)
341 if (POWER_CTRL(ctrl)) {
342 pciehp_get_power_status(ctrl, &getstatus);
344 ctrl_info(ctrl, "Slot(%s): Already disabled\n",
350 remove_board(ctrl, safe_removal);
354 static int pciehp_disable_slot(struct controller *ctrl, bool safe_removal)
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);
362 mutex_lock(&ctrl->state_lock);
363 ctrl->state = OFF_STATE;
364 mutex_unlock(&ctrl->state_lock);
369 int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot)
371 struct controller *ctrl = to_ctrl(hotplug_slot);
373 mutex_lock(&ctrl->state_lock);
374 switch (ctrl->state) {
375 case BLINKINGON_STATE:
377 mutex_unlock(&ctrl->state_lock);
379 * The IRQ thread becomes a no-op if the user pulls out the
380 * card before the thread wakes up, so initialize to -ENODEV.
382 ctrl->request_result = -ENODEV;
383 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
384 wait_event(ctrl->requester,
385 !atomic_read(&ctrl->pending_events) &&
387 return ctrl->request_result;
389 ctrl_info(ctrl, "Slot(%s): Already in powering on state\n",
392 case BLINKINGOFF_STATE:
395 ctrl_info(ctrl, "Slot(%s): Already enabled\n",
399 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
400 slot_name(ctrl), ctrl->state);
403 mutex_unlock(&ctrl->state_lock);
408 int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot)
410 struct controller *ctrl = to_ctrl(hotplug_slot);
412 mutex_lock(&ctrl->state_lock);
413 switch (ctrl->state) {
414 case BLINKINGOFF_STATE:
416 mutex_unlock(&ctrl->state_lock);
417 pciehp_request(ctrl, DISABLE_SLOT);
418 wait_event(ctrl->requester,
419 !atomic_read(&ctrl->pending_events) &&
421 return ctrl->request_result;
423 ctrl_info(ctrl, "Slot(%s): Already in powering off state\n",
426 case BLINKINGON_STATE:
429 ctrl_info(ctrl, "Slot(%s): Already disabled\n",
433 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
434 slot_name(ctrl), ctrl->state);
437 mutex_unlock(&ctrl->state_lock);