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
set_slot_off(struct controller * ctrl)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 */
board_added(struct controller * ctrl)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 */
remove_board(struct controller * ctrl,bool safe_removal)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
pciehp_request(struct controller * ctrl,int action)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
pciehp_queue_pushbutton_work(struct work_struct * work)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
pciehp_handle_button_press(struct controller * ctrl)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): 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 we
185 * press the attention again before the 5 sec. limit
186 * expires to cancel hot-add or hot-remove
187 */
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
pciehp_handle_disable_request(struct controller * ctrl)211 void 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
pciehp_handle_presence_or_link_change(struct controller * ctrl,u32 events)226 void 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
__pciehp_enable_slot(struct controller * ctrl)293 static 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
pciehp_enable_slot(struct controller * ctrl)318 static 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
__pciehp_disable_slot(struct controller * ctrl,bool safe_removal)337 static 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
pciehp_disable_slot(struct controller * ctrl,bool safe_removal)354 static 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
pciehp_sysfs_enable_slot(struct hotplug_slot * hotplug_slot)369 int 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 the
380 * 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
pciehp_sysfs_disable_slot(struct hotplug_slot * hotplug_slot)408 int 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