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): Powering off due to button press\n",
170 slot_name(ctrl));
171 } else {
172 ctrl->state = BLINKINGON_STATE;
173 ctrl_info(ctrl, "Slot(%s) Powering on due to button press\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 ctrl_info(ctrl, "Slot(%s): Button cancel\n", slot_name(ctrl));
189 cancel_delayed_work(&ctrl->button_work);
190 if (ctrl->state == BLINKINGOFF_STATE) {
191 ctrl->state = ON_STATE;
192 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_ON,
193 PCI_EXP_SLTCTL_ATTN_IND_OFF);
194 } else {
195 ctrl->state = OFF_STATE;
196 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
197 PCI_EXP_SLTCTL_ATTN_IND_OFF);
198 }
199 ctrl_info(ctrl, "Slot(%s): Action canceled due to button press\n",
200 slot_name(ctrl));
201 break;
202 default:
203 ctrl_err(ctrl, "Slot(%s): Ignoring invalid state %#x\n",
204 slot_name(ctrl), ctrl->state);
205 break;
206 }
207 mutex_unlock(&ctrl->state_lock);
208 }
209
pciehp_handle_disable_request(struct controller * ctrl)210 void pciehp_handle_disable_request(struct controller *ctrl)
211 {
212 mutex_lock(&ctrl->state_lock);
213 switch (ctrl->state) {
214 case BLINKINGON_STATE:
215 case BLINKINGOFF_STATE:
216 cancel_delayed_work(&ctrl->button_work);
217 break;
218 }
219 ctrl->state = POWEROFF_STATE;
220 mutex_unlock(&ctrl->state_lock);
221
222 ctrl->request_result = pciehp_disable_slot(ctrl, SAFE_REMOVAL);
223 }
224
pciehp_handle_presence_or_link_change(struct controller * ctrl,u32 events)225 void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events)
226 {
227 int present, link_active;
228
229 /*
230 * If the slot is on and presence or link has changed, turn it off.
231 * Even if it's occupied again, we cannot assume the card is the same.
232 */
233 mutex_lock(&ctrl->state_lock);
234 switch (ctrl->state) {
235 case BLINKINGOFF_STATE:
236 cancel_delayed_work(&ctrl->button_work);
237 fallthrough;
238 case ON_STATE:
239 ctrl->state = POWEROFF_STATE;
240 mutex_unlock(&ctrl->state_lock);
241 if (events & PCI_EXP_SLTSTA_DLLSC)
242 ctrl_info(ctrl, "Slot(%s): Link Down\n",
243 slot_name(ctrl));
244 if (events & PCI_EXP_SLTSTA_PDC)
245 ctrl_info(ctrl, "Slot(%s): Card not present\n",
246 slot_name(ctrl));
247 pciehp_disable_slot(ctrl, SURPRISE_REMOVAL);
248 break;
249 default:
250 mutex_unlock(&ctrl->state_lock);
251 break;
252 }
253
254 /* Turn the slot on if it's occupied or link is up */
255 mutex_lock(&ctrl->state_lock);
256 present = pciehp_card_present(ctrl);
257 link_active = pciehp_check_link_active(ctrl);
258 if (present <= 0 && link_active <= 0) {
259 if (ctrl->state == BLINKINGON_STATE) {
260 ctrl->state = OFF_STATE;
261 cancel_delayed_work(&ctrl->button_work);
262 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
263 INDICATOR_NOOP);
264 ctrl_info(ctrl, "Slot(%s): Card not present\n",
265 slot_name(ctrl));
266 }
267 mutex_unlock(&ctrl->state_lock);
268 return;
269 }
270
271 switch (ctrl->state) {
272 case BLINKINGON_STATE:
273 cancel_delayed_work(&ctrl->button_work);
274 fallthrough;
275 case OFF_STATE:
276 ctrl->state = POWERON_STATE;
277 mutex_unlock(&ctrl->state_lock);
278 if (present)
279 ctrl_info(ctrl, "Slot(%s): Card present\n",
280 slot_name(ctrl));
281 if (link_active)
282 ctrl_info(ctrl, "Slot(%s): Link Up\n",
283 slot_name(ctrl));
284 ctrl->request_result = pciehp_enable_slot(ctrl);
285 break;
286 default:
287 mutex_unlock(&ctrl->state_lock);
288 break;
289 }
290 }
291
__pciehp_enable_slot(struct controller * ctrl)292 static int __pciehp_enable_slot(struct controller *ctrl)
293 {
294 u8 getstatus = 0;
295
296 if (MRL_SENS(ctrl)) {
297 pciehp_get_latch_status(ctrl, &getstatus);
298 if (getstatus) {
299 ctrl_info(ctrl, "Slot(%s): Latch open\n",
300 slot_name(ctrl));
301 return -ENODEV;
302 }
303 }
304
305 if (POWER_CTRL(ctrl)) {
306 pciehp_get_power_status(ctrl, &getstatus);
307 if (getstatus) {
308 ctrl_info(ctrl, "Slot(%s): Already enabled\n",
309 slot_name(ctrl));
310 return 0;
311 }
312 }
313
314 return board_added(ctrl);
315 }
316
pciehp_enable_slot(struct controller * ctrl)317 static int pciehp_enable_slot(struct controller *ctrl)
318 {
319 int ret;
320
321 pm_runtime_get_sync(&ctrl->pcie->port->dev);
322 ret = __pciehp_enable_slot(ctrl);
323 if (ret && ATTN_BUTTN(ctrl))
324 /* may be blinking */
325 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
326 INDICATOR_NOOP);
327 pm_runtime_put(&ctrl->pcie->port->dev);
328
329 mutex_lock(&ctrl->state_lock);
330 ctrl->state = ret ? OFF_STATE : ON_STATE;
331 mutex_unlock(&ctrl->state_lock);
332
333 return ret;
334 }
335
__pciehp_disable_slot(struct controller * ctrl,bool safe_removal)336 static int __pciehp_disable_slot(struct controller *ctrl, bool safe_removal)
337 {
338 u8 getstatus = 0;
339
340 if (POWER_CTRL(ctrl)) {
341 pciehp_get_power_status(ctrl, &getstatus);
342 if (!getstatus) {
343 ctrl_info(ctrl, "Slot(%s): Already disabled\n",
344 slot_name(ctrl));
345 return -EINVAL;
346 }
347 }
348
349 remove_board(ctrl, safe_removal);
350 return 0;
351 }
352
pciehp_disable_slot(struct controller * ctrl,bool safe_removal)353 static int pciehp_disable_slot(struct controller *ctrl, bool safe_removal)
354 {
355 int ret;
356
357 pm_runtime_get_sync(&ctrl->pcie->port->dev);
358 ret = __pciehp_disable_slot(ctrl, safe_removal);
359 pm_runtime_put(&ctrl->pcie->port->dev);
360
361 mutex_lock(&ctrl->state_lock);
362 ctrl->state = OFF_STATE;
363 mutex_unlock(&ctrl->state_lock);
364
365 return ret;
366 }
367
pciehp_sysfs_enable_slot(struct hotplug_slot * hotplug_slot)368 int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot)
369 {
370 struct controller *ctrl = to_ctrl(hotplug_slot);
371
372 mutex_lock(&ctrl->state_lock);
373 switch (ctrl->state) {
374 case BLINKINGON_STATE:
375 case OFF_STATE:
376 mutex_unlock(&ctrl->state_lock);
377 /*
378 * The IRQ thread becomes a no-op if the user pulls out the
379 * card before the thread wakes up, so initialize to -ENODEV.
380 */
381 ctrl->request_result = -ENODEV;
382 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
383 wait_event(ctrl->requester,
384 !atomic_read(&ctrl->pending_events) &&
385 !ctrl->ist_running);
386 return ctrl->request_result;
387 case POWERON_STATE:
388 ctrl_info(ctrl, "Slot(%s): Already in powering on state\n",
389 slot_name(ctrl));
390 break;
391 case BLINKINGOFF_STATE:
392 case ON_STATE:
393 case POWEROFF_STATE:
394 ctrl_info(ctrl, "Slot(%s): Already enabled\n",
395 slot_name(ctrl));
396 break;
397 default:
398 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
399 slot_name(ctrl), ctrl->state);
400 break;
401 }
402 mutex_unlock(&ctrl->state_lock);
403
404 return -ENODEV;
405 }
406
pciehp_sysfs_disable_slot(struct hotplug_slot * hotplug_slot)407 int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot)
408 {
409 struct controller *ctrl = to_ctrl(hotplug_slot);
410
411 mutex_lock(&ctrl->state_lock);
412 switch (ctrl->state) {
413 case BLINKINGOFF_STATE:
414 case ON_STATE:
415 mutex_unlock(&ctrl->state_lock);
416 pciehp_request(ctrl, DISABLE_SLOT);
417 wait_event(ctrl->requester,
418 !atomic_read(&ctrl->pending_events) &&
419 !ctrl->ist_running);
420 return ctrl->request_result;
421 case POWEROFF_STATE:
422 ctrl_info(ctrl, "Slot(%s): Already in powering off state\n",
423 slot_name(ctrl));
424 break;
425 case BLINKINGON_STATE:
426 case OFF_STATE:
427 case POWERON_STATE:
428 ctrl_info(ctrl, "Slot(%s): Already disabled\n",
429 slot_name(ctrl));
430 break;
431 default:
432 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
433 slot_name(ctrl), ctrl->state);
434 break;
435 }
436 mutex_unlock(&ctrl->state_lock);
437
438 return -ENODEV;
439 }
440