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 ctrl_err(ctrl, "Failed to check link status\n");
78 goto err_exit;
79 }
80
81 /* Check for a power fault */
82 if (ctrl->power_fault_detected || pciehp_query_power_fault(ctrl)) {
83 ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(ctrl));
84 retval = -EIO;
85 goto err_exit;
86 }
87
88 retval = pciehp_configure_device(ctrl);
89 if (retval) {
90 if (retval != -EEXIST) {
91 ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
92 pci_domain_nr(parent), parent->number);
93 goto err_exit;
94 }
95 }
96
97 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_ON,
98 PCI_EXP_SLTCTL_ATTN_IND_OFF);
99 return 0;
100
101 err_exit:
102 set_slot_off(ctrl);
103 return retval;
104 }
105
106 /**
107 * remove_board - Turn off slot and Power Indicator
108 * @ctrl: PCIe hotplug controller where board is being removed
109 * @safe_removal: whether the board is safely removed (versus surprise removed)
110 */
remove_board(struct controller * ctrl,bool safe_removal)111 static void remove_board(struct controller *ctrl, bool safe_removal)
112 {
113 pciehp_unconfigure_device(ctrl, safe_removal);
114
115 if (POWER_CTRL(ctrl)) {
116 pciehp_power_off_slot(ctrl);
117
118 /*
119 * After turning power off, we must wait for at least 1 second
120 * before taking any action that relies on power having been
121 * removed from the slot/adapter.
122 */
123 msleep(1000);
124
125 /* Ignore link or presence changes caused by power off */
126 atomic_and(~(PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_PDC),
127 &ctrl->pending_events);
128 }
129
130 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
131 INDICATOR_NOOP);
132 }
133
134 static int pciehp_enable_slot(struct controller *ctrl);
135 static int pciehp_disable_slot(struct controller *ctrl, bool safe_removal);
136
pciehp_request(struct controller * ctrl,int action)137 void pciehp_request(struct controller *ctrl, int action)
138 {
139 atomic_or(action, &ctrl->pending_events);
140 if (!pciehp_poll_mode)
141 irq_wake_thread(ctrl->pcie->irq, ctrl);
142 }
143
pciehp_queue_pushbutton_work(struct work_struct * work)144 void pciehp_queue_pushbutton_work(struct work_struct *work)
145 {
146 struct controller *ctrl = container_of(work, struct controller,
147 button_work.work);
148
149 mutex_lock(&ctrl->state_lock);
150 switch (ctrl->state) {
151 case BLINKINGOFF_STATE:
152 pciehp_request(ctrl, DISABLE_SLOT);
153 break;
154 case BLINKINGON_STATE:
155 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
156 break;
157 default:
158 break;
159 }
160 mutex_unlock(&ctrl->state_lock);
161 }
162
pciehp_handle_button_press(struct controller * ctrl)163 void pciehp_handle_button_press(struct controller *ctrl)
164 {
165 mutex_lock(&ctrl->state_lock);
166 switch (ctrl->state) {
167 case OFF_STATE:
168 case ON_STATE:
169 if (ctrl->state == ON_STATE) {
170 ctrl->state = BLINKINGOFF_STATE;
171 ctrl_info(ctrl, "Slot(%s): Powering off due to button press\n",
172 slot_name(ctrl));
173 } else {
174 ctrl->state = BLINKINGON_STATE;
175 ctrl_info(ctrl, "Slot(%s) Powering on due to button press\n",
176 slot_name(ctrl));
177 }
178 /* blink power indicator and turn off attention */
179 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_BLINK,
180 PCI_EXP_SLTCTL_ATTN_IND_OFF);
181 schedule_delayed_work(&ctrl->button_work, 5 * HZ);
182 break;
183 case BLINKINGOFF_STATE:
184 case BLINKINGON_STATE:
185 /*
186 * Cancel if we are still blinking; this means that we
187 * press the attention again before the 5 sec. limit
188 * expires to cancel hot-add or hot-remove
189 */
190 ctrl_info(ctrl, "Slot(%s): Button cancel\n", slot_name(ctrl));
191 cancel_delayed_work(&ctrl->button_work);
192 if (ctrl->state == BLINKINGOFF_STATE) {
193 ctrl->state = ON_STATE;
194 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_ON,
195 PCI_EXP_SLTCTL_ATTN_IND_OFF);
196 } else {
197 ctrl->state = OFF_STATE;
198 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
199 PCI_EXP_SLTCTL_ATTN_IND_OFF);
200 }
201 ctrl_info(ctrl, "Slot(%s): Action canceled due to button press\n",
202 slot_name(ctrl));
203 break;
204 default:
205 ctrl_err(ctrl, "Slot(%s): Ignoring invalid state %#x\n",
206 slot_name(ctrl), ctrl->state);
207 break;
208 }
209 mutex_unlock(&ctrl->state_lock);
210 }
211
pciehp_handle_disable_request(struct controller * ctrl)212 void pciehp_handle_disable_request(struct controller *ctrl)
213 {
214 mutex_lock(&ctrl->state_lock);
215 switch (ctrl->state) {
216 case BLINKINGON_STATE:
217 case BLINKINGOFF_STATE:
218 cancel_delayed_work(&ctrl->button_work);
219 break;
220 }
221 ctrl->state = POWEROFF_STATE;
222 mutex_unlock(&ctrl->state_lock);
223
224 ctrl->request_result = pciehp_disable_slot(ctrl, SAFE_REMOVAL);
225 }
226
pciehp_handle_presence_or_link_change(struct controller * ctrl,u32 events)227 void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events)
228 {
229 int present, link_active;
230
231 /*
232 * If the slot is on and presence or link has changed, turn it off.
233 * Even if it's occupied again, we cannot assume the card is the same.
234 */
235 mutex_lock(&ctrl->state_lock);
236 switch (ctrl->state) {
237 case BLINKINGOFF_STATE:
238 cancel_delayed_work(&ctrl->button_work);
239 /* fall through */
240 case ON_STATE:
241 ctrl->state = POWEROFF_STATE;
242 mutex_unlock(&ctrl->state_lock);
243 if (events & PCI_EXP_SLTSTA_DLLSC)
244 ctrl_info(ctrl, "Slot(%s): Link Down\n",
245 slot_name(ctrl));
246 if (events & PCI_EXP_SLTSTA_PDC)
247 ctrl_info(ctrl, "Slot(%s): Card not present\n",
248 slot_name(ctrl));
249 pciehp_disable_slot(ctrl, SURPRISE_REMOVAL);
250 break;
251 default:
252 mutex_unlock(&ctrl->state_lock);
253 break;
254 }
255
256 /* Turn the slot on if it's occupied or link is up */
257 mutex_lock(&ctrl->state_lock);
258 present = pciehp_card_present(ctrl);
259 link_active = pciehp_check_link_active(ctrl);
260 if (present <= 0 && link_active <= 0) {
261 if (ctrl->state == BLINKINGON_STATE) {
262 ctrl->state = OFF_STATE;
263 cancel_delayed_work(&ctrl->button_work);
264 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
265 INDICATOR_NOOP);
266 ctrl_info(ctrl, "Slot(%s): Card not present\n",
267 slot_name(ctrl));
268 }
269 mutex_unlock(&ctrl->state_lock);
270 return;
271 }
272
273 switch (ctrl->state) {
274 case BLINKINGON_STATE:
275 cancel_delayed_work(&ctrl->button_work);
276 /* fall through */
277 case OFF_STATE:
278 ctrl->state = POWERON_STATE;
279 mutex_unlock(&ctrl->state_lock);
280 if (present)
281 ctrl_info(ctrl, "Slot(%s): Card present\n",
282 slot_name(ctrl));
283 if (link_active)
284 ctrl_info(ctrl, "Slot(%s): Link Up\n",
285 slot_name(ctrl));
286 ctrl->request_result = pciehp_enable_slot(ctrl);
287 break;
288 default:
289 mutex_unlock(&ctrl->state_lock);
290 break;
291 }
292 }
293
__pciehp_enable_slot(struct controller * ctrl)294 static int __pciehp_enable_slot(struct controller *ctrl)
295 {
296 u8 getstatus = 0;
297
298 if (MRL_SENS(ctrl)) {
299 pciehp_get_latch_status(ctrl, &getstatus);
300 if (getstatus) {
301 ctrl_info(ctrl, "Slot(%s): Latch open\n",
302 slot_name(ctrl));
303 return -ENODEV;
304 }
305 }
306
307 if (POWER_CTRL(ctrl)) {
308 pciehp_get_power_status(ctrl, &getstatus);
309 if (getstatus) {
310 ctrl_info(ctrl, "Slot(%s): Already enabled\n",
311 slot_name(ctrl));
312 return 0;
313 }
314 }
315
316 return board_added(ctrl);
317 }
318
pciehp_enable_slot(struct controller * ctrl)319 static int pciehp_enable_slot(struct controller *ctrl)
320 {
321 int ret;
322
323 pm_runtime_get_sync(&ctrl->pcie->port->dev);
324 ret = __pciehp_enable_slot(ctrl);
325 if (ret && ATTN_BUTTN(ctrl))
326 /* may be blinking */
327 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
328 INDICATOR_NOOP);
329 pm_runtime_put(&ctrl->pcie->port->dev);
330
331 mutex_lock(&ctrl->state_lock);
332 ctrl->state = ret ? OFF_STATE : ON_STATE;
333 mutex_unlock(&ctrl->state_lock);
334
335 return ret;
336 }
337
__pciehp_disable_slot(struct controller * ctrl,bool safe_removal)338 static int __pciehp_disable_slot(struct controller *ctrl, bool safe_removal)
339 {
340 u8 getstatus = 0;
341
342 if (POWER_CTRL(ctrl)) {
343 pciehp_get_power_status(ctrl, &getstatus);
344 if (!getstatus) {
345 ctrl_info(ctrl, "Slot(%s): Already disabled\n",
346 slot_name(ctrl));
347 return -EINVAL;
348 }
349 }
350
351 remove_board(ctrl, safe_removal);
352 return 0;
353 }
354
pciehp_disable_slot(struct controller * ctrl,bool safe_removal)355 static int pciehp_disable_slot(struct controller *ctrl, bool safe_removal)
356 {
357 int ret;
358
359 pm_runtime_get_sync(&ctrl->pcie->port->dev);
360 ret = __pciehp_disable_slot(ctrl, safe_removal);
361 pm_runtime_put(&ctrl->pcie->port->dev);
362
363 mutex_lock(&ctrl->state_lock);
364 ctrl->state = OFF_STATE;
365 mutex_unlock(&ctrl->state_lock);
366
367 return ret;
368 }
369
pciehp_sysfs_enable_slot(struct hotplug_slot * hotplug_slot)370 int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot)
371 {
372 struct controller *ctrl = to_ctrl(hotplug_slot);
373
374 mutex_lock(&ctrl->state_lock);
375 switch (ctrl->state) {
376 case BLINKINGON_STATE:
377 case OFF_STATE:
378 mutex_unlock(&ctrl->state_lock);
379 /*
380 * The IRQ thread becomes a no-op if the user pulls out the
381 * card before the thread wakes up, so initialize to -ENODEV.
382 */
383 ctrl->request_result = -ENODEV;
384 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
385 wait_event(ctrl->requester,
386 !atomic_read(&ctrl->pending_events) &&
387 !ctrl->ist_running);
388 return ctrl->request_result;
389 case POWERON_STATE:
390 ctrl_info(ctrl, "Slot(%s): Already in powering on state\n",
391 slot_name(ctrl));
392 break;
393 case BLINKINGOFF_STATE:
394 case ON_STATE:
395 case POWEROFF_STATE:
396 ctrl_info(ctrl, "Slot(%s): Already enabled\n",
397 slot_name(ctrl));
398 break;
399 default:
400 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
401 slot_name(ctrl), ctrl->state);
402 break;
403 }
404 mutex_unlock(&ctrl->state_lock);
405
406 return -ENODEV;
407 }
408
pciehp_sysfs_disable_slot(struct hotplug_slot * hotplug_slot)409 int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot)
410 {
411 struct controller *ctrl = to_ctrl(hotplug_slot);
412
413 mutex_lock(&ctrl->state_lock);
414 switch (ctrl->state) {
415 case BLINKINGOFF_STATE:
416 case ON_STATE:
417 mutex_unlock(&ctrl->state_lock);
418 pciehp_request(ctrl, DISABLE_SLOT);
419 wait_event(ctrl->requester,
420 !atomic_read(&ctrl->pending_events) &&
421 !ctrl->ist_running);
422 return ctrl->request_result;
423 case POWEROFF_STATE:
424 ctrl_info(ctrl, "Slot(%s): Already in powering off state\n",
425 slot_name(ctrl));
426 break;
427 case BLINKINGON_STATE:
428 case OFF_STATE:
429 case POWERON_STATE:
430 ctrl_info(ctrl, "Slot(%s): Already disabled\n",
431 slot_name(ctrl));
432 break;
433 default:
434 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
435 slot_name(ctrl), ctrl->state);
436 break;
437 }
438 mutex_unlock(&ctrl->state_lock);
439
440 return -ENODEV;
441 }
442