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 bool 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 && !link_active) {
261 mutex_unlock(&ctrl->state_lock);
262 return;
263 }
264
265 switch (ctrl->state) {
266 case BLINKINGON_STATE:
267 cancel_delayed_work(&ctrl->button_work);
268 /* fall through */
269 case OFF_STATE:
270 ctrl->state = POWERON_STATE;
271 mutex_unlock(&ctrl->state_lock);
272 if (present)
273 ctrl_info(ctrl, "Slot(%s): Card present\n",
274 slot_name(ctrl));
275 if (link_active)
276 ctrl_info(ctrl, "Slot(%s): Link Up\n",
277 slot_name(ctrl));
278 ctrl->request_result = pciehp_enable_slot(ctrl);
279 break;
280 default:
281 mutex_unlock(&ctrl->state_lock);
282 break;
283 }
284 }
285
__pciehp_enable_slot(struct controller * ctrl)286 static int __pciehp_enable_slot(struct controller *ctrl)
287 {
288 u8 getstatus = 0;
289
290 if (MRL_SENS(ctrl)) {
291 pciehp_get_latch_status(ctrl, &getstatus);
292 if (getstatus) {
293 ctrl_info(ctrl, "Slot(%s): Latch open\n",
294 slot_name(ctrl));
295 return -ENODEV;
296 }
297 }
298
299 if (POWER_CTRL(ctrl)) {
300 pciehp_get_power_status(ctrl, &getstatus);
301 if (getstatus) {
302 ctrl_info(ctrl, "Slot(%s): Already enabled\n",
303 slot_name(ctrl));
304 return 0;
305 }
306 }
307
308 return board_added(ctrl);
309 }
310
pciehp_enable_slot(struct controller * ctrl)311 static int pciehp_enable_slot(struct controller *ctrl)
312 {
313 int ret;
314
315 pm_runtime_get_sync(&ctrl->pcie->port->dev);
316 ret = __pciehp_enable_slot(ctrl);
317 if (ret && ATTN_BUTTN(ctrl))
318 /* may be blinking */
319 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
320 INDICATOR_NOOP);
321 pm_runtime_put(&ctrl->pcie->port->dev);
322
323 mutex_lock(&ctrl->state_lock);
324 ctrl->state = ret ? OFF_STATE : ON_STATE;
325 mutex_unlock(&ctrl->state_lock);
326
327 return ret;
328 }
329
__pciehp_disable_slot(struct controller * ctrl,bool safe_removal)330 static int __pciehp_disable_slot(struct controller *ctrl, bool safe_removal)
331 {
332 u8 getstatus = 0;
333
334 if (POWER_CTRL(ctrl)) {
335 pciehp_get_power_status(ctrl, &getstatus);
336 if (!getstatus) {
337 ctrl_info(ctrl, "Slot(%s): Already disabled\n",
338 slot_name(ctrl));
339 return -EINVAL;
340 }
341 }
342
343 remove_board(ctrl, safe_removal);
344 return 0;
345 }
346
pciehp_disable_slot(struct controller * ctrl,bool safe_removal)347 static int pciehp_disable_slot(struct controller *ctrl, bool safe_removal)
348 {
349 int ret;
350
351 pm_runtime_get_sync(&ctrl->pcie->port->dev);
352 ret = __pciehp_disable_slot(ctrl, safe_removal);
353 pm_runtime_put(&ctrl->pcie->port->dev);
354
355 mutex_lock(&ctrl->state_lock);
356 ctrl->state = OFF_STATE;
357 mutex_unlock(&ctrl->state_lock);
358
359 return ret;
360 }
361
pciehp_sysfs_enable_slot(struct hotplug_slot * hotplug_slot)362 int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot)
363 {
364 struct controller *ctrl = to_ctrl(hotplug_slot);
365
366 mutex_lock(&ctrl->state_lock);
367 switch (ctrl->state) {
368 case BLINKINGON_STATE:
369 case OFF_STATE:
370 mutex_unlock(&ctrl->state_lock);
371 /*
372 * The IRQ thread becomes a no-op if the user pulls out the
373 * card before the thread wakes up, so initialize to -ENODEV.
374 */
375 ctrl->request_result = -ENODEV;
376 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
377 wait_event(ctrl->requester,
378 !atomic_read(&ctrl->pending_events));
379 return ctrl->request_result;
380 case POWERON_STATE:
381 ctrl_info(ctrl, "Slot(%s): Already in powering on state\n",
382 slot_name(ctrl));
383 break;
384 case BLINKINGOFF_STATE:
385 case ON_STATE:
386 case POWEROFF_STATE:
387 ctrl_info(ctrl, "Slot(%s): Already enabled\n",
388 slot_name(ctrl));
389 break;
390 default:
391 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
392 slot_name(ctrl), ctrl->state);
393 break;
394 }
395 mutex_unlock(&ctrl->state_lock);
396
397 return -ENODEV;
398 }
399
pciehp_sysfs_disable_slot(struct hotplug_slot * hotplug_slot)400 int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot)
401 {
402 struct controller *ctrl = to_ctrl(hotplug_slot);
403
404 mutex_lock(&ctrl->state_lock);
405 switch (ctrl->state) {
406 case BLINKINGOFF_STATE:
407 case ON_STATE:
408 mutex_unlock(&ctrl->state_lock);
409 pciehp_request(ctrl, DISABLE_SLOT);
410 wait_event(ctrl->requester,
411 !atomic_read(&ctrl->pending_events));
412 return ctrl->request_result;
413 case POWEROFF_STATE:
414 ctrl_info(ctrl, "Slot(%s): Already in powering off state\n",
415 slot_name(ctrl));
416 break;
417 case BLINKINGON_STATE:
418 case OFF_STATE:
419 case POWERON_STATE:
420 ctrl_info(ctrl, "Slot(%s): Already disabled\n",
421 slot_name(ctrl));
422 break;
423 default:
424 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
425 slot_name(ctrl), ctrl->state);
426 break;
427 }
428 mutex_unlock(&ctrl->state_lock);
429
430 return -ENODEV;
431 }
432
