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 #include <linux/module.h>
17 #include <linux/kernel.h>
18 #include <linux/types.h>
19 #include <linux/slab.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/pci.h>
22 #include "../pci.h"
23 #include "pciehp.h"
24
25 /* The following routines constitute the bulk of the
26 hotplug controller logic
27 */
28
set_slot_off(struct controller * ctrl,struct slot * pslot)29 static void set_slot_off(struct controller *ctrl, struct slot *pslot)
30 {
31 /* turn off slot, turn on Amber LED, turn off Green LED if supported*/
32 if (POWER_CTRL(ctrl)) {
33 pciehp_power_off_slot(pslot);
34
35 /*
36 * After turning power off, we must wait for at least 1 second
37 * before taking any action that relies on power having been
38 * removed from the slot/adapter.
39 */
40 msleep(1000);
41 }
42
43 pciehp_green_led_off(pslot);
44 pciehp_set_attention_status(pslot, 1);
45 }
46
47 /**
48 * board_added - Called after a board has been added to the system.
49 * @p_slot: &slot where board is added
50 *
51 * Turns power on for the board.
52 * Configures board.
53 */
board_added(struct slot * p_slot)54 static int board_added(struct slot *p_slot)
55 {
56 int retval = 0;
57 struct controller *ctrl = p_slot->ctrl;
58 struct pci_bus *parent = ctrl->pcie->port->subordinate;
59
60 if (POWER_CTRL(ctrl)) {
61 /* Power on slot */
62 retval = pciehp_power_on_slot(p_slot);
63 if (retval)
64 return retval;
65 }
66
67 pciehp_green_led_blink(p_slot);
68
69 /* Check link training status */
70 retval = pciehp_check_link_status(ctrl);
71 if (retval) {
72 ctrl_err(ctrl, "Failed to check link status\n");
73 goto err_exit;
74 }
75
76 /* Check for a power fault */
77 if (ctrl->power_fault_detected || pciehp_query_power_fault(p_slot)) {
78 ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(p_slot));
79 retval = -EIO;
80 goto err_exit;
81 }
82
83 retval = pciehp_configure_device(p_slot);
84 if (retval) {
85 if (retval != -EEXIST) {
86 ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
87 pci_domain_nr(parent), parent->number);
88 goto err_exit;
89 }
90 }
91
92 pciehp_green_led_on(p_slot);
93 pciehp_set_attention_status(p_slot, 0);
94 return 0;
95
96 err_exit:
97 set_slot_off(ctrl, p_slot);
98 return retval;
99 }
100
101 /**
102 * remove_board - Turns off slot and LEDs
103 * @p_slot: slot where board is being removed
104 */
remove_board(struct slot * p_slot)105 static void remove_board(struct slot *p_slot)
106 {
107 struct controller *ctrl = p_slot->ctrl;
108
109 pciehp_unconfigure_device(p_slot);
110
111 if (POWER_CTRL(ctrl)) {
112 pciehp_power_off_slot(p_slot);
113
114 /*
115 * After turning power off, we must wait for at least 1 second
116 * before taking any action that relies on power having been
117 * removed from the slot/adapter.
118 */
119 msleep(1000);
120 }
121
122 /* turn off Green LED */
123 pciehp_green_led_off(p_slot);
124 }
125
126 static int pciehp_enable_slot(struct slot *slot);
127 static int pciehp_disable_slot(struct slot *slot);
128
pciehp_request(struct controller * ctrl,int action)129 void pciehp_request(struct controller *ctrl, int action)
130 {
131 atomic_or(action, &ctrl->pending_events);
132 if (!pciehp_poll_mode)
133 irq_wake_thread(ctrl->pcie->irq, ctrl);
134 }
135
pciehp_queue_pushbutton_work(struct work_struct * work)136 void pciehp_queue_pushbutton_work(struct work_struct *work)
137 {
138 struct slot *p_slot = container_of(work, struct slot, work.work);
139 struct controller *ctrl = p_slot->ctrl;
140
141 mutex_lock(&p_slot->lock);
142 switch (p_slot->state) {
143 case BLINKINGOFF_STATE:
144 pciehp_request(ctrl, DISABLE_SLOT);
145 break;
146 case BLINKINGON_STATE:
147 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
148 break;
149 default:
150 break;
151 }
152 mutex_unlock(&p_slot->lock);
153 }
154
pciehp_handle_button_press(struct slot * p_slot)155 void pciehp_handle_button_press(struct slot *p_slot)
156 {
157 struct controller *ctrl = p_slot->ctrl;
158
159 mutex_lock(&p_slot->lock);
160 switch (p_slot->state) {
161 case OFF_STATE:
162 case ON_STATE:
163 if (p_slot->state == ON_STATE) {
164 p_slot->state = BLINKINGOFF_STATE;
165 ctrl_info(ctrl, "Slot(%s): Powering off due to button press\n",
166 slot_name(p_slot));
167 } else {
168 p_slot->state = BLINKINGON_STATE;
169 ctrl_info(ctrl, "Slot(%s) Powering on due to button press\n",
170 slot_name(p_slot));
171 }
172 /* blink green LED and turn off amber */
173 pciehp_green_led_blink(p_slot);
174 pciehp_set_attention_status(p_slot, 0);
175 schedule_delayed_work(&p_slot->work, 5 * HZ);
176 break;
177 case BLINKINGOFF_STATE:
178 case BLINKINGON_STATE:
179 /*
180 * Cancel if we are still blinking; this means that we
181 * press the attention again before the 5 sec. limit
182 * expires to cancel hot-add or hot-remove
183 */
184 ctrl_info(ctrl, "Slot(%s): Button cancel\n", slot_name(p_slot));
185 cancel_delayed_work(&p_slot->work);
186 if (p_slot->state == BLINKINGOFF_STATE) {
187 p_slot->state = ON_STATE;
188 pciehp_green_led_on(p_slot);
189 } else {
190 p_slot->state = OFF_STATE;
191 pciehp_green_led_off(p_slot);
192 }
193 pciehp_set_attention_status(p_slot, 0);
194 ctrl_info(ctrl, "Slot(%s): Action canceled due to button press\n",
195 slot_name(p_slot));
196 break;
197 default:
198 ctrl_err(ctrl, "Slot(%s): Ignoring invalid state %#x\n",
199 slot_name(p_slot), p_slot->state);
200 break;
201 }
202 mutex_unlock(&p_slot->lock);
203 }
204
pciehp_handle_disable_request(struct slot * slot)205 void pciehp_handle_disable_request(struct slot *slot)
206 {
207 struct controller *ctrl = slot->ctrl;
208
209 mutex_lock(&slot->lock);
210 switch (slot->state) {
211 case BLINKINGON_STATE:
212 case BLINKINGOFF_STATE:
213 cancel_delayed_work(&slot->work);
214 break;
215 }
216 slot->state = POWEROFF_STATE;
217 mutex_unlock(&slot->lock);
218
219 ctrl->request_result = pciehp_disable_slot(slot);
220 }
221
pciehp_handle_presence_or_link_change(struct slot * slot,u32 events)222 void pciehp_handle_presence_or_link_change(struct slot *slot, u32 events)
223 {
224 struct controller *ctrl = slot->ctrl;
225 bool link_active;
226 u8 present;
227
228 /*
229 * If the slot is on and presence or link has changed, turn it off.
230 * Even if it's occupied again, we cannot assume the card is the same.
231 */
232 mutex_lock(&slot->lock);
233 switch (slot->state) {
234 case BLINKINGOFF_STATE:
235 cancel_delayed_work(&slot->work);
236 /* fall through */
237 case ON_STATE:
238 slot->state = POWEROFF_STATE;
239 mutex_unlock(&slot->lock);
240 if (events & PCI_EXP_SLTSTA_DLLSC)
241 ctrl_info(ctrl, "Slot(%s): Link Down\n",
242 slot_name(slot));
243 if (events & PCI_EXP_SLTSTA_PDC)
244 ctrl_info(ctrl, "Slot(%s): Card not present\n",
245 slot_name(slot));
246 pciehp_disable_slot(slot);
247 break;
248 default:
249 mutex_unlock(&slot->lock);
250 break;
251 }
252
253 /* Turn the slot on if it's occupied or link is up */
254 mutex_lock(&slot->lock);
255 pciehp_get_adapter_status(slot, &present);
256 link_active = pciehp_check_link_active(ctrl);
257 if (!present && !link_active) {
258 mutex_unlock(&slot->lock);
259 return;
260 }
261
262 switch (slot->state) {
263 case BLINKINGON_STATE:
264 cancel_delayed_work(&slot->work);
265 /* fall through */
266 case OFF_STATE:
267 slot->state = POWERON_STATE;
268 mutex_unlock(&slot->lock);
269 if (present)
270 ctrl_info(ctrl, "Slot(%s): Card present\n",
271 slot_name(slot));
272 if (link_active)
273 ctrl_info(ctrl, "Slot(%s): Link Up\n",
274 slot_name(slot));
275 ctrl->request_result = pciehp_enable_slot(slot);
276 break;
277 default:
278 mutex_unlock(&slot->lock);
279 break;
280 }
281 }
282
__pciehp_enable_slot(struct slot * p_slot)283 static int __pciehp_enable_slot(struct slot *p_slot)
284 {
285 u8 getstatus = 0;
286 struct controller *ctrl = p_slot->ctrl;
287
288 pciehp_get_adapter_status(p_slot, &getstatus);
289 if (!getstatus) {
290 ctrl_info(ctrl, "Slot(%s): No adapter\n", slot_name(p_slot));
291 return -ENODEV;
292 }
293 if (MRL_SENS(p_slot->ctrl)) {
294 pciehp_get_latch_status(p_slot, &getstatus);
295 if (getstatus) {
296 ctrl_info(ctrl, "Slot(%s): Latch open\n",
297 slot_name(p_slot));
298 return -ENODEV;
299 }
300 }
301
302 if (POWER_CTRL(p_slot->ctrl)) {
303 pciehp_get_power_status(p_slot, &getstatus);
304 if (getstatus) {
305 ctrl_info(ctrl, "Slot(%s): Already enabled\n",
306 slot_name(p_slot));
307 return 0;
308 }
309 }
310
311 return board_added(p_slot);
312 }
313
pciehp_enable_slot(struct slot * slot)314 static int pciehp_enable_slot(struct slot *slot)
315 {
316 struct controller *ctrl = slot->ctrl;
317 int ret;
318
319 pm_runtime_get_sync(&ctrl->pcie->port->dev);
320 ret = __pciehp_enable_slot(slot);
321 if (ret && ATTN_BUTTN(ctrl))
322 pciehp_green_led_off(slot); /* may be blinking */
323 pm_runtime_put(&ctrl->pcie->port->dev);
324
325 mutex_lock(&slot->lock);
326 slot->state = ret ? OFF_STATE : ON_STATE;
327 mutex_unlock(&slot->lock);
328
329 return ret;
330 }
331
__pciehp_disable_slot(struct slot * p_slot)332 static int __pciehp_disable_slot(struct slot *p_slot)
333 {
334 u8 getstatus = 0;
335 struct controller *ctrl = p_slot->ctrl;
336
337 if (POWER_CTRL(p_slot->ctrl)) {
338 pciehp_get_power_status(p_slot, &getstatus);
339 if (!getstatus) {
340 ctrl_info(ctrl, "Slot(%s): Already disabled\n",
341 slot_name(p_slot));
342 return -EINVAL;
343 }
344 }
345
346 remove_board(p_slot);
347 return 0;
348 }
349
pciehp_disable_slot(struct slot * slot)350 static int pciehp_disable_slot(struct slot *slot)
351 {
352 struct controller *ctrl = slot->ctrl;
353 int ret;
354
355 pm_runtime_get_sync(&ctrl->pcie->port->dev);
356 ret = __pciehp_disable_slot(slot);
357 pm_runtime_put(&ctrl->pcie->port->dev);
358
359 mutex_lock(&slot->lock);
360 slot->state = OFF_STATE;
361 mutex_unlock(&slot->lock);
362
363 return ret;
364 }
365
pciehp_sysfs_enable_slot(struct slot * p_slot)366 int pciehp_sysfs_enable_slot(struct slot *p_slot)
367 {
368 struct controller *ctrl = p_slot->ctrl;
369
370 mutex_lock(&p_slot->lock);
371 switch (p_slot->state) {
372 case BLINKINGON_STATE:
373 case OFF_STATE:
374 mutex_unlock(&p_slot->lock);
375 /*
376 * The IRQ thread becomes a no-op if the user pulls out the
377 * card before the thread wakes up, so initialize to -ENODEV.
378 */
379 ctrl->request_result = -ENODEV;
380 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
381 wait_event(ctrl->requester,
382 !atomic_read(&ctrl->pending_events));
383 return ctrl->request_result;
384 case POWERON_STATE:
385 ctrl_info(ctrl, "Slot(%s): Already in powering on state\n",
386 slot_name(p_slot));
387 break;
388 case BLINKINGOFF_STATE:
389 case ON_STATE:
390 case POWEROFF_STATE:
391 ctrl_info(ctrl, "Slot(%s): Already enabled\n",
392 slot_name(p_slot));
393 break;
394 default:
395 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
396 slot_name(p_slot), p_slot->state);
397 break;
398 }
399 mutex_unlock(&p_slot->lock);
400
401 return -ENODEV;
402 }
403
pciehp_sysfs_disable_slot(struct slot * p_slot)404 int pciehp_sysfs_disable_slot(struct slot *p_slot)
405 {
406 struct controller *ctrl = p_slot->ctrl;
407
408 mutex_lock(&p_slot->lock);
409 switch (p_slot->state) {
410 case BLINKINGOFF_STATE:
411 case ON_STATE:
412 mutex_unlock(&p_slot->lock);
413 pciehp_request(ctrl, DISABLE_SLOT);
414 wait_event(ctrl->requester,
415 !atomic_read(&ctrl->pending_events));
416 return ctrl->request_result;
417 case POWEROFF_STATE:
418 ctrl_info(ctrl, "Slot(%s): Already in powering off state\n",
419 slot_name(p_slot));
420 break;
421 case BLINKINGON_STATE:
422 case OFF_STATE:
423 case POWERON_STATE:
424 ctrl_info(ctrl, "Slot(%s): Already disabled\n",
425 slot_name(p_slot));
426 break;
427 default:
428 ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
429 slot_name(p_slot), p_slot->state);
430 break;
431 }
432 mutex_unlock(&p_slot->lock);
433
434 return -ENODEV;
435 }
436
