summaryrefslogtreecommitdiff
path: root/drivers/pci/hotplug/pciehp_ctrl.c
blob: 3f3df4c29f6e1d40112343e91f902735a6b4d535 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
// SPDX-License-Identifier: GPL-2.0+
/*
 * PCI Express Hot Plug Controller Driver
 *
 * Copyright (C) 1995,2001 Compaq Computer Corporation
 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
 * Copyright (C) 2001 IBM Corp.
 * Copyright (C) 2003-2004 Intel Corporation
 *
 * All rights reserved.
 *
 * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
 *
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/pm_runtime.h>
#include <linux/pci.h>
#include "pciehp.h"

/* The following routines constitute the bulk of the
   hotplug controller logic
 */

#define SAFE_REMOVAL	 true
#define SURPRISE_REMOVAL false

static void set_slot_off(struct controller *ctrl)
{
	/* turn off slot, turn on Amber LED, turn off Green LED if supported*/
	if (POWER_CTRL(ctrl)) {
		pciehp_power_off_slot(ctrl);

		/*
		 * After turning power off, we must wait for at least 1 second
		 * before taking any action that relies on power having been
		 * removed from the slot/adapter.
		 */
		msleep(1000);
	}

	pciehp_green_led_off(ctrl);
	pciehp_set_attention_status(ctrl, 1);
}

/**
 * board_added - Called after a board has been added to the system.
 * @ctrl: PCIe hotplug controller where board is added
 *
 * Turns power on for the board.
 * Configures board.
 */
static int board_added(struct controller *ctrl)
{
	int retval = 0;
	struct pci_bus *parent = ctrl->pcie->port->subordinate;

	if (POWER_CTRL(ctrl)) {
		/* Power on slot */
		retval = pciehp_power_on_slot(ctrl);
		if (retval)
			return retval;
	}

	pciehp_green_led_blink(ctrl);

	/* Check link training status */
	retval = pciehp_check_link_status(ctrl);
	if (retval) {
		ctrl_err(ctrl, "Failed to check link status\n");
		goto err_exit;
	}

	/* Check for a power fault */
	if (ctrl->power_fault_detected || pciehp_query_power_fault(ctrl)) {
		ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(ctrl));
		retval = -EIO;
		goto err_exit;
	}

	retval = pciehp_configure_device(ctrl);
	if (retval) {
		if (retval != -EEXIST) {
			ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
				 pci_domain_nr(parent), parent->number);
			goto err_exit;
		}
	}

	pciehp_green_led_on(ctrl);
	pciehp_set_attention_status(ctrl, 0);
	return 0;

err_exit:
	set_slot_off(ctrl);
	return retval;
}

/**
 * remove_board - Turns off slot and LEDs
 * @ctrl: PCIe hotplug controller where board is being removed
 * @safe_removal: whether the board is safely removed (versus surprise removed)
 */
static void remove_board(struct controller *ctrl, bool safe_removal)
{
	pciehp_unconfigure_device(ctrl, safe_removal);

	if (POWER_CTRL(ctrl)) {
		pciehp_power_off_slot(ctrl);

		/*
		 * After turning power off, we must wait for at least 1 second
		 * before taking any action that relies on power having been
		 * removed from the slot/adapter.
		 */
		msleep(1000);
	}

	/* turn off Green LED */
	pciehp_green_led_off(ctrl);
}

static int pciehp_enable_slot(struct controller *ctrl);
static int pciehp_disable_slot(struct controller *ctrl, bool safe_removal);

void pciehp_request(struct controller *ctrl, int action)
{
	atomic_or(action, &ctrl->pending_events);
	if (!pciehp_poll_mode)
		irq_wake_thread(ctrl->pcie->irq, ctrl);
}

void pciehp_queue_pushbutton_work(struct work_struct *work)
{
	struct controller *ctrl = container_of(work, struct controller,
					       button_work.work);

	mutex_lock(&ctrl->state_lock);
	switch (ctrl->state) {
	case BLINKINGOFF_STATE:
		pciehp_request(ctrl, DISABLE_SLOT);
		break;
	case BLINKINGON_STATE:
		pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
		break;
	default:
		break;
	}
	mutex_unlock(&ctrl->state_lock);
}

void pciehp_handle_button_press(struct controller *ctrl)
{
	mutex_lock(&ctrl->state_lock);
	switch (ctrl->state) {
	case OFF_STATE:
	case ON_STATE:
		if (ctrl->state == ON_STATE) {
			ctrl->state = BLINKINGOFF_STATE;
			ctrl_info(ctrl, "Slot(%s): Powering off due to button press\n",
				  slot_name(ctrl));
		} else {
			ctrl->state = BLINKINGON_STATE;
			ctrl_info(ctrl, "Slot(%s) Powering on due to button press\n",
				  slot_name(ctrl));
		}
		/* blink green LED and turn off amber */
		pciehp_green_led_blink(ctrl);
		pciehp_set_attention_status(ctrl, 0);
		schedule_delayed_work(&ctrl->button_work, 5 * HZ);
		break;
	case BLINKINGOFF_STATE:
	case BLINKINGON_STATE:
		/*
		 * Cancel if we are still blinking; this means that we
		 * press the attention again before the 5 sec. limit
		 * expires to cancel hot-add or hot-remove
		 */
		ctrl_info(ctrl, "Slot(%s): Button cancel\n", slot_name(ctrl));
		cancel_delayed_work(&ctrl->button_work);
		if (ctrl->state == BLINKINGOFF_STATE) {
			ctrl->state = ON_STATE;
			pciehp_green_led_on(ctrl);
		} else {
			ctrl->state = OFF_STATE;
			pciehp_green_led_off(ctrl);
		}
		pciehp_set_attention_status(ctrl, 0);
		ctrl_info(ctrl, "Slot(%s): Action canceled due to button press\n",
			  slot_name(ctrl));
		break;
	default:
		ctrl_err(ctrl, "Slot(%s): Ignoring invalid state %#x\n",
			 slot_name(ctrl), ctrl->state);
		break;
	}
	mutex_unlock(&ctrl->state_lock);
}

void pciehp_handle_disable_request(struct controller *ctrl)
{
	mutex_lock(&ctrl->state_lock);
	switch (ctrl->state) {
	case BLINKINGON_STATE:
	case BLINKINGOFF_STATE:
		cancel_delayed_work(&ctrl->button_work);
		break;
	}
	ctrl->state = POWEROFF_STATE;
	mutex_unlock(&ctrl->state_lock);

	ctrl->request_result = pciehp_disable_slot(ctrl, SAFE_REMOVAL);
}

void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events)
{
	bool present, link_active;

	/*
	 * If the slot is on and presence or link has changed, turn it off.
	 * Even if it's occupied again, we cannot assume the card is the same.
	 */
	mutex_lock(&ctrl->state_lock);
	switch (ctrl->state) {
	case BLINKINGOFF_STATE:
		cancel_delayed_work(&ctrl->button_work);
		/* fall through */
	case ON_STATE:
		ctrl->state = POWEROFF_STATE;
		mutex_unlock(&ctrl->state_lock);
		if (events & PCI_EXP_SLTSTA_DLLSC)
			ctrl_info(ctrl, "Slot(%s): Link Down\n",
				  slot_name(ctrl));
		if (events & PCI_EXP_SLTSTA_PDC)
			ctrl_info(ctrl, "Slot(%s): Card not present\n",
				  slot_name(ctrl));
		pciehp_disable_slot(ctrl, SURPRISE_REMOVAL);
		break;
	default:
		mutex_unlock(&ctrl->state_lock);
		break;
	}

	/* Turn the slot on if it's occupied or link is up */
	mutex_lock(&ctrl->state_lock);
	present = pciehp_card_present(ctrl);
	link_active = pciehp_check_link_active(ctrl);
	if (!present && !link_active) {
		mutex_unlock(&ctrl->state_lock);
		return;
	}

	switch (ctrl->state) {
	case BLINKINGON_STATE:
		cancel_delayed_work(&ctrl->button_work);
		/* fall through */
	case OFF_STATE:
		ctrl->state = POWERON_STATE;
		mutex_unlock(&ctrl->state_lock);
		if (present)
			ctrl_info(ctrl, "Slot(%s): Card present\n",
				  slot_name(ctrl));
		if (link_active)
			ctrl_info(ctrl, "Slot(%s): Link Up\n",
				  slot_name(ctrl));
		ctrl->request_result = pciehp_enable_slot(ctrl);
		break;
	default:
		mutex_unlock(&ctrl->state_lock);
		break;
	}
}

static int __pciehp_enable_slot(struct controller *ctrl)
{
	u8 getstatus = 0;

	if (MRL_SENS(ctrl)) {
		pciehp_get_latch_status(ctrl, &getstatus);
		if (getstatus) {
			ctrl_info(ctrl, "Slot(%s): Latch open\n",
				  slot_name(ctrl));
			return -ENODEV;
		}
	}

	if (POWER_CTRL(ctrl)) {
		pciehp_get_power_status(ctrl, &getstatus);
		if (getstatus) {
			ctrl_info(ctrl, "Slot(%s): Already enabled\n",
				  slot_name(ctrl));
			return 0;
		}
	}

	return board_added(ctrl);
}

static int pciehp_enable_slot(struct controller *ctrl)
{
	int ret;

	pm_runtime_get_sync(&ctrl->pcie->port->dev);
	ret = __pciehp_enable_slot(ctrl);
	if (ret && ATTN_BUTTN(ctrl))
		pciehp_green_led_off(ctrl); /* may be blinking */
	pm_runtime_put(&ctrl->pcie->port->dev);

	mutex_lock(&ctrl->state_lock);
	ctrl->state = ret ? OFF_STATE : ON_STATE;
	mutex_unlock(&ctrl->state_lock);

	return ret;
}

static int __pciehp_disable_slot(struct controller *ctrl, bool safe_removal)
{
	u8 getstatus = 0;

	if (POWER_CTRL(ctrl)) {
		pciehp_get_power_status(ctrl, &getstatus);
		if (!getstatus) {
			ctrl_info(ctrl, "Slot(%s): Already disabled\n",
				  slot_name(ctrl));
			return -EINVAL;
		}
	}

	remove_board(ctrl, safe_removal);
	return 0;
}

static int pciehp_disable_slot(struct controller *ctrl, bool safe_removal)
{
	int ret;

	pm_runtime_get_sync(&ctrl->pcie->port->dev);
	ret = __pciehp_disable_slot(ctrl, safe_removal);
	pm_runtime_put(&ctrl->pcie->port->dev);

	mutex_lock(&ctrl->state_lock);
	ctrl->state = OFF_STATE;
	mutex_unlock(&ctrl->state_lock);

	return ret;
}

int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot)
{
	struct controller *ctrl = to_ctrl(hotplug_slot);

	mutex_lock(&ctrl->state_lock);
	switch (ctrl->state) {
	case BLINKINGON_STATE:
	case OFF_STATE:
		mutex_unlock(&ctrl->state_lock);
		/*
		 * The IRQ thread becomes a no-op if the user pulls out the
		 * card before the thread wakes up, so initialize to -ENODEV.
		 */
		ctrl->request_result = -ENODEV;
		pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
		wait_event(ctrl->requester,
			   !atomic_read(&ctrl->pending_events));
		return ctrl->request_result;
	case POWERON_STATE:
		ctrl_info(ctrl, "Slot(%s): Already in powering on state\n",
			  slot_name(ctrl));
		break;
	case BLINKINGOFF_STATE:
	case ON_STATE:
	case POWEROFF_STATE:
		ctrl_info(ctrl, "Slot(%s): Already enabled\n",
			  slot_name(ctrl));
		break;
	default:
		ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
			 slot_name(ctrl), ctrl->state);
		break;
	}
	mutex_unlock(&ctrl->state_lock);

	return -ENODEV;
}

int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot)
{
	struct controller *ctrl = to_ctrl(hotplug_slot);

	mutex_lock(&ctrl->state_lock);
	switch (ctrl->state) {
	case BLINKINGOFF_STATE:
	case ON_STATE:
		mutex_unlock(&ctrl->state_lock);
		pciehp_request(ctrl, DISABLE_SLOT);
		wait_event(ctrl->requester,
			   !atomic_read(&ctrl->pending_events));
		return ctrl->request_result;
	case POWEROFF_STATE:
		ctrl_info(ctrl, "Slot(%s): Already in powering off state\n",
			  slot_name(ctrl));
		break;
	case BLINKINGON_STATE:
	case OFF_STATE:
	case POWERON_STATE:
		ctrl_info(ctrl, "Slot(%s): Already disabled\n",
			  slot_name(ctrl));
		break;
	default:
		ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
			 slot_name(ctrl), ctrl->state);
		break;
	}
	mutex_unlock(&ctrl->state_lock);

	return -ENODEV;
}