xref: /linux/drivers/pci/hotplug/pciehp_hpc.c (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
1 /*
2  * PCI Express PCI Hot Plug Driver
3  *
4  * Copyright (C) 1995,2001 Compaq Computer Corporation
5  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
6  * Copyright (C) 2001 IBM Corp.
7  * Copyright (C) 2003-2004 Intel Corporation
8  *
9  * All rights reserved.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or (at
14  * your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
19  * NON INFRINGEMENT.  See the GNU General Public License for more
20  * details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25  *
26  * Send feedback to <greg@kroah.com>,<kristen.c.accardi@intel.com>
27  *
28  */
29 
30 #include <linux/kernel.h>
31 #include <linux/module.h>
32 #include <linux/types.h>
33 #include <linux/signal.h>
34 #include <linux/jiffies.h>
35 #include <linux/timer.h>
36 #include <linux/pci.h>
37 #include <linux/interrupt.h>
38 #include <linux/time.h>
39 #include <linux/slab.h>
40 
41 #include "../pci.h"
42 #include "pciehp.h"
43 
44 static inline struct pci_dev *ctrl_dev(struct controller *ctrl)
45 {
46 	return ctrl->pcie->port;
47 }
48 
49 static irqreturn_t pcie_isr(int irq, void *dev_id);
50 static void start_int_poll_timer(struct controller *ctrl, int sec);
51 
52 /* This is the interrupt polling timeout function. */
53 static void int_poll_timeout(unsigned long data)
54 {
55 	struct controller *ctrl = (struct controller *)data;
56 
57 	/* Poll for interrupt events.  regs == NULL => polling */
58 	pcie_isr(0, ctrl);
59 
60 	init_timer(&ctrl->poll_timer);
61 	if (!pciehp_poll_time)
62 		pciehp_poll_time = 2; /* default polling interval is 2 sec */
63 
64 	start_int_poll_timer(ctrl, pciehp_poll_time);
65 }
66 
67 /* This function starts the interrupt polling timer. */
68 static void start_int_poll_timer(struct controller *ctrl, int sec)
69 {
70 	/* Clamp to sane value */
71 	if ((sec <= 0) || (sec > 60))
72 		sec = 2;
73 
74 	ctrl->poll_timer.function = &int_poll_timeout;
75 	ctrl->poll_timer.data = (unsigned long)ctrl;
76 	ctrl->poll_timer.expires = jiffies + sec * HZ;
77 	add_timer(&ctrl->poll_timer);
78 }
79 
80 static inline int pciehp_request_irq(struct controller *ctrl)
81 {
82 	int retval, irq = ctrl->pcie->irq;
83 
84 	/* Install interrupt polling timer. Start with 10 sec delay */
85 	if (pciehp_poll_mode) {
86 		init_timer(&ctrl->poll_timer);
87 		start_int_poll_timer(ctrl, 10);
88 		return 0;
89 	}
90 
91 	/* Installs the interrupt handler */
92 	retval = request_irq(irq, pcie_isr, IRQF_SHARED, MY_NAME, ctrl);
93 	if (retval)
94 		ctrl_err(ctrl, "Cannot get irq %d for the hotplug controller\n",
95 			 irq);
96 	return retval;
97 }
98 
99 static inline void pciehp_free_irq(struct controller *ctrl)
100 {
101 	if (pciehp_poll_mode)
102 		del_timer_sync(&ctrl->poll_timer);
103 	else
104 		free_irq(ctrl->pcie->irq, ctrl);
105 }
106 
107 static int pcie_poll_cmd(struct controller *ctrl, int timeout)
108 {
109 	struct pci_dev *pdev = ctrl_dev(ctrl);
110 	u16 slot_status;
111 
112 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
113 	if (slot_status & PCI_EXP_SLTSTA_CC) {
114 		pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
115 					   PCI_EXP_SLTSTA_CC);
116 		return 1;
117 	}
118 	while (timeout > 0) {
119 		msleep(10);
120 		timeout -= 10;
121 		pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
122 		if (slot_status & PCI_EXP_SLTSTA_CC) {
123 			pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
124 						   PCI_EXP_SLTSTA_CC);
125 			return 1;
126 		}
127 	}
128 	return 0;	/* timeout */
129 }
130 
131 static void pcie_wait_cmd(struct controller *ctrl)
132 {
133 	unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
134 	unsigned long duration = msecs_to_jiffies(msecs);
135 	unsigned long cmd_timeout = ctrl->cmd_started + duration;
136 	unsigned long now, timeout;
137 	int rc;
138 
139 	/*
140 	 * If the controller does not generate notifications for command
141 	 * completions, we never need to wait between writes.
142 	 */
143 	if (NO_CMD_CMPL(ctrl))
144 		return;
145 
146 	if (!ctrl->cmd_busy)
147 		return;
148 
149 	/*
150 	 * Even if the command has already timed out, we want to call
151 	 * pcie_poll_cmd() so it can clear PCI_EXP_SLTSTA_CC.
152 	 */
153 	now = jiffies;
154 	if (time_before_eq(cmd_timeout, now))
155 		timeout = 1;
156 	else
157 		timeout = cmd_timeout - now;
158 
159 	if (ctrl->slot_ctrl & PCI_EXP_SLTCTL_HPIE &&
160 	    ctrl->slot_ctrl & PCI_EXP_SLTCTL_CCIE)
161 		rc = wait_event_timeout(ctrl->queue, !ctrl->cmd_busy, timeout);
162 	else
163 		rc = pcie_poll_cmd(ctrl, jiffies_to_msecs(timeout));
164 
165 	/*
166 	 * Controllers with errata like Intel CF118 don't generate
167 	 * completion notifications unless the power/indicator/interlock
168 	 * control bits are changed.  On such controllers, we'll emit this
169 	 * timeout message when we wait for completion of commands that
170 	 * don't change those bits, e.g., commands that merely enable
171 	 * interrupts.
172 	 */
173 	if (!rc)
174 		ctrl_info(ctrl, "Timeout on hotplug command %#06x (issued %u msec ago)\n",
175 			  ctrl->slot_ctrl,
176 			  jiffies_to_msecs(jiffies - ctrl->cmd_started));
177 }
178 
179 /**
180  * pcie_write_cmd - Issue controller command
181  * @ctrl: controller to which the command is issued
182  * @cmd:  command value written to slot control register
183  * @mask: bitmask of slot control register to be modified
184  */
185 static void pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
186 {
187 	struct pci_dev *pdev = ctrl_dev(ctrl);
188 	u16 slot_ctrl;
189 
190 	mutex_lock(&ctrl->ctrl_lock);
191 
192 	/* Wait for any previous command that might still be in progress */
193 	pcie_wait_cmd(ctrl);
194 
195 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
196 	slot_ctrl &= ~mask;
197 	slot_ctrl |= (cmd & mask);
198 	ctrl->cmd_busy = 1;
199 	smp_mb();
200 	pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, slot_ctrl);
201 	ctrl->cmd_started = jiffies;
202 	ctrl->slot_ctrl = slot_ctrl;
203 
204 	mutex_unlock(&ctrl->ctrl_lock);
205 }
206 
207 bool pciehp_check_link_active(struct controller *ctrl)
208 {
209 	struct pci_dev *pdev = ctrl_dev(ctrl);
210 	u16 lnk_status;
211 	bool ret;
212 
213 	pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
214 	ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
215 
216 	if (ret)
217 		ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
218 
219 	return ret;
220 }
221 
222 static void __pcie_wait_link_active(struct controller *ctrl, bool active)
223 {
224 	int timeout = 1000;
225 
226 	if (pciehp_check_link_active(ctrl) == active)
227 		return;
228 	while (timeout > 0) {
229 		msleep(10);
230 		timeout -= 10;
231 		if (pciehp_check_link_active(ctrl) == active)
232 			return;
233 	}
234 	ctrl_dbg(ctrl, "Data Link Layer Link Active not %s in 1000 msec\n",
235 			active ? "set" : "cleared");
236 }
237 
238 static void pcie_wait_link_active(struct controller *ctrl)
239 {
240 	__pcie_wait_link_active(ctrl, true);
241 }
242 
243 static bool pci_bus_check_dev(struct pci_bus *bus, int devfn)
244 {
245 	u32 l;
246 	int count = 0;
247 	int delay = 1000, step = 20;
248 	bool found = false;
249 
250 	do {
251 		found = pci_bus_read_dev_vendor_id(bus, devfn, &l, 0);
252 		count++;
253 
254 		if (found)
255 			break;
256 
257 		msleep(step);
258 		delay -= step;
259 	} while (delay > 0);
260 
261 	if (count > 1 && pciehp_debug)
262 		printk(KERN_DEBUG "pci %04x:%02x:%02x.%d id reading try %d times with interval %d ms to get %08x\n",
263 			pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
264 			PCI_FUNC(devfn), count, step, l);
265 
266 	return found;
267 }
268 
269 int pciehp_check_link_status(struct controller *ctrl)
270 {
271 	struct pci_dev *pdev = ctrl_dev(ctrl);
272 	bool found;
273 	u16 lnk_status;
274 
275 	/*
276 	 * Data Link Layer Link Active Reporting must be capable for
277 	 * hot-plug capable downstream port. But old controller might
278 	 * not implement it. In this case, we wait for 1000 ms.
279 	*/
280 	if (ctrl->link_active_reporting)
281 		pcie_wait_link_active(ctrl);
282 	else
283 		msleep(1000);
284 
285 	/* wait 100ms before read pci conf, and try in 1s */
286 	msleep(100);
287 	found = pci_bus_check_dev(ctrl->pcie->port->subordinate,
288 					PCI_DEVFN(0, 0));
289 
290 	pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
291 	ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
292 	if ((lnk_status & PCI_EXP_LNKSTA_LT) ||
293 	    !(lnk_status & PCI_EXP_LNKSTA_NLW)) {
294 		ctrl_err(ctrl, "Link Training Error occurs\n");
295 		return -1;
296 	}
297 
298 	pcie_update_link_speed(ctrl->pcie->port->subordinate, lnk_status);
299 
300 	if (!found)
301 		return -1;
302 
303 	return 0;
304 }
305 
306 static int __pciehp_link_set(struct controller *ctrl, bool enable)
307 {
308 	struct pci_dev *pdev = ctrl_dev(ctrl);
309 	u16 lnk_ctrl;
310 
311 	pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &lnk_ctrl);
312 
313 	if (enable)
314 		lnk_ctrl &= ~PCI_EXP_LNKCTL_LD;
315 	else
316 		lnk_ctrl |= PCI_EXP_LNKCTL_LD;
317 
318 	pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, lnk_ctrl);
319 	ctrl_dbg(ctrl, "%s: lnk_ctrl = %x\n", __func__, lnk_ctrl);
320 	return 0;
321 }
322 
323 static int pciehp_link_enable(struct controller *ctrl)
324 {
325 	return __pciehp_link_set(ctrl, true);
326 }
327 
328 void pciehp_get_attention_status(struct slot *slot, u8 *status)
329 {
330 	struct controller *ctrl = slot->ctrl;
331 	struct pci_dev *pdev = ctrl_dev(ctrl);
332 	u16 slot_ctrl;
333 
334 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
335 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x, value read %x\n", __func__,
336 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
337 
338 	switch (slot_ctrl & PCI_EXP_SLTCTL_AIC) {
339 	case PCI_EXP_SLTCTL_ATTN_IND_ON:
340 		*status = 1;	/* On */
341 		break;
342 	case PCI_EXP_SLTCTL_ATTN_IND_BLINK:
343 		*status = 2;	/* Blink */
344 		break;
345 	case PCI_EXP_SLTCTL_ATTN_IND_OFF:
346 		*status = 0;	/* Off */
347 		break;
348 	default:
349 		*status = 0xFF;
350 		break;
351 	}
352 }
353 
354 void pciehp_get_power_status(struct slot *slot, u8 *status)
355 {
356 	struct controller *ctrl = slot->ctrl;
357 	struct pci_dev *pdev = ctrl_dev(ctrl);
358 	u16 slot_ctrl;
359 
360 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
361 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x value read %x\n", __func__,
362 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
363 
364 	switch (slot_ctrl & PCI_EXP_SLTCTL_PCC) {
365 	case PCI_EXP_SLTCTL_PWR_ON:
366 		*status = 1;	/* On */
367 		break;
368 	case PCI_EXP_SLTCTL_PWR_OFF:
369 		*status = 0;	/* Off */
370 		break;
371 	default:
372 		*status = 0xFF;
373 		break;
374 	}
375 }
376 
377 void pciehp_get_latch_status(struct slot *slot, u8 *status)
378 {
379 	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
380 	u16 slot_status;
381 
382 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
383 	*status = !!(slot_status & PCI_EXP_SLTSTA_MRLSS);
384 }
385 
386 void pciehp_get_adapter_status(struct slot *slot, u8 *status)
387 {
388 	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
389 	u16 slot_status;
390 
391 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
392 	*status = !!(slot_status & PCI_EXP_SLTSTA_PDS);
393 }
394 
395 int pciehp_query_power_fault(struct slot *slot)
396 {
397 	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
398 	u16 slot_status;
399 
400 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
401 	return !!(slot_status & PCI_EXP_SLTSTA_PFD);
402 }
403 
404 void pciehp_set_attention_status(struct slot *slot, u8 value)
405 {
406 	struct controller *ctrl = slot->ctrl;
407 	u16 slot_cmd;
408 
409 	if (!ATTN_LED(ctrl))
410 		return;
411 
412 	switch (value) {
413 	case 0:		/* turn off */
414 		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_OFF;
415 		break;
416 	case 1:		/* turn on */
417 		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_ON;
418 		break;
419 	case 2:		/* turn blink */
420 		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_BLINK;
421 		break;
422 	default:
423 		return;
424 	}
425 	pcie_write_cmd(ctrl, slot_cmd, PCI_EXP_SLTCTL_AIC);
426 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
427 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
428 }
429 
430 void pciehp_green_led_on(struct slot *slot)
431 {
432 	struct controller *ctrl = slot->ctrl;
433 
434 	if (!PWR_LED(ctrl))
435 		return;
436 
437 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_IND_ON, PCI_EXP_SLTCTL_PIC);
438 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
439 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
440 		 PCI_EXP_SLTCTL_PWR_IND_ON);
441 }
442 
443 void pciehp_green_led_off(struct slot *slot)
444 {
445 	struct controller *ctrl = slot->ctrl;
446 
447 	if (!PWR_LED(ctrl))
448 		return;
449 
450 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF, PCI_EXP_SLTCTL_PIC);
451 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
452 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
453 		 PCI_EXP_SLTCTL_PWR_IND_OFF);
454 }
455 
456 void pciehp_green_led_blink(struct slot *slot)
457 {
458 	struct controller *ctrl = slot->ctrl;
459 
460 	if (!PWR_LED(ctrl))
461 		return;
462 
463 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_IND_BLINK, PCI_EXP_SLTCTL_PIC);
464 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
465 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
466 		 PCI_EXP_SLTCTL_PWR_IND_BLINK);
467 }
468 
469 int pciehp_power_on_slot(struct slot *slot)
470 {
471 	struct controller *ctrl = slot->ctrl;
472 	struct pci_dev *pdev = ctrl_dev(ctrl);
473 	u16 slot_status;
474 	int retval;
475 
476 	/* Clear sticky power-fault bit from previous power failures */
477 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
478 	if (slot_status & PCI_EXP_SLTSTA_PFD)
479 		pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
480 					   PCI_EXP_SLTSTA_PFD);
481 	ctrl->power_fault_detected = 0;
482 
483 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_ON, PCI_EXP_SLTCTL_PCC);
484 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
485 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
486 		 PCI_EXP_SLTCTL_PWR_ON);
487 
488 	retval = pciehp_link_enable(ctrl);
489 	if (retval)
490 		ctrl_err(ctrl, "%s: Can not enable the link!\n", __func__);
491 
492 	return retval;
493 }
494 
495 void pciehp_power_off_slot(struct slot *slot)
496 {
497 	struct controller *ctrl = slot->ctrl;
498 
499 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_OFF, PCI_EXP_SLTCTL_PCC);
500 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
501 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
502 		 PCI_EXP_SLTCTL_PWR_OFF);
503 }
504 
505 static irqreturn_t pcie_isr(int irq, void *dev_id)
506 {
507 	struct controller *ctrl = (struct controller *)dev_id;
508 	struct pci_dev *pdev = ctrl_dev(ctrl);
509 	struct pci_bus *subordinate = pdev->subordinate;
510 	struct pci_dev *dev;
511 	struct slot *slot = ctrl->slot;
512 	u16 detected, intr_loc;
513 
514 	/*
515 	 * In order to guarantee that all interrupt events are
516 	 * serviced, we need to re-inspect Slot Status register after
517 	 * clearing what is presumed to be the last pending interrupt.
518 	 */
519 	intr_loc = 0;
520 	do {
521 		pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &detected);
522 
523 		detected &= (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
524 			     PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC |
525 			     PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC);
526 		detected &= ~intr_loc;
527 		intr_loc |= detected;
528 		if (!intr_loc)
529 			return IRQ_NONE;
530 		if (detected)
531 			pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
532 						   intr_loc);
533 	} while (detected);
534 
535 	ctrl_dbg(ctrl, "%s: intr_loc %x\n", __func__, intr_loc);
536 
537 	/* Check Command Complete Interrupt Pending */
538 	if (intr_loc & PCI_EXP_SLTSTA_CC) {
539 		ctrl->cmd_busy = 0;
540 		smp_mb();
541 		wake_up(&ctrl->queue);
542 	}
543 
544 	if (subordinate) {
545 		list_for_each_entry(dev, &subordinate->devices, bus_list) {
546 			if (dev->ignore_hotplug) {
547 				ctrl_dbg(ctrl, "ignoring hotplug event %#06x (%s requested no hotplug)\n",
548 					 intr_loc, pci_name(dev));
549 				return IRQ_HANDLED;
550 			}
551 		}
552 	}
553 
554 	if (!(intr_loc & ~PCI_EXP_SLTSTA_CC))
555 		return IRQ_HANDLED;
556 
557 	/* Check MRL Sensor Changed */
558 	if (intr_loc & PCI_EXP_SLTSTA_MRLSC)
559 		pciehp_handle_switch_change(slot);
560 
561 	/* Check Attention Button Pressed */
562 	if (intr_loc & PCI_EXP_SLTSTA_ABP)
563 		pciehp_handle_attention_button(slot);
564 
565 	/* Check Presence Detect Changed */
566 	if (intr_loc & PCI_EXP_SLTSTA_PDC)
567 		pciehp_handle_presence_change(slot);
568 
569 	/* Check Power Fault Detected */
570 	if ((intr_loc & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
571 		ctrl->power_fault_detected = 1;
572 		pciehp_handle_power_fault(slot);
573 	}
574 
575 	if (intr_loc & PCI_EXP_SLTSTA_DLLSC)
576 		pciehp_handle_linkstate_change(slot);
577 
578 	return IRQ_HANDLED;
579 }
580 
581 void pcie_enable_notification(struct controller *ctrl)
582 {
583 	u16 cmd, mask;
584 
585 	/*
586 	 * TBD: Power fault detected software notification support.
587 	 *
588 	 * Power fault detected software notification is not enabled
589 	 * now, because it caused power fault detected interrupt storm
590 	 * on some machines. On those machines, power fault detected
591 	 * bit in the slot status register was set again immediately
592 	 * when it is cleared in the interrupt service routine, and
593 	 * next power fault detected interrupt was notified again.
594 	 */
595 
596 	/*
597 	 * Always enable link events: thus link-up and link-down shall
598 	 * always be treated as hotplug and unplug respectively. Enable
599 	 * presence detect only if Attention Button is not present.
600 	 */
601 	cmd = PCI_EXP_SLTCTL_DLLSCE;
602 	if (ATTN_BUTTN(ctrl))
603 		cmd |= PCI_EXP_SLTCTL_ABPE;
604 	else
605 		cmd |= PCI_EXP_SLTCTL_PDCE;
606 	if (MRL_SENS(ctrl))
607 		cmd |= PCI_EXP_SLTCTL_MRLSCE;
608 	if (!pciehp_poll_mode)
609 		cmd |= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE;
610 
611 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
612 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
613 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
614 		PCI_EXP_SLTCTL_DLLSCE);
615 
616 	pcie_write_cmd(ctrl, cmd, mask);
617 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
618 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, cmd);
619 }
620 
621 static void pcie_disable_notification(struct controller *ctrl)
622 {
623 	u16 mask;
624 
625 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
626 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
627 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
628 		PCI_EXP_SLTCTL_DLLSCE);
629 	pcie_write_cmd(ctrl, 0, mask);
630 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
631 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0);
632 }
633 
634 /*
635  * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary
636  * bus reset of the bridge, but at the same time we want to ensure that it is
637  * not seen as a hot-unplug, followed by the hot-plug of the device. Thus,
638  * disable link state notification and presence detection change notification
639  * momentarily, if we see that they could interfere. Also, clear any spurious
640  * events after.
641  */
642 int pciehp_reset_slot(struct slot *slot, int probe)
643 {
644 	struct controller *ctrl = slot->ctrl;
645 	struct pci_dev *pdev = ctrl_dev(ctrl);
646 	u16 stat_mask = 0, ctrl_mask = 0;
647 
648 	if (probe)
649 		return 0;
650 
651 	if (!ATTN_BUTTN(ctrl)) {
652 		ctrl_mask |= PCI_EXP_SLTCTL_PDCE;
653 		stat_mask |= PCI_EXP_SLTSTA_PDC;
654 	}
655 	ctrl_mask |= PCI_EXP_SLTCTL_DLLSCE;
656 	stat_mask |= PCI_EXP_SLTSTA_DLLSC;
657 
658 	pcie_write_cmd(ctrl, 0, ctrl_mask);
659 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
660 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0);
661 	if (pciehp_poll_mode)
662 		del_timer_sync(&ctrl->poll_timer);
663 
664 	pci_reset_bridge_secondary_bus(ctrl->pcie->port);
665 
666 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, stat_mask);
667 	pcie_write_cmd(ctrl, ctrl_mask, ctrl_mask);
668 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
669 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, ctrl_mask);
670 	if (pciehp_poll_mode)
671 		int_poll_timeout(ctrl->poll_timer.data);
672 
673 	return 0;
674 }
675 
676 int pcie_init_notification(struct controller *ctrl)
677 {
678 	if (pciehp_request_irq(ctrl))
679 		return -1;
680 	pcie_enable_notification(ctrl);
681 	ctrl->notification_enabled = 1;
682 	return 0;
683 }
684 
685 static void pcie_shutdown_notification(struct controller *ctrl)
686 {
687 	if (ctrl->notification_enabled) {
688 		pcie_disable_notification(ctrl);
689 		pciehp_free_irq(ctrl);
690 		ctrl->notification_enabled = 0;
691 	}
692 }
693 
694 static int pcie_init_slot(struct controller *ctrl)
695 {
696 	struct slot *slot;
697 
698 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
699 	if (!slot)
700 		return -ENOMEM;
701 
702 	slot->wq = alloc_workqueue("pciehp-%u", 0, 0, PSN(ctrl));
703 	if (!slot->wq)
704 		goto abort;
705 
706 	slot->ctrl = ctrl;
707 	mutex_init(&slot->lock);
708 	mutex_init(&slot->hotplug_lock);
709 	INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
710 	ctrl->slot = slot;
711 	return 0;
712 abort:
713 	kfree(slot);
714 	return -ENOMEM;
715 }
716 
717 static void pcie_cleanup_slot(struct controller *ctrl)
718 {
719 	struct slot *slot = ctrl->slot;
720 	cancel_delayed_work(&slot->work);
721 	destroy_workqueue(slot->wq);
722 	kfree(slot);
723 }
724 
725 static inline void dbg_ctrl(struct controller *ctrl)
726 {
727 	int i;
728 	u16 reg16;
729 	struct pci_dev *pdev = ctrl->pcie->port;
730 
731 	if (!pciehp_debug)
732 		return;
733 
734 	ctrl_info(ctrl, "Hotplug Controller:\n");
735 	ctrl_info(ctrl, "  Seg/Bus/Dev/Func/IRQ : %s IRQ %d\n",
736 		  pci_name(pdev), pdev->irq);
737 	ctrl_info(ctrl, "  Vendor ID            : 0x%04x\n", pdev->vendor);
738 	ctrl_info(ctrl, "  Device ID            : 0x%04x\n", pdev->device);
739 	ctrl_info(ctrl, "  Subsystem ID         : 0x%04x\n",
740 		  pdev->subsystem_device);
741 	ctrl_info(ctrl, "  Subsystem Vendor ID  : 0x%04x\n",
742 		  pdev->subsystem_vendor);
743 	ctrl_info(ctrl, "  PCIe Cap offset      : 0x%02x\n",
744 		  pci_pcie_cap(pdev));
745 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
746 		if (!pci_resource_len(pdev, i))
747 			continue;
748 		ctrl_info(ctrl, "  PCI resource [%d]     : %pR\n",
749 			  i, &pdev->resource[i]);
750 	}
751 	ctrl_info(ctrl, "Slot Capabilities      : 0x%08x\n", ctrl->slot_cap);
752 	ctrl_info(ctrl, "  Physical Slot Number : %d\n", PSN(ctrl));
753 	ctrl_info(ctrl, "  Attention Button     : %3s\n",
754 		  ATTN_BUTTN(ctrl) ? "yes" : "no");
755 	ctrl_info(ctrl, "  Power Controller     : %3s\n",
756 		  POWER_CTRL(ctrl) ? "yes" : "no");
757 	ctrl_info(ctrl, "  MRL Sensor           : %3s\n",
758 		  MRL_SENS(ctrl)   ? "yes" : "no");
759 	ctrl_info(ctrl, "  Attention Indicator  : %3s\n",
760 		  ATTN_LED(ctrl)   ? "yes" : "no");
761 	ctrl_info(ctrl, "  Power Indicator      : %3s\n",
762 		  PWR_LED(ctrl)    ? "yes" : "no");
763 	ctrl_info(ctrl, "  Hot-Plug Surprise    : %3s\n",
764 		  HP_SUPR_RM(ctrl) ? "yes" : "no");
765 	ctrl_info(ctrl, "  EMI Present          : %3s\n",
766 		  EMI(ctrl)        ? "yes" : "no");
767 	ctrl_info(ctrl, "  Command Completed    : %3s\n",
768 		  NO_CMD_CMPL(ctrl) ? "no" : "yes");
769 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &reg16);
770 	ctrl_info(ctrl, "Slot Status            : 0x%04x\n", reg16);
771 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &reg16);
772 	ctrl_info(ctrl, "Slot Control           : 0x%04x\n", reg16);
773 }
774 
775 #define FLAG(x, y)	(((x) & (y)) ? '+' : '-')
776 
777 struct controller *pcie_init(struct pcie_device *dev)
778 {
779 	struct controller *ctrl;
780 	u32 slot_cap, link_cap;
781 	struct pci_dev *pdev = dev->port;
782 
783 	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
784 	if (!ctrl) {
785 		dev_err(&dev->device, "%s: Out of memory\n", __func__);
786 		goto abort;
787 	}
788 	ctrl->pcie = dev;
789 	pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
790 	ctrl->slot_cap = slot_cap;
791 	mutex_init(&ctrl->ctrl_lock);
792 	init_waitqueue_head(&ctrl->queue);
793 	dbg_ctrl(ctrl);
794 
795 	/* Check if Data Link Layer Link Active Reporting is implemented */
796 	pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap);
797 	if (link_cap & PCI_EXP_LNKCAP_DLLLARC) {
798 		ctrl_dbg(ctrl, "Link Active Reporting supported\n");
799 		ctrl->link_active_reporting = 1;
800 	}
801 
802 	/* Clear all remaining event bits in Slot Status register */
803 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
804 		PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
805 		PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC |
806 		PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC);
807 
808 	ctrl_info(ctrl, "Slot #%d AttnBtn%c AttnInd%c PwrInd%c PwrCtrl%c MRL%c Interlock%c NoCompl%c LLActRep%c\n",
809 		(slot_cap & PCI_EXP_SLTCAP_PSN) >> 19,
810 		FLAG(slot_cap, PCI_EXP_SLTCAP_ABP),
811 		FLAG(slot_cap, PCI_EXP_SLTCAP_AIP),
812 		FLAG(slot_cap, PCI_EXP_SLTCAP_PIP),
813 		FLAG(slot_cap, PCI_EXP_SLTCAP_PCP),
814 		FLAG(slot_cap, PCI_EXP_SLTCAP_MRLSP),
815 		FLAG(slot_cap, PCI_EXP_SLTCAP_EIP),
816 		FLAG(slot_cap, PCI_EXP_SLTCAP_NCCS),
817 		FLAG(link_cap, PCI_EXP_LNKCAP_DLLLARC));
818 
819 	if (pcie_init_slot(ctrl))
820 		goto abort_ctrl;
821 
822 	return ctrl;
823 
824 abort_ctrl:
825 	kfree(ctrl);
826 abort:
827 	return NULL;
828 }
829 
830 void pciehp_release_ctrl(struct controller *ctrl)
831 {
832 	pcie_shutdown_notification(ctrl);
833 	pcie_cleanup_slot(ctrl);
834 	kfree(ctrl);
835 }
836