xref: /linux/drivers/pci/hotplug/pciehp_hpc.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 	while (true) {
113 		pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
114 		if (slot_status == (u16) ~0) {
115 			ctrl_info(ctrl, "%s: no response from device\n",
116 				  __func__);
117 			return 0;
118 		}
119 
120 		if (slot_status & PCI_EXP_SLTSTA_CC) {
121 			pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
122 						   PCI_EXP_SLTSTA_CC);
123 			return 1;
124 		}
125 		if (timeout < 0)
126 			break;
127 		msleep(10);
128 		timeout -= 10;
129 	}
130 	return 0;	/* timeout */
131 }
132 
133 static void pcie_wait_cmd(struct controller *ctrl)
134 {
135 	unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
136 	unsigned long duration = msecs_to_jiffies(msecs);
137 	unsigned long cmd_timeout = ctrl->cmd_started + duration;
138 	unsigned long now, timeout;
139 	int rc;
140 
141 	/*
142 	 * If the controller does not generate notifications for command
143 	 * completions, we never need to wait between writes.
144 	 */
145 	if (NO_CMD_CMPL(ctrl))
146 		return;
147 
148 	if (!ctrl->cmd_busy)
149 		return;
150 
151 	/*
152 	 * Even if the command has already timed out, we want to call
153 	 * pcie_poll_cmd() so it can clear PCI_EXP_SLTSTA_CC.
154 	 */
155 	now = jiffies;
156 	if (time_before_eq(cmd_timeout, now))
157 		timeout = 1;
158 	else
159 		timeout = cmd_timeout - now;
160 
161 	if (ctrl->slot_ctrl & PCI_EXP_SLTCTL_HPIE &&
162 	    ctrl->slot_ctrl & PCI_EXP_SLTCTL_CCIE)
163 		rc = wait_event_timeout(ctrl->queue, !ctrl->cmd_busy, timeout);
164 	else
165 		rc = pcie_poll_cmd(ctrl, jiffies_to_msecs(timeout));
166 
167 	/*
168 	 * Controllers with errata like Intel CF118 don't generate
169 	 * completion notifications unless the power/indicator/interlock
170 	 * control bits are changed.  On such controllers, we'll emit this
171 	 * timeout message when we wait for completion of commands that
172 	 * don't change those bits, e.g., commands that merely enable
173 	 * interrupts.
174 	 */
175 	if (!rc)
176 		ctrl_info(ctrl, "Timeout on hotplug command %#06x (issued %u msec ago)\n",
177 			  ctrl->slot_ctrl,
178 			  jiffies_to_msecs(jiffies - ctrl->cmd_started));
179 }
180 
181 static void pcie_do_write_cmd(struct controller *ctrl, u16 cmd,
182 			      u16 mask, bool wait)
183 {
184 	struct pci_dev *pdev = ctrl_dev(ctrl);
185 	u16 slot_ctrl;
186 
187 	mutex_lock(&ctrl->ctrl_lock);
188 
189 	/*
190 	 * Always wait for any previous command that might still be in progress
191 	 */
192 	pcie_wait_cmd(ctrl);
193 
194 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
195 	if (slot_ctrl == (u16) ~0) {
196 		ctrl_info(ctrl, "%s: no response from device\n", __func__);
197 		goto out;
198 	}
199 
200 	slot_ctrl &= ~mask;
201 	slot_ctrl |= (cmd & mask);
202 	ctrl->cmd_busy = 1;
203 	smp_mb();
204 	pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, slot_ctrl);
205 	ctrl->cmd_started = jiffies;
206 	ctrl->slot_ctrl = slot_ctrl;
207 
208 	/*
209 	 * Optionally wait for the hardware to be ready for a new command,
210 	 * indicating completion of the above issued command.
211 	 */
212 	if (wait)
213 		pcie_wait_cmd(ctrl);
214 
215 out:
216 	mutex_unlock(&ctrl->ctrl_lock);
217 }
218 
219 /**
220  * pcie_write_cmd - Issue controller command
221  * @ctrl: controller to which the command is issued
222  * @cmd:  command value written to slot control register
223  * @mask: bitmask of slot control register to be modified
224  */
225 static void pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
226 {
227 	pcie_do_write_cmd(ctrl, cmd, mask, true);
228 }
229 
230 /* Same as above without waiting for the hardware to latch */
231 static void pcie_write_cmd_nowait(struct controller *ctrl, u16 cmd, u16 mask)
232 {
233 	pcie_do_write_cmd(ctrl, cmd, mask, false);
234 }
235 
236 bool pciehp_check_link_active(struct controller *ctrl)
237 {
238 	struct pci_dev *pdev = ctrl_dev(ctrl);
239 	u16 lnk_status;
240 	bool ret;
241 
242 	pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
243 	ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
244 
245 	if (ret)
246 		ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
247 
248 	return ret;
249 }
250 
251 static void __pcie_wait_link_active(struct controller *ctrl, bool active)
252 {
253 	int timeout = 1000;
254 
255 	if (pciehp_check_link_active(ctrl) == active)
256 		return;
257 	while (timeout > 0) {
258 		msleep(10);
259 		timeout -= 10;
260 		if (pciehp_check_link_active(ctrl) == active)
261 			return;
262 	}
263 	ctrl_dbg(ctrl, "Data Link Layer Link Active not %s in 1000 msec\n",
264 			active ? "set" : "cleared");
265 }
266 
267 static void pcie_wait_link_active(struct controller *ctrl)
268 {
269 	__pcie_wait_link_active(ctrl, true);
270 }
271 
272 static bool pci_bus_check_dev(struct pci_bus *bus, int devfn)
273 {
274 	u32 l;
275 	int count = 0;
276 	int delay = 1000, step = 20;
277 	bool found = false;
278 
279 	do {
280 		found = pci_bus_read_dev_vendor_id(bus, devfn, &l, 0);
281 		count++;
282 
283 		if (found)
284 			break;
285 
286 		msleep(step);
287 		delay -= step;
288 	} while (delay > 0);
289 
290 	if (count > 1 && pciehp_debug)
291 		printk(KERN_DEBUG "pci %04x:%02x:%02x.%d id reading try %d times with interval %d ms to get %08x\n",
292 			pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
293 			PCI_FUNC(devfn), count, step, l);
294 
295 	return found;
296 }
297 
298 int pciehp_check_link_status(struct controller *ctrl)
299 {
300 	struct pci_dev *pdev = ctrl_dev(ctrl);
301 	bool found;
302 	u16 lnk_status;
303 
304 	/*
305 	 * Data Link Layer Link Active Reporting must be capable for
306 	 * hot-plug capable downstream port. But old controller might
307 	 * not implement it. In this case, we wait for 1000 ms.
308 	*/
309 	if (ctrl->link_active_reporting)
310 		pcie_wait_link_active(ctrl);
311 	else
312 		msleep(1000);
313 
314 	/* wait 100ms before read pci conf, and try in 1s */
315 	msleep(100);
316 	found = pci_bus_check_dev(ctrl->pcie->port->subordinate,
317 					PCI_DEVFN(0, 0));
318 
319 	pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
320 	ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
321 	if ((lnk_status & PCI_EXP_LNKSTA_LT) ||
322 	    !(lnk_status & PCI_EXP_LNKSTA_NLW)) {
323 		ctrl_err(ctrl, "link training error: status %#06x\n",
324 			 lnk_status);
325 		return -1;
326 	}
327 
328 	pcie_update_link_speed(ctrl->pcie->port->subordinate, lnk_status);
329 
330 	if (!found)
331 		return -1;
332 
333 	return 0;
334 }
335 
336 static int __pciehp_link_set(struct controller *ctrl, bool enable)
337 {
338 	struct pci_dev *pdev = ctrl_dev(ctrl);
339 	u16 lnk_ctrl;
340 
341 	pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &lnk_ctrl);
342 
343 	if (enable)
344 		lnk_ctrl &= ~PCI_EXP_LNKCTL_LD;
345 	else
346 		lnk_ctrl |= PCI_EXP_LNKCTL_LD;
347 
348 	pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, lnk_ctrl);
349 	ctrl_dbg(ctrl, "%s: lnk_ctrl = %x\n", __func__, lnk_ctrl);
350 	return 0;
351 }
352 
353 static int pciehp_link_enable(struct controller *ctrl)
354 {
355 	return __pciehp_link_set(ctrl, true);
356 }
357 
358 void pciehp_get_attention_status(struct slot *slot, u8 *status)
359 {
360 	struct controller *ctrl = slot->ctrl;
361 	struct pci_dev *pdev = ctrl_dev(ctrl);
362 	u16 slot_ctrl;
363 
364 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
365 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x, value read %x\n", __func__,
366 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
367 
368 	switch (slot_ctrl & PCI_EXP_SLTCTL_AIC) {
369 	case PCI_EXP_SLTCTL_ATTN_IND_ON:
370 		*status = 1;	/* On */
371 		break;
372 	case PCI_EXP_SLTCTL_ATTN_IND_BLINK:
373 		*status = 2;	/* Blink */
374 		break;
375 	case PCI_EXP_SLTCTL_ATTN_IND_OFF:
376 		*status = 0;	/* Off */
377 		break;
378 	default:
379 		*status = 0xFF;
380 		break;
381 	}
382 }
383 
384 void pciehp_get_power_status(struct slot *slot, u8 *status)
385 {
386 	struct controller *ctrl = slot->ctrl;
387 	struct pci_dev *pdev = ctrl_dev(ctrl);
388 	u16 slot_ctrl;
389 
390 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
391 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x value read %x\n", __func__,
392 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
393 
394 	switch (slot_ctrl & PCI_EXP_SLTCTL_PCC) {
395 	case PCI_EXP_SLTCTL_PWR_ON:
396 		*status = 1;	/* On */
397 		break;
398 	case PCI_EXP_SLTCTL_PWR_OFF:
399 		*status = 0;	/* Off */
400 		break;
401 	default:
402 		*status = 0xFF;
403 		break;
404 	}
405 }
406 
407 void pciehp_get_latch_status(struct slot *slot, u8 *status)
408 {
409 	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
410 	u16 slot_status;
411 
412 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
413 	*status = !!(slot_status & PCI_EXP_SLTSTA_MRLSS);
414 }
415 
416 void pciehp_get_adapter_status(struct slot *slot, u8 *status)
417 {
418 	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
419 	u16 slot_status;
420 
421 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
422 	*status = !!(slot_status & PCI_EXP_SLTSTA_PDS);
423 }
424 
425 int pciehp_query_power_fault(struct slot *slot)
426 {
427 	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
428 	u16 slot_status;
429 
430 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
431 	return !!(slot_status & PCI_EXP_SLTSTA_PFD);
432 }
433 
434 void pciehp_set_attention_status(struct slot *slot, u8 value)
435 {
436 	struct controller *ctrl = slot->ctrl;
437 	u16 slot_cmd;
438 
439 	if (!ATTN_LED(ctrl))
440 		return;
441 
442 	switch (value) {
443 	case 0:		/* turn off */
444 		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_OFF;
445 		break;
446 	case 1:		/* turn on */
447 		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_ON;
448 		break;
449 	case 2:		/* turn blink */
450 		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_BLINK;
451 		break;
452 	default:
453 		return;
454 	}
455 	pcie_write_cmd_nowait(ctrl, slot_cmd, PCI_EXP_SLTCTL_AIC);
456 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
457 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
458 }
459 
460 void pciehp_green_led_on(struct slot *slot)
461 {
462 	struct controller *ctrl = slot->ctrl;
463 
464 	if (!PWR_LED(ctrl))
465 		return;
466 
467 	pcie_write_cmd_nowait(ctrl, PCI_EXP_SLTCTL_PWR_IND_ON,
468 			      PCI_EXP_SLTCTL_PIC);
469 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
470 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
471 		 PCI_EXP_SLTCTL_PWR_IND_ON);
472 }
473 
474 void pciehp_green_led_off(struct slot *slot)
475 {
476 	struct controller *ctrl = slot->ctrl;
477 
478 	if (!PWR_LED(ctrl))
479 		return;
480 
481 	pcie_write_cmd_nowait(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
482 			      PCI_EXP_SLTCTL_PIC);
483 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
484 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
485 		 PCI_EXP_SLTCTL_PWR_IND_OFF);
486 }
487 
488 void pciehp_green_led_blink(struct slot *slot)
489 {
490 	struct controller *ctrl = slot->ctrl;
491 
492 	if (!PWR_LED(ctrl))
493 		return;
494 
495 	pcie_write_cmd_nowait(ctrl, PCI_EXP_SLTCTL_PWR_IND_BLINK,
496 			      PCI_EXP_SLTCTL_PIC);
497 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
498 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
499 		 PCI_EXP_SLTCTL_PWR_IND_BLINK);
500 }
501 
502 int pciehp_power_on_slot(struct slot *slot)
503 {
504 	struct controller *ctrl = slot->ctrl;
505 	struct pci_dev *pdev = ctrl_dev(ctrl);
506 	u16 slot_status;
507 	int retval;
508 
509 	/* Clear sticky power-fault bit from previous power failures */
510 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
511 	if (slot_status & PCI_EXP_SLTSTA_PFD)
512 		pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
513 					   PCI_EXP_SLTSTA_PFD);
514 	ctrl->power_fault_detected = 0;
515 
516 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_ON, PCI_EXP_SLTCTL_PCC);
517 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
518 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
519 		 PCI_EXP_SLTCTL_PWR_ON);
520 
521 	retval = pciehp_link_enable(ctrl);
522 	if (retval)
523 		ctrl_err(ctrl, "%s: Can not enable the link!\n", __func__);
524 
525 	return retval;
526 }
527 
528 void pciehp_power_off_slot(struct slot *slot)
529 {
530 	struct controller *ctrl = slot->ctrl;
531 
532 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_OFF, PCI_EXP_SLTCTL_PCC);
533 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
534 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
535 		 PCI_EXP_SLTCTL_PWR_OFF);
536 }
537 
538 static irqreturn_t pcie_isr(int irq, void *dev_id)
539 {
540 	struct controller *ctrl = (struct controller *)dev_id;
541 	struct pci_dev *pdev = ctrl_dev(ctrl);
542 	struct pci_bus *subordinate = pdev->subordinate;
543 	struct pci_dev *dev;
544 	struct slot *slot = ctrl->slot;
545 	u16 detected, intr_loc;
546 	u8 present;
547 	bool link;
548 
549 	/*
550 	 * In order to guarantee that all interrupt events are
551 	 * serviced, we need to re-inspect Slot Status register after
552 	 * clearing what is presumed to be the last pending interrupt.
553 	 */
554 	intr_loc = 0;
555 	do {
556 		pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &detected);
557 		if (detected == (u16) ~0) {
558 			ctrl_info(ctrl, "%s: no response from device\n",
559 				  __func__);
560 			return IRQ_HANDLED;
561 		}
562 
563 		detected &= (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
564 			     PCI_EXP_SLTSTA_PDC |
565 			     PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC);
566 		detected &= ~intr_loc;
567 		intr_loc |= detected;
568 		if (!intr_loc)
569 			return IRQ_NONE;
570 		if (detected)
571 			pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
572 						   intr_loc);
573 	} while (detected);
574 
575 	ctrl_dbg(ctrl, "pending interrupts %#06x from Slot Status\n", intr_loc);
576 
577 	/* Check Command Complete Interrupt Pending */
578 	if (intr_loc & PCI_EXP_SLTSTA_CC) {
579 		ctrl->cmd_busy = 0;
580 		smp_mb();
581 		wake_up(&ctrl->queue);
582 	}
583 
584 	if (subordinate) {
585 		list_for_each_entry(dev, &subordinate->devices, bus_list) {
586 			if (dev->ignore_hotplug) {
587 				ctrl_dbg(ctrl, "ignoring hotplug event %#06x (%s requested no hotplug)\n",
588 					 intr_loc, pci_name(dev));
589 				return IRQ_HANDLED;
590 			}
591 		}
592 	}
593 
594 	if (!(intr_loc & ~PCI_EXP_SLTSTA_CC))
595 		return IRQ_HANDLED;
596 
597 	/* Check Attention Button Pressed */
598 	if (intr_loc & PCI_EXP_SLTSTA_ABP) {
599 		ctrl_info(ctrl, "Button pressed on Slot(%s)\n",
600 			  slot_name(slot));
601 		pciehp_queue_interrupt_event(slot, INT_BUTTON_PRESS);
602 	}
603 
604 	/* Check Presence Detect Changed */
605 	if (intr_loc & PCI_EXP_SLTSTA_PDC) {
606 		pciehp_get_adapter_status(slot, &present);
607 		ctrl_info(ctrl, "Card %spresent on Slot(%s)\n",
608 			  present ? "" : "not ", slot_name(slot));
609 		pciehp_queue_interrupt_event(slot, present ? INT_PRESENCE_ON :
610 					     INT_PRESENCE_OFF);
611 	}
612 
613 	/* Check Power Fault Detected */
614 	if ((intr_loc & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
615 		ctrl->power_fault_detected = 1;
616 		ctrl_err(ctrl, "Power fault on slot %s\n", slot_name(slot));
617 		pciehp_queue_interrupt_event(slot, INT_POWER_FAULT);
618 	}
619 
620 	if (intr_loc & PCI_EXP_SLTSTA_DLLSC) {
621 		link = pciehp_check_link_active(ctrl);
622 		ctrl_info(ctrl, "slot(%s): Link %s event\n",
623 			  slot_name(slot), link ? "Up" : "Down");
624 		pciehp_queue_interrupt_event(slot, link ? INT_LINK_UP :
625 					     INT_LINK_DOWN);
626 	}
627 
628 	return IRQ_HANDLED;
629 }
630 
631 void pcie_enable_notification(struct controller *ctrl)
632 {
633 	u16 cmd, mask;
634 
635 	/*
636 	 * TBD: Power fault detected software notification support.
637 	 *
638 	 * Power fault detected software notification is not enabled
639 	 * now, because it caused power fault detected interrupt storm
640 	 * on some machines. On those machines, power fault detected
641 	 * bit in the slot status register was set again immediately
642 	 * when it is cleared in the interrupt service routine, and
643 	 * next power fault detected interrupt was notified again.
644 	 */
645 
646 	/*
647 	 * Always enable link events: thus link-up and link-down shall
648 	 * always be treated as hotplug and unplug respectively. Enable
649 	 * presence detect only if Attention Button is not present.
650 	 */
651 	cmd = PCI_EXP_SLTCTL_DLLSCE;
652 	if (ATTN_BUTTN(ctrl))
653 		cmd |= PCI_EXP_SLTCTL_ABPE;
654 	else
655 		cmd |= PCI_EXP_SLTCTL_PDCE;
656 	if (!pciehp_poll_mode)
657 		cmd |= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE;
658 
659 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
660 		PCI_EXP_SLTCTL_PFDE |
661 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
662 		PCI_EXP_SLTCTL_DLLSCE);
663 
664 	pcie_write_cmd_nowait(ctrl, cmd, mask);
665 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
666 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, cmd);
667 }
668 
669 static void pcie_disable_notification(struct controller *ctrl)
670 {
671 	u16 mask;
672 
673 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
674 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
675 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
676 		PCI_EXP_SLTCTL_DLLSCE);
677 	pcie_write_cmd(ctrl, 0, mask);
678 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
679 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0);
680 }
681 
682 /*
683  * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary
684  * bus reset of the bridge, but at the same time we want to ensure that it is
685  * not seen as a hot-unplug, followed by the hot-plug of the device. Thus,
686  * disable link state notification and presence detection change notification
687  * momentarily, if we see that they could interfere. Also, clear any spurious
688  * events after.
689  */
690 int pciehp_reset_slot(struct slot *slot, int probe)
691 {
692 	struct controller *ctrl = slot->ctrl;
693 	struct pci_dev *pdev = ctrl_dev(ctrl);
694 	u16 stat_mask = 0, ctrl_mask = 0;
695 
696 	if (probe)
697 		return 0;
698 
699 	if (!ATTN_BUTTN(ctrl)) {
700 		ctrl_mask |= PCI_EXP_SLTCTL_PDCE;
701 		stat_mask |= PCI_EXP_SLTSTA_PDC;
702 	}
703 	ctrl_mask |= PCI_EXP_SLTCTL_DLLSCE;
704 	stat_mask |= PCI_EXP_SLTSTA_DLLSC;
705 
706 	pcie_write_cmd(ctrl, 0, ctrl_mask);
707 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
708 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0);
709 	if (pciehp_poll_mode)
710 		del_timer_sync(&ctrl->poll_timer);
711 
712 	pci_reset_bridge_secondary_bus(ctrl->pcie->port);
713 
714 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, stat_mask);
715 	pcie_write_cmd_nowait(ctrl, ctrl_mask, ctrl_mask);
716 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
717 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, ctrl_mask);
718 	if (pciehp_poll_mode)
719 		int_poll_timeout(ctrl->poll_timer.data);
720 
721 	return 0;
722 }
723 
724 int pcie_init_notification(struct controller *ctrl)
725 {
726 	if (pciehp_request_irq(ctrl))
727 		return -1;
728 	pcie_enable_notification(ctrl);
729 	ctrl->notification_enabled = 1;
730 	return 0;
731 }
732 
733 static void pcie_shutdown_notification(struct controller *ctrl)
734 {
735 	if (ctrl->notification_enabled) {
736 		pcie_disable_notification(ctrl);
737 		pciehp_free_irq(ctrl);
738 		ctrl->notification_enabled = 0;
739 	}
740 }
741 
742 static int pcie_init_slot(struct controller *ctrl)
743 {
744 	struct slot *slot;
745 
746 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
747 	if (!slot)
748 		return -ENOMEM;
749 
750 	slot->wq = alloc_workqueue("pciehp-%u", 0, 0, PSN(ctrl));
751 	if (!slot->wq)
752 		goto abort;
753 
754 	slot->ctrl = ctrl;
755 	mutex_init(&slot->lock);
756 	mutex_init(&slot->hotplug_lock);
757 	INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
758 	ctrl->slot = slot;
759 	return 0;
760 abort:
761 	kfree(slot);
762 	return -ENOMEM;
763 }
764 
765 static void pcie_cleanup_slot(struct controller *ctrl)
766 {
767 	struct slot *slot = ctrl->slot;
768 	cancel_delayed_work(&slot->work);
769 	destroy_workqueue(slot->wq);
770 	kfree(slot);
771 }
772 
773 static inline void dbg_ctrl(struct controller *ctrl)
774 {
775 	struct pci_dev *pdev = ctrl->pcie->port;
776 	u16 reg16;
777 
778 	if (!pciehp_debug)
779 		return;
780 
781 	ctrl_info(ctrl, "Slot Capabilities      : 0x%08x\n", ctrl->slot_cap);
782 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &reg16);
783 	ctrl_info(ctrl, "Slot Status            : 0x%04x\n", reg16);
784 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &reg16);
785 	ctrl_info(ctrl, "Slot Control           : 0x%04x\n", reg16);
786 }
787 
788 #define FLAG(x, y)	(((x) & (y)) ? '+' : '-')
789 
790 struct controller *pcie_init(struct pcie_device *dev)
791 {
792 	struct controller *ctrl;
793 	u32 slot_cap, link_cap;
794 	struct pci_dev *pdev = dev->port;
795 
796 	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
797 	if (!ctrl) {
798 		dev_err(&dev->device, "%s: Out of memory\n", __func__);
799 		goto abort;
800 	}
801 	ctrl->pcie = dev;
802 	pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
803 	ctrl->slot_cap = slot_cap;
804 	mutex_init(&ctrl->ctrl_lock);
805 	init_waitqueue_head(&ctrl->queue);
806 	dbg_ctrl(ctrl);
807 
808 	/* Check if Data Link Layer Link Active Reporting is implemented */
809 	pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap);
810 	if (link_cap & PCI_EXP_LNKCAP_DLLLARC)
811 		ctrl->link_active_reporting = 1;
812 
813 	/* Clear all remaining event bits in Slot Status register */
814 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
815 		PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
816 		PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC |
817 		PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC);
818 
819 	ctrl_info(ctrl, "Slot #%d AttnBtn%c PwrCtrl%c MRL%c AttnInd%c PwrInd%c HotPlug%c Surprise%c Interlock%c NoCompl%c LLActRep%c\n",
820 		(slot_cap & PCI_EXP_SLTCAP_PSN) >> 19,
821 		FLAG(slot_cap, PCI_EXP_SLTCAP_ABP),
822 		FLAG(slot_cap, PCI_EXP_SLTCAP_PCP),
823 		FLAG(slot_cap, PCI_EXP_SLTCAP_MRLSP),
824 		FLAG(slot_cap, PCI_EXP_SLTCAP_AIP),
825 		FLAG(slot_cap, PCI_EXP_SLTCAP_PIP),
826 		FLAG(slot_cap, PCI_EXP_SLTCAP_HPC),
827 		FLAG(slot_cap, PCI_EXP_SLTCAP_HPS),
828 		FLAG(slot_cap, PCI_EXP_SLTCAP_EIP),
829 		FLAG(slot_cap, PCI_EXP_SLTCAP_NCCS),
830 		FLAG(link_cap, PCI_EXP_LNKCAP_DLLLARC));
831 
832 	if (pcie_init_slot(ctrl))
833 		goto abort_ctrl;
834 
835 	return ctrl;
836 
837 abort_ctrl:
838 	kfree(ctrl);
839 abort:
840 	return NULL;
841 }
842 
843 void pciehp_release_ctrl(struct controller *ctrl)
844 {
845 	pcie_shutdown_notification(ctrl);
846 	pcie_cleanup_slot(ctrl);
847 	kfree(ctrl);
848 }
849