xref: /linux/drivers/pci/hotplug/pciehp_hpc.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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 int pciehp_get_raw_indicator_status(struct hotplug_slot *hotplug_slot,
359 				    u8 *status)
360 {
361 	struct slot *slot = hotplug_slot->private;
362 	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
363 	u16 slot_ctrl;
364 
365 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
366 	*status = (slot_ctrl & (PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC)) >> 6;
367 	return 0;
368 }
369 
370 void pciehp_get_attention_status(struct slot *slot, u8 *status)
371 {
372 	struct controller *ctrl = slot->ctrl;
373 	struct pci_dev *pdev = ctrl_dev(ctrl);
374 	u16 slot_ctrl;
375 
376 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
377 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x, value read %x\n", __func__,
378 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
379 
380 	switch (slot_ctrl & PCI_EXP_SLTCTL_AIC) {
381 	case PCI_EXP_SLTCTL_ATTN_IND_ON:
382 		*status = 1;	/* On */
383 		break;
384 	case PCI_EXP_SLTCTL_ATTN_IND_BLINK:
385 		*status = 2;	/* Blink */
386 		break;
387 	case PCI_EXP_SLTCTL_ATTN_IND_OFF:
388 		*status = 0;	/* Off */
389 		break;
390 	default:
391 		*status = 0xFF;
392 		break;
393 	}
394 }
395 
396 void pciehp_get_power_status(struct slot *slot, u8 *status)
397 {
398 	struct controller *ctrl = slot->ctrl;
399 	struct pci_dev *pdev = ctrl_dev(ctrl);
400 	u16 slot_ctrl;
401 
402 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
403 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x value read %x\n", __func__,
404 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
405 
406 	switch (slot_ctrl & PCI_EXP_SLTCTL_PCC) {
407 	case PCI_EXP_SLTCTL_PWR_ON:
408 		*status = 1;	/* On */
409 		break;
410 	case PCI_EXP_SLTCTL_PWR_OFF:
411 		*status = 0;	/* Off */
412 		break;
413 	default:
414 		*status = 0xFF;
415 		break;
416 	}
417 }
418 
419 void pciehp_get_latch_status(struct slot *slot, u8 *status)
420 {
421 	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
422 	u16 slot_status;
423 
424 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
425 	*status = !!(slot_status & PCI_EXP_SLTSTA_MRLSS);
426 }
427 
428 void pciehp_get_adapter_status(struct slot *slot, u8 *status)
429 {
430 	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
431 	u16 slot_status;
432 
433 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
434 	*status = !!(slot_status & PCI_EXP_SLTSTA_PDS);
435 }
436 
437 int pciehp_query_power_fault(struct slot *slot)
438 {
439 	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
440 	u16 slot_status;
441 
442 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
443 	return !!(slot_status & PCI_EXP_SLTSTA_PFD);
444 }
445 
446 int pciehp_set_raw_indicator_status(struct hotplug_slot *hotplug_slot,
447 				    u8 status)
448 {
449 	struct slot *slot = hotplug_slot->private;
450 	struct controller *ctrl = slot->ctrl;
451 
452 	pcie_write_cmd_nowait(ctrl, status << 6,
453 			      PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC);
454 	return 0;
455 }
456 
457 void pciehp_set_attention_status(struct slot *slot, u8 value)
458 {
459 	struct controller *ctrl = slot->ctrl;
460 	u16 slot_cmd;
461 
462 	if (!ATTN_LED(ctrl))
463 		return;
464 
465 	switch (value) {
466 	case 0:		/* turn off */
467 		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_OFF;
468 		break;
469 	case 1:		/* turn on */
470 		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_ON;
471 		break;
472 	case 2:		/* turn blink */
473 		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_BLINK;
474 		break;
475 	default:
476 		return;
477 	}
478 	pcie_write_cmd_nowait(ctrl, slot_cmd, PCI_EXP_SLTCTL_AIC);
479 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
480 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
481 }
482 
483 void pciehp_green_led_on(struct slot *slot)
484 {
485 	struct controller *ctrl = slot->ctrl;
486 
487 	if (!PWR_LED(ctrl))
488 		return;
489 
490 	pcie_write_cmd_nowait(ctrl, PCI_EXP_SLTCTL_PWR_IND_ON,
491 			      PCI_EXP_SLTCTL_PIC);
492 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
493 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
494 		 PCI_EXP_SLTCTL_PWR_IND_ON);
495 }
496 
497 void pciehp_green_led_off(struct slot *slot)
498 {
499 	struct controller *ctrl = slot->ctrl;
500 
501 	if (!PWR_LED(ctrl))
502 		return;
503 
504 	pcie_write_cmd_nowait(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
505 			      PCI_EXP_SLTCTL_PIC);
506 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
507 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
508 		 PCI_EXP_SLTCTL_PWR_IND_OFF);
509 }
510 
511 void pciehp_green_led_blink(struct slot *slot)
512 {
513 	struct controller *ctrl = slot->ctrl;
514 
515 	if (!PWR_LED(ctrl))
516 		return;
517 
518 	pcie_write_cmd_nowait(ctrl, PCI_EXP_SLTCTL_PWR_IND_BLINK,
519 			      PCI_EXP_SLTCTL_PIC);
520 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
521 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
522 		 PCI_EXP_SLTCTL_PWR_IND_BLINK);
523 }
524 
525 int pciehp_power_on_slot(struct slot *slot)
526 {
527 	struct controller *ctrl = slot->ctrl;
528 	struct pci_dev *pdev = ctrl_dev(ctrl);
529 	u16 slot_status;
530 	int retval;
531 
532 	/* Clear sticky power-fault bit from previous power failures */
533 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
534 	if (slot_status & PCI_EXP_SLTSTA_PFD)
535 		pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
536 					   PCI_EXP_SLTSTA_PFD);
537 	ctrl->power_fault_detected = 0;
538 
539 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_ON, PCI_EXP_SLTCTL_PCC);
540 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
541 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
542 		 PCI_EXP_SLTCTL_PWR_ON);
543 
544 	retval = pciehp_link_enable(ctrl);
545 	if (retval)
546 		ctrl_err(ctrl, "%s: Can not enable the link!\n", __func__);
547 
548 	return retval;
549 }
550 
551 void pciehp_power_off_slot(struct slot *slot)
552 {
553 	struct controller *ctrl = slot->ctrl;
554 
555 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_OFF, PCI_EXP_SLTCTL_PCC);
556 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
557 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
558 		 PCI_EXP_SLTCTL_PWR_OFF);
559 }
560 
561 static irqreturn_t pciehp_isr(int irq, void *dev_id)
562 {
563 	struct controller *ctrl = (struct controller *)dev_id;
564 	struct pci_dev *pdev = ctrl_dev(ctrl);
565 	struct pci_bus *subordinate = pdev->subordinate;
566 	struct pci_dev *dev;
567 	struct slot *slot = ctrl->slot;
568 	u16 status, events;
569 	u8 present;
570 	bool link;
571 
572 	/* Interrupts cannot originate from a controller that's asleep */
573 	if (pdev->current_state == PCI_D3cold)
574 		return IRQ_NONE;
575 
576 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status);
577 	if (status == (u16) ~0) {
578 		ctrl_info(ctrl, "%s: no response from device\n", __func__);
579 		return IRQ_NONE;
580 	}
581 
582 	/*
583 	 * Slot Status contains plain status bits as well as event
584 	 * notification bits; right now we only want the event bits.
585 	 */
586 	events = status & (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
587 			   PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_CC |
588 			   PCI_EXP_SLTSTA_DLLSC);
589 	if (!events)
590 		return IRQ_NONE;
591 
592 	/* Capture link status before clearing interrupts */
593 	if (events & PCI_EXP_SLTSTA_DLLSC)
594 		link = pciehp_check_link_active(ctrl);
595 
596 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, events);
597 	ctrl_dbg(ctrl, "pending interrupts %#06x from Slot Status\n", events);
598 
599 	/* Check Command Complete Interrupt Pending */
600 	if (events & PCI_EXP_SLTSTA_CC) {
601 		ctrl->cmd_busy = 0;
602 		smp_mb();
603 		wake_up(&ctrl->queue);
604 	}
605 
606 	if (subordinate) {
607 		list_for_each_entry(dev, &subordinate->devices, bus_list) {
608 			if (dev->ignore_hotplug) {
609 				ctrl_dbg(ctrl, "ignoring hotplug event %#06x (%s requested no hotplug)\n",
610 					 events, pci_name(dev));
611 				return IRQ_HANDLED;
612 			}
613 		}
614 	}
615 
616 	/* Check Attention Button Pressed */
617 	if (events & PCI_EXP_SLTSTA_ABP) {
618 		ctrl_info(ctrl, "Slot(%s): Attention button pressed\n",
619 			  slot_name(slot));
620 		pciehp_queue_interrupt_event(slot, INT_BUTTON_PRESS);
621 	}
622 
623 	/*
624 	 * Check Link Status Changed at higher precedence than Presence
625 	 * Detect Changed.  The PDS value may be set to "card present" from
626 	 * out-of-band detection, which may be in conflict with a Link Down
627 	 * and cause the wrong event to queue.
628 	 */
629 	if (events & PCI_EXP_SLTSTA_DLLSC) {
630 		ctrl_info(ctrl, "Slot(%s): Link %s\n", slot_name(slot),
631 			  link ? "Up" : "Down");
632 		pciehp_queue_interrupt_event(slot, link ? INT_LINK_UP :
633 					     INT_LINK_DOWN);
634 	} else if (events & PCI_EXP_SLTSTA_PDC) {
635 		present = !!(status & PCI_EXP_SLTSTA_PDS);
636 		ctrl_info(ctrl, "Slot(%s): Card %spresent\n", slot_name(slot),
637 			  present ? "" : "not ");
638 		pciehp_queue_interrupt_event(slot, present ? INT_PRESENCE_ON :
639 					     INT_PRESENCE_OFF);
640 	}
641 
642 	/* Check Power Fault Detected */
643 	if ((events & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
644 		ctrl->power_fault_detected = 1;
645 		ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(slot));
646 		pciehp_queue_interrupt_event(slot, INT_POWER_FAULT);
647 	}
648 
649 	return IRQ_HANDLED;
650 }
651 
652 static irqreturn_t pcie_isr(int irq, void *dev_id)
653 {
654 	irqreturn_t rc, handled = IRQ_NONE;
655 
656 	/*
657 	 * To guarantee that all interrupt events are serviced, we need to
658 	 * re-inspect Slot Status register after clearing what is presumed
659 	 * to be the last pending interrupt.
660 	 */
661 	do {
662 		rc = pciehp_isr(irq, dev_id);
663 		if (rc == IRQ_HANDLED)
664 			handled = IRQ_HANDLED;
665 	} while (rc == IRQ_HANDLED);
666 
667 	/* Return IRQ_HANDLED if we handled one or more events */
668 	return handled;
669 }
670 
671 void pcie_enable_notification(struct controller *ctrl)
672 {
673 	u16 cmd, mask;
674 
675 	/*
676 	 * TBD: Power fault detected software notification support.
677 	 *
678 	 * Power fault detected software notification is not enabled
679 	 * now, because it caused power fault detected interrupt storm
680 	 * on some machines. On those machines, power fault detected
681 	 * bit in the slot status register was set again immediately
682 	 * when it is cleared in the interrupt service routine, and
683 	 * next power fault detected interrupt was notified again.
684 	 */
685 
686 	/*
687 	 * Always enable link events: thus link-up and link-down shall
688 	 * always be treated as hotplug and unplug respectively. Enable
689 	 * presence detect only if Attention Button is not present.
690 	 */
691 	cmd = PCI_EXP_SLTCTL_DLLSCE;
692 	if (ATTN_BUTTN(ctrl))
693 		cmd |= PCI_EXP_SLTCTL_ABPE;
694 	else
695 		cmd |= PCI_EXP_SLTCTL_PDCE;
696 	if (!pciehp_poll_mode)
697 		cmd |= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE;
698 
699 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
700 		PCI_EXP_SLTCTL_PFDE |
701 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
702 		PCI_EXP_SLTCTL_DLLSCE);
703 
704 	pcie_write_cmd_nowait(ctrl, cmd, mask);
705 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
706 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, cmd);
707 }
708 
709 static void pcie_disable_notification(struct controller *ctrl)
710 {
711 	u16 mask;
712 
713 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
714 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
715 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
716 		PCI_EXP_SLTCTL_DLLSCE);
717 	pcie_write_cmd(ctrl, 0, mask);
718 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
719 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0);
720 }
721 
722 /*
723  * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary
724  * bus reset of the bridge, but at the same time we want to ensure that it is
725  * not seen as a hot-unplug, followed by the hot-plug of the device. Thus,
726  * disable link state notification and presence detection change notification
727  * momentarily, if we see that they could interfere. Also, clear any spurious
728  * events after.
729  */
730 int pciehp_reset_slot(struct slot *slot, int probe)
731 {
732 	struct controller *ctrl = slot->ctrl;
733 	struct pci_dev *pdev = ctrl_dev(ctrl);
734 	u16 stat_mask = 0, ctrl_mask = 0;
735 
736 	if (probe)
737 		return 0;
738 
739 	if (!ATTN_BUTTN(ctrl)) {
740 		ctrl_mask |= PCI_EXP_SLTCTL_PDCE;
741 		stat_mask |= PCI_EXP_SLTSTA_PDC;
742 	}
743 	ctrl_mask |= PCI_EXP_SLTCTL_DLLSCE;
744 	stat_mask |= PCI_EXP_SLTSTA_DLLSC;
745 
746 	pcie_write_cmd(ctrl, 0, ctrl_mask);
747 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
748 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0);
749 	if (pciehp_poll_mode)
750 		del_timer_sync(&ctrl->poll_timer);
751 
752 	pci_reset_bridge_secondary_bus(ctrl->pcie->port);
753 
754 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, stat_mask);
755 	pcie_write_cmd_nowait(ctrl, ctrl_mask, ctrl_mask);
756 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
757 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, ctrl_mask);
758 	if (pciehp_poll_mode)
759 		int_poll_timeout(ctrl->poll_timer.data);
760 
761 	return 0;
762 }
763 
764 int pcie_init_notification(struct controller *ctrl)
765 {
766 	if (pciehp_request_irq(ctrl))
767 		return -1;
768 	pcie_enable_notification(ctrl);
769 	ctrl->notification_enabled = 1;
770 	return 0;
771 }
772 
773 static void pcie_shutdown_notification(struct controller *ctrl)
774 {
775 	if (ctrl->notification_enabled) {
776 		pcie_disable_notification(ctrl);
777 		pciehp_free_irq(ctrl);
778 		ctrl->notification_enabled = 0;
779 	}
780 }
781 
782 static int pcie_init_slot(struct controller *ctrl)
783 {
784 	struct slot *slot;
785 
786 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
787 	if (!slot)
788 		return -ENOMEM;
789 
790 	slot->wq = alloc_workqueue("pciehp-%u", 0, 0, PSN(ctrl));
791 	if (!slot->wq)
792 		goto abort;
793 
794 	slot->ctrl = ctrl;
795 	mutex_init(&slot->lock);
796 	mutex_init(&slot->hotplug_lock);
797 	INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
798 	ctrl->slot = slot;
799 	return 0;
800 abort:
801 	kfree(slot);
802 	return -ENOMEM;
803 }
804 
805 static void pcie_cleanup_slot(struct controller *ctrl)
806 {
807 	struct slot *slot = ctrl->slot;
808 	cancel_delayed_work(&slot->work);
809 	destroy_workqueue(slot->wq);
810 	kfree(slot);
811 }
812 
813 static inline void dbg_ctrl(struct controller *ctrl)
814 {
815 	struct pci_dev *pdev = ctrl->pcie->port;
816 	u16 reg16;
817 
818 	if (!pciehp_debug)
819 		return;
820 
821 	ctrl_info(ctrl, "Slot Capabilities      : 0x%08x\n", ctrl->slot_cap);
822 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &reg16);
823 	ctrl_info(ctrl, "Slot Status            : 0x%04x\n", reg16);
824 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &reg16);
825 	ctrl_info(ctrl, "Slot Control           : 0x%04x\n", reg16);
826 }
827 
828 #define FLAG(x, y)	(((x) & (y)) ? '+' : '-')
829 
830 struct controller *pcie_init(struct pcie_device *dev)
831 {
832 	struct controller *ctrl;
833 	u32 slot_cap, link_cap;
834 	struct pci_dev *pdev = dev->port;
835 
836 	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
837 	if (!ctrl) {
838 		dev_err(&dev->device, "%s: Out of memory\n", __func__);
839 		goto abort;
840 	}
841 	ctrl->pcie = dev;
842 	pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
843 
844 	if (pdev->hotplug_user_indicators)
845 		slot_cap &= ~(PCI_EXP_SLTCAP_AIP | PCI_EXP_SLTCAP_PIP);
846 
847 	ctrl->slot_cap = slot_cap;
848 	mutex_init(&ctrl->ctrl_lock);
849 	init_waitqueue_head(&ctrl->queue);
850 	dbg_ctrl(ctrl);
851 
852 	/* Check if Data Link Layer Link Active Reporting is implemented */
853 	pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap);
854 	if (link_cap & PCI_EXP_LNKCAP_DLLLARC)
855 		ctrl->link_active_reporting = 1;
856 
857 	/* Clear all remaining event bits in Slot Status register */
858 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
859 		PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
860 		PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC |
861 		PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC);
862 
863 	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",
864 		(slot_cap & PCI_EXP_SLTCAP_PSN) >> 19,
865 		FLAG(slot_cap, PCI_EXP_SLTCAP_ABP),
866 		FLAG(slot_cap, PCI_EXP_SLTCAP_PCP),
867 		FLAG(slot_cap, PCI_EXP_SLTCAP_MRLSP),
868 		FLAG(slot_cap, PCI_EXP_SLTCAP_AIP),
869 		FLAG(slot_cap, PCI_EXP_SLTCAP_PIP),
870 		FLAG(slot_cap, PCI_EXP_SLTCAP_HPC),
871 		FLAG(slot_cap, PCI_EXP_SLTCAP_HPS),
872 		FLAG(slot_cap, PCI_EXP_SLTCAP_EIP),
873 		FLAG(slot_cap, PCI_EXP_SLTCAP_NCCS),
874 		FLAG(link_cap, PCI_EXP_LNKCAP_DLLLARC));
875 
876 	if (pcie_init_slot(ctrl))
877 		goto abort_ctrl;
878 
879 	return ctrl;
880 
881 abort_ctrl:
882 	kfree(ctrl);
883 abort:
884 	return NULL;
885 }
886 
887 void pciehp_release_ctrl(struct controller *ctrl)
888 {
889 	pcie_shutdown_notification(ctrl);
890 	pcie_cleanup_slot(ctrl);
891 	kfree(ctrl);
892 }
893