xref: /openbmc/linux/drivers/pci/hotplug/pciehp_hpc.c (revision 293d5b43)
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 	/* Interrupts cannot originate from a controller that's asleep */
550 	if (pdev->current_state == PCI_D3cold)
551 		return IRQ_NONE;
552 
553 	/*
554 	 * In order to guarantee that all interrupt events are
555 	 * serviced, we need to re-inspect Slot Status register after
556 	 * clearing what is presumed to be the last pending interrupt.
557 	 */
558 	intr_loc = 0;
559 	do {
560 		pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &detected);
561 		if (detected == (u16) ~0) {
562 			ctrl_info(ctrl, "%s: no response from device\n",
563 				  __func__);
564 			return IRQ_HANDLED;
565 		}
566 
567 		detected &= (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
568 			     PCI_EXP_SLTSTA_PDC |
569 			     PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC);
570 		detected &= ~intr_loc;
571 		intr_loc |= detected;
572 		if (!intr_loc)
573 			return IRQ_NONE;
574 		if (detected)
575 			pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
576 						   intr_loc);
577 	} while (detected);
578 
579 	ctrl_dbg(ctrl, "pending interrupts %#06x from Slot Status\n", intr_loc);
580 
581 	/* Check Command Complete Interrupt Pending */
582 	if (intr_loc & PCI_EXP_SLTSTA_CC) {
583 		ctrl->cmd_busy = 0;
584 		smp_mb();
585 		wake_up(&ctrl->queue);
586 	}
587 
588 	if (subordinate) {
589 		list_for_each_entry(dev, &subordinate->devices, bus_list) {
590 			if (dev->ignore_hotplug) {
591 				ctrl_dbg(ctrl, "ignoring hotplug event %#06x (%s requested no hotplug)\n",
592 					 intr_loc, pci_name(dev));
593 				return IRQ_HANDLED;
594 			}
595 		}
596 	}
597 
598 	if (!(intr_loc & ~PCI_EXP_SLTSTA_CC))
599 		return IRQ_HANDLED;
600 
601 	/* Check Attention Button Pressed */
602 	if (intr_loc & PCI_EXP_SLTSTA_ABP) {
603 		ctrl_info(ctrl, "Button pressed on Slot(%s)\n",
604 			  slot_name(slot));
605 		pciehp_queue_interrupt_event(slot, INT_BUTTON_PRESS);
606 	}
607 
608 	/* Check Presence Detect Changed */
609 	if (intr_loc & PCI_EXP_SLTSTA_PDC) {
610 		pciehp_get_adapter_status(slot, &present);
611 		ctrl_info(ctrl, "Card %spresent on Slot(%s)\n",
612 			  present ? "" : "not ", slot_name(slot));
613 		pciehp_queue_interrupt_event(slot, present ? INT_PRESENCE_ON :
614 					     INT_PRESENCE_OFF);
615 	}
616 
617 	/* Check Power Fault Detected */
618 	if ((intr_loc & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
619 		ctrl->power_fault_detected = 1;
620 		ctrl_err(ctrl, "Power fault on slot %s\n", slot_name(slot));
621 		pciehp_queue_interrupt_event(slot, INT_POWER_FAULT);
622 	}
623 
624 	if (intr_loc & PCI_EXP_SLTSTA_DLLSC) {
625 		link = pciehp_check_link_active(ctrl);
626 		ctrl_info(ctrl, "slot(%s): Link %s event\n",
627 			  slot_name(slot), link ? "Up" : "Down");
628 		pciehp_queue_interrupt_event(slot, link ? INT_LINK_UP :
629 					     INT_LINK_DOWN);
630 	}
631 
632 	return IRQ_HANDLED;
633 }
634 
635 void pcie_enable_notification(struct controller *ctrl)
636 {
637 	u16 cmd, mask;
638 
639 	/*
640 	 * TBD: Power fault detected software notification support.
641 	 *
642 	 * Power fault detected software notification is not enabled
643 	 * now, because it caused power fault detected interrupt storm
644 	 * on some machines. On those machines, power fault detected
645 	 * bit in the slot status register was set again immediately
646 	 * when it is cleared in the interrupt service routine, and
647 	 * next power fault detected interrupt was notified again.
648 	 */
649 
650 	/*
651 	 * Always enable link events: thus link-up and link-down shall
652 	 * always be treated as hotplug and unplug respectively. Enable
653 	 * presence detect only if Attention Button is not present.
654 	 */
655 	cmd = PCI_EXP_SLTCTL_DLLSCE;
656 	if (ATTN_BUTTN(ctrl))
657 		cmd |= PCI_EXP_SLTCTL_ABPE;
658 	else
659 		cmd |= PCI_EXP_SLTCTL_PDCE;
660 	if (!pciehp_poll_mode)
661 		cmd |= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE;
662 
663 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
664 		PCI_EXP_SLTCTL_PFDE |
665 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
666 		PCI_EXP_SLTCTL_DLLSCE);
667 
668 	pcie_write_cmd_nowait(ctrl, cmd, mask);
669 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
670 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, cmd);
671 }
672 
673 static void pcie_disable_notification(struct controller *ctrl)
674 {
675 	u16 mask;
676 
677 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
678 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
679 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
680 		PCI_EXP_SLTCTL_DLLSCE);
681 	pcie_write_cmd(ctrl, 0, mask);
682 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
683 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0);
684 }
685 
686 /*
687  * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary
688  * bus reset of the bridge, but at the same time we want to ensure that it is
689  * not seen as a hot-unplug, followed by the hot-plug of the device. Thus,
690  * disable link state notification and presence detection change notification
691  * momentarily, if we see that they could interfere. Also, clear any spurious
692  * events after.
693  */
694 int pciehp_reset_slot(struct slot *slot, int probe)
695 {
696 	struct controller *ctrl = slot->ctrl;
697 	struct pci_dev *pdev = ctrl_dev(ctrl);
698 	u16 stat_mask = 0, ctrl_mask = 0;
699 
700 	if (probe)
701 		return 0;
702 
703 	if (!ATTN_BUTTN(ctrl)) {
704 		ctrl_mask |= PCI_EXP_SLTCTL_PDCE;
705 		stat_mask |= PCI_EXP_SLTSTA_PDC;
706 	}
707 	ctrl_mask |= PCI_EXP_SLTCTL_DLLSCE;
708 	stat_mask |= PCI_EXP_SLTSTA_DLLSC;
709 
710 	pcie_write_cmd(ctrl, 0, ctrl_mask);
711 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
712 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0);
713 	if (pciehp_poll_mode)
714 		del_timer_sync(&ctrl->poll_timer);
715 
716 	pci_reset_bridge_secondary_bus(ctrl->pcie->port);
717 
718 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, stat_mask);
719 	pcie_write_cmd_nowait(ctrl, ctrl_mask, ctrl_mask);
720 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
721 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, ctrl_mask);
722 	if (pciehp_poll_mode)
723 		int_poll_timeout(ctrl->poll_timer.data);
724 
725 	return 0;
726 }
727 
728 int pcie_init_notification(struct controller *ctrl)
729 {
730 	if (pciehp_request_irq(ctrl))
731 		return -1;
732 	pcie_enable_notification(ctrl);
733 	ctrl->notification_enabled = 1;
734 	return 0;
735 }
736 
737 static void pcie_shutdown_notification(struct controller *ctrl)
738 {
739 	if (ctrl->notification_enabled) {
740 		pcie_disable_notification(ctrl);
741 		pciehp_free_irq(ctrl);
742 		ctrl->notification_enabled = 0;
743 	}
744 }
745 
746 static int pcie_init_slot(struct controller *ctrl)
747 {
748 	struct slot *slot;
749 
750 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
751 	if (!slot)
752 		return -ENOMEM;
753 
754 	slot->wq = alloc_workqueue("pciehp-%u", 0, 0, PSN(ctrl));
755 	if (!slot->wq)
756 		goto abort;
757 
758 	slot->ctrl = ctrl;
759 	mutex_init(&slot->lock);
760 	mutex_init(&slot->hotplug_lock);
761 	INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
762 	ctrl->slot = slot;
763 	return 0;
764 abort:
765 	kfree(slot);
766 	return -ENOMEM;
767 }
768 
769 static void pcie_cleanup_slot(struct controller *ctrl)
770 {
771 	struct slot *slot = ctrl->slot;
772 	cancel_delayed_work(&slot->work);
773 	destroy_workqueue(slot->wq);
774 	kfree(slot);
775 }
776 
777 static inline void dbg_ctrl(struct controller *ctrl)
778 {
779 	struct pci_dev *pdev = ctrl->pcie->port;
780 	u16 reg16;
781 
782 	if (!pciehp_debug)
783 		return;
784 
785 	ctrl_info(ctrl, "Slot Capabilities      : 0x%08x\n", ctrl->slot_cap);
786 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &reg16);
787 	ctrl_info(ctrl, "Slot Status            : 0x%04x\n", reg16);
788 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &reg16);
789 	ctrl_info(ctrl, "Slot Control           : 0x%04x\n", reg16);
790 }
791 
792 #define FLAG(x, y)	(((x) & (y)) ? '+' : '-')
793 
794 struct controller *pcie_init(struct pcie_device *dev)
795 {
796 	struct controller *ctrl;
797 	u32 slot_cap, link_cap;
798 	struct pci_dev *pdev = dev->port;
799 
800 	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
801 	if (!ctrl) {
802 		dev_err(&dev->device, "%s: Out of memory\n", __func__);
803 		goto abort;
804 	}
805 	ctrl->pcie = dev;
806 	pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
807 	ctrl->slot_cap = slot_cap;
808 	mutex_init(&ctrl->ctrl_lock);
809 	init_waitqueue_head(&ctrl->queue);
810 	dbg_ctrl(ctrl);
811 
812 	/* Check if Data Link Layer Link Active Reporting is implemented */
813 	pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap);
814 	if (link_cap & PCI_EXP_LNKCAP_DLLLARC)
815 		ctrl->link_active_reporting = 1;
816 
817 	/* Clear all remaining event bits in Slot Status register */
818 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
819 		PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
820 		PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC |
821 		PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC);
822 
823 	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",
824 		(slot_cap & PCI_EXP_SLTCAP_PSN) >> 19,
825 		FLAG(slot_cap, PCI_EXP_SLTCAP_ABP),
826 		FLAG(slot_cap, PCI_EXP_SLTCAP_PCP),
827 		FLAG(slot_cap, PCI_EXP_SLTCAP_MRLSP),
828 		FLAG(slot_cap, PCI_EXP_SLTCAP_AIP),
829 		FLAG(slot_cap, PCI_EXP_SLTCAP_PIP),
830 		FLAG(slot_cap, PCI_EXP_SLTCAP_HPC),
831 		FLAG(slot_cap, PCI_EXP_SLTCAP_HPS),
832 		FLAG(slot_cap, PCI_EXP_SLTCAP_EIP),
833 		FLAG(slot_cap, PCI_EXP_SLTCAP_NCCS),
834 		FLAG(link_cap, PCI_EXP_LNKCAP_DLLLARC));
835 
836 	if (pcie_init_slot(ctrl))
837 		goto abort_ctrl;
838 
839 	return ctrl;
840 
841 abort_ctrl:
842 	kfree(ctrl);
843 abort:
844 	return NULL;
845 }
846 
847 void pciehp_release_ctrl(struct controller *ctrl)
848 {
849 	pcie_shutdown_notification(ctrl);
850 	pcie_cleanup_slot(ctrl);
851 	kfree(ctrl);
852 }
853