xref: /openbmc/linux/drivers/pci/hotplug/pciehp_hpc.c (revision 6c870213d6f3a25981c10728f46294a3bed1703f)
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)
108 {
109 	struct pci_dev *pdev = ctrl_dev(ctrl);
110 	u16 slot_status;
111 	int timeout = 1000;
112 
113 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
114 	if (slot_status & PCI_EXP_SLTSTA_CC) {
115 		pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
116 					   PCI_EXP_SLTSTA_CC);
117 		return 1;
118 	}
119 	while (timeout > 0) {
120 		msleep(10);
121 		timeout -= 10;
122 		pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
123 		if (slot_status & PCI_EXP_SLTSTA_CC) {
124 			pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
125 						   PCI_EXP_SLTSTA_CC);
126 			return 1;
127 		}
128 	}
129 	return 0;	/* timeout */
130 }
131 
132 static void pcie_wait_cmd(struct controller *ctrl, int poll)
133 {
134 	unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
135 	unsigned long timeout = msecs_to_jiffies(msecs);
136 	int rc;
137 
138 	if (poll)
139 		rc = pcie_poll_cmd(ctrl);
140 	else
141 		rc = wait_event_timeout(ctrl->queue, !ctrl->cmd_busy, timeout);
142 	if (!rc)
143 		ctrl_dbg(ctrl, "Command not completed in 1000 msec\n");
144 }
145 
146 /**
147  * pcie_write_cmd - Issue controller command
148  * @ctrl: controller to which the command is issued
149  * @cmd:  command value written to slot control register
150  * @mask: bitmask of slot control register to be modified
151  */
152 static void pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
153 {
154 	struct pci_dev *pdev = ctrl_dev(ctrl);
155 	u16 slot_status;
156 	u16 slot_ctrl;
157 
158 	mutex_lock(&ctrl->ctrl_lock);
159 
160 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
161 	if (slot_status & PCI_EXP_SLTSTA_CC) {
162 		if (!ctrl->no_cmd_complete) {
163 			/*
164 			 * After 1 sec and CMD_COMPLETED still not set, just
165 			 * proceed forward to issue the next command according
166 			 * to spec. Just print out the error message.
167 			 */
168 			ctrl_dbg(ctrl, "CMD_COMPLETED not clear after 1 sec\n");
169 		} else if (!NO_CMD_CMPL(ctrl)) {
170 			/*
171 			 * This controller seems to notify of command completed
172 			 * event even though it supports none of power
173 			 * controller, attention led, power led and EMI.
174 			 */
175 			ctrl_dbg(ctrl, "Unexpected CMD_COMPLETED. Need to "
176 				 "wait for command completed event.\n");
177 			ctrl->no_cmd_complete = 0;
178 		} else {
179 			ctrl_dbg(ctrl, "Unexpected CMD_COMPLETED. Maybe "
180 				 "the controller is broken.\n");
181 		}
182 	}
183 
184 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
185 	slot_ctrl &= ~mask;
186 	slot_ctrl |= (cmd & mask);
187 	ctrl->cmd_busy = 1;
188 	smp_mb();
189 	pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, slot_ctrl);
190 
191 	/*
192 	 * Wait for command completion.
193 	 */
194 	if (!ctrl->no_cmd_complete) {
195 		int poll = 0;
196 		/*
197 		 * if hotplug interrupt is not enabled or command
198 		 * completed interrupt is not enabled, we need to poll
199 		 * command completed event.
200 		 */
201 		if (!(slot_ctrl & PCI_EXP_SLTCTL_HPIE) ||
202 		    !(slot_ctrl & PCI_EXP_SLTCTL_CCIE))
203 			poll = 1;
204                 pcie_wait_cmd(ctrl, poll);
205 	}
206 	mutex_unlock(&ctrl->ctrl_lock);
207 }
208 
209 bool pciehp_check_link_active(struct controller *ctrl)
210 {
211 	struct pci_dev *pdev = ctrl_dev(ctrl);
212 	u16 lnk_status;
213 	bool ret;
214 
215 	pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
216 	ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
217 
218 	if (ret)
219 		ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
220 
221 	return ret;
222 }
223 
224 static void __pcie_wait_link_active(struct controller *ctrl, bool active)
225 {
226 	int timeout = 1000;
227 
228 	if (pciehp_check_link_active(ctrl) == active)
229 		return;
230 	while (timeout > 0) {
231 		msleep(10);
232 		timeout -= 10;
233 		if (pciehp_check_link_active(ctrl) == active)
234 			return;
235 	}
236 	ctrl_dbg(ctrl, "Data Link Layer Link Active not %s in 1000 msec\n",
237 			active ? "set" : "cleared");
238 }
239 
240 static void pcie_wait_link_active(struct controller *ctrl)
241 {
242 	__pcie_wait_link_active(ctrl, true);
243 }
244 
245 static bool pci_bus_check_dev(struct pci_bus *bus, int devfn)
246 {
247 	u32 l;
248 	int count = 0;
249 	int delay = 1000, step = 20;
250 	bool found = false;
251 
252 	do {
253 		found = pci_bus_read_dev_vendor_id(bus, devfn, &l, 0);
254 		count++;
255 
256 		if (found)
257 			break;
258 
259 		msleep(step);
260 		delay -= step;
261 	} while (delay > 0);
262 
263 	if (count > 1 && pciehp_debug)
264 		printk(KERN_DEBUG "pci %04x:%02x:%02x.%d id reading try %d times with interval %d ms to get %08x\n",
265 			pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
266 			PCI_FUNC(devfn), count, step, l);
267 
268 	return found;
269 }
270 
271 int pciehp_check_link_status(struct controller *ctrl)
272 {
273 	struct pci_dev *pdev = ctrl_dev(ctrl);
274 	bool found;
275 	u16 lnk_status;
276 
277         /*
278          * Data Link Layer Link Active Reporting must be capable for
279          * hot-plug capable downstream port. But old controller might
280          * not implement it. In this case, we wait for 1000 ms.
281          */
282         if (ctrl->link_active_reporting)
283                 pcie_wait_link_active(ctrl);
284         else
285                 msleep(1000);
286 
287 	/* wait 100ms before read pci conf, and try in 1s */
288 	msleep(100);
289 	found = pci_bus_check_dev(ctrl->pcie->port->subordinate,
290 					PCI_DEVFN(0, 0));
291 
292 	pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
293 	ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
294 	if ((lnk_status & PCI_EXP_LNKSTA_LT) ||
295 	    !(lnk_status & PCI_EXP_LNKSTA_NLW)) {
296 		ctrl_err(ctrl, "Link Training Error occurs \n");
297 		return -1;
298 	}
299 
300 	pcie_update_link_speed(ctrl->pcie->port->subordinate, lnk_status);
301 
302 	if (!found)
303 		return -1;
304 
305 	return 0;
306 }
307 
308 static int __pciehp_link_set(struct controller *ctrl, bool enable)
309 {
310 	struct pci_dev *pdev = ctrl_dev(ctrl);
311 	u16 lnk_ctrl;
312 
313 	pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &lnk_ctrl);
314 
315 	if (enable)
316 		lnk_ctrl &= ~PCI_EXP_LNKCTL_LD;
317 	else
318 		lnk_ctrl |= PCI_EXP_LNKCTL_LD;
319 
320 	pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, lnk_ctrl);
321 	ctrl_dbg(ctrl, "%s: lnk_ctrl = %x\n", __func__, lnk_ctrl);
322 	return 0;
323 }
324 
325 static int pciehp_link_enable(struct controller *ctrl)
326 {
327 	return __pciehp_link_set(ctrl, true);
328 }
329 
330 void pciehp_get_attention_status(struct slot *slot, u8 *status)
331 {
332 	struct controller *ctrl = slot->ctrl;
333 	struct pci_dev *pdev = ctrl_dev(ctrl);
334 	u16 slot_ctrl;
335 
336 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
337 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x, value read %x\n", __func__,
338 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
339 
340 	switch (slot_ctrl & PCI_EXP_SLTCTL_AIC) {
341 	case PCI_EXP_SLTCTL_ATTN_IND_ON:
342 		*status = 1;	/* On */
343 		break;
344 	case PCI_EXP_SLTCTL_ATTN_IND_BLINK:
345 		*status = 2;	/* Blink */
346 		break;
347 	case PCI_EXP_SLTCTL_ATTN_IND_OFF:
348 		*status = 0;	/* Off */
349 		break;
350 	default:
351 		*status = 0xFF;
352 		break;
353 	}
354 }
355 
356 void pciehp_get_power_status(struct slot *slot, u8 *status)
357 {
358 	struct controller *ctrl = slot->ctrl;
359 	struct pci_dev *pdev = ctrl_dev(ctrl);
360 	u16 slot_ctrl;
361 
362 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
363 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x value read %x\n", __func__,
364 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
365 
366 	switch (slot_ctrl & PCI_EXP_SLTCTL_PCC) {
367 	case PCI_EXP_SLTCTL_PWR_ON:
368 		*status = 1;	/* On */
369 		break;
370 	case PCI_EXP_SLTCTL_PWR_OFF:
371 		*status = 0;	/* Off */
372 		break;
373 	default:
374 		*status = 0xFF;
375 		break;
376 	}
377 }
378 
379 void pciehp_get_latch_status(struct slot *slot, u8 *status)
380 {
381 	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
382 	u16 slot_status;
383 
384 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
385 	*status = !!(slot_status & PCI_EXP_SLTSTA_MRLSS);
386 }
387 
388 void pciehp_get_adapter_status(struct slot *slot, u8 *status)
389 {
390 	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
391 	u16 slot_status;
392 
393 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
394 	*status = !!(slot_status & PCI_EXP_SLTSTA_PDS);
395 }
396 
397 int pciehp_query_power_fault(struct slot *slot)
398 {
399 	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
400 	u16 slot_status;
401 
402 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
403 	return !!(slot_status & PCI_EXP_SLTSTA_PFD);
404 }
405 
406 void pciehp_set_attention_status(struct slot *slot, u8 value)
407 {
408 	struct controller *ctrl = slot->ctrl;
409 	u16 slot_cmd;
410 
411 	if (!ATTN_LED(ctrl))
412 		return;
413 
414 	switch (value) {
415 	case 0 :	/* turn off */
416 		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_OFF;
417 		break;
418 	case 1:		/* turn on */
419 		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_ON;
420 		break;
421 	case 2:		/* turn blink */
422 		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_BLINK;
423 		break;
424 	default:
425 		return;
426 	}
427 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
428 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
429 	pcie_write_cmd(ctrl, slot_cmd, PCI_EXP_SLTCTL_AIC);
430 }
431 
432 void pciehp_green_led_on(struct slot *slot)
433 {
434 	struct controller *ctrl = slot->ctrl;
435 
436 	if (!PWR_LED(ctrl))
437 		return;
438 
439 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_IND_ON, PCI_EXP_SLTCTL_PIC);
440 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
441 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
442 		 PCI_EXP_SLTCTL_PWR_IND_ON);
443 }
444 
445 void pciehp_green_led_off(struct slot *slot)
446 {
447 	struct controller *ctrl = slot->ctrl;
448 
449 	if (!PWR_LED(ctrl))
450 		return;
451 
452 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF, PCI_EXP_SLTCTL_PIC);
453 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
454 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
455 		 PCI_EXP_SLTCTL_PWR_IND_OFF);
456 }
457 
458 void pciehp_green_led_blink(struct slot *slot)
459 {
460 	struct controller *ctrl = slot->ctrl;
461 
462 	if (!PWR_LED(ctrl))
463 		return;
464 
465 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_IND_BLINK, PCI_EXP_SLTCTL_PIC);
466 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
467 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
468 		 PCI_EXP_SLTCTL_PWR_IND_BLINK);
469 }
470 
471 int pciehp_power_on_slot(struct slot * slot)
472 {
473 	struct controller *ctrl = slot->ctrl;
474 	struct pci_dev *pdev = ctrl_dev(ctrl);
475 	u16 slot_status;
476 	int retval;
477 
478 	/* Clear sticky power-fault bit from previous power failures */
479 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
480 	if (slot_status & PCI_EXP_SLTSTA_PFD)
481 		pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
482 					   PCI_EXP_SLTSTA_PFD);
483 	ctrl->power_fault_detected = 0;
484 
485 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_ON, PCI_EXP_SLTCTL_PCC);
486 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
487 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
488 		 PCI_EXP_SLTCTL_PWR_ON);
489 
490 	retval = pciehp_link_enable(ctrl);
491 	if (retval)
492 		ctrl_err(ctrl, "%s: Can not enable the link!\n", __func__);
493 
494 	return retval;
495 }
496 
497 void pciehp_power_off_slot(struct slot * slot)
498 {
499 	struct controller *ctrl = slot->ctrl;
500 
501 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_OFF, PCI_EXP_SLTCTL_PCC);
502 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
503 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
504 		 PCI_EXP_SLTCTL_PWR_OFF);
505 }
506 
507 static irqreturn_t pcie_isr(int irq, void *dev_id)
508 {
509 	struct controller *ctrl = (struct controller *)dev_id;
510 	struct pci_dev *pdev = ctrl_dev(ctrl);
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 (!(intr_loc & ~PCI_EXP_SLTSTA_CC))
545 		return IRQ_HANDLED;
546 
547 	/* Check MRL Sensor Changed */
548 	if (intr_loc & PCI_EXP_SLTSTA_MRLSC)
549 		pciehp_handle_switch_change(slot);
550 
551 	/* Check Attention Button Pressed */
552 	if (intr_loc & PCI_EXP_SLTSTA_ABP)
553 		pciehp_handle_attention_button(slot);
554 
555 	/* Check Presence Detect Changed */
556 	if (intr_loc & PCI_EXP_SLTSTA_PDC)
557 		pciehp_handle_presence_change(slot);
558 
559 	/* Check Power Fault Detected */
560 	if ((intr_loc & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
561 		ctrl->power_fault_detected = 1;
562 		pciehp_handle_power_fault(slot);
563 	}
564 
565 	if (intr_loc & PCI_EXP_SLTSTA_DLLSC)
566 		pciehp_handle_linkstate_change(slot);
567 
568 	return IRQ_HANDLED;
569 }
570 
571 void pcie_enable_notification(struct controller *ctrl)
572 {
573 	u16 cmd, mask;
574 
575 	/*
576 	 * TBD: Power fault detected software notification support.
577 	 *
578 	 * Power fault detected software notification is not enabled
579 	 * now, because it caused power fault detected interrupt storm
580 	 * on some machines. On those machines, power fault detected
581 	 * bit in the slot status register was set again immediately
582 	 * when it is cleared in the interrupt service routine, and
583 	 * next power fault detected interrupt was notified again.
584 	 */
585 
586 	/*
587 	 * Always enable link events: thus link-up and link-down shall
588 	 * always be treated as hotplug and unplug respectively. Enable
589 	 * presence detect only if Attention Button is not present.
590 	 */
591 	cmd = PCI_EXP_SLTCTL_DLLSCE;
592 	if (ATTN_BUTTN(ctrl))
593 		cmd |= PCI_EXP_SLTCTL_ABPE;
594 	else
595 		cmd |= PCI_EXP_SLTCTL_PDCE;
596 	if (MRL_SENS(ctrl))
597 		cmd |= PCI_EXP_SLTCTL_MRLSCE;
598 	if (!pciehp_poll_mode)
599 		cmd |= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE;
600 
601 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
602 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
603 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
604 		PCI_EXP_SLTCTL_DLLSCE);
605 
606 	pcie_write_cmd(ctrl, cmd, mask);
607 }
608 
609 static void pcie_disable_notification(struct controller *ctrl)
610 {
611 	u16 mask;
612 
613 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
614 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
615 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
616 		PCI_EXP_SLTCTL_DLLSCE);
617 	pcie_write_cmd(ctrl, 0, mask);
618 }
619 
620 /*
621  * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary
622  * bus reset of the bridge, but at the same time we want to ensure that it is
623  * not seen as a hot-unplug, followed by the hot-plug of the device. Thus,
624  * disable link state notification and presence detection change notification
625  * momentarily, if we see that they could interfere. Also, clear any spurious
626  * events after.
627  */
628 int pciehp_reset_slot(struct slot *slot, int probe)
629 {
630 	struct controller *ctrl = slot->ctrl;
631 	struct pci_dev *pdev = ctrl_dev(ctrl);
632 	u16 stat_mask = 0, ctrl_mask = 0;
633 
634 	if (probe)
635 		return 0;
636 
637 	if (!ATTN_BUTTN(ctrl)) {
638 		ctrl_mask |= PCI_EXP_SLTCTL_PDCE;
639 		stat_mask |= PCI_EXP_SLTSTA_PDC;
640 	}
641 	ctrl_mask |= PCI_EXP_SLTCTL_DLLSCE;
642 	stat_mask |= PCI_EXP_SLTSTA_DLLSC;
643 
644 	pcie_write_cmd(ctrl, 0, ctrl_mask);
645 	if (pciehp_poll_mode)
646 		del_timer_sync(&ctrl->poll_timer);
647 
648 	pci_reset_bridge_secondary_bus(ctrl->pcie->port);
649 
650 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, stat_mask);
651 	pcie_write_cmd(ctrl, ctrl_mask, ctrl_mask);
652 	if (pciehp_poll_mode)
653 		int_poll_timeout(ctrl->poll_timer.data);
654 
655 	return 0;
656 }
657 
658 int pcie_init_notification(struct controller *ctrl)
659 {
660 	if (pciehp_request_irq(ctrl))
661 		return -1;
662 	pcie_enable_notification(ctrl);
663 	ctrl->notification_enabled = 1;
664 	return 0;
665 }
666 
667 static void pcie_shutdown_notification(struct controller *ctrl)
668 {
669 	if (ctrl->notification_enabled) {
670 		pcie_disable_notification(ctrl);
671 		pciehp_free_irq(ctrl);
672 		ctrl->notification_enabled = 0;
673 	}
674 }
675 
676 static int pcie_init_slot(struct controller *ctrl)
677 {
678 	struct slot *slot;
679 
680 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
681 	if (!slot)
682 		return -ENOMEM;
683 
684 	slot->wq = alloc_workqueue("pciehp-%u", 0, 0, PSN(ctrl));
685 	if (!slot->wq)
686 		goto abort;
687 
688 	slot->ctrl = ctrl;
689 	mutex_init(&slot->lock);
690 	mutex_init(&slot->hotplug_lock);
691 	INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
692 	ctrl->slot = slot;
693 	return 0;
694 abort:
695 	kfree(slot);
696 	return -ENOMEM;
697 }
698 
699 static void pcie_cleanup_slot(struct controller *ctrl)
700 {
701 	struct slot *slot = ctrl->slot;
702 	cancel_delayed_work(&slot->work);
703 	destroy_workqueue(slot->wq);
704 	kfree(slot);
705 }
706 
707 static inline void dbg_ctrl(struct controller *ctrl)
708 {
709 	int i;
710 	u16 reg16;
711 	struct pci_dev *pdev = ctrl->pcie->port;
712 
713 	if (!pciehp_debug)
714 		return;
715 
716 	ctrl_info(ctrl, "Hotplug Controller:\n");
717 	ctrl_info(ctrl, "  Seg/Bus/Dev/Func/IRQ : %s IRQ %d\n",
718 		  pci_name(pdev), pdev->irq);
719 	ctrl_info(ctrl, "  Vendor ID            : 0x%04x\n", pdev->vendor);
720 	ctrl_info(ctrl, "  Device ID            : 0x%04x\n", pdev->device);
721 	ctrl_info(ctrl, "  Subsystem ID         : 0x%04x\n",
722 		  pdev->subsystem_device);
723 	ctrl_info(ctrl, "  Subsystem Vendor ID  : 0x%04x\n",
724 		  pdev->subsystem_vendor);
725 	ctrl_info(ctrl, "  PCIe Cap offset      : 0x%02x\n",
726 		  pci_pcie_cap(pdev));
727 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
728 		if (!pci_resource_len(pdev, i))
729 			continue;
730 		ctrl_info(ctrl, "  PCI resource [%d]     : %pR\n",
731 			  i, &pdev->resource[i]);
732 	}
733 	ctrl_info(ctrl, "Slot Capabilities      : 0x%08x\n", ctrl->slot_cap);
734 	ctrl_info(ctrl, "  Physical Slot Number : %d\n", PSN(ctrl));
735 	ctrl_info(ctrl, "  Attention Button     : %3s\n",
736 		  ATTN_BUTTN(ctrl) ? "yes" : "no");
737 	ctrl_info(ctrl, "  Power Controller     : %3s\n",
738 		  POWER_CTRL(ctrl) ? "yes" : "no");
739 	ctrl_info(ctrl, "  MRL Sensor           : %3s\n",
740 		  MRL_SENS(ctrl)   ? "yes" : "no");
741 	ctrl_info(ctrl, "  Attention Indicator  : %3s\n",
742 		  ATTN_LED(ctrl)   ? "yes" : "no");
743 	ctrl_info(ctrl, "  Power Indicator      : %3s\n",
744 		  PWR_LED(ctrl)    ? "yes" : "no");
745 	ctrl_info(ctrl, "  Hot-Plug Surprise    : %3s\n",
746 		  HP_SUPR_RM(ctrl) ? "yes" : "no");
747 	ctrl_info(ctrl, "  EMI Present          : %3s\n",
748 		  EMI(ctrl)        ? "yes" : "no");
749 	ctrl_info(ctrl, "  Command Completed    : %3s\n",
750 		  NO_CMD_CMPL(ctrl) ? "no" : "yes");
751 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &reg16);
752 	ctrl_info(ctrl, "Slot Status            : 0x%04x\n", reg16);
753 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &reg16);
754 	ctrl_info(ctrl, "Slot Control           : 0x%04x\n", reg16);
755 }
756 
757 #define FLAG(x,y)	(((x) & (y)) ? '+' : '-')
758 
759 struct controller *pcie_init(struct pcie_device *dev)
760 {
761 	struct controller *ctrl;
762 	u32 slot_cap, link_cap;
763 	struct pci_dev *pdev = dev->port;
764 
765 	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
766 	if (!ctrl) {
767 		dev_err(&dev->device, "%s: Out of memory\n", __func__);
768 		goto abort;
769 	}
770 	ctrl->pcie = dev;
771 	pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
772 	ctrl->slot_cap = slot_cap;
773 	mutex_init(&ctrl->ctrl_lock);
774 	init_waitqueue_head(&ctrl->queue);
775 	dbg_ctrl(ctrl);
776 	/*
777 	 * Controller doesn't notify of command completion if the "No
778 	 * Command Completed Support" bit is set in Slot Capability
779 	 * register or the controller supports none of power
780 	 * controller, attention led, power led and EMI.
781 	 */
782 	if (NO_CMD_CMPL(ctrl) ||
783 	    !(POWER_CTRL(ctrl) | ATTN_LED(ctrl) | PWR_LED(ctrl) | EMI(ctrl)))
784 	    ctrl->no_cmd_complete = 1;
785 
786         /* Check if Data Link Layer Link Active Reporting is implemented */
787         pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap);
788         if (link_cap & PCI_EXP_LNKCAP_DLLLARC) {
789                 ctrl_dbg(ctrl, "Link Active Reporting supported\n");
790                 ctrl->link_active_reporting = 1;
791         }
792 
793 	/* Clear all remaining event bits in Slot Status register */
794 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
795 		PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
796 		PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC |
797 		PCI_EXP_SLTSTA_CC);
798 
799 	/* Disable software notification */
800 	pcie_disable_notification(ctrl);
801 
802 	ctrl_info(ctrl, "Slot #%d AttnBtn%c AttnInd%c PwrInd%c PwrCtrl%c MRL%c Interlock%c NoCompl%c LLActRep%c\n",
803 		(slot_cap & PCI_EXP_SLTCAP_PSN) >> 19,
804 		FLAG(slot_cap, PCI_EXP_SLTCAP_ABP),
805 		FLAG(slot_cap, PCI_EXP_SLTCAP_AIP),
806 		FLAG(slot_cap, PCI_EXP_SLTCAP_PIP),
807 		FLAG(slot_cap, PCI_EXP_SLTCAP_PCP),
808 		FLAG(slot_cap, PCI_EXP_SLTCAP_MRLSP),
809 		FLAG(slot_cap, PCI_EXP_SLTCAP_EIP),
810 		FLAG(slot_cap, PCI_EXP_SLTCAP_NCCS),
811 		FLAG(link_cap, PCI_EXP_LNKCAP_DLLLARC));
812 
813 	if (pcie_init_slot(ctrl))
814 		goto abort_ctrl;
815 
816 	return ctrl;
817 
818 abort_ctrl:
819 	kfree(ctrl);
820 abort:
821 	return NULL;
822 }
823 
824 void pciehp_release_ctrl(struct controller *ctrl)
825 {
826 	pcie_shutdown_notification(ctrl);
827 	pcie_cleanup_slot(ctrl);
828 	kfree(ctrl);
829 }
830