xref: /openbmc/linux/drivers/pci/hotplug/pciehp_hpc.c (revision e8e0929d)
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 
40 #include "../pci.h"
41 #include "pciehp.h"
42 
43 static atomic_t pciehp_num_controllers = ATOMIC_INIT(0);
44 
45 static inline int pciehp_readw(struct controller *ctrl, int reg, u16 *value)
46 {
47 	struct pci_dev *dev = ctrl->pcie->port;
48 	return pci_read_config_word(dev, ctrl->cap_base + reg, value);
49 }
50 
51 static inline int pciehp_readl(struct controller *ctrl, int reg, u32 *value)
52 {
53 	struct pci_dev *dev = ctrl->pcie->port;
54 	return pci_read_config_dword(dev, ctrl->cap_base + reg, value);
55 }
56 
57 static inline int pciehp_writew(struct controller *ctrl, int reg, u16 value)
58 {
59 	struct pci_dev *dev = ctrl->pcie->port;
60 	return pci_write_config_word(dev, ctrl->cap_base + reg, value);
61 }
62 
63 static inline int pciehp_writel(struct controller *ctrl, int reg, u32 value)
64 {
65 	struct pci_dev *dev = ctrl->pcie->port;
66 	return pci_write_config_dword(dev, ctrl->cap_base + reg, value);
67 }
68 
69 /* Power Control Command */
70 #define POWER_ON	0
71 #define POWER_OFF	PCI_EXP_SLTCTL_PCC
72 
73 static irqreturn_t pcie_isr(int irq, void *dev_id);
74 static void start_int_poll_timer(struct controller *ctrl, int sec);
75 
76 /* This is the interrupt polling timeout function. */
77 static void int_poll_timeout(unsigned long data)
78 {
79 	struct controller *ctrl = (struct controller *)data;
80 
81 	/* Poll for interrupt events.  regs == NULL => polling */
82 	pcie_isr(0, ctrl);
83 
84 	init_timer(&ctrl->poll_timer);
85 	if (!pciehp_poll_time)
86 		pciehp_poll_time = 2; /* default polling interval is 2 sec */
87 
88 	start_int_poll_timer(ctrl, pciehp_poll_time);
89 }
90 
91 /* This function starts the interrupt polling timer. */
92 static void start_int_poll_timer(struct controller *ctrl, int sec)
93 {
94 	/* Clamp to sane value */
95 	if ((sec <= 0) || (sec > 60))
96         	sec = 2;
97 
98 	ctrl->poll_timer.function = &int_poll_timeout;
99 	ctrl->poll_timer.data = (unsigned long)ctrl;
100 	ctrl->poll_timer.expires = jiffies + sec * HZ;
101 	add_timer(&ctrl->poll_timer);
102 }
103 
104 static inline int pciehp_request_irq(struct controller *ctrl)
105 {
106 	int retval, irq = ctrl->pcie->irq;
107 
108 	/* Install interrupt polling timer. Start with 10 sec delay */
109 	if (pciehp_poll_mode) {
110 		init_timer(&ctrl->poll_timer);
111 		start_int_poll_timer(ctrl, 10);
112 		return 0;
113 	}
114 
115 	/* Installs the interrupt handler */
116 	retval = request_irq(irq, pcie_isr, IRQF_SHARED, MY_NAME, ctrl);
117 	if (retval)
118 		ctrl_err(ctrl, "Cannot get irq %d for the hotplug controller\n",
119 			 irq);
120 	return retval;
121 }
122 
123 static inline void pciehp_free_irq(struct controller *ctrl)
124 {
125 	if (pciehp_poll_mode)
126 		del_timer_sync(&ctrl->poll_timer);
127 	else
128 		free_irq(ctrl->pcie->irq, ctrl);
129 }
130 
131 static int pcie_poll_cmd(struct controller *ctrl)
132 {
133 	u16 slot_status;
134 	int err, timeout = 1000;
135 
136 	err = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
137 	if (!err && (slot_status & PCI_EXP_SLTSTA_CC)) {
138 		pciehp_writew(ctrl, PCI_EXP_SLTSTA, PCI_EXP_SLTSTA_CC);
139 		return 1;
140 	}
141 	while (timeout > 0) {
142 		msleep(10);
143 		timeout -= 10;
144 		err = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
145 		if (!err && (slot_status & PCI_EXP_SLTSTA_CC)) {
146 			pciehp_writew(ctrl, PCI_EXP_SLTSTA, PCI_EXP_SLTSTA_CC);
147 			return 1;
148 		}
149 	}
150 	return 0;	/* timeout */
151 }
152 
153 static void pcie_wait_cmd(struct controller *ctrl, int poll)
154 {
155 	unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
156 	unsigned long timeout = msecs_to_jiffies(msecs);
157 	int rc;
158 
159 	if (poll)
160 		rc = pcie_poll_cmd(ctrl);
161 	else
162 		rc = wait_event_timeout(ctrl->queue, !ctrl->cmd_busy, timeout);
163 	if (!rc)
164 		ctrl_dbg(ctrl, "Command not completed in 1000 msec\n");
165 }
166 
167 /**
168  * pcie_write_cmd - Issue controller command
169  * @ctrl: controller to which the command is issued
170  * @cmd:  command value written to slot control register
171  * @mask: bitmask of slot control register to be modified
172  */
173 static int pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
174 {
175 	int retval = 0;
176 	u16 slot_status;
177 	u16 slot_ctrl;
178 
179 	mutex_lock(&ctrl->ctrl_lock);
180 
181 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
182 	if (retval) {
183 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
184 			 __func__);
185 		goto out;
186 	}
187 
188 	if (slot_status & PCI_EXP_SLTSTA_CC) {
189 		if (!ctrl->no_cmd_complete) {
190 			/*
191 			 * After 1 sec and CMD_COMPLETED still not set, just
192 			 * proceed forward to issue the next command according
193 			 * to spec. Just print out the error message.
194 			 */
195 			ctrl_dbg(ctrl, "CMD_COMPLETED not clear after 1 sec\n");
196 		} else if (!NO_CMD_CMPL(ctrl)) {
197 			/*
198 			 * This controller semms to notify of command completed
199 			 * event even though it supports none of power
200 			 * controller, attention led, power led and EMI.
201 			 */
202 			ctrl_dbg(ctrl, "Unexpected CMD_COMPLETED. Need to "
203 				 "wait for command completed event.\n");
204 			ctrl->no_cmd_complete = 0;
205 		} else {
206 			ctrl_dbg(ctrl, "Unexpected CMD_COMPLETED. Maybe "
207 				 "the controller is broken.\n");
208 		}
209 	}
210 
211 	retval = pciehp_readw(ctrl, PCI_EXP_SLTCTL, &slot_ctrl);
212 	if (retval) {
213 		ctrl_err(ctrl, "%s: Cannot read SLOTCTRL register\n", __func__);
214 		goto out;
215 	}
216 
217 	slot_ctrl &= ~mask;
218 	slot_ctrl |= (cmd & mask);
219 	ctrl->cmd_busy = 1;
220 	smp_mb();
221 	retval = pciehp_writew(ctrl, PCI_EXP_SLTCTL, slot_ctrl);
222 	if (retval)
223 		ctrl_err(ctrl, "Cannot write to SLOTCTRL register\n");
224 
225 	/*
226 	 * Wait for command completion.
227 	 */
228 	if (!retval && !ctrl->no_cmd_complete) {
229 		int poll = 0;
230 		/*
231 		 * if hotplug interrupt is not enabled or command
232 		 * completed interrupt is not enabled, we need to poll
233 		 * command completed event.
234 		 */
235 		if (!(slot_ctrl & PCI_EXP_SLTCTL_HPIE) ||
236 		    !(slot_ctrl & PCI_EXP_SLTCTL_CCIE))
237 			poll = 1;
238                 pcie_wait_cmd(ctrl, poll);
239 	}
240  out:
241 	mutex_unlock(&ctrl->ctrl_lock);
242 	return retval;
243 }
244 
245 static inline int check_link_active(struct controller *ctrl)
246 {
247 	u16 link_status;
248 
249 	if (pciehp_readw(ctrl, PCI_EXP_LNKSTA, &link_status))
250 		return 0;
251 	return !!(link_status & PCI_EXP_LNKSTA_DLLLA);
252 }
253 
254 static void pcie_wait_link_active(struct controller *ctrl)
255 {
256 	int timeout = 1000;
257 
258 	if (check_link_active(ctrl))
259 		return;
260 	while (timeout > 0) {
261 		msleep(10);
262 		timeout -= 10;
263 		if (check_link_active(ctrl))
264 			return;
265 	}
266 	ctrl_dbg(ctrl, "Data Link Layer Link Active not set in 1000 msec\n");
267 }
268 
269 int pciehp_check_link_status(struct controller *ctrl)
270 {
271 	u16 lnk_status;
272 	int retval = 0;
273 
274         /*
275          * Data Link Layer Link Active Reporting must be capable for
276          * hot-plug capable downstream port. But old controller might
277          * not implement it. In this case, we wait for 1000 ms.
278          */
279         if (ctrl->link_active_reporting){
280                 /* Wait for Data Link Layer Link Active bit to be set */
281                 pcie_wait_link_active(ctrl);
282                 /*
283                  * We must wait for 100 ms after the Data Link Layer
284                  * Link Active bit reads 1b before initiating a
285                  * configuration access to the hot added device.
286                  */
287                 msleep(100);
288         } else
289                 msleep(1000);
290 
291 	retval = pciehp_readw(ctrl, PCI_EXP_LNKSTA, &lnk_status);
292 	if (retval) {
293 		ctrl_err(ctrl, "Cannot read LNKSTATUS register\n");
294 		return retval;
295 	}
296 
297 	ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
298 	if ((lnk_status & PCI_EXP_LNKSTA_LT) ||
299 	    !(lnk_status & PCI_EXP_LNKSTA_NLW)) {
300 		ctrl_err(ctrl, "Link Training Error occurs \n");
301 		retval = -1;
302 		return retval;
303 	}
304 
305 	return retval;
306 }
307 
308 int pciehp_get_attention_status(struct slot *slot, u8 *status)
309 {
310 	struct controller *ctrl = slot->ctrl;
311 	u16 slot_ctrl;
312 	u8 atten_led_state;
313 	int retval = 0;
314 
315 	retval = pciehp_readw(ctrl, PCI_EXP_SLTCTL, &slot_ctrl);
316 	if (retval) {
317 		ctrl_err(ctrl, "%s: Cannot read SLOTCTRL register\n", __func__);
318 		return retval;
319 	}
320 
321 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x, value read %x\n",
322 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_ctrl);
323 
324 	atten_led_state = (slot_ctrl & PCI_EXP_SLTCTL_AIC) >> 6;
325 
326 	switch (atten_led_state) {
327 	case 0:
328 		*status = 0xFF;	/* Reserved */
329 		break;
330 	case 1:
331 		*status = 1;	/* On */
332 		break;
333 	case 2:
334 		*status = 2;	/* Blink */
335 		break;
336 	case 3:
337 		*status = 0;	/* Off */
338 		break;
339 	default:
340 		*status = 0xFF;
341 		break;
342 	}
343 
344 	return 0;
345 }
346 
347 int pciehp_get_power_status(struct slot *slot, u8 *status)
348 {
349 	struct controller *ctrl = slot->ctrl;
350 	u16 slot_ctrl;
351 	u8 pwr_state;
352 	int	retval = 0;
353 
354 	retval = pciehp_readw(ctrl, PCI_EXP_SLTCTL, &slot_ctrl);
355 	if (retval) {
356 		ctrl_err(ctrl, "%s: Cannot read SLOTCTRL register\n", __func__);
357 		return retval;
358 	}
359 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x value read %x\n",
360 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_ctrl);
361 
362 	pwr_state = (slot_ctrl & PCI_EXP_SLTCTL_PCC) >> 10;
363 
364 	switch (pwr_state) {
365 	case 0:
366 		*status = 1;
367 		break;
368 	case 1:
369 		*status = 0;
370 		break;
371 	default:
372 		*status = 0xFF;
373 		break;
374 	}
375 
376 	return retval;
377 }
378 
379 int pciehp_get_latch_status(struct slot *slot, u8 *status)
380 {
381 	struct controller *ctrl = slot->ctrl;
382 	u16 slot_status;
383 	int retval;
384 
385 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
386 	if (retval) {
387 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
388 			 __func__);
389 		return retval;
390 	}
391 	*status = !!(slot_status & PCI_EXP_SLTSTA_MRLSS);
392 	return 0;
393 }
394 
395 int pciehp_get_adapter_status(struct slot *slot, u8 *status)
396 {
397 	struct controller *ctrl = slot->ctrl;
398 	u16 slot_status;
399 	int retval;
400 
401 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
402 	if (retval) {
403 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
404 			 __func__);
405 		return retval;
406 	}
407 	*status = !!(slot_status & PCI_EXP_SLTSTA_PDS);
408 	return 0;
409 }
410 
411 int pciehp_query_power_fault(struct slot *slot)
412 {
413 	struct controller *ctrl = slot->ctrl;
414 	u16 slot_status;
415 	int retval;
416 
417 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
418 	if (retval) {
419 		ctrl_err(ctrl, "Cannot check for power fault\n");
420 		return retval;
421 	}
422 	return !!(slot_status & PCI_EXP_SLTSTA_PFD);
423 }
424 
425 int pciehp_set_attention_status(struct slot *slot, u8 value)
426 {
427 	struct controller *ctrl = slot->ctrl;
428 	u16 slot_cmd;
429 	u16 cmd_mask;
430 	int rc;
431 
432 	cmd_mask = PCI_EXP_SLTCTL_AIC;
433 	switch (value) {
434 		case 0 :	/* turn off */
435 			slot_cmd = 0x00C0;
436 			break;
437 		case 1:		/* turn on */
438 			slot_cmd = 0x0040;
439 			break;
440 		case 2:		/* turn blink */
441 			slot_cmd = 0x0080;
442 			break;
443 		default:
444 			return -1;
445 	}
446 	rc = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
447 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n",
448 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd);
449 
450 	return rc;
451 }
452 
453 void pciehp_green_led_on(struct slot *slot)
454 {
455 	struct controller *ctrl = slot->ctrl;
456 	u16 slot_cmd;
457 	u16 cmd_mask;
458 
459 	slot_cmd = 0x0100;
460 	cmd_mask = PCI_EXP_SLTCTL_PIC;
461 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
462 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n",
463 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd);
464 }
465 
466 void pciehp_green_led_off(struct slot *slot)
467 {
468 	struct controller *ctrl = slot->ctrl;
469 	u16 slot_cmd;
470 	u16 cmd_mask;
471 
472 	slot_cmd = 0x0300;
473 	cmd_mask = PCI_EXP_SLTCTL_PIC;
474 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
475 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n",
476 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd);
477 }
478 
479 void pciehp_green_led_blink(struct slot *slot)
480 {
481 	struct controller *ctrl = slot->ctrl;
482 	u16 slot_cmd;
483 	u16 cmd_mask;
484 
485 	slot_cmd = 0x0200;
486 	cmd_mask = PCI_EXP_SLTCTL_PIC;
487 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
488 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n",
489 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd);
490 }
491 
492 int pciehp_power_on_slot(struct slot * slot)
493 {
494 	struct controller *ctrl = slot->ctrl;
495 	u16 slot_cmd;
496 	u16 cmd_mask;
497 	u16 slot_status;
498 	int retval = 0;
499 
500 	/* Clear sticky power-fault bit from previous power failures */
501 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
502 	if (retval) {
503 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
504 			 __func__);
505 		return retval;
506 	}
507 	slot_status &= PCI_EXP_SLTSTA_PFD;
508 	if (slot_status) {
509 		retval = pciehp_writew(ctrl, PCI_EXP_SLTSTA, slot_status);
510 		if (retval) {
511 			ctrl_err(ctrl,
512 				 "%s: Cannot write to SLOTSTATUS register\n",
513 				 __func__);
514 			return retval;
515 		}
516 	}
517 
518 	slot_cmd = POWER_ON;
519 	cmd_mask = PCI_EXP_SLTCTL_PCC;
520 	if (!pciehp_poll_mode) {
521 		/* Enable power fault detection turned off at power off time */
522 		slot_cmd |= PCI_EXP_SLTCTL_PFDE;
523 		cmd_mask |= PCI_EXP_SLTCTL_PFDE;
524 	}
525 
526 	retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
527 	if (retval) {
528 		ctrl_err(ctrl, "Write %x command failed!\n", slot_cmd);
529 		return retval;
530 	}
531 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n",
532 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd);
533 
534 	ctrl->power_fault_detected = 0;
535 	return retval;
536 }
537 
538 static inline int pcie_mask_bad_dllp(struct controller *ctrl)
539 {
540 	struct pci_dev *dev = ctrl->pcie->port;
541 	int pos;
542 	u32 reg;
543 
544 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
545 	if (!pos)
546 		return 0;
547 	pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, &reg);
548 	if (reg & PCI_ERR_COR_BAD_DLLP)
549 		return 0;
550 	reg |= PCI_ERR_COR_BAD_DLLP;
551 	pci_write_config_dword(dev, pos + PCI_ERR_COR_MASK, reg);
552 	return 1;
553 }
554 
555 static inline void pcie_unmask_bad_dllp(struct controller *ctrl)
556 {
557 	struct pci_dev *dev = ctrl->pcie->port;
558 	u32 reg;
559 	int pos;
560 
561 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
562 	if (!pos)
563 		return;
564 	pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, &reg);
565 	if (!(reg & PCI_ERR_COR_BAD_DLLP))
566 		return;
567 	reg &= ~PCI_ERR_COR_BAD_DLLP;
568 	pci_write_config_dword(dev, pos + PCI_ERR_COR_MASK, reg);
569 }
570 
571 int pciehp_power_off_slot(struct slot * slot)
572 {
573 	struct controller *ctrl = slot->ctrl;
574 	u16 slot_cmd;
575 	u16 cmd_mask;
576 	int retval = 0;
577 	int changed;
578 
579 	/*
580 	 * Set Bad DLLP Mask bit in Correctable Error Mask
581 	 * Register. This is the workaround against Bad DLLP error
582 	 * that sometimes happens during turning power off the slot
583 	 * which conforms to PCI Express 1.0a spec.
584 	 */
585 	changed = pcie_mask_bad_dllp(ctrl);
586 
587 	slot_cmd = POWER_OFF;
588 	cmd_mask = PCI_EXP_SLTCTL_PCC;
589 	if (!pciehp_poll_mode) {
590 		/* Disable power fault detection */
591 		slot_cmd &= ~PCI_EXP_SLTCTL_PFDE;
592 		cmd_mask |= PCI_EXP_SLTCTL_PFDE;
593 	}
594 
595 	retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
596 	if (retval) {
597 		ctrl_err(ctrl, "Write command failed!\n");
598 		retval = -1;
599 		goto out;
600 	}
601 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n",
602 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd);
603  out:
604 	if (changed)
605 		pcie_unmask_bad_dllp(ctrl);
606 
607 	return retval;
608 }
609 
610 static irqreturn_t pcie_isr(int irq, void *dev_id)
611 {
612 	struct controller *ctrl = (struct controller *)dev_id;
613 	struct slot *slot = ctrl->slot;
614 	u16 detected, intr_loc;
615 
616 	/*
617 	 * In order to guarantee that all interrupt events are
618 	 * serviced, we need to re-inspect Slot Status register after
619 	 * clearing what is presumed to be the last pending interrupt.
620 	 */
621 	intr_loc = 0;
622 	do {
623 		if (pciehp_readw(ctrl, PCI_EXP_SLTSTA, &detected)) {
624 			ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS\n",
625 				 __func__);
626 			return IRQ_NONE;
627 		}
628 
629 		detected &= (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
630 			     PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC |
631 			     PCI_EXP_SLTSTA_CC);
632 		detected &= ~intr_loc;
633 		intr_loc |= detected;
634 		if (!intr_loc)
635 			return IRQ_NONE;
636 		if (detected && pciehp_writew(ctrl, PCI_EXP_SLTSTA, intr_loc)) {
637 			ctrl_err(ctrl, "%s: Cannot write to SLOTSTATUS\n",
638 				 __func__);
639 			return IRQ_NONE;
640 		}
641 	} while (detected);
642 
643 	ctrl_dbg(ctrl, "%s: intr_loc %x\n", __func__, intr_loc);
644 
645 	/* Check Command Complete Interrupt Pending */
646 	if (intr_loc & PCI_EXP_SLTSTA_CC) {
647 		ctrl->cmd_busy = 0;
648 		smp_mb();
649 		wake_up(&ctrl->queue);
650 	}
651 
652 	if (!(intr_loc & ~PCI_EXP_SLTSTA_CC))
653 		return IRQ_HANDLED;
654 
655 	/* Check MRL Sensor Changed */
656 	if (intr_loc & PCI_EXP_SLTSTA_MRLSC)
657 		pciehp_handle_switch_change(slot);
658 
659 	/* Check Attention Button Pressed */
660 	if (intr_loc & PCI_EXP_SLTSTA_ABP)
661 		pciehp_handle_attention_button(slot);
662 
663 	/* Check Presence Detect Changed */
664 	if (intr_loc & PCI_EXP_SLTSTA_PDC)
665 		pciehp_handle_presence_change(slot);
666 
667 	/* Check Power Fault Detected */
668 	if ((intr_loc & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
669 		ctrl->power_fault_detected = 1;
670 		pciehp_handle_power_fault(slot);
671 	}
672 	return IRQ_HANDLED;
673 }
674 
675 int pciehp_get_max_link_speed(struct slot *slot, enum pci_bus_speed *value)
676 {
677 	struct controller *ctrl = slot->ctrl;
678 	enum pcie_link_speed lnk_speed;
679 	u32	lnk_cap;
680 	int retval = 0;
681 
682 	retval = pciehp_readl(ctrl, PCI_EXP_LNKCAP, &lnk_cap);
683 	if (retval) {
684 		ctrl_err(ctrl, "%s: Cannot read LNKCAP register\n", __func__);
685 		return retval;
686 	}
687 
688 	switch (lnk_cap & 0x000F) {
689 	case 1:
690 		lnk_speed = PCIE_2_5GB;
691 		break;
692 	case 2:
693 		lnk_speed = PCIE_5_0GB;
694 		break;
695 	default:
696 		lnk_speed = PCIE_LNK_SPEED_UNKNOWN;
697 		break;
698 	}
699 
700 	*value = lnk_speed;
701 	ctrl_dbg(ctrl, "Max link speed = %d\n", lnk_speed);
702 
703 	return retval;
704 }
705 
706 int pciehp_get_max_lnk_width(struct slot *slot,
707 				 enum pcie_link_width *value)
708 {
709 	struct controller *ctrl = slot->ctrl;
710 	enum pcie_link_width lnk_wdth;
711 	u32	lnk_cap;
712 	int retval = 0;
713 
714 	retval = pciehp_readl(ctrl, PCI_EXP_LNKCAP, &lnk_cap);
715 	if (retval) {
716 		ctrl_err(ctrl, "%s: Cannot read LNKCAP register\n", __func__);
717 		return retval;
718 	}
719 
720 	switch ((lnk_cap & PCI_EXP_LNKSTA_NLW) >> 4){
721 	case 0:
722 		lnk_wdth = PCIE_LNK_WIDTH_RESRV;
723 		break;
724 	case 1:
725 		lnk_wdth = PCIE_LNK_X1;
726 		break;
727 	case 2:
728 		lnk_wdth = PCIE_LNK_X2;
729 		break;
730 	case 4:
731 		lnk_wdth = PCIE_LNK_X4;
732 		break;
733 	case 8:
734 		lnk_wdth = PCIE_LNK_X8;
735 		break;
736 	case 12:
737 		lnk_wdth = PCIE_LNK_X12;
738 		break;
739 	case 16:
740 		lnk_wdth = PCIE_LNK_X16;
741 		break;
742 	case 32:
743 		lnk_wdth = PCIE_LNK_X32;
744 		break;
745 	default:
746 		lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
747 		break;
748 	}
749 
750 	*value = lnk_wdth;
751 	ctrl_dbg(ctrl, "Max link width = %d\n", lnk_wdth);
752 
753 	return retval;
754 }
755 
756 int pciehp_get_cur_link_speed(struct slot *slot, enum pci_bus_speed *value)
757 {
758 	struct controller *ctrl = slot->ctrl;
759 	enum pcie_link_speed lnk_speed = PCI_SPEED_UNKNOWN;
760 	int retval = 0;
761 	u16 lnk_status;
762 
763 	retval = pciehp_readw(ctrl, PCI_EXP_LNKSTA, &lnk_status);
764 	if (retval) {
765 		ctrl_err(ctrl, "%s: Cannot read LNKSTATUS register\n",
766 			 __func__);
767 		return retval;
768 	}
769 
770 	switch (lnk_status & PCI_EXP_LNKSTA_CLS) {
771 	case 1:
772 		lnk_speed = PCIE_2_5GB;
773 		break;
774 	case 2:
775 		lnk_speed = PCIE_5_0GB;
776 		break;
777 	default:
778 		lnk_speed = PCIE_LNK_SPEED_UNKNOWN;
779 		break;
780 	}
781 
782 	*value = lnk_speed;
783 	ctrl_dbg(ctrl, "Current link speed = %d\n", lnk_speed);
784 
785 	return retval;
786 }
787 
788 int pciehp_get_cur_lnk_width(struct slot *slot,
789 				 enum pcie_link_width *value)
790 {
791 	struct controller *ctrl = slot->ctrl;
792 	enum pcie_link_width lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
793 	int retval = 0;
794 	u16 lnk_status;
795 
796 	retval = pciehp_readw(ctrl, PCI_EXP_LNKSTA, &lnk_status);
797 	if (retval) {
798 		ctrl_err(ctrl, "%s: Cannot read LNKSTATUS register\n",
799 			 __func__);
800 		return retval;
801 	}
802 
803 	switch ((lnk_status & PCI_EXP_LNKSTA_NLW) >> 4){
804 	case 0:
805 		lnk_wdth = PCIE_LNK_WIDTH_RESRV;
806 		break;
807 	case 1:
808 		lnk_wdth = PCIE_LNK_X1;
809 		break;
810 	case 2:
811 		lnk_wdth = PCIE_LNK_X2;
812 		break;
813 	case 4:
814 		lnk_wdth = PCIE_LNK_X4;
815 		break;
816 	case 8:
817 		lnk_wdth = PCIE_LNK_X8;
818 		break;
819 	case 12:
820 		lnk_wdth = PCIE_LNK_X12;
821 		break;
822 	case 16:
823 		lnk_wdth = PCIE_LNK_X16;
824 		break;
825 	case 32:
826 		lnk_wdth = PCIE_LNK_X32;
827 		break;
828 	default:
829 		lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
830 		break;
831 	}
832 
833 	*value = lnk_wdth;
834 	ctrl_dbg(ctrl, "Current link width = %d\n", lnk_wdth);
835 
836 	return retval;
837 }
838 
839 int pcie_enable_notification(struct controller *ctrl)
840 {
841 	u16 cmd, mask;
842 
843 	cmd = PCI_EXP_SLTCTL_PDCE;
844 	if (ATTN_BUTTN(ctrl))
845 		cmd |= PCI_EXP_SLTCTL_ABPE;
846 	if (POWER_CTRL(ctrl))
847 		cmd |= PCI_EXP_SLTCTL_PFDE;
848 	if (MRL_SENS(ctrl))
849 		cmd |= PCI_EXP_SLTCTL_MRLSCE;
850 	if (!pciehp_poll_mode)
851 		cmd |= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE;
852 
853 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
854 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
855 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE);
856 
857 	if (pcie_write_cmd(ctrl, cmd, mask)) {
858 		ctrl_err(ctrl, "Cannot enable software notification\n");
859 		return -1;
860 	}
861 	return 0;
862 }
863 
864 static void pcie_disable_notification(struct controller *ctrl)
865 {
866 	u16 mask;
867 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
868 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
869 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE);
870 	if (pcie_write_cmd(ctrl, 0, mask))
871 		ctrl_warn(ctrl, "Cannot disable software notification\n");
872 }
873 
874 int pcie_init_notification(struct controller *ctrl)
875 {
876 	if (pciehp_request_irq(ctrl))
877 		return -1;
878 	if (pcie_enable_notification(ctrl)) {
879 		pciehp_free_irq(ctrl);
880 		return -1;
881 	}
882 	ctrl->notification_enabled = 1;
883 	return 0;
884 }
885 
886 static void pcie_shutdown_notification(struct controller *ctrl)
887 {
888 	if (ctrl->notification_enabled) {
889 		pcie_disable_notification(ctrl);
890 		pciehp_free_irq(ctrl);
891 		ctrl->notification_enabled = 0;
892 	}
893 }
894 
895 static int pcie_init_slot(struct controller *ctrl)
896 {
897 	struct slot *slot;
898 
899 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
900 	if (!slot)
901 		return -ENOMEM;
902 
903 	slot->ctrl = ctrl;
904 	mutex_init(&slot->lock);
905 	INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
906 	ctrl->slot = slot;
907 	return 0;
908 }
909 
910 static void pcie_cleanup_slot(struct controller *ctrl)
911 {
912 	struct slot *slot = ctrl->slot;
913 	cancel_delayed_work(&slot->work);
914 	flush_scheduled_work();
915 	flush_workqueue(pciehp_wq);
916 	kfree(slot);
917 }
918 
919 static inline void dbg_ctrl(struct controller *ctrl)
920 {
921 	int i;
922 	u16 reg16;
923 	struct pci_dev *pdev = ctrl->pcie->port;
924 
925 	if (!pciehp_debug)
926 		return;
927 
928 	ctrl_info(ctrl, "Hotplug Controller:\n");
929 	ctrl_info(ctrl, "  Seg/Bus/Dev/Func/IRQ : %s IRQ %d\n",
930 		  pci_name(pdev), pdev->irq);
931 	ctrl_info(ctrl, "  Vendor ID            : 0x%04x\n", pdev->vendor);
932 	ctrl_info(ctrl, "  Device ID            : 0x%04x\n", pdev->device);
933 	ctrl_info(ctrl, "  Subsystem ID         : 0x%04x\n",
934 		  pdev->subsystem_device);
935 	ctrl_info(ctrl, "  Subsystem Vendor ID  : 0x%04x\n",
936 		  pdev->subsystem_vendor);
937 	ctrl_info(ctrl, "  PCIe Cap offset      : 0x%02x\n", ctrl->cap_base);
938 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
939 		if (!pci_resource_len(pdev, i))
940 			continue;
941 		ctrl_info(ctrl, "  PCI resource [%d]     : 0x%llx@0x%llx\n",
942 			  i, (unsigned long long)pci_resource_len(pdev, i),
943 			  (unsigned long long)pci_resource_start(pdev, i));
944 	}
945 	ctrl_info(ctrl, "Slot Capabilities      : 0x%08x\n", ctrl->slot_cap);
946 	ctrl_info(ctrl, "  Physical Slot Number : %d\n", PSN(ctrl));
947 	ctrl_info(ctrl, "  Attention Button     : %3s\n",
948 		  ATTN_BUTTN(ctrl) ? "yes" : "no");
949 	ctrl_info(ctrl, "  Power Controller     : %3s\n",
950 		  POWER_CTRL(ctrl) ? "yes" : "no");
951 	ctrl_info(ctrl, "  MRL Sensor           : %3s\n",
952 		  MRL_SENS(ctrl)   ? "yes" : "no");
953 	ctrl_info(ctrl, "  Attention Indicator  : %3s\n",
954 		  ATTN_LED(ctrl)   ? "yes" : "no");
955 	ctrl_info(ctrl, "  Power Indicator      : %3s\n",
956 		  PWR_LED(ctrl)    ? "yes" : "no");
957 	ctrl_info(ctrl, "  Hot-Plug Surprise    : %3s\n",
958 		  HP_SUPR_RM(ctrl) ? "yes" : "no");
959 	ctrl_info(ctrl, "  EMI Present          : %3s\n",
960 		  EMI(ctrl)        ? "yes" : "no");
961 	ctrl_info(ctrl, "  Command Completed    : %3s\n",
962 		  NO_CMD_CMPL(ctrl) ? "no" : "yes");
963 	pciehp_readw(ctrl, PCI_EXP_SLTSTA, &reg16);
964 	ctrl_info(ctrl, "Slot Status            : 0x%04x\n", reg16);
965 	pciehp_readw(ctrl, PCI_EXP_SLTCTL, &reg16);
966 	ctrl_info(ctrl, "Slot Control           : 0x%04x\n", reg16);
967 }
968 
969 struct controller *pcie_init(struct pcie_device *dev)
970 {
971 	struct controller *ctrl;
972 	u32 slot_cap, link_cap;
973 	struct pci_dev *pdev = dev->port;
974 
975 	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
976 	if (!ctrl) {
977 		dev_err(&dev->device, "%s: Out of memory\n", __func__);
978 		goto abort;
979 	}
980 	ctrl->pcie = dev;
981 	ctrl->cap_base = pci_find_capability(pdev, PCI_CAP_ID_EXP);
982 	if (!ctrl->cap_base) {
983 		ctrl_err(ctrl, "Cannot find PCI Express capability\n");
984 		goto abort_ctrl;
985 	}
986 	if (pciehp_readl(ctrl, PCI_EXP_SLTCAP, &slot_cap)) {
987 		ctrl_err(ctrl, "Cannot read SLOTCAP register\n");
988 		goto abort_ctrl;
989 	}
990 
991 	ctrl->slot_cap = slot_cap;
992 	mutex_init(&ctrl->ctrl_lock);
993 	init_waitqueue_head(&ctrl->queue);
994 	dbg_ctrl(ctrl);
995 	/*
996 	 * Controller doesn't notify of command completion if the "No
997 	 * Command Completed Support" bit is set in Slot Capability
998 	 * register or the controller supports none of power
999 	 * controller, attention led, power led and EMI.
1000 	 */
1001 	if (NO_CMD_CMPL(ctrl) ||
1002 	    !(POWER_CTRL(ctrl) | ATTN_LED(ctrl) | PWR_LED(ctrl) | EMI(ctrl)))
1003 	    ctrl->no_cmd_complete = 1;
1004 
1005         /* Check if Data Link Layer Link Active Reporting is implemented */
1006         if (pciehp_readl(ctrl, PCI_EXP_LNKCAP, &link_cap)) {
1007                 ctrl_err(ctrl, "%s: Cannot read LNKCAP register\n", __func__);
1008                 goto abort_ctrl;
1009         }
1010         if (link_cap & PCI_EXP_LNKCAP_DLLLARC) {
1011                 ctrl_dbg(ctrl, "Link Active Reporting supported\n");
1012                 ctrl->link_active_reporting = 1;
1013         }
1014 
1015 	/* Clear all remaining event bits in Slot Status register */
1016 	if (pciehp_writew(ctrl, PCI_EXP_SLTSTA, 0x1f))
1017 		goto abort_ctrl;
1018 
1019 	/* Disable sotfware notification */
1020 	pcie_disable_notification(ctrl);
1021 
1022 	/*
1023 	 * If this is the first controller to be initialized,
1024 	 * initialize the pciehp work queue
1025 	 */
1026 	if (atomic_add_return(1, &pciehp_num_controllers) == 1) {
1027 		pciehp_wq = create_singlethread_workqueue("pciehpd");
1028 		if (!pciehp_wq)
1029 			goto abort_ctrl;
1030 	}
1031 
1032 	ctrl_info(ctrl, "HPC vendor_id %x device_id %x ss_vid %x ss_did %x\n",
1033 		  pdev->vendor, pdev->device, pdev->subsystem_vendor,
1034 		  pdev->subsystem_device);
1035 
1036 	if (pcie_init_slot(ctrl))
1037 		goto abort_ctrl;
1038 
1039 	return ctrl;
1040 
1041 abort_ctrl:
1042 	kfree(ctrl);
1043 abort:
1044 	return NULL;
1045 }
1046 
1047 void pciehp_release_ctrl(struct controller *ctrl)
1048 {
1049 	pcie_shutdown_notification(ctrl);
1050 	pcie_cleanup_slot(ctrl);
1051 	/*
1052 	 * If this is the last controller to be released, destroy the
1053 	 * pciehp work queue
1054 	 */
1055 	if (atomic_dec_and_test(&pciehp_num_controllers))
1056 		destroy_workqueue(pciehp_wq);
1057 	kfree(ctrl);
1058 }
1059