xref: /openbmc/linux/drivers/pci/hotplug/pciehp_hpc.c (revision b04b4f78)
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->pci_dev;
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->pci_dev;
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->pci_dev;
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->pci_dev;
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 static int hpc_check_lnk_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 static int hpc_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 static int hpc_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 static int hpc_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 static int hpc_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 static int hpc_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 static int hpc_get_emi_status(struct slot *slot, u8 *status)
426 {
427 	struct controller *ctrl = slot->ctrl;
428 	u16 slot_status;
429 	int retval;
430 
431 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
432 	if (retval) {
433 		ctrl_err(ctrl, "Cannot check EMI status\n");
434 		return retval;
435 	}
436 	*status = !!(slot_status & PCI_EXP_SLTSTA_EIS);
437 	return retval;
438 }
439 
440 static int hpc_toggle_emi(struct slot *slot)
441 {
442 	u16 slot_cmd;
443 	u16 cmd_mask;
444 	int rc;
445 
446 	slot_cmd = PCI_EXP_SLTCTL_EIC;
447 	cmd_mask = PCI_EXP_SLTCTL_EIC;
448 	rc = pcie_write_cmd(slot->ctrl, slot_cmd, cmd_mask);
449 	slot->last_emi_toggle = get_seconds();
450 
451 	return rc;
452 }
453 
454 static int hpc_set_attention_status(struct slot *slot, u8 value)
455 {
456 	struct controller *ctrl = slot->ctrl;
457 	u16 slot_cmd;
458 	u16 cmd_mask;
459 	int rc;
460 
461 	cmd_mask = PCI_EXP_SLTCTL_AIC;
462 	switch (value) {
463 		case 0 :	/* turn off */
464 			slot_cmd = 0x00C0;
465 			break;
466 		case 1:		/* turn on */
467 			slot_cmd = 0x0040;
468 			break;
469 		case 2:		/* turn blink */
470 			slot_cmd = 0x0080;
471 			break;
472 		default:
473 			return -1;
474 	}
475 	rc = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
476 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n",
477 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd);
478 
479 	return rc;
480 }
481 
482 static void hpc_set_green_led_on(struct slot *slot)
483 {
484 	struct controller *ctrl = slot->ctrl;
485 	u16 slot_cmd;
486 	u16 cmd_mask;
487 
488 	slot_cmd = 0x0100;
489 	cmd_mask = PCI_EXP_SLTCTL_PIC;
490 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
491 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n",
492 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd);
493 }
494 
495 static void hpc_set_green_led_off(struct slot *slot)
496 {
497 	struct controller *ctrl = slot->ctrl;
498 	u16 slot_cmd;
499 	u16 cmd_mask;
500 
501 	slot_cmd = 0x0300;
502 	cmd_mask = PCI_EXP_SLTCTL_PIC;
503 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
504 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n",
505 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd);
506 }
507 
508 static void hpc_set_green_led_blink(struct slot *slot)
509 {
510 	struct controller *ctrl = slot->ctrl;
511 	u16 slot_cmd;
512 	u16 cmd_mask;
513 
514 	slot_cmd = 0x0200;
515 	cmd_mask = PCI_EXP_SLTCTL_PIC;
516 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
517 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n",
518 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd);
519 }
520 
521 static int hpc_power_on_slot(struct slot * slot)
522 {
523 	struct controller *ctrl = slot->ctrl;
524 	u16 slot_cmd;
525 	u16 cmd_mask;
526 	u16 slot_status;
527 	int retval = 0;
528 
529 	ctrl_dbg(ctrl, "%s: slot->hp_slot %x\n", __func__, slot->hp_slot);
530 
531 	/* Clear sticky power-fault bit from previous power failures */
532 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
533 	if (retval) {
534 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
535 			 __func__);
536 		return retval;
537 	}
538 	slot_status &= PCI_EXP_SLTSTA_PFD;
539 	if (slot_status) {
540 		retval = pciehp_writew(ctrl, PCI_EXP_SLTSTA, slot_status);
541 		if (retval) {
542 			ctrl_err(ctrl,
543 				 "%s: Cannot write to SLOTSTATUS register\n",
544 				 __func__);
545 			return retval;
546 		}
547 	}
548 
549 	slot_cmd = POWER_ON;
550 	cmd_mask = PCI_EXP_SLTCTL_PCC;
551 	if (!pciehp_poll_mode) {
552 		/* Enable power fault detection turned off at power off time */
553 		slot_cmd |= PCI_EXP_SLTCTL_PFDE;
554 		cmd_mask |= PCI_EXP_SLTCTL_PFDE;
555 	}
556 
557 	retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
558 	if (retval) {
559 		ctrl_err(ctrl, "Write %x command failed!\n", slot_cmd);
560 		return retval;
561 	}
562 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n",
563 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd);
564 
565 	ctrl->power_fault_detected = 0;
566 	return retval;
567 }
568 
569 static inline int pcie_mask_bad_dllp(struct controller *ctrl)
570 {
571 	struct pci_dev *dev = ctrl->pci_dev;
572 	int pos;
573 	u32 reg;
574 
575 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
576 	if (!pos)
577 		return 0;
578 	pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, &reg);
579 	if (reg & PCI_ERR_COR_BAD_DLLP)
580 		return 0;
581 	reg |= PCI_ERR_COR_BAD_DLLP;
582 	pci_write_config_dword(dev, pos + PCI_ERR_COR_MASK, reg);
583 	return 1;
584 }
585 
586 static inline void pcie_unmask_bad_dllp(struct controller *ctrl)
587 {
588 	struct pci_dev *dev = ctrl->pci_dev;
589 	u32 reg;
590 	int pos;
591 
592 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
593 	if (!pos)
594 		return;
595 	pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, &reg);
596 	if (!(reg & PCI_ERR_COR_BAD_DLLP))
597 		return;
598 	reg &= ~PCI_ERR_COR_BAD_DLLP;
599 	pci_write_config_dword(dev, pos + PCI_ERR_COR_MASK, reg);
600 }
601 
602 static int hpc_power_off_slot(struct slot * slot)
603 {
604 	struct controller *ctrl = slot->ctrl;
605 	u16 slot_cmd;
606 	u16 cmd_mask;
607 	int retval = 0;
608 	int changed;
609 
610 	ctrl_dbg(ctrl, "%s: slot->hp_slot %x\n", __func__, slot->hp_slot);
611 
612 	/*
613 	 * Set Bad DLLP Mask bit in Correctable Error Mask
614 	 * Register. This is the workaround against Bad DLLP error
615 	 * that sometimes happens during turning power off the slot
616 	 * which conforms to PCI Express 1.0a spec.
617 	 */
618 	changed = pcie_mask_bad_dllp(ctrl);
619 
620 	slot_cmd = POWER_OFF;
621 	cmd_mask = PCI_EXP_SLTCTL_PCC;
622 	if (!pciehp_poll_mode) {
623 		/* Disable power fault detection */
624 		slot_cmd &= ~PCI_EXP_SLTCTL_PFDE;
625 		cmd_mask |= PCI_EXP_SLTCTL_PFDE;
626 	}
627 
628 	retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
629 	if (retval) {
630 		ctrl_err(ctrl, "Write command failed!\n");
631 		retval = -1;
632 		goto out;
633 	}
634 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n",
635 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd);
636  out:
637 	if (changed)
638 		pcie_unmask_bad_dllp(ctrl);
639 
640 	return retval;
641 }
642 
643 static irqreturn_t pcie_isr(int irq, void *dev_id)
644 {
645 	struct controller *ctrl = (struct controller *)dev_id;
646 	u16 detected, intr_loc;
647 	struct slot *p_slot;
648 
649 	/*
650 	 * In order to guarantee that all interrupt events are
651 	 * serviced, we need to re-inspect Slot Status register after
652 	 * clearing what is presumed to be the last pending interrupt.
653 	 */
654 	intr_loc = 0;
655 	do {
656 		if (pciehp_readw(ctrl, PCI_EXP_SLTSTA, &detected)) {
657 			ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS\n",
658 				 __func__);
659 			return IRQ_NONE;
660 		}
661 
662 		detected &= (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
663 			     PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC |
664 			     PCI_EXP_SLTSTA_CC);
665 		detected &= ~intr_loc;
666 		intr_loc |= detected;
667 		if (!intr_loc)
668 			return IRQ_NONE;
669 		if (detected && pciehp_writew(ctrl, PCI_EXP_SLTSTA, intr_loc)) {
670 			ctrl_err(ctrl, "%s: Cannot write to SLOTSTATUS\n",
671 				 __func__);
672 			return IRQ_NONE;
673 		}
674 	} while (detected);
675 
676 	ctrl_dbg(ctrl, "%s: intr_loc %x\n", __func__, intr_loc);
677 
678 	/* Check Command Complete Interrupt Pending */
679 	if (intr_loc & PCI_EXP_SLTSTA_CC) {
680 		ctrl->cmd_busy = 0;
681 		smp_mb();
682 		wake_up(&ctrl->queue);
683 	}
684 
685 	if (!(intr_loc & ~PCI_EXP_SLTSTA_CC))
686 		return IRQ_HANDLED;
687 
688 	p_slot = pciehp_find_slot(ctrl, ctrl->slot_device_offset);
689 
690 	/* Check MRL Sensor Changed */
691 	if (intr_loc & PCI_EXP_SLTSTA_MRLSC)
692 		pciehp_handle_switch_change(p_slot);
693 
694 	/* Check Attention Button Pressed */
695 	if (intr_loc & PCI_EXP_SLTSTA_ABP)
696 		pciehp_handle_attention_button(p_slot);
697 
698 	/* Check Presence Detect Changed */
699 	if (intr_loc & PCI_EXP_SLTSTA_PDC)
700 		pciehp_handle_presence_change(p_slot);
701 
702 	/* Check Power Fault Detected */
703 	if ((intr_loc & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
704 		ctrl->power_fault_detected = 1;
705 		pciehp_handle_power_fault(p_slot);
706 	}
707 	return IRQ_HANDLED;
708 }
709 
710 static int hpc_get_max_lnk_speed(struct slot *slot, enum pci_bus_speed *value)
711 {
712 	struct controller *ctrl = slot->ctrl;
713 	enum pcie_link_speed lnk_speed;
714 	u32	lnk_cap;
715 	int retval = 0;
716 
717 	retval = pciehp_readl(ctrl, PCI_EXP_LNKCAP, &lnk_cap);
718 	if (retval) {
719 		ctrl_err(ctrl, "%s: Cannot read LNKCAP register\n", __func__);
720 		return retval;
721 	}
722 
723 	switch (lnk_cap & 0x000F) {
724 	case 1:
725 		lnk_speed = PCIE_2PT5GB;
726 		break;
727 	default:
728 		lnk_speed = PCIE_LNK_SPEED_UNKNOWN;
729 		break;
730 	}
731 
732 	*value = lnk_speed;
733 	ctrl_dbg(ctrl, "Max link speed = %d\n", lnk_speed);
734 
735 	return retval;
736 }
737 
738 static int hpc_get_max_lnk_width(struct slot *slot,
739 				 enum pcie_link_width *value)
740 {
741 	struct controller *ctrl = slot->ctrl;
742 	enum pcie_link_width lnk_wdth;
743 	u32	lnk_cap;
744 	int retval = 0;
745 
746 	retval = pciehp_readl(ctrl, PCI_EXP_LNKCAP, &lnk_cap);
747 	if (retval) {
748 		ctrl_err(ctrl, "%s: Cannot read LNKCAP register\n", __func__);
749 		return retval;
750 	}
751 
752 	switch ((lnk_cap & PCI_EXP_LNKSTA_NLW) >> 4){
753 	case 0:
754 		lnk_wdth = PCIE_LNK_WIDTH_RESRV;
755 		break;
756 	case 1:
757 		lnk_wdth = PCIE_LNK_X1;
758 		break;
759 	case 2:
760 		lnk_wdth = PCIE_LNK_X2;
761 		break;
762 	case 4:
763 		lnk_wdth = PCIE_LNK_X4;
764 		break;
765 	case 8:
766 		lnk_wdth = PCIE_LNK_X8;
767 		break;
768 	case 12:
769 		lnk_wdth = PCIE_LNK_X12;
770 		break;
771 	case 16:
772 		lnk_wdth = PCIE_LNK_X16;
773 		break;
774 	case 32:
775 		lnk_wdth = PCIE_LNK_X32;
776 		break;
777 	default:
778 		lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
779 		break;
780 	}
781 
782 	*value = lnk_wdth;
783 	ctrl_dbg(ctrl, "Max link width = %d\n", lnk_wdth);
784 
785 	return retval;
786 }
787 
788 static int hpc_get_cur_lnk_speed(struct slot *slot, enum pci_bus_speed *value)
789 {
790 	struct controller *ctrl = slot->ctrl;
791 	enum pcie_link_speed lnk_speed = PCI_SPEED_UNKNOWN;
792 	int retval = 0;
793 	u16 lnk_status;
794 
795 	retval = pciehp_readw(ctrl, PCI_EXP_LNKSTA, &lnk_status);
796 	if (retval) {
797 		ctrl_err(ctrl, "%s: Cannot read LNKSTATUS register\n",
798 			 __func__);
799 		return retval;
800 	}
801 
802 	switch (lnk_status & PCI_EXP_LNKSTA_CLS) {
803 	case 1:
804 		lnk_speed = PCIE_2PT5GB;
805 		break;
806 	default:
807 		lnk_speed = PCIE_LNK_SPEED_UNKNOWN;
808 		break;
809 	}
810 
811 	*value = lnk_speed;
812 	ctrl_dbg(ctrl, "Current link speed = %d\n", lnk_speed);
813 
814 	return retval;
815 }
816 
817 static int hpc_get_cur_lnk_width(struct slot *slot,
818 				 enum pcie_link_width *value)
819 {
820 	struct controller *ctrl = slot->ctrl;
821 	enum pcie_link_width lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
822 	int retval = 0;
823 	u16 lnk_status;
824 
825 	retval = pciehp_readw(ctrl, PCI_EXP_LNKSTA, &lnk_status);
826 	if (retval) {
827 		ctrl_err(ctrl, "%s: Cannot read LNKSTATUS register\n",
828 			 __func__);
829 		return retval;
830 	}
831 
832 	switch ((lnk_status & PCI_EXP_LNKSTA_NLW) >> 4){
833 	case 0:
834 		lnk_wdth = PCIE_LNK_WIDTH_RESRV;
835 		break;
836 	case 1:
837 		lnk_wdth = PCIE_LNK_X1;
838 		break;
839 	case 2:
840 		lnk_wdth = PCIE_LNK_X2;
841 		break;
842 	case 4:
843 		lnk_wdth = PCIE_LNK_X4;
844 		break;
845 	case 8:
846 		lnk_wdth = PCIE_LNK_X8;
847 		break;
848 	case 12:
849 		lnk_wdth = PCIE_LNK_X12;
850 		break;
851 	case 16:
852 		lnk_wdth = PCIE_LNK_X16;
853 		break;
854 	case 32:
855 		lnk_wdth = PCIE_LNK_X32;
856 		break;
857 	default:
858 		lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
859 		break;
860 	}
861 
862 	*value = lnk_wdth;
863 	ctrl_dbg(ctrl, "Current link width = %d\n", lnk_wdth);
864 
865 	return retval;
866 }
867 
868 static void pcie_release_ctrl(struct controller *ctrl);
869 static struct hpc_ops pciehp_hpc_ops = {
870 	.power_on_slot			= hpc_power_on_slot,
871 	.power_off_slot			= hpc_power_off_slot,
872 	.set_attention_status		= hpc_set_attention_status,
873 	.get_power_status		= hpc_get_power_status,
874 	.get_attention_status		= hpc_get_attention_status,
875 	.get_latch_status		= hpc_get_latch_status,
876 	.get_adapter_status		= hpc_get_adapter_status,
877 	.get_emi_status			= hpc_get_emi_status,
878 	.toggle_emi			= hpc_toggle_emi,
879 
880 	.get_max_bus_speed		= hpc_get_max_lnk_speed,
881 	.get_cur_bus_speed		= hpc_get_cur_lnk_speed,
882 	.get_max_lnk_width		= hpc_get_max_lnk_width,
883 	.get_cur_lnk_width		= hpc_get_cur_lnk_width,
884 
885 	.query_power_fault		= hpc_query_power_fault,
886 	.green_led_on			= hpc_set_green_led_on,
887 	.green_led_off			= hpc_set_green_led_off,
888 	.green_led_blink		= hpc_set_green_led_blink,
889 
890 	.release_ctlr			= pcie_release_ctrl,
891 	.check_lnk_status		= hpc_check_lnk_status,
892 };
893 
894 int pcie_enable_notification(struct controller *ctrl)
895 {
896 	u16 cmd, mask;
897 
898 	cmd = PCI_EXP_SLTCTL_PDCE;
899 	if (ATTN_BUTTN(ctrl))
900 		cmd |= PCI_EXP_SLTCTL_ABPE;
901 	if (POWER_CTRL(ctrl))
902 		cmd |= PCI_EXP_SLTCTL_PFDE;
903 	if (MRL_SENS(ctrl))
904 		cmd |= PCI_EXP_SLTCTL_MRLSCE;
905 	if (!pciehp_poll_mode)
906 		cmd |= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE;
907 
908 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
909 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
910 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE);
911 
912 	if (pcie_write_cmd(ctrl, cmd, mask)) {
913 		ctrl_err(ctrl, "Cannot enable software notification\n");
914 		return -1;
915 	}
916 	return 0;
917 }
918 
919 static void pcie_disable_notification(struct controller *ctrl)
920 {
921 	u16 mask;
922 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
923 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
924 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE);
925 	if (pcie_write_cmd(ctrl, 0, mask))
926 		ctrl_warn(ctrl, "Cannot disable software notification\n");
927 }
928 
929 int pcie_init_notification(struct controller *ctrl)
930 {
931 	if (pciehp_request_irq(ctrl))
932 		return -1;
933 	if (pcie_enable_notification(ctrl)) {
934 		pciehp_free_irq(ctrl);
935 		return -1;
936 	}
937 	ctrl->notification_enabled = 1;
938 	return 0;
939 }
940 
941 static void pcie_shutdown_notification(struct controller *ctrl)
942 {
943 	if (ctrl->notification_enabled) {
944 		pcie_disable_notification(ctrl);
945 		pciehp_free_irq(ctrl);
946 		ctrl->notification_enabled = 0;
947 	}
948 }
949 
950 static int pcie_init_slot(struct controller *ctrl)
951 {
952 	struct slot *slot;
953 
954 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
955 	if (!slot)
956 		return -ENOMEM;
957 
958 	slot->hp_slot = 0;
959 	slot->ctrl = ctrl;
960 	slot->bus = ctrl->pci_dev->subordinate->number;
961 	slot->device = ctrl->slot_device_offset + slot->hp_slot;
962 	slot->hpc_ops = ctrl->hpc_ops;
963 	slot->number = ctrl->first_slot;
964 	mutex_init(&slot->lock);
965 	INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
966 	list_add(&slot->slot_list, &ctrl->slot_list);
967 	return 0;
968 }
969 
970 static void pcie_cleanup_slot(struct controller *ctrl)
971 {
972 	struct slot *slot;
973 	slot = list_first_entry(&ctrl->slot_list, struct slot, slot_list);
974 	list_del(&slot->slot_list);
975 	cancel_delayed_work(&slot->work);
976 	flush_scheduled_work();
977 	flush_workqueue(pciehp_wq);
978 	kfree(slot);
979 }
980 
981 static inline void dbg_ctrl(struct controller *ctrl)
982 {
983 	int i;
984 	u16 reg16;
985 	struct pci_dev *pdev = ctrl->pci_dev;
986 
987 	if (!pciehp_debug)
988 		return;
989 
990 	ctrl_info(ctrl, "Hotplug Controller:\n");
991 	ctrl_info(ctrl, "  Seg/Bus/Dev/Func/IRQ : %s IRQ %d\n",
992 		  pci_name(pdev), pdev->irq);
993 	ctrl_info(ctrl, "  Vendor ID            : 0x%04x\n", pdev->vendor);
994 	ctrl_info(ctrl, "  Device ID            : 0x%04x\n", pdev->device);
995 	ctrl_info(ctrl, "  Subsystem ID         : 0x%04x\n",
996 		  pdev->subsystem_device);
997 	ctrl_info(ctrl, "  Subsystem Vendor ID  : 0x%04x\n",
998 		  pdev->subsystem_vendor);
999 	ctrl_info(ctrl, "  PCIe Cap offset      : 0x%02x\n", ctrl->cap_base);
1000 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
1001 		if (!pci_resource_len(pdev, i))
1002 			continue;
1003 		ctrl_info(ctrl, "  PCI resource [%d]     : 0x%llx@0x%llx\n",
1004 			  i, (unsigned long long)pci_resource_len(pdev, i),
1005 			  (unsigned long long)pci_resource_start(pdev, i));
1006 	}
1007 	ctrl_info(ctrl, "Slot Capabilities      : 0x%08x\n", ctrl->slot_cap);
1008 	ctrl_info(ctrl, "  Physical Slot Number : %d\n", ctrl->first_slot);
1009 	ctrl_info(ctrl, "  Attention Button     : %3s\n",
1010 		  ATTN_BUTTN(ctrl) ? "yes" : "no");
1011 	ctrl_info(ctrl, "  Power Controller     : %3s\n",
1012 		  POWER_CTRL(ctrl) ? "yes" : "no");
1013 	ctrl_info(ctrl, "  MRL Sensor           : %3s\n",
1014 		  MRL_SENS(ctrl)   ? "yes" : "no");
1015 	ctrl_info(ctrl, "  Attention Indicator  : %3s\n",
1016 		  ATTN_LED(ctrl)   ? "yes" : "no");
1017 	ctrl_info(ctrl, "  Power Indicator      : %3s\n",
1018 		  PWR_LED(ctrl)    ? "yes" : "no");
1019 	ctrl_info(ctrl, "  Hot-Plug Surprise    : %3s\n",
1020 		  HP_SUPR_RM(ctrl) ? "yes" : "no");
1021 	ctrl_info(ctrl, "  EMI Present          : %3s\n",
1022 		  EMI(ctrl)        ? "yes" : "no");
1023 	ctrl_info(ctrl, "  Command Completed    : %3s\n",
1024 		  NO_CMD_CMPL(ctrl) ? "no" : "yes");
1025 	pciehp_readw(ctrl, PCI_EXP_SLTSTA, &reg16);
1026 	ctrl_info(ctrl, "Slot Status            : 0x%04x\n", reg16);
1027 	pciehp_readw(ctrl, PCI_EXP_SLTCTL, &reg16);
1028 	ctrl_info(ctrl, "Slot Control           : 0x%04x\n", reg16);
1029 }
1030 
1031 struct controller *pcie_init(struct pcie_device *dev)
1032 {
1033 	struct controller *ctrl;
1034 	u32 slot_cap, link_cap;
1035 	struct pci_dev *pdev = dev->port;
1036 
1037 	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
1038 	if (!ctrl) {
1039 		dev_err(&dev->device, "%s: Out of memory\n", __func__);
1040 		goto abort;
1041 	}
1042 	INIT_LIST_HEAD(&ctrl->slot_list);
1043 
1044 	ctrl->pcie = dev;
1045 	ctrl->pci_dev = pdev;
1046 	ctrl->cap_base = pci_find_capability(pdev, PCI_CAP_ID_EXP);
1047 	if (!ctrl->cap_base) {
1048 		ctrl_err(ctrl, "Cannot find PCI Express capability\n");
1049 		goto abort_ctrl;
1050 	}
1051 	if (pciehp_readl(ctrl, PCI_EXP_SLTCAP, &slot_cap)) {
1052 		ctrl_err(ctrl, "Cannot read SLOTCAP register\n");
1053 		goto abort_ctrl;
1054 	}
1055 
1056 	ctrl->slot_cap = slot_cap;
1057 	ctrl->first_slot = slot_cap >> 19;
1058 	ctrl->slot_device_offset = 0;
1059 	ctrl->num_slots = 1;
1060 	ctrl->hpc_ops = &pciehp_hpc_ops;
1061 	mutex_init(&ctrl->crit_sect);
1062 	mutex_init(&ctrl->ctrl_lock);
1063 	init_waitqueue_head(&ctrl->queue);
1064 	dbg_ctrl(ctrl);
1065 	/*
1066 	 * Controller doesn't notify of command completion if the "No
1067 	 * Command Completed Support" bit is set in Slot Capability
1068 	 * register or the controller supports none of power
1069 	 * controller, attention led, power led and EMI.
1070 	 */
1071 	if (NO_CMD_CMPL(ctrl) ||
1072 	    !(POWER_CTRL(ctrl) | ATTN_LED(ctrl) | PWR_LED(ctrl) | EMI(ctrl)))
1073 	    ctrl->no_cmd_complete = 1;
1074 
1075         /* Check if Data Link Layer Link Active Reporting is implemented */
1076         if (pciehp_readl(ctrl, PCI_EXP_LNKCAP, &link_cap)) {
1077                 ctrl_err(ctrl, "%s: Cannot read LNKCAP register\n", __func__);
1078                 goto abort_ctrl;
1079         }
1080         if (link_cap & PCI_EXP_LNKCAP_DLLLARC) {
1081                 ctrl_dbg(ctrl, "Link Active Reporting supported\n");
1082                 ctrl->link_active_reporting = 1;
1083         }
1084 
1085 	/* Clear all remaining event bits in Slot Status register */
1086 	if (pciehp_writew(ctrl, PCI_EXP_SLTSTA, 0x1f))
1087 		goto abort_ctrl;
1088 
1089 	/* Disable sotfware notification */
1090 	pcie_disable_notification(ctrl);
1091 
1092 	/*
1093 	 * If this is the first controller to be initialized,
1094 	 * initialize the pciehp work queue
1095 	 */
1096 	if (atomic_add_return(1, &pciehp_num_controllers) == 1) {
1097 		pciehp_wq = create_singlethread_workqueue("pciehpd");
1098 		if (!pciehp_wq)
1099 			goto abort_ctrl;
1100 	}
1101 
1102 	ctrl_info(ctrl, "HPC vendor_id %x device_id %x ss_vid %x ss_did %x\n",
1103 		  pdev->vendor, pdev->device, pdev->subsystem_vendor,
1104 		  pdev->subsystem_device);
1105 
1106 	if (pcie_init_slot(ctrl))
1107 		goto abort_ctrl;
1108 
1109 	return ctrl;
1110 
1111 abort_ctrl:
1112 	kfree(ctrl);
1113 abort:
1114 	return NULL;
1115 }
1116 
1117 void pcie_release_ctrl(struct controller *ctrl)
1118 {
1119 	pcie_shutdown_notification(ctrl);
1120 	pcie_cleanup_slot(ctrl);
1121 	/*
1122 	 * If this is the last controller to be released, destroy the
1123 	 * pciehp work queue
1124 	 */
1125 	if (atomic_dec_and_test(&pciehp_num_controllers))
1126 		destroy_workqueue(pciehp_wq);
1127 	kfree(ctrl);
1128 }
1129