xref: /openbmc/linux/drivers/pci/hotplug/pciehp_hpc.c (revision a09d2831)
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, pci_pcie_cap(dev) + 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, pci_pcie_cap(dev) + 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, pci_pcie_cap(dev) + 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, pci_pcie_cap(dev) + 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", __func__,
322 		 pci_pcie_cap(ctrl->pcie->port) + 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", __func__,
360 		 pci_pcie_cap(ctrl->pcie->port) + 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 
431 	cmd_mask = PCI_EXP_SLTCTL_AIC;
432 	switch (value) {
433 	case 0 :	/* turn off */
434 		slot_cmd = 0x00C0;
435 		break;
436 	case 1:		/* turn on */
437 		slot_cmd = 0x0040;
438 		break;
439 	case 2:		/* turn blink */
440 		slot_cmd = 0x0080;
441 		break;
442 	default:
443 		return -EINVAL;
444 	}
445 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
446 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
447 	return pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
448 }
449 
450 void pciehp_green_led_on(struct slot *slot)
451 {
452 	struct controller *ctrl = slot->ctrl;
453 	u16 slot_cmd;
454 	u16 cmd_mask;
455 
456 	slot_cmd = 0x0100;
457 	cmd_mask = PCI_EXP_SLTCTL_PIC;
458 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
459 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
460 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
461 }
462 
463 void pciehp_green_led_off(struct slot *slot)
464 {
465 	struct controller *ctrl = slot->ctrl;
466 	u16 slot_cmd;
467 	u16 cmd_mask;
468 
469 	slot_cmd = 0x0300;
470 	cmd_mask = PCI_EXP_SLTCTL_PIC;
471 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
472 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
473 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
474 }
475 
476 void pciehp_green_led_blink(struct slot *slot)
477 {
478 	struct controller *ctrl = slot->ctrl;
479 	u16 slot_cmd;
480 	u16 cmd_mask;
481 
482 	slot_cmd = 0x0200;
483 	cmd_mask = PCI_EXP_SLTCTL_PIC;
484 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
485 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
486 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
487 }
488 
489 int pciehp_power_on_slot(struct slot * slot)
490 {
491 	struct controller *ctrl = slot->ctrl;
492 	u16 slot_cmd;
493 	u16 cmd_mask;
494 	u16 slot_status;
495 	int retval = 0;
496 
497 	/* Clear sticky power-fault bit from previous power failures */
498 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
499 	if (retval) {
500 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
501 			 __func__);
502 		return retval;
503 	}
504 	slot_status &= PCI_EXP_SLTSTA_PFD;
505 	if (slot_status) {
506 		retval = pciehp_writew(ctrl, PCI_EXP_SLTSTA, slot_status);
507 		if (retval) {
508 			ctrl_err(ctrl,
509 				 "%s: Cannot write to SLOTSTATUS register\n",
510 				 __func__);
511 			return retval;
512 		}
513 	}
514 	ctrl->power_fault_detected = 0;
515 
516 	slot_cmd = POWER_ON;
517 	cmd_mask = PCI_EXP_SLTCTL_PCC;
518 	retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
519 	if (retval) {
520 		ctrl_err(ctrl, "Write %x command failed!\n", slot_cmd);
521 		return retval;
522 	}
523 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
524 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
525 
526 	return retval;
527 }
528 
529 int pciehp_power_off_slot(struct slot * slot)
530 {
531 	struct controller *ctrl = slot->ctrl;
532 	u16 slot_cmd;
533 	u16 cmd_mask;
534 	int retval;
535 
536 	slot_cmd = POWER_OFF;
537 	cmd_mask = PCI_EXP_SLTCTL_PCC;
538 	retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
539 	if (retval) {
540 		ctrl_err(ctrl, "Write command failed!\n");
541 		return retval;
542 	}
543 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
544 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
545 	return 0;
546 }
547 
548 static irqreturn_t pcie_isr(int irq, void *dev_id)
549 {
550 	struct controller *ctrl = (struct controller *)dev_id;
551 	struct slot *slot = ctrl->slot;
552 	u16 detected, intr_loc;
553 
554 	/*
555 	 * In order to guarantee that all interrupt events are
556 	 * serviced, we need to re-inspect Slot Status register after
557 	 * clearing what is presumed to be the last pending interrupt.
558 	 */
559 	intr_loc = 0;
560 	do {
561 		if (pciehp_readw(ctrl, PCI_EXP_SLTSTA, &detected)) {
562 			ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS\n",
563 				 __func__);
564 			return IRQ_NONE;
565 		}
566 
567 		detected &= (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
568 			     PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC |
569 			     PCI_EXP_SLTSTA_CC);
570 		detected &= ~intr_loc;
571 		intr_loc |= detected;
572 		if (!intr_loc)
573 			return IRQ_NONE;
574 		if (detected && pciehp_writew(ctrl, PCI_EXP_SLTSTA, intr_loc)) {
575 			ctrl_err(ctrl, "%s: Cannot write to SLOTSTATUS\n",
576 				 __func__);
577 			return IRQ_NONE;
578 		}
579 	} while (detected);
580 
581 	ctrl_dbg(ctrl, "%s: intr_loc %x\n", __func__, intr_loc);
582 
583 	/* Check Command Complete Interrupt Pending */
584 	if (intr_loc & PCI_EXP_SLTSTA_CC) {
585 		ctrl->cmd_busy = 0;
586 		smp_mb();
587 		wake_up(&ctrl->queue);
588 	}
589 
590 	if (!(intr_loc & ~PCI_EXP_SLTSTA_CC))
591 		return IRQ_HANDLED;
592 
593 	/* Check MRL Sensor Changed */
594 	if (intr_loc & PCI_EXP_SLTSTA_MRLSC)
595 		pciehp_handle_switch_change(slot);
596 
597 	/* Check Attention Button Pressed */
598 	if (intr_loc & PCI_EXP_SLTSTA_ABP)
599 		pciehp_handle_attention_button(slot);
600 
601 	/* Check Presence Detect Changed */
602 	if (intr_loc & PCI_EXP_SLTSTA_PDC)
603 		pciehp_handle_presence_change(slot);
604 
605 	/* Check Power Fault Detected */
606 	if ((intr_loc & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
607 		ctrl->power_fault_detected = 1;
608 		pciehp_handle_power_fault(slot);
609 	}
610 	return IRQ_HANDLED;
611 }
612 
613 int pciehp_get_max_link_speed(struct slot *slot, enum pci_bus_speed *value)
614 {
615 	struct controller *ctrl = slot->ctrl;
616 	enum pcie_link_speed lnk_speed;
617 	u32	lnk_cap;
618 	int retval = 0;
619 
620 	retval = pciehp_readl(ctrl, PCI_EXP_LNKCAP, &lnk_cap);
621 	if (retval) {
622 		ctrl_err(ctrl, "%s: Cannot read LNKCAP register\n", __func__);
623 		return retval;
624 	}
625 
626 	switch (lnk_cap & 0x000F) {
627 	case 1:
628 		lnk_speed = PCIE_2_5GB;
629 		break;
630 	case 2:
631 		lnk_speed = PCIE_5_0GB;
632 		break;
633 	default:
634 		lnk_speed = PCIE_LNK_SPEED_UNKNOWN;
635 		break;
636 	}
637 
638 	*value = lnk_speed;
639 	ctrl_dbg(ctrl, "Max link speed = %d\n", lnk_speed);
640 
641 	return retval;
642 }
643 
644 int pciehp_get_max_lnk_width(struct slot *slot,
645 				 enum pcie_link_width *value)
646 {
647 	struct controller *ctrl = slot->ctrl;
648 	enum pcie_link_width lnk_wdth;
649 	u32	lnk_cap;
650 	int retval = 0;
651 
652 	retval = pciehp_readl(ctrl, PCI_EXP_LNKCAP, &lnk_cap);
653 	if (retval) {
654 		ctrl_err(ctrl, "%s: Cannot read LNKCAP register\n", __func__);
655 		return retval;
656 	}
657 
658 	switch ((lnk_cap & PCI_EXP_LNKSTA_NLW) >> 4){
659 	case 0:
660 		lnk_wdth = PCIE_LNK_WIDTH_RESRV;
661 		break;
662 	case 1:
663 		lnk_wdth = PCIE_LNK_X1;
664 		break;
665 	case 2:
666 		lnk_wdth = PCIE_LNK_X2;
667 		break;
668 	case 4:
669 		lnk_wdth = PCIE_LNK_X4;
670 		break;
671 	case 8:
672 		lnk_wdth = PCIE_LNK_X8;
673 		break;
674 	case 12:
675 		lnk_wdth = PCIE_LNK_X12;
676 		break;
677 	case 16:
678 		lnk_wdth = PCIE_LNK_X16;
679 		break;
680 	case 32:
681 		lnk_wdth = PCIE_LNK_X32;
682 		break;
683 	default:
684 		lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
685 		break;
686 	}
687 
688 	*value = lnk_wdth;
689 	ctrl_dbg(ctrl, "Max link width = %d\n", lnk_wdth);
690 
691 	return retval;
692 }
693 
694 int pciehp_get_cur_link_speed(struct slot *slot, enum pci_bus_speed *value)
695 {
696 	struct controller *ctrl = slot->ctrl;
697 	enum pcie_link_speed lnk_speed = PCI_SPEED_UNKNOWN;
698 	int retval = 0;
699 	u16 lnk_status;
700 
701 	retval = pciehp_readw(ctrl, PCI_EXP_LNKSTA, &lnk_status);
702 	if (retval) {
703 		ctrl_err(ctrl, "%s: Cannot read LNKSTATUS register\n",
704 			 __func__);
705 		return retval;
706 	}
707 
708 	switch (lnk_status & PCI_EXP_LNKSTA_CLS) {
709 	case 1:
710 		lnk_speed = PCIE_2_5GB;
711 		break;
712 	case 2:
713 		lnk_speed = PCIE_5_0GB;
714 		break;
715 	default:
716 		lnk_speed = PCIE_LNK_SPEED_UNKNOWN;
717 		break;
718 	}
719 
720 	*value = lnk_speed;
721 	ctrl_dbg(ctrl, "Current link speed = %d\n", lnk_speed);
722 
723 	return retval;
724 }
725 
726 int pciehp_get_cur_lnk_width(struct slot *slot,
727 				 enum pcie_link_width *value)
728 {
729 	struct controller *ctrl = slot->ctrl;
730 	enum pcie_link_width lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
731 	int retval = 0;
732 	u16 lnk_status;
733 
734 	retval = pciehp_readw(ctrl, PCI_EXP_LNKSTA, &lnk_status);
735 	if (retval) {
736 		ctrl_err(ctrl, "%s: Cannot read LNKSTATUS register\n",
737 			 __func__);
738 		return retval;
739 	}
740 
741 	switch ((lnk_status & PCI_EXP_LNKSTA_NLW) >> 4){
742 	case 0:
743 		lnk_wdth = PCIE_LNK_WIDTH_RESRV;
744 		break;
745 	case 1:
746 		lnk_wdth = PCIE_LNK_X1;
747 		break;
748 	case 2:
749 		lnk_wdth = PCIE_LNK_X2;
750 		break;
751 	case 4:
752 		lnk_wdth = PCIE_LNK_X4;
753 		break;
754 	case 8:
755 		lnk_wdth = PCIE_LNK_X8;
756 		break;
757 	case 12:
758 		lnk_wdth = PCIE_LNK_X12;
759 		break;
760 	case 16:
761 		lnk_wdth = PCIE_LNK_X16;
762 		break;
763 	case 32:
764 		lnk_wdth = PCIE_LNK_X32;
765 		break;
766 	default:
767 		lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
768 		break;
769 	}
770 
771 	*value = lnk_wdth;
772 	ctrl_dbg(ctrl, "Current link width = %d\n", lnk_wdth);
773 
774 	return retval;
775 }
776 
777 int pcie_enable_notification(struct controller *ctrl)
778 {
779 	u16 cmd, mask;
780 
781 	/*
782 	 * TBD: Power fault detected software notification support.
783 	 *
784 	 * Power fault detected software notification is not enabled
785 	 * now, because it caused power fault detected interrupt storm
786 	 * on some machines. On those machines, power fault detected
787 	 * bit in the slot status register was set again immediately
788 	 * when it is cleared in the interrupt service routine, and
789 	 * next power fault detected interrupt was notified again.
790 	 */
791 	cmd = PCI_EXP_SLTCTL_PDCE;
792 	if (ATTN_BUTTN(ctrl))
793 		cmd |= PCI_EXP_SLTCTL_ABPE;
794 	if (MRL_SENS(ctrl))
795 		cmd |= PCI_EXP_SLTCTL_MRLSCE;
796 	if (!pciehp_poll_mode)
797 		cmd |= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE;
798 
799 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
800 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
801 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE);
802 
803 	if (pcie_write_cmd(ctrl, cmd, mask)) {
804 		ctrl_err(ctrl, "Cannot enable software notification\n");
805 		return -1;
806 	}
807 	return 0;
808 }
809 
810 static void pcie_disable_notification(struct controller *ctrl)
811 {
812 	u16 mask;
813 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
814 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
815 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
816 		PCI_EXP_SLTCTL_DLLSCE);
817 	if (pcie_write_cmd(ctrl, 0, mask))
818 		ctrl_warn(ctrl, "Cannot disable software notification\n");
819 }
820 
821 int pcie_init_notification(struct controller *ctrl)
822 {
823 	if (pciehp_request_irq(ctrl))
824 		return -1;
825 	if (pcie_enable_notification(ctrl)) {
826 		pciehp_free_irq(ctrl);
827 		return -1;
828 	}
829 	ctrl->notification_enabled = 1;
830 	return 0;
831 }
832 
833 static void pcie_shutdown_notification(struct controller *ctrl)
834 {
835 	if (ctrl->notification_enabled) {
836 		pcie_disable_notification(ctrl);
837 		pciehp_free_irq(ctrl);
838 		ctrl->notification_enabled = 0;
839 	}
840 }
841 
842 static int pcie_init_slot(struct controller *ctrl)
843 {
844 	struct slot *slot;
845 
846 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
847 	if (!slot)
848 		return -ENOMEM;
849 
850 	slot->ctrl = ctrl;
851 	mutex_init(&slot->lock);
852 	INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
853 	ctrl->slot = slot;
854 	return 0;
855 }
856 
857 static void pcie_cleanup_slot(struct controller *ctrl)
858 {
859 	struct slot *slot = ctrl->slot;
860 	cancel_delayed_work(&slot->work);
861 	flush_scheduled_work();
862 	flush_workqueue(pciehp_wq);
863 	kfree(slot);
864 }
865 
866 static inline void dbg_ctrl(struct controller *ctrl)
867 {
868 	int i;
869 	u16 reg16;
870 	struct pci_dev *pdev = ctrl->pcie->port;
871 
872 	if (!pciehp_debug)
873 		return;
874 
875 	ctrl_info(ctrl, "Hotplug Controller:\n");
876 	ctrl_info(ctrl, "  Seg/Bus/Dev/Func/IRQ : %s IRQ %d\n",
877 		  pci_name(pdev), pdev->irq);
878 	ctrl_info(ctrl, "  Vendor ID            : 0x%04x\n", pdev->vendor);
879 	ctrl_info(ctrl, "  Device ID            : 0x%04x\n", pdev->device);
880 	ctrl_info(ctrl, "  Subsystem ID         : 0x%04x\n",
881 		  pdev->subsystem_device);
882 	ctrl_info(ctrl, "  Subsystem Vendor ID  : 0x%04x\n",
883 		  pdev->subsystem_vendor);
884 	ctrl_info(ctrl, "  PCIe Cap offset      : 0x%02x\n",
885 		  pci_pcie_cap(pdev));
886 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
887 		if (!pci_resource_len(pdev, i))
888 			continue;
889 		ctrl_info(ctrl, "  PCI resource [%d]     : 0x%llx@0x%llx\n",
890 			  i, (unsigned long long)pci_resource_len(pdev, i),
891 			  (unsigned long long)pci_resource_start(pdev, i));
892 	}
893 	ctrl_info(ctrl, "Slot Capabilities      : 0x%08x\n", ctrl->slot_cap);
894 	ctrl_info(ctrl, "  Physical Slot Number : %d\n", PSN(ctrl));
895 	ctrl_info(ctrl, "  Attention Button     : %3s\n",
896 		  ATTN_BUTTN(ctrl) ? "yes" : "no");
897 	ctrl_info(ctrl, "  Power Controller     : %3s\n",
898 		  POWER_CTRL(ctrl) ? "yes" : "no");
899 	ctrl_info(ctrl, "  MRL Sensor           : %3s\n",
900 		  MRL_SENS(ctrl)   ? "yes" : "no");
901 	ctrl_info(ctrl, "  Attention Indicator  : %3s\n",
902 		  ATTN_LED(ctrl)   ? "yes" : "no");
903 	ctrl_info(ctrl, "  Power Indicator      : %3s\n",
904 		  PWR_LED(ctrl)    ? "yes" : "no");
905 	ctrl_info(ctrl, "  Hot-Plug Surprise    : %3s\n",
906 		  HP_SUPR_RM(ctrl) ? "yes" : "no");
907 	ctrl_info(ctrl, "  EMI Present          : %3s\n",
908 		  EMI(ctrl)        ? "yes" : "no");
909 	ctrl_info(ctrl, "  Command Completed    : %3s\n",
910 		  NO_CMD_CMPL(ctrl) ? "no" : "yes");
911 	pciehp_readw(ctrl, PCI_EXP_SLTSTA, &reg16);
912 	ctrl_info(ctrl, "Slot Status            : 0x%04x\n", reg16);
913 	pciehp_readw(ctrl, PCI_EXP_SLTCTL, &reg16);
914 	ctrl_info(ctrl, "Slot Control           : 0x%04x\n", reg16);
915 }
916 
917 struct controller *pcie_init(struct pcie_device *dev)
918 {
919 	struct controller *ctrl;
920 	u32 slot_cap, link_cap;
921 	struct pci_dev *pdev = dev->port;
922 
923 	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
924 	if (!ctrl) {
925 		dev_err(&dev->device, "%s: Out of memory\n", __func__);
926 		goto abort;
927 	}
928 	ctrl->pcie = dev;
929 	if (!pci_pcie_cap(pdev)) {
930 		ctrl_err(ctrl, "Cannot find PCI Express capability\n");
931 		goto abort_ctrl;
932 	}
933 	if (pciehp_readl(ctrl, PCI_EXP_SLTCAP, &slot_cap)) {
934 		ctrl_err(ctrl, "Cannot read SLOTCAP register\n");
935 		goto abort_ctrl;
936 	}
937 
938 	ctrl->slot_cap = slot_cap;
939 	mutex_init(&ctrl->ctrl_lock);
940 	init_waitqueue_head(&ctrl->queue);
941 	dbg_ctrl(ctrl);
942 	/*
943 	 * Controller doesn't notify of command completion if the "No
944 	 * Command Completed Support" bit is set in Slot Capability
945 	 * register or the controller supports none of power
946 	 * controller, attention led, power led and EMI.
947 	 */
948 	if (NO_CMD_CMPL(ctrl) ||
949 	    !(POWER_CTRL(ctrl) | ATTN_LED(ctrl) | PWR_LED(ctrl) | EMI(ctrl)))
950 	    ctrl->no_cmd_complete = 1;
951 
952         /* Check if Data Link Layer Link Active Reporting is implemented */
953         if (pciehp_readl(ctrl, PCI_EXP_LNKCAP, &link_cap)) {
954                 ctrl_err(ctrl, "%s: Cannot read LNKCAP register\n", __func__);
955                 goto abort_ctrl;
956         }
957         if (link_cap & PCI_EXP_LNKCAP_DLLLARC) {
958                 ctrl_dbg(ctrl, "Link Active Reporting supported\n");
959                 ctrl->link_active_reporting = 1;
960         }
961 
962 	/* Clear all remaining event bits in Slot Status register */
963 	if (pciehp_writew(ctrl, PCI_EXP_SLTSTA, 0x1f))
964 		goto abort_ctrl;
965 
966 	/* Disable sotfware notification */
967 	pcie_disable_notification(ctrl);
968 
969 	/*
970 	 * If this is the first controller to be initialized,
971 	 * initialize the pciehp work queue
972 	 */
973 	if (atomic_add_return(1, &pciehp_num_controllers) == 1) {
974 		pciehp_wq = create_singlethread_workqueue("pciehpd");
975 		if (!pciehp_wq)
976 			goto abort_ctrl;
977 	}
978 
979 	ctrl_info(ctrl, "HPC vendor_id %x device_id %x ss_vid %x ss_did %x\n",
980 		  pdev->vendor, pdev->device, pdev->subsystem_vendor,
981 		  pdev->subsystem_device);
982 
983 	if (pcie_init_slot(ctrl))
984 		goto abort_ctrl;
985 
986 	return ctrl;
987 
988 abort_ctrl:
989 	kfree(ctrl);
990 abort:
991 	return NULL;
992 }
993 
994 void pciehp_release_ctrl(struct controller *ctrl)
995 {
996 	pcie_shutdown_notification(ctrl);
997 	pcie_cleanup_slot(ctrl);
998 	/*
999 	 * If this is the last controller to be released, destroy the
1000 	 * pciehp work queue
1001 	 */
1002 	if (atomic_dec_and_test(&pciehp_num_controllers))
1003 		destroy_workqueue(pciehp_wq);
1004 	kfree(ctrl);
1005 }
1006