xref: /linux/drivers/pci/hotplug/pciehp_hpc.c (revision 5499b45190237ca90dd2ac86395cf464fe1f4cc7)
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 	u16 lnk_status;
496 	int retval = 0;
497 
498 	/* Clear sticky power-fault bit from previous power failures */
499 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
500 	if (retval) {
501 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
502 			 __func__);
503 		return retval;
504 	}
505 	slot_status &= PCI_EXP_SLTSTA_PFD;
506 	if (slot_status) {
507 		retval = pciehp_writew(ctrl, PCI_EXP_SLTSTA, slot_status);
508 		if (retval) {
509 			ctrl_err(ctrl,
510 				 "%s: Cannot write to SLOTSTATUS register\n",
511 				 __func__);
512 			return retval;
513 		}
514 	}
515 	ctrl->power_fault_detected = 0;
516 
517 	slot_cmd = POWER_ON;
518 	cmd_mask = PCI_EXP_SLTCTL_PCC;
519 	retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
520 	if (retval) {
521 		ctrl_err(ctrl, "Write %x command failed!\n", slot_cmd);
522 		return retval;
523 	}
524 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
525 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
526 
527 	retval = pciehp_readw(ctrl, PCI_EXP_LNKSTA, &lnk_status);
528 	if (retval) {
529 		ctrl_err(ctrl, "%s: Cannot read LNKSTA register\n",
530 				__func__);
531 		return retval;
532 	}
533 	pcie_update_link_speed(ctrl->pcie->port->subordinate, lnk_status);
534 
535 	return retval;
536 }
537 
538 int pciehp_power_off_slot(struct slot * slot)
539 {
540 	struct controller *ctrl = slot->ctrl;
541 	u16 slot_cmd;
542 	u16 cmd_mask;
543 	int retval;
544 
545 	slot_cmd = POWER_OFF;
546 	cmd_mask = PCI_EXP_SLTCTL_PCC;
547 	retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
548 	if (retval) {
549 		ctrl_err(ctrl, "Write command failed!\n");
550 		return retval;
551 	}
552 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
553 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
554 	return 0;
555 }
556 
557 static irqreturn_t pcie_isr(int irq, void *dev_id)
558 {
559 	struct controller *ctrl = (struct controller *)dev_id;
560 	struct slot *slot = ctrl->slot;
561 	u16 detected, intr_loc;
562 
563 	/*
564 	 * In order to guarantee that all interrupt events are
565 	 * serviced, we need to re-inspect Slot Status register after
566 	 * clearing what is presumed to be the last pending interrupt.
567 	 */
568 	intr_loc = 0;
569 	do {
570 		if (pciehp_readw(ctrl, PCI_EXP_SLTSTA, &detected)) {
571 			ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS\n",
572 				 __func__);
573 			return IRQ_NONE;
574 		}
575 
576 		detected &= (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
577 			     PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC |
578 			     PCI_EXP_SLTSTA_CC);
579 		detected &= ~intr_loc;
580 		intr_loc |= detected;
581 		if (!intr_loc)
582 			return IRQ_NONE;
583 		if (detected && pciehp_writew(ctrl, PCI_EXP_SLTSTA, intr_loc)) {
584 			ctrl_err(ctrl, "%s: Cannot write to SLOTSTATUS\n",
585 				 __func__);
586 			return IRQ_NONE;
587 		}
588 	} while (detected);
589 
590 	ctrl_dbg(ctrl, "%s: intr_loc %x\n", __func__, intr_loc);
591 
592 	/* Check Command Complete Interrupt Pending */
593 	if (intr_loc & PCI_EXP_SLTSTA_CC) {
594 		ctrl->cmd_busy = 0;
595 		smp_mb();
596 		wake_up(&ctrl->queue);
597 	}
598 
599 	if (!(intr_loc & ~PCI_EXP_SLTSTA_CC))
600 		return IRQ_HANDLED;
601 
602 	/* Check MRL Sensor Changed */
603 	if (intr_loc & PCI_EXP_SLTSTA_MRLSC)
604 		pciehp_handle_switch_change(slot);
605 
606 	/* Check Attention Button Pressed */
607 	if (intr_loc & PCI_EXP_SLTSTA_ABP)
608 		pciehp_handle_attention_button(slot);
609 
610 	/* Check Presence Detect Changed */
611 	if (intr_loc & PCI_EXP_SLTSTA_PDC)
612 		pciehp_handle_presence_change(slot);
613 
614 	/* Check Power Fault Detected */
615 	if ((intr_loc & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
616 		ctrl->power_fault_detected = 1;
617 		pciehp_handle_power_fault(slot);
618 	}
619 	return IRQ_HANDLED;
620 }
621 
622 int pciehp_get_max_lnk_width(struct slot *slot,
623 				 enum pcie_link_width *value)
624 {
625 	struct controller *ctrl = slot->ctrl;
626 	enum pcie_link_width lnk_wdth;
627 	u32	lnk_cap;
628 	int retval = 0;
629 
630 	retval = pciehp_readl(ctrl, PCI_EXP_LNKCAP, &lnk_cap);
631 	if (retval) {
632 		ctrl_err(ctrl, "%s: Cannot read LNKCAP register\n", __func__);
633 		return retval;
634 	}
635 
636 	switch ((lnk_cap & PCI_EXP_LNKSTA_NLW) >> 4){
637 	case 0:
638 		lnk_wdth = PCIE_LNK_WIDTH_RESRV;
639 		break;
640 	case 1:
641 		lnk_wdth = PCIE_LNK_X1;
642 		break;
643 	case 2:
644 		lnk_wdth = PCIE_LNK_X2;
645 		break;
646 	case 4:
647 		lnk_wdth = PCIE_LNK_X4;
648 		break;
649 	case 8:
650 		lnk_wdth = PCIE_LNK_X8;
651 		break;
652 	case 12:
653 		lnk_wdth = PCIE_LNK_X12;
654 		break;
655 	case 16:
656 		lnk_wdth = PCIE_LNK_X16;
657 		break;
658 	case 32:
659 		lnk_wdth = PCIE_LNK_X32;
660 		break;
661 	default:
662 		lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
663 		break;
664 	}
665 
666 	*value = lnk_wdth;
667 	ctrl_dbg(ctrl, "Max link width = %d\n", lnk_wdth);
668 
669 	return retval;
670 }
671 
672 int pciehp_get_cur_lnk_width(struct slot *slot,
673 				 enum pcie_link_width *value)
674 {
675 	struct controller *ctrl = slot->ctrl;
676 	enum pcie_link_width lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
677 	int retval = 0;
678 	u16 lnk_status;
679 
680 	retval = pciehp_readw(ctrl, PCI_EXP_LNKSTA, &lnk_status);
681 	if (retval) {
682 		ctrl_err(ctrl, "%s: Cannot read LNKSTATUS register\n",
683 			 __func__);
684 		return retval;
685 	}
686 
687 	switch ((lnk_status & PCI_EXP_LNKSTA_NLW) >> 4){
688 	case 0:
689 		lnk_wdth = PCIE_LNK_WIDTH_RESRV;
690 		break;
691 	case 1:
692 		lnk_wdth = PCIE_LNK_X1;
693 		break;
694 	case 2:
695 		lnk_wdth = PCIE_LNK_X2;
696 		break;
697 	case 4:
698 		lnk_wdth = PCIE_LNK_X4;
699 		break;
700 	case 8:
701 		lnk_wdth = PCIE_LNK_X8;
702 		break;
703 	case 12:
704 		lnk_wdth = PCIE_LNK_X12;
705 		break;
706 	case 16:
707 		lnk_wdth = PCIE_LNK_X16;
708 		break;
709 	case 32:
710 		lnk_wdth = PCIE_LNK_X32;
711 		break;
712 	default:
713 		lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
714 		break;
715 	}
716 
717 	*value = lnk_wdth;
718 	ctrl_dbg(ctrl, "Current link width = %d\n", lnk_wdth);
719 
720 	return retval;
721 }
722 
723 int pcie_enable_notification(struct controller *ctrl)
724 {
725 	u16 cmd, mask;
726 
727 	/*
728 	 * TBD: Power fault detected software notification support.
729 	 *
730 	 * Power fault detected software notification is not enabled
731 	 * now, because it caused power fault detected interrupt storm
732 	 * on some machines. On those machines, power fault detected
733 	 * bit in the slot status register was set again immediately
734 	 * when it is cleared in the interrupt service routine, and
735 	 * next power fault detected interrupt was notified again.
736 	 */
737 	cmd = PCI_EXP_SLTCTL_PDCE;
738 	if (ATTN_BUTTN(ctrl))
739 		cmd |= PCI_EXP_SLTCTL_ABPE;
740 	if (MRL_SENS(ctrl))
741 		cmd |= PCI_EXP_SLTCTL_MRLSCE;
742 	if (!pciehp_poll_mode)
743 		cmd |= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE;
744 
745 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
746 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
747 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE);
748 
749 	if (pcie_write_cmd(ctrl, cmd, mask)) {
750 		ctrl_err(ctrl, "Cannot enable software notification\n");
751 		return -1;
752 	}
753 	return 0;
754 }
755 
756 static void pcie_disable_notification(struct controller *ctrl)
757 {
758 	u16 mask;
759 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
760 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
761 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
762 		PCI_EXP_SLTCTL_DLLSCE);
763 	if (pcie_write_cmd(ctrl, 0, mask))
764 		ctrl_warn(ctrl, "Cannot disable software notification\n");
765 }
766 
767 int pcie_init_notification(struct controller *ctrl)
768 {
769 	if (pciehp_request_irq(ctrl))
770 		return -1;
771 	if (pcie_enable_notification(ctrl)) {
772 		pciehp_free_irq(ctrl);
773 		return -1;
774 	}
775 	ctrl->notification_enabled = 1;
776 	return 0;
777 }
778 
779 static void pcie_shutdown_notification(struct controller *ctrl)
780 {
781 	if (ctrl->notification_enabled) {
782 		pcie_disable_notification(ctrl);
783 		pciehp_free_irq(ctrl);
784 		ctrl->notification_enabled = 0;
785 	}
786 }
787 
788 static int pcie_init_slot(struct controller *ctrl)
789 {
790 	struct slot *slot;
791 
792 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
793 	if (!slot)
794 		return -ENOMEM;
795 
796 	slot->ctrl = ctrl;
797 	mutex_init(&slot->lock);
798 	INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
799 	ctrl->slot = slot;
800 	return 0;
801 }
802 
803 static void pcie_cleanup_slot(struct controller *ctrl)
804 {
805 	struct slot *slot = ctrl->slot;
806 	cancel_delayed_work(&slot->work);
807 	flush_scheduled_work();
808 	flush_workqueue(pciehp_wq);
809 	kfree(slot);
810 }
811 
812 static inline void dbg_ctrl(struct controller *ctrl)
813 {
814 	int i;
815 	u16 reg16;
816 	struct pci_dev *pdev = ctrl->pcie->port;
817 
818 	if (!pciehp_debug)
819 		return;
820 
821 	ctrl_info(ctrl, "Hotplug Controller:\n");
822 	ctrl_info(ctrl, "  Seg/Bus/Dev/Func/IRQ : %s IRQ %d\n",
823 		  pci_name(pdev), pdev->irq);
824 	ctrl_info(ctrl, "  Vendor ID            : 0x%04x\n", pdev->vendor);
825 	ctrl_info(ctrl, "  Device ID            : 0x%04x\n", pdev->device);
826 	ctrl_info(ctrl, "  Subsystem ID         : 0x%04x\n",
827 		  pdev->subsystem_device);
828 	ctrl_info(ctrl, "  Subsystem Vendor ID  : 0x%04x\n",
829 		  pdev->subsystem_vendor);
830 	ctrl_info(ctrl, "  PCIe Cap offset      : 0x%02x\n",
831 		  pci_pcie_cap(pdev));
832 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
833 		if (!pci_resource_len(pdev, i))
834 			continue;
835 		ctrl_info(ctrl, "  PCI resource [%d]     : 0x%llx@0x%llx\n",
836 			  i, (unsigned long long)pci_resource_len(pdev, i),
837 			  (unsigned long long)pci_resource_start(pdev, i));
838 	}
839 	ctrl_info(ctrl, "Slot Capabilities      : 0x%08x\n", ctrl->slot_cap);
840 	ctrl_info(ctrl, "  Physical Slot Number : %d\n", PSN(ctrl));
841 	ctrl_info(ctrl, "  Attention Button     : %3s\n",
842 		  ATTN_BUTTN(ctrl) ? "yes" : "no");
843 	ctrl_info(ctrl, "  Power Controller     : %3s\n",
844 		  POWER_CTRL(ctrl) ? "yes" : "no");
845 	ctrl_info(ctrl, "  MRL Sensor           : %3s\n",
846 		  MRL_SENS(ctrl)   ? "yes" : "no");
847 	ctrl_info(ctrl, "  Attention Indicator  : %3s\n",
848 		  ATTN_LED(ctrl)   ? "yes" : "no");
849 	ctrl_info(ctrl, "  Power Indicator      : %3s\n",
850 		  PWR_LED(ctrl)    ? "yes" : "no");
851 	ctrl_info(ctrl, "  Hot-Plug Surprise    : %3s\n",
852 		  HP_SUPR_RM(ctrl) ? "yes" : "no");
853 	ctrl_info(ctrl, "  EMI Present          : %3s\n",
854 		  EMI(ctrl)        ? "yes" : "no");
855 	ctrl_info(ctrl, "  Command Completed    : %3s\n",
856 		  NO_CMD_CMPL(ctrl) ? "no" : "yes");
857 	pciehp_readw(ctrl, PCI_EXP_SLTSTA, &reg16);
858 	ctrl_info(ctrl, "Slot Status            : 0x%04x\n", reg16);
859 	pciehp_readw(ctrl, PCI_EXP_SLTCTL, &reg16);
860 	ctrl_info(ctrl, "Slot Control           : 0x%04x\n", reg16);
861 }
862 
863 struct controller *pcie_init(struct pcie_device *dev)
864 {
865 	struct controller *ctrl;
866 	u32 slot_cap, link_cap;
867 	struct pci_dev *pdev = dev->port;
868 
869 	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
870 	if (!ctrl) {
871 		dev_err(&dev->device, "%s: Out of memory\n", __func__);
872 		goto abort;
873 	}
874 	ctrl->pcie = dev;
875 	if (!pci_pcie_cap(pdev)) {
876 		ctrl_err(ctrl, "Cannot find PCI Express capability\n");
877 		goto abort_ctrl;
878 	}
879 	if (pciehp_readl(ctrl, PCI_EXP_SLTCAP, &slot_cap)) {
880 		ctrl_err(ctrl, "Cannot read SLOTCAP register\n");
881 		goto abort_ctrl;
882 	}
883 
884 	ctrl->slot_cap = slot_cap;
885 	mutex_init(&ctrl->ctrl_lock);
886 	init_waitqueue_head(&ctrl->queue);
887 	dbg_ctrl(ctrl);
888 	/*
889 	 * Controller doesn't notify of command completion if the "No
890 	 * Command Completed Support" bit is set in Slot Capability
891 	 * register or the controller supports none of power
892 	 * controller, attention led, power led and EMI.
893 	 */
894 	if (NO_CMD_CMPL(ctrl) ||
895 	    !(POWER_CTRL(ctrl) | ATTN_LED(ctrl) | PWR_LED(ctrl) | EMI(ctrl)))
896 	    ctrl->no_cmd_complete = 1;
897 
898         /* Check if Data Link Layer Link Active Reporting is implemented */
899         if (pciehp_readl(ctrl, PCI_EXP_LNKCAP, &link_cap)) {
900                 ctrl_err(ctrl, "%s: Cannot read LNKCAP register\n", __func__);
901                 goto abort_ctrl;
902         }
903         if (link_cap & PCI_EXP_LNKCAP_DLLLARC) {
904                 ctrl_dbg(ctrl, "Link Active Reporting supported\n");
905                 ctrl->link_active_reporting = 1;
906         }
907 
908 	/* Clear all remaining event bits in Slot Status register */
909 	if (pciehp_writew(ctrl, PCI_EXP_SLTSTA, 0x1f))
910 		goto abort_ctrl;
911 
912 	/* Disable sotfware notification */
913 	pcie_disable_notification(ctrl);
914 
915 	/*
916 	 * If this is the first controller to be initialized,
917 	 * initialize the pciehp work queue
918 	 */
919 	if (atomic_add_return(1, &pciehp_num_controllers) == 1) {
920 		pciehp_wq = create_singlethread_workqueue("pciehpd");
921 		if (!pciehp_wq)
922 			goto abort_ctrl;
923 	}
924 
925 	ctrl_info(ctrl, "HPC vendor_id %x device_id %x ss_vid %x ss_did %x\n",
926 		  pdev->vendor, pdev->device, pdev->subsystem_vendor,
927 		  pdev->subsystem_device);
928 
929 	if (pcie_init_slot(ctrl))
930 		goto abort_ctrl;
931 
932 	return ctrl;
933 
934 abort_ctrl:
935 	kfree(ctrl);
936 abort:
937 	return NULL;
938 }
939 
940 void pciehp_release_ctrl(struct controller *ctrl)
941 {
942 	pcie_shutdown_notification(ctrl);
943 	pcie_cleanup_slot(ctrl);
944 	/*
945 	 * If this is the last controller to be released, destroy the
946 	 * pciehp work queue
947 	 */
948 	if (atomic_dec_and_test(&pciehp_num_controllers))
949 		destroy_workqueue(pciehp_wq);
950 	kfree(ctrl);
951 }
952