xref: /linux/drivers/pci/hotplug/pciehp_hpc.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
1 /*
2  * PCI Express PCI Hot Plug Driver
3  *
4  * Copyright (C) 1995,2001 Compaq Computer Corporation
5  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
6  * Copyright (C) 2001 IBM Corp.
7  * Copyright (C) 2003-2004 Intel Corporation
8  *
9  * All rights reserved.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or (at
14  * your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
19  * NON INFRINGEMENT.  See the GNU General Public License for more
20  * details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25  *
26  * Send feedback to <greg@kroah.com>,<kristen.c.accardi@intel.com>
27  *
28  */
29 
30 #include <linux/kernel.h>
31 #include <linux/module.h>
32 #include <linux/types.h>
33 #include <linux/signal.h>
34 #include <linux/jiffies.h>
35 #include <linux/timer.h>
36 #include <linux/pci.h>
37 #include <linux/interrupt.h>
38 #include <linux/time.h>
39 #include <linux/slab.h>
40 
41 #include "../pci.h"
42 #include "pciehp.h"
43 
44 static inline int pciehp_readw(struct controller *ctrl, int reg, u16 *value)
45 {
46 	struct pci_dev *dev = ctrl->pcie->port;
47 	return pci_read_config_word(dev, pci_pcie_cap(dev) + reg, value);
48 }
49 
50 static inline int pciehp_readl(struct controller *ctrl, int reg, u32 *value)
51 {
52 	struct pci_dev *dev = ctrl->pcie->port;
53 	return pci_read_config_dword(dev, pci_pcie_cap(dev) + reg, value);
54 }
55 
56 static inline int pciehp_writew(struct controller *ctrl, int reg, u16 value)
57 {
58 	struct pci_dev *dev = ctrl->pcie->port;
59 	return pci_write_config_word(dev, pci_pcie_cap(dev) + reg, value);
60 }
61 
62 static inline int pciehp_writel(struct controller *ctrl, int reg, u32 value)
63 {
64 	struct pci_dev *dev = ctrl->pcie->port;
65 	return pci_write_config_dword(dev, pci_pcie_cap(dev) + reg, value);
66 }
67 
68 /* Power Control Command */
69 #define POWER_ON	0
70 #define POWER_OFF	PCI_EXP_SLTCTL_PCC
71 
72 static irqreturn_t pcie_isr(int irq, void *dev_id);
73 static void start_int_poll_timer(struct controller *ctrl, int sec);
74 
75 /* This is the interrupt polling timeout function. */
76 static void int_poll_timeout(unsigned long data)
77 {
78 	struct controller *ctrl = (struct controller *)data;
79 
80 	/* Poll for interrupt events.  regs == NULL => polling */
81 	pcie_isr(0, ctrl);
82 
83 	init_timer(&ctrl->poll_timer);
84 	if (!pciehp_poll_time)
85 		pciehp_poll_time = 2; /* default polling interval is 2 sec */
86 
87 	start_int_poll_timer(ctrl, pciehp_poll_time);
88 }
89 
90 /* This function starts the interrupt polling timer. */
91 static void start_int_poll_timer(struct controller *ctrl, int sec)
92 {
93 	/* Clamp to sane value */
94 	if ((sec <= 0) || (sec > 60))
95         	sec = 2;
96 
97 	ctrl->poll_timer.function = &int_poll_timeout;
98 	ctrl->poll_timer.data = (unsigned long)ctrl;
99 	ctrl->poll_timer.expires = jiffies + sec * HZ;
100 	add_timer(&ctrl->poll_timer);
101 }
102 
103 static inline int pciehp_request_irq(struct controller *ctrl)
104 {
105 	int retval, irq = ctrl->pcie->irq;
106 
107 	/* Install interrupt polling timer. Start with 10 sec delay */
108 	if (pciehp_poll_mode) {
109 		init_timer(&ctrl->poll_timer);
110 		start_int_poll_timer(ctrl, 10);
111 		return 0;
112 	}
113 
114 	/* Installs the interrupt handler */
115 	retval = request_irq(irq, pcie_isr, IRQF_SHARED, MY_NAME, ctrl);
116 	if (retval)
117 		ctrl_err(ctrl, "Cannot get irq %d for the hotplug controller\n",
118 			 irq);
119 	return retval;
120 }
121 
122 static inline void pciehp_free_irq(struct controller *ctrl)
123 {
124 	if (pciehp_poll_mode)
125 		del_timer_sync(&ctrl->poll_timer);
126 	else
127 		free_irq(ctrl->pcie->irq, ctrl);
128 }
129 
130 static int pcie_poll_cmd(struct controller *ctrl)
131 {
132 	u16 slot_status;
133 	int err, timeout = 1000;
134 
135 	err = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
136 	if (!err && (slot_status & PCI_EXP_SLTSTA_CC)) {
137 		pciehp_writew(ctrl, PCI_EXP_SLTSTA, PCI_EXP_SLTSTA_CC);
138 		return 1;
139 	}
140 	while (timeout > 0) {
141 		msleep(10);
142 		timeout -= 10;
143 		err = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
144 		if (!err && (slot_status & PCI_EXP_SLTSTA_CC)) {
145 			pciehp_writew(ctrl, PCI_EXP_SLTSTA, PCI_EXP_SLTSTA_CC);
146 			return 1;
147 		}
148 	}
149 	return 0;	/* timeout */
150 }
151 
152 static void pcie_wait_cmd(struct controller *ctrl, int poll)
153 {
154 	unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
155 	unsigned long timeout = msecs_to_jiffies(msecs);
156 	int rc;
157 
158 	if (poll)
159 		rc = pcie_poll_cmd(ctrl);
160 	else
161 		rc = wait_event_timeout(ctrl->queue, !ctrl->cmd_busy, timeout);
162 	if (!rc)
163 		ctrl_dbg(ctrl, "Command not completed in 1000 msec\n");
164 }
165 
166 /**
167  * pcie_write_cmd - Issue controller command
168  * @ctrl: controller to which the command is issued
169  * @cmd:  command value written to slot control register
170  * @mask: bitmask of slot control register to be modified
171  */
172 static int pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
173 {
174 	int retval = 0;
175 	u16 slot_status;
176 	u16 slot_ctrl;
177 
178 	mutex_lock(&ctrl->ctrl_lock);
179 
180 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
181 	if (retval) {
182 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
183 			 __func__);
184 		goto out;
185 	}
186 
187 	if (slot_status & PCI_EXP_SLTSTA_CC) {
188 		if (!ctrl->no_cmd_complete) {
189 			/*
190 			 * After 1 sec and CMD_COMPLETED still not set, just
191 			 * proceed forward to issue the next command according
192 			 * to spec. Just print out the error message.
193 			 */
194 			ctrl_dbg(ctrl, "CMD_COMPLETED not clear after 1 sec\n");
195 		} else if (!NO_CMD_CMPL(ctrl)) {
196 			/*
197 			 * This controller semms to notify of command completed
198 			 * event even though it supports none of power
199 			 * controller, attention led, power led and EMI.
200 			 */
201 			ctrl_dbg(ctrl, "Unexpected CMD_COMPLETED. Need to "
202 				 "wait for command completed event.\n");
203 			ctrl->no_cmd_complete = 0;
204 		} else {
205 			ctrl_dbg(ctrl, "Unexpected CMD_COMPLETED. Maybe "
206 				 "the controller is broken.\n");
207 		}
208 	}
209 
210 	retval = pciehp_readw(ctrl, PCI_EXP_SLTCTL, &slot_ctrl);
211 	if (retval) {
212 		ctrl_err(ctrl, "%s: Cannot read SLOTCTRL register\n", __func__);
213 		goto out;
214 	}
215 
216 	slot_ctrl &= ~mask;
217 	slot_ctrl |= (cmd & mask);
218 	ctrl->cmd_busy = 1;
219 	smp_mb();
220 	retval = pciehp_writew(ctrl, PCI_EXP_SLTCTL, slot_ctrl);
221 	if (retval)
222 		ctrl_err(ctrl, "Cannot write to SLOTCTRL register\n");
223 
224 	/*
225 	 * Wait for command completion.
226 	 */
227 	if (!retval && !ctrl->no_cmd_complete) {
228 		int poll = 0;
229 		/*
230 		 * if hotplug interrupt is not enabled or command
231 		 * completed interrupt is not enabled, we need to poll
232 		 * command completed event.
233 		 */
234 		if (!(slot_ctrl & PCI_EXP_SLTCTL_HPIE) ||
235 		    !(slot_ctrl & PCI_EXP_SLTCTL_CCIE))
236 			poll = 1;
237                 pcie_wait_cmd(ctrl, poll);
238 	}
239  out:
240 	mutex_unlock(&ctrl->ctrl_lock);
241 	return retval;
242 }
243 
244 static inline int check_link_active(struct controller *ctrl)
245 {
246 	u16 link_status;
247 
248 	if (pciehp_readw(ctrl, PCI_EXP_LNKSTA, &link_status))
249 		return 0;
250 	return !!(link_status & PCI_EXP_LNKSTA_DLLLA);
251 }
252 
253 static void pcie_wait_link_active(struct controller *ctrl)
254 {
255 	int timeout = 1000;
256 
257 	if (check_link_active(ctrl))
258 		return;
259 	while (timeout > 0) {
260 		msleep(10);
261 		timeout -= 10;
262 		if (check_link_active(ctrl))
263 			return;
264 	}
265 	ctrl_dbg(ctrl, "Data Link Layer Link Active not set in 1000 msec\n");
266 }
267 
268 int pciehp_check_link_status(struct controller *ctrl)
269 {
270 	u16 lnk_status;
271 	int retval = 0;
272 
273         /*
274          * Data Link Layer Link Active Reporting must be capable for
275          * hot-plug capable downstream port. But old controller might
276          * not implement it. In this case, we wait for 1000 ms.
277          */
278         if (ctrl->link_active_reporting)
279                 pcie_wait_link_active(ctrl);
280         else
281                 msleep(1000);
282 
283 	/*
284 	 * Need to wait for 1000 ms after Data Link Layer Link Active
285 	 * (DLLLA) bit reads 1b before sending configuration request.
286 	 * We need it before checking Link Training (LT) bit becuase
287 	 * LT is still set even after DLLLA bit is set on some platform.
288 	 */
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 	/*
306 	 * If the port supports Link speeds greater than 5.0 GT/s, we
307 	 * must wait for 100 ms after Link training completes before
308 	 * sending configuration request.
309 	 */
310 	if (ctrl->pcie->port->subordinate->max_bus_speed > PCIE_SPEED_5_0GT)
311 		msleep(100);
312 
313 	pcie_update_link_speed(ctrl->pcie->port->subordinate, lnk_status);
314 
315 	return retval;
316 }
317 
318 int pciehp_get_attention_status(struct slot *slot, u8 *status)
319 {
320 	struct controller *ctrl = slot->ctrl;
321 	u16 slot_ctrl;
322 	u8 atten_led_state;
323 	int retval = 0;
324 
325 	retval = pciehp_readw(ctrl, PCI_EXP_SLTCTL, &slot_ctrl);
326 	if (retval) {
327 		ctrl_err(ctrl, "%s: Cannot read SLOTCTRL register\n", __func__);
328 		return retval;
329 	}
330 
331 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x, value read %x\n", __func__,
332 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
333 
334 	atten_led_state = (slot_ctrl & PCI_EXP_SLTCTL_AIC) >> 6;
335 
336 	switch (atten_led_state) {
337 	case 0:
338 		*status = 0xFF;	/* Reserved */
339 		break;
340 	case 1:
341 		*status = 1;	/* On */
342 		break;
343 	case 2:
344 		*status = 2;	/* Blink */
345 		break;
346 	case 3:
347 		*status = 0;	/* Off */
348 		break;
349 	default:
350 		*status = 0xFF;
351 		break;
352 	}
353 
354 	return 0;
355 }
356 
357 int pciehp_get_power_status(struct slot *slot, u8 *status)
358 {
359 	struct controller *ctrl = slot->ctrl;
360 	u16 slot_ctrl;
361 	u8 pwr_state;
362 	int	retval = 0;
363 
364 	retval = pciehp_readw(ctrl, PCI_EXP_SLTCTL, &slot_ctrl);
365 	if (retval) {
366 		ctrl_err(ctrl, "%s: Cannot read SLOTCTRL register\n", __func__);
367 		return retval;
368 	}
369 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x value read %x\n", __func__,
370 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
371 
372 	pwr_state = (slot_ctrl & PCI_EXP_SLTCTL_PCC) >> 10;
373 
374 	switch (pwr_state) {
375 	case 0:
376 		*status = 1;
377 		break;
378 	case 1:
379 		*status = 0;
380 		break;
381 	default:
382 		*status = 0xFF;
383 		break;
384 	}
385 
386 	return retval;
387 }
388 
389 int pciehp_get_latch_status(struct slot *slot, u8 *status)
390 {
391 	struct controller *ctrl = slot->ctrl;
392 	u16 slot_status;
393 	int retval;
394 
395 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
396 	if (retval) {
397 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
398 			 __func__);
399 		return retval;
400 	}
401 	*status = !!(slot_status & PCI_EXP_SLTSTA_MRLSS);
402 	return 0;
403 }
404 
405 int pciehp_get_adapter_status(struct slot *slot, u8 *status)
406 {
407 	struct controller *ctrl = slot->ctrl;
408 	u16 slot_status;
409 	int retval;
410 
411 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
412 	if (retval) {
413 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
414 			 __func__);
415 		return retval;
416 	}
417 	*status = !!(slot_status & PCI_EXP_SLTSTA_PDS);
418 	return 0;
419 }
420 
421 int pciehp_query_power_fault(struct slot *slot)
422 {
423 	struct controller *ctrl = slot->ctrl;
424 	u16 slot_status;
425 	int retval;
426 
427 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
428 	if (retval) {
429 		ctrl_err(ctrl, "Cannot check for power fault\n");
430 		return retval;
431 	}
432 	return !!(slot_status & PCI_EXP_SLTSTA_PFD);
433 }
434 
435 int pciehp_set_attention_status(struct slot *slot, u8 value)
436 {
437 	struct controller *ctrl = slot->ctrl;
438 	u16 slot_cmd;
439 	u16 cmd_mask;
440 
441 	cmd_mask = PCI_EXP_SLTCTL_AIC;
442 	switch (value) {
443 	case 0 :	/* turn off */
444 		slot_cmd = 0x00C0;
445 		break;
446 	case 1:		/* turn on */
447 		slot_cmd = 0x0040;
448 		break;
449 	case 2:		/* turn blink */
450 		slot_cmd = 0x0080;
451 		break;
452 	default:
453 		return -EINVAL;
454 	}
455 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
456 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
457 	return pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
458 }
459 
460 void pciehp_green_led_on(struct slot *slot)
461 {
462 	struct controller *ctrl = slot->ctrl;
463 	u16 slot_cmd;
464 	u16 cmd_mask;
465 
466 	slot_cmd = 0x0100;
467 	cmd_mask = PCI_EXP_SLTCTL_PIC;
468 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
469 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
470 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
471 }
472 
473 void pciehp_green_led_off(struct slot *slot)
474 {
475 	struct controller *ctrl = slot->ctrl;
476 	u16 slot_cmd;
477 	u16 cmd_mask;
478 
479 	slot_cmd = 0x0300;
480 	cmd_mask = PCI_EXP_SLTCTL_PIC;
481 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
482 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
483 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
484 }
485 
486 void pciehp_green_led_blink(struct slot *slot)
487 {
488 	struct controller *ctrl = slot->ctrl;
489 	u16 slot_cmd;
490 	u16 cmd_mask;
491 
492 	slot_cmd = 0x0200;
493 	cmd_mask = PCI_EXP_SLTCTL_PIC;
494 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
495 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
496 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
497 }
498 
499 int pciehp_power_on_slot(struct slot * slot)
500 {
501 	struct controller *ctrl = slot->ctrl;
502 	u16 slot_cmd;
503 	u16 cmd_mask;
504 	u16 slot_status;
505 	int retval = 0;
506 
507 	/* Clear sticky power-fault bit from previous power failures */
508 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
509 	if (retval) {
510 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
511 			 __func__);
512 		return retval;
513 	}
514 	slot_status &= PCI_EXP_SLTSTA_PFD;
515 	if (slot_status) {
516 		retval = pciehp_writew(ctrl, PCI_EXP_SLTSTA, slot_status);
517 		if (retval) {
518 			ctrl_err(ctrl,
519 				 "%s: Cannot write to SLOTSTATUS register\n",
520 				 __func__);
521 			return retval;
522 		}
523 	}
524 	ctrl->power_fault_detected = 0;
525 
526 	slot_cmd = POWER_ON;
527 	cmd_mask = PCI_EXP_SLTCTL_PCC;
528 	retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
529 	if (retval) {
530 		ctrl_err(ctrl, "Write %x command failed!\n", slot_cmd);
531 		return retval;
532 	}
533 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
534 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
535 
536 	return retval;
537 }
538 
539 int pciehp_power_off_slot(struct slot * slot)
540 {
541 	struct controller *ctrl = slot->ctrl;
542 	u16 slot_cmd;
543 	u16 cmd_mask;
544 	int retval;
545 
546 	slot_cmd = POWER_OFF;
547 	cmd_mask = PCI_EXP_SLTCTL_PCC;
548 	retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
549 	if (retval) {
550 		ctrl_err(ctrl, "Write command failed!\n");
551 		return retval;
552 	}
553 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
554 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
555 	return 0;
556 }
557 
558 static irqreturn_t pcie_isr(int irq, void *dev_id)
559 {
560 	struct controller *ctrl = (struct controller *)dev_id;
561 	struct slot *slot = ctrl->slot;
562 	u16 detected, intr_loc;
563 
564 	/*
565 	 * In order to guarantee that all interrupt events are
566 	 * serviced, we need to re-inspect Slot Status register after
567 	 * clearing what is presumed to be the last pending interrupt.
568 	 */
569 	intr_loc = 0;
570 	do {
571 		if (pciehp_readw(ctrl, PCI_EXP_SLTSTA, &detected)) {
572 			ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS\n",
573 				 __func__);
574 			return IRQ_NONE;
575 		}
576 
577 		detected &= (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
578 			     PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC |
579 			     PCI_EXP_SLTSTA_CC);
580 		detected &= ~intr_loc;
581 		intr_loc |= detected;
582 		if (!intr_loc)
583 			return IRQ_NONE;
584 		if (detected && pciehp_writew(ctrl, PCI_EXP_SLTSTA, intr_loc)) {
585 			ctrl_err(ctrl, "%s: Cannot write to SLOTSTATUS\n",
586 				 __func__);
587 			return IRQ_NONE;
588 		}
589 	} while (detected);
590 
591 	ctrl_dbg(ctrl, "%s: intr_loc %x\n", __func__, intr_loc);
592 
593 	/* Check Command Complete Interrupt Pending */
594 	if (intr_loc & PCI_EXP_SLTSTA_CC) {
595 		ctrl->cmd_busy = 0;
596 		smp_mb();
597 		wake_up(&ctrl->queue);
598 	}
599 
600 	if (!(intr_loc & ~PCI_EXP_SLTSTA_CC))
601 		return IRQ_HANDLED;
602 
603 	/* Check MRL Sensor Changed */
604 	if (intr_loc & PCI_EXP_SLTSTA_MRLSC)
605 		pciehp_handle_switch_change(slot);
606 
607 	/* Check Attention Button Pressed */
608 	if (intr_loc & PCI_EXP_SLTSTA_ABP)
609 		pciehp_handle_attention_button(slot);
610 
611 	/* Check Presence Detect Changed */
612 	if (intr_loc & PCI_EXP_SLTSTA_PDC)
613 		pciehp_handle_presence_change(slot);
614 
615 	/* Check Power Fault Detected */
616 	if ((intr_loc & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
617 		ctrl->power_fault_detected = 1;
618 		pciehp_handle_power_fault(slot);
619 	}
620 	return IRQ_HANDLED;
621 }
622 
623 int pciehp_get_max_lnk_width(struct slot *slot,
624 				 enum pcie_link_width *value)
625 {
626 	struct controller *ctrl = slot->ctrl;
627 	enum pcie_link_width lnk_wdth;
628 	u32	lnk_cap;
629 	int retval = 0;
630 
631 	retval = pciehp_readl(ctrl, PCI_EXP_LNKCAP, &lnk_cap);
632 	if (retval) {
633 		ctrl_err(ctrl, "%s: Cannot read LNKCAP register\n", __func__);
634 		return retval;
635 	}
636 
637 	switch ((lnk_cap & PCI_EXP_LNKSTA_NLW) >> 4){
638 	case 0:
639 		lnk_wdth = PCIE_LNK_WIDTH_RESRV;
640 		break;
641 	case 1:
642 		lnk_wdth = PCIE_LNK_X1;
643 		break;
644 	case 2:
645 		lnk_wdth = PCIE_LNK_X2;
646 		break;
647 	case 4:
648 		lnk_wdth = PCIE_LNK_X4;
649 		break;
650 	case 8:
651 		lnk_wdth = PCIE_LNK_X8;
652 		break;
653 	case 12:
654 		lnk_wdth = PCIE_LNK_X12;
655 		break;
656 	case 16:
657 		lnk_wdth = PCIE_LNK_X16;
658 		break;
659 	case 32:
660 		lnk_wdth = PCIE_LNK_X32;
661 		break;
662 	default:
663 		lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
664 		break;
665 	}
666 
667 	*value = lnk_wdth;
668 	ctrl_dbg(ctrl, "Max link width = %d\n", lnk_wdth);
669 
670 	return retval;
671 }
672 
673 int pciehp_get_cur_lnk_width(struct slot *slot,
674 				 enum pcie_link_width *value)
675 {
676 	struct controller *ctrl = slot->ctrl;
677 	enum pcie_link_width lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
678 	int retval = 0;
679 	u16 lnk_status;
680 
681 	retval = pciehp_readw(ctrl, PCI_EXP_LNKSTA, &lnk_status);
682 	if (retval) {
683 		ctrl_err(ctrl, "%s: Cannot read LNKSTATUS register\n",
684 			 __func__);
685 		return retval;
686 	}
687 
688 	switch ((lnk_status & PCI_EXP_LNKSTA_NLW) >> 4){
689 	case 0:
690 		lnk_wdth = PCIE_LNK_WIDTH_RESRV;
691 		break;
692 	case 1:
693 		lnk_wdth = PCIE_LNK_X1;
694 		break;
695 	case 2:
696 		lnk_wdth = PCIE_LNK_X2;
697 		break;
698 	case 4:
699 		lnk_wdth = PCIE_LNK_X4;
700 		break;
701 	case 8:
702 		lnk_wdth = PCIE_LNK_X8;
703 		break;
704 	case 12:
705 		lnk_wdth = PCIE_LNK_X12;
706 		break;
707 	case 16:
708 		lnk_wdth = PCIE_LNK_X16;
709 		break;
710 	case 32:
711 		lnk_wdth = PCIE_LNK_X32;
712 		break;
713 	default:
714 		lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
715 		break;
716 	}
717 
718 	*value = lnk_wdth;
719 	ctrl_dbg(ctrl, "Current link width = %d\n", lnk_wdth);
720 
721 	return retval;
722 }
723 
724 int pcie_enable_notification(struct controller *ctrl)
725 {
726 	u16 cmd, mask;
727 
728 	/*
729 	 * TBD: Power fault detected software notification support.
730 	 *
731 	 * Power fault detected software notification is not enabled
732 	 * now, because it caused power fault detected interrupt storm
733 	 * on some machines. On those machines, power fault detected
734 	 * bit in the slot status register was set again immediately
735 	 * when it is cleared in the interrupt service routine, and
736 	 * next power fault detected interrupt was notified again.
737 	 */
738 	cmd = PCI_EXP_SLTCTL_PDCE;
739 	if (ATTN_BUTTN(ctrl))
740 		cmd |= PCI_EXP_SLTCTL_ABPE;
741 	if (MRL_SENS(ctrl))
742 		cmd |= PCI_EXP_SLTCTL_MRLSCE;
743 	if (!pciehp_poll_mode)
744 		cmd |= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE;
745 
746 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
747 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
748 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE);
749 
750 	if (pcie_write_cmd(ctrl, cmd, mask)) {
751 		ctrl_err(ctrl, "Cannot enable software notification\n");
752 		return -1;
753 	}
754 	return 0;
755 }
756 
757 static void pcie_disable_notification(struct controller *ctrl)
758 {
759 	u16 mask;
760 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
761 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
762 		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
763 		PCI_EXP_SLTCTL_DLLSCE);
764 	if (pcie_write_cmd(ctrl, 0, mask))
765 		ctrl_warn(ctrl, "Cannot disable software notification\n");
766 }
767 
768 int pcie_init_notification(struct controller *ctrl)
769 {
770 	if (pciehp_request_irq(ctrl))
771 		return -1;
772 	if (pcie_enable_notification(ctrl)) {
773 		pciehp_free_irq(ctrl);
774 		return -1;
775 	}
776 	ctrl->notification_enabled = 1;
777 	return 0;
778 }
779 
780 static void pcie_shutdown_notification(struct controller *ctrl)
781 {
782 	if (ctrl->notification_enabled) {
783 		pcie_disable_notification(ctrl);
784 		pciehp_free_irq(ctrl);
785 		ctrl->notification_enabled = 0;
786 	}
787 }
788 
789 static int pcie_init_slot(struct controller *ctrl)
790 {
791 	struct slot *slot;
792 
793 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
794 	if (!slot)
795 		return -ENOMEM;
796 
797 	slot->ctrl = ctrl;
798 	mutex_init(&slot->lock);
799 	INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
800 	ctrl->slot = slot;
801 	return 0;
802 }
803 
804 static void pcie_cleanup_slot(struct controller *ctrl)
805 {
806 	struct slot *slot = ctrl->slot;
807 	cancel_delayed_work(&slot->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]     : %pR\n",
836 			  i, &pdev->resource[i]);
837 	}
838 	ctrl_info(ctrl, "Slot Capabilities      : 0x%08x\n", ctrl->slot_cap);
839 	ctrl_info(ctrl, "  Physical Slot Number : %d\n", PSN(ctrl));
840 	ctrl_info(ctrl, "  Attention Button     : %3s\n",
841 		  ATTN_BUTTN(ctrl) ? "yes" : "no");
842 	ctrl_info(ctrl, "  Power Controller     : %3s\n",
843 		  POWER_CTRL(ctrl) ? "yes" : "no");
844 	ctrl_info(ctrl, "  MRL Sensor           : %3s\n",
845 		  MRL_SENS(ctrl)   ? "yes" : "no");
846 	ctrl_info(ctrl, "  Attention Indicator  : %3s\n",
847 		  ATTN_LED(ctrl)   ? "yes" : "no");
848 	ctrl_info(ctrl, "  Power Indicator      : %3s\n",
849 		  PWR_LED(ctrl)    ? "yes" : "no");
850 	ctrl_info(ctrl, "  Hot-Plug Surprise    : %3s\n",
851 		  HP_SUPR_RM(ctrl) ? "yes" : "no");
852 	ctrl_info(ctrl, "  EMI Present          : %3s\n",
853 		  EMI(ctrl)        ? "yes" : "no");
854 	ctrl_info(ctrl, "  Command Completed    : %3s\n",
855 		  NO_CMD_CMPL(ctrl) ? "no" : "yes");
856 	pciehp_readw(ctrl, PCI_EXP_SLTSTA, &reg16);
857 	ctrl_info(ctrl, "Slot Status            : 0x%04x\n", reg16);
858 	pciehp_readw(ctrl, PCI_EXP_SLTCTL, &reg16);
859 	ctrl_info(ctrl, "Slot Control           : 0x%04x\n", reg16);
860 }
861 
862 struct controller *pcie_init(struct pcie_device *dev)
863 {
864 	struct controller *ctrl;
865 	u32 slot_cap, link_cap;
866 	struct pci_dev *pdev = dev->port;
867 
868 	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
869 	if (!ctrl) {
870 		dev_err(&dev->device, "%s: Out of memory\n", __func__);
871 		goto abort;
872 	}
873 	ctrl->pcie = dev;
874 	if (!pci_pcie_cap(pdev)) {
875 		ctrl_err(ctrl, "Cannot find PCI Express capability\n");
876 		goto abort_ctrl;
877 	}
878 	if (pciehp_readl(ctrl, PCI_EXP_SLTCAP, &slot_cap)) {
879 		ctrl_err(ctrl, "Cannot read SLOTCAP register\n");
880 		goto abort_ctrl;
881 	}
882 
883 	ctrl->slot_cap = slot_cap;
884 	mutex_init(&ctrl->ctrl_lock);
885 	init_waitqueue_head(&ctrl->queue);
886 	dbg_ctrl(ctrl);
887 	/*
888 	 * Controller doesn't notify of command completion if the "No
889 	 * Command Completed Support" bit is set in Slot Capability
890 	 * register or the controller supports none of power
891 	 * controller, attention led, power led and EMI.
892 	 */
893 	if (NO_CMD_CMPL(ctrl) ||
894 	    !(POWER_CTRL(ctrl) | ATTN_LED(ctrl) | PWR_LED(ctrl) | EMI(ctrl)))
895 	    ctrl->no_cmd_complete = 1;
896 
897         /* Check if Data Link Layer Link Active Reporting is implemented */
898         if (pciehp_readl(ctrl, PCI_EXP_LNKCAP, &link_cap)) {
899                 ctrl_err(ctrl, "%s: Cannot read LNKCAP register\n", __func__);
900                 goto abort_ctrl;
901         }
902         if (link_cap & PCI_EXP_LNKCAP_DLLLARC) {
903                 ctrl_dbg(ctrl, "Link Active Reporting supported\n");
904                 ctrl->link_active_reporting = 1;
905         }
906 
907 	/* Clear all remaining event bits in Slot Status register */
908 	if (pciehp_writew(ctrl, PCI_EXP_SLTSTA, 0x1f))
909 		goto abort_ctrl;
910 
911 	/* Disable sotfware notification */
912 	pcie_disable_notification(ctrl);
913 
914 	ctrl_info(ctrl, "HPC vendor_id %x device_id %x ss_vid %x ss_did %x\n",
915 		  pdev->vendor, pdev->device, pdev->subsystem_vendor,
916 		  pdev->subsystem_device);
917 
918 	if (pcie_init_slot(ctrl))
919 		goto abort_ctrl;
920 
921 	return ctrl;
922 
923 abort_ctrl:
924 	kfree(ctrl);
925 abort:
926 	return NULL;
927 }
928 
929 void pciehp_release_ctrl(struct controller *ctrl)
930 {
931 	pcie_shutdown_notification(ctrl);
932 	pcie_cleanup_slot(ctrl);
933 	kfree(ctrl);
934 }
935