xref: /linux/drivers/pci/hotplug/pciehp_hpc.c (revision cc4589ebfae6f8dbb5cf880a0a67eedab3416492)
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 atomic_t pciehp_num_controllers = ATOMIC_INIT(0);
45 
46 static inline int pciehp_readw(struct controller *ctrl, int reg, u16 *value)
47 {
48 	struct pci_dev *dev = ctrl->pcie->port;
49 	return pci_read_config_word(dev, pci_pcie_cap(dev) + reg, value);
50 }
51 
52 static inline int pciehp_readl(struct controller *ctrl, int reg, u32 *value)
53 {
54 	struct pci_dev *dev = ctrl->pcie->port;
55 	return pci_read_config_dword(dev, pci_pcie_cap(dev) + reg, value);
56 }
57 
58 static inline int pciehp_writew(struct controller *ctrl, int reg, u16 value)
59 {
60 	struct pci_dev *dev = ctrl->pcie->port;
61 	return pci_write_config_word(dev, pci_pcie_cap(dev) + reg, value);
62 }
63 
64 static inline int pciehp_writel(struct controller *ctrl, int reg, u32 value)
65 {
66 	struct pci_dev *dev = ctrl->pcie->port;
67 	return pci_write_config_dword(dev, pci_pcie_cap(dev) + reg, value);
68 }
69 
70 /* Power Control Command */
71 #define POWER_ON	0
72 #define POWER_OFF	PCI_EXP_SLTCTL_PCC
73 
74 static irqreturn_t pcie_isr(int irq, void *dev_id);
75 static void start_int_poll_timer(struct controller *ctrl, int sec);
76 
77 /* This is the interrupt polling timeout function. */
78 static void int_poll_timeout(unsigned long data)
79 {
80 	struct controller *ctrl = (struct controller *)data;
81 
82 	/* Poll for interrupt events.  regs == NULL => polling */
83 	pcie_isr(0, ctrl);
84 
85 	init_timer(&ctrl->poll_timer);
86 	if (!pciehp_poll_time)
87 		pciehp_poll_time = 2; /* default polling interval is 2 sec */
88 
89 	start_int_poll_timer(ctrl, pciehp_poll_time);
90 }
91 
92 /* This function starts the interrupt polling timer. */
93 static void start_int_poll_timer(struct controller *ctrl, int sec)
94 {
95 	/* Clamp to sane value */
96 	if ((sec <= 0) || (sec > 60))
97         	sec = 2;
98 
99 	ctrl->poll_timer.function = &int_poll_timeout;
100 	ctrl->poll_timer.data = (unsigned long)ctrl;
101 	ctrl->poll_timer.expires = jiffies + sec * HZ;
102 	add_timer(&ctrl->poll_timer);
103 }
104 
105 static inline int pciehp_request_irq(struct controller *ctrl)
106 {
107 	int retval, irq = ctrl->pcie->irq;
108 
109 	/* Install interrupt polling timer. Start with 10 sec delay */
110 	if (pciehp_poll_mode) {
111 		init_timer(&ctrl->poll_timer);
112 		start_int_poll_timer(ctrl, 10);
113 		return 0;
114 	}
115 
116 	/* Installs the interrupt handler */
117 	retval = request_irq(irq, pcie_isr, IRQF_SHARED, MY_NAME, ctrl);
118 	if (retval)
119 		ctrl_err(ctrl, "Cannot get irq %d for the hotplug controller\n",
120 			 irq);
121 	return retval;
122 }
123 
124 static inline void pciehp_free_irq(struct controller *ctrl)
125 {
126 	if (pciehp_poll_mode)
127 		del_timer_sync(&ctrl->poll_timer);
128 	else
129 		free_irq(ctrl->pcie->irq, ctrl);
130 }
131 
132 static int pcie_poll_cmd(struct controller *ctrl)
133 {
134 	u16 slot_status;
135 	int err, timeout = 1000;
136 
137 	err = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
138 	if (!err && (slot_status & PCI_EXP_SLTSTA_CC)) {
139 		pciehp_writew(ctrl, PCI_EXP_SLTSTA, PCI_EXP_SLTSTA_CC);
140 		return 1;
141 	}
142 	while (timeout > 0) {
143 		msleep(10);
144 		timeout -= 10;
145 		err = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
146 		if (!err && (slot_status & PCI_EXP_SLTSTA_CC)) {
147 			pciehp_writew(ctrl, PCI_EXP_SLTSTA, PCI_EXP_SLTSTA_CC);
148 			return 1;
149 		}
150 	}
151 	return 0;	/* timeout */
152 }
153 
154 static void pcie_wait_cmd(struct controller *ctrl, int poll)
155 {
156 	unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
157 	unsigned long timeout = msecs_to_jiffies(msecs);
158 	int rc;
159 
160 	if (poll)
161 		rc = pcie_poll_cmd(ctrl);
162 	else
163 		rc = wait_event_timeout(ctrl->queue, !ctrl->cmd_busy, timeout);
164 	if (!rc)
165 		ctrl_dbg(ctrl, "Command not completed in 1000 msec\n");
166 }
167 
168 /**
169  * pcie_write_cmd - Issue controller command
170  * @ctrl: controller to which the command is issued
171  * @cmd:  command value written to slot control register
172  * @mask: bitmask of slot control register to be modified
173  */
174 static int pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
175 {
176 	int retval = 0;
177 	u16 slot_status;
178 	u16 slot_ctrl;
179 
180 	mutex_lock(&ctrl->ctrl_lock);
181 
182 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
183 	if (retval) {
184 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
185 			 __func__);
186 		goto out;
187 	}
188 
189 	if (slot_status & PCI_EXP_SLTSTA_CC) {
190 		if (!ctrl->no_cmd_complete) {
191 			/*
192 			 * After 1 sec and CMD_COMPLETED still not set, just
193 			 * proceed forward to issue the next command according
194 			 * to spec. Just print out the error message.
195 			 */
196 			ctrl_dbg(ctrl, "CMD_COMPLETED not clear after 1 sec\n");
197 		} else if (!NO_CMD_CMPL(ctrl)) {
198 			/*
199 			 * This controller semms to notify of command completed
200 			 * event even though it supports none of power
201 			 * controller, attention led, power led and EMI.
202 			 */
203 			ctrl_dbg(ctrl, "Unexpected CMD_COMPLETED. Need to "
204 				 "wait for command completed event.\n");
205 			ctrl->no_cmd_complete = 0;
206 		} else {
207 			ctrl_dbg(ctrl, "Unexpected CMD_COMPLETED. Maybe "
208 				 "the controller is broken.\n");
209 		}
210 	}
211 
212 	retval = pciehp_readw(ctrl, PCI_EXP_SLTCTL, &slot_ctrl);
213 	if (retval) {
214 		ctrl_err(ctrl, "%s: Cannot read SLOTCTRL register\n", __func__);
215 		goto out;
216 	}
217 
218 	slot_ctrl &= ~mask;
219 	slot_ctrl |= (cmd & mask);
220 	ctrl->cmd_busy = 1;
221 	smp_mb();
222 	retval = pciehp_writew(ctrl, PCI_EXP_SLTCTL, slot_ctrl);
223 	if (retval)
224 		ctrl_err(ctrl, "Cannot write to SLOTCTRL register\n");
225 
226 	/*
227 	 * Wait for command completion.
228 	 */
229 	if (!retval && !ctrl->no_cmd_complete) {
230 		int poll = 0;
231 		/*
232 		 * if hotplug interrupt is not enabled or command
233 		 * completed interrupt is not enabled, we need to poll
234 		 * command completed event.
235 		 */
236 		if (!(slot_ctrl & PCI_EXP_SLTCTL_HPIE) ||
237 		    !(slot_ctrl & PCI_EXP_SLTCTL_CCIE))
238 			poll = 1;
239                 pcie_wait_cmd(ctrl, poll);
240 	}
241  out:
242 	mutex_unlock(&ctrl->ctrl_lock);
243 	return retval;
244 }
245 
246 static inline int check_link_active(struct controller *ctrl)
247 {
248 	u16 link_status;
249 
250 	if (pciehp_readw(ctrl, PCI_EXP_LNKSTA, &link_status))
251 		return 0;
252 	return !!(link_status & PCI_EXP_LNKSTA_DLLLA);
253 }
254 
255 static void pcie_wait_link_active(struct controller *ctrl)
256 {
257 	int timeout = 1000;
258 
259 	if (check_link_active(ctrl))
260 		return;
261 	while (timeout > 0) {
262 		msleep(10);
263 		timeout -= 10;
264 		if (check_link_active(ctrl))
265 			return;
266 	}
267 	ctrl_dbg(ctrl, "Data Link Layer Link Active not set in 1000 msec\n");
268 }
269 
270 int pciehp_check_link_status(struct controller *ctrl)
271 {
272 	u16 lnk_status;
273 	int retval = 0;
274 
275         /*
276          * Data Link Layer Link Active Reporting must be capable for
277          * hot-plug capable downstream port. But old controller might
278          * not implement it. In this case, we wait for 1000 ms.
279          */
280         if (ctrl->link_active_reporting){
281                 /* Wait for Data Link Layer Link Active bit to be set */
282                 pcie_wait_link_active(ctrl);
283                 /*
284                  * We must wait for 100 ms after the Data Link Layer
285                  * Link Active bit reads 1b before initiating a
286                  * configuration access to the hot added device.
287                  */
288                 msleep(100);
289         } else
290                 msleep(1000);
291 
292 	retval = pciehp_readw(ctrl, PCI_EXP_LNKSTA, &lnk_status);
293 	if (retval) {
294 		ctrl_err(ctrl, "Cannot read LNKSTATUS register\n");
295 		return retval;
296 	}
297 
298 	ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
299 	if ((lnk_status & PCI_EXP_LNKSTA_LT) ||
300 	    !(lnk_status & PCI_EXP_LNKSTA_NLW)) {
301 		ctrl_err(ctrl, "Link Training Error occurs \n");
302 		retval = -1;
303 		return retval;
304 	}
305 
306 	return retval;
307 }
308 
309 int pciehp_get_attention_status(struct slot *slot, u8 *status)
310 {
311 	struct controller *ctrl = slot->ctrl;
312 	u16 slot_ctrl;
313 	u8 atten_led_state;
314 	int retval = 0;
315 
316 	retval = pciehp_readw(ctrl, PCI_EXP_SLTCTL, &slot_ctrl);
317 	if (retval) {
318 		ctrl_err(ctrl, "%s: Cannot read SLOTCTRL register\n", __func__);
319 		return retval;
320 	}
321 
322 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x, value read %x\n", __func__,
323 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
324 
325 	atten_led_state = (slot_ctrl & PCI_EXP_SLTCTL_AIC) >> 6;
326 
327 	switch (atten_led_state) {
328 	case 0:
329 		*status = 0xFF;	/* Reserved */
330 		break;
331 	case 1:
332 		*status = 1;	/* On */
333 		break;
334 	case 2:
335 		*status = 2;	/* Blink */
336 		break;
337 	case 3:
338 		*status = 0;	/* Off */
339 		break;
340 	default:
341 		*status = 0xFF;
342 		break;
343 	}
344 
345 	return 0;
346 }
347 
348 int pciehp_get_power_status(struct slot *slot, u8 *status)
349 {
350 	struct controller *ctrl = slot->ctrl;
351 	u16 slot_ctrl;
352 	u8 pwr_state;
353 	int	retval = 0;
354 
355 	retval = pciehp_readw(ctrl, PCI_EXP_SLTCTL, &slot_ctrl);
356 	if (retval) {
357 		ctrl_err(ctrl, "%s: Cannot read SLOTCTRL register\n", __func__);
358 		return retval;
359 	}
360 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x value read %x\n", __func__,
361 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
362 
363 	pwr_state = (slot_ctrl & PCI_EXP_SLTCTL_PCC) >> 10;
364 
365 	switch (pwr_state) {
366 	case 0:
367 		*status = 1;
368 		break;
369 	case 1:
370 		*status = 0;
371 		break;
372 	default:
373 		*status = 0xFF;
374 		break;
375 	}
376 
377 	return retval;
378 }
379 
380 int pciehp_get_latch_status(struct slot *slot, u8 *status)
381 {
382 	struct controller *ctrl = slot->ctrl;
383 	u16 slot_status;
384 	int retval;
385 
386 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
387 	if (retval) {
388 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
389 			 __func__);
390 		return retval;
391 	}
392 	*status = !!(slot_status & PCI_EXP_SLTSTA_MRLSS);
393 	return 0;
394 }
395 
396 int pciehp_get_adapter_status(struct slot *slot, u8 *status)
397 {
398 	struct controller *ctrl = slot->ctrl;
399 	u16 slot_status;
400 	int retval;
401 
402 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
403 	if (retval) {
404 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
405 			 __func__);
406 		return retval;
407 	}
408 	*status = !!(slot_status & PCI_EXP_SLTSTA_PDS);
409 	return 0;
410 }
411 
412 int pciehp_query_power_fault(struct slot *slot)
413 {
414 	struct controller *ctrl = slot->ctrl;
415 	u16 slot_status;
416 	int retval;
417 
418 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
419 	if (retval) {
420 		ctrl_err(ctrl, "Cannot check for power fault\n");
421 		return retval;
422 	}
423 	return !!(slot_status & PCI_EXP_SLTSTA_PFD);
424 }
425 
426 int pciehp_set_attention_status(struct slot *slot, u8 value)
427 {
428 	struct controller *ctrl = slot->ctrl;
429 	u16 slot_cmd;
430 	u16 cmd_mask;
431 
432 	cmd_mask = PCI_EXP_SLTCTL_AIC;
433 	switch (value) {
434 	case 0 :	/* turn off */
435 		slot_cmd = 0x00C0;
436 		break;
437 	case 1:		/* turn on */
438 		slot_cmd = 0x0040;
439 		break;
440 	case 2:		/* turn blink */
441 		slot_cmd = 0x0080;
442 		break;
443 	default:
444 		return -EINVAL;
445 	}
446 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
447 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
448 	return pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
449 }
450 
451 void pciehp_green_led_on(struct slot *slot)
452 {
453 	struct controller *ctrl = slot->ctrl;
454 	u16 slot_cmd;
455 	u16 cmd_mask;
456 
457 	slot_cmd = 0x0100;
458 	cmd_mask = PCI_EXP_SLTCTL_PIC;
459 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
460 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
461 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
462 }
463 
464 void pciehp_green_led_off(struct slot *slot)
465 {
466 	struct controller *ctrl = slot->ctrl;
467 	u16 slot_cmd;
468 	u16 cmd_mask;
469 
470 	slot_cmd = 0x0300;
471 	cmd_mask = PCI_EXP_SLTCTL_PIC;
472 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
473 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
474 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
475 }
476 
477 void pciehp_green_led_blink(struct slot *slot)
478 {
479 	struct controller *ctrl = slot->ctrl;
480 	u16 slot_cmd;
481 	u16 cmd_mask;
482 
483 	slot_cmd = 0x0200;
484 	cmd_mask = PCI_EXP_SLTCTL_PIC;
485 	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
486 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
487 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
488 }
489 
490 int pciehp_power_on_slot(struct slot * slot)
491 {
492 	struct controller *ctrl = slot->ctrl;
493 	u16 slot_cmd;
494 	u16 cmd_mask;
495 	u16 slot_status;
496 	u16 lnk_status;
497 	int retval = 0;
498 
499 	/* Clear sticky power-fault bit from previous power failures */
500 	retval = pciehp_readw(ctrl, PCI_EXP_SLTSTA, &slot_status);
501 	if (retval) {
502 		ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n",
503 			 __func__);
504 		return retval;
505 	}
506 	slot_status &= PCI_EXP_SLTSTA_PFD;
507 	if (slot_status) {
508 		retval = pciehp_writew(ctrl, PCI_EXP_SLTSTA, slot_status);
509 		if (retval) {
510 			ctrl_err(ctrl,
511 				 "%s: Cannot write to SLOTSTATUS register\n",
512 				 __func__);
513 			return retval;
514 		}
515 	}
516 	ctrl->power_fault_detected = 0;
517 
518 	slot_cmd = POWER_ON;
519 	cmd_mask = PCI_EXP_SLTCTL_PCC;
520 	retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
521 	if (retval) {
522 		ctrl_err(ctrl, "Write %x command failed!\n", slot_cmd);
523 		return retval;
524 	}
525 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
526 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
527 
528 	retval = pciehp_readw(ctrl, PCI_EXP_LNKSTA, &lnk_status);
529 	if (retval) {
530 		ctrl_err(ctrl, "%s: Cannot read LNKSTA register\n",
531 				__func__);
532 		return retval;
533 	}
534 	pcie_update_link_speed(ctrl->pcie->port->subordinate, lnk_status);
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_scheduled_work();
809 	flush_workqueue(pciehp_wq);
810 	kfree(slot);
811 }
812 
813 static inline void dbg_ctrl(struct controller *ctrl)
814 {
815 	int i;
816 	u16 reg16;
817 	struct pci_dev *pdev = ctrl->pcie->port;
818 
819 	if (!pciehp_debug)
820 		return;
821 
822 	ctrl_info(ctrl, "Hotplug Controller:\n");
823 	ctrl_info(ctrl, "  Seg/Bus/Dev/Func/IRQ : %s IRQ %d\n",
824 		  pci_name(pdev), pdev->irq);
825 	ctrl_info(ctrl, "  Vendor ID            : 0x%04x\n", pdev->vendor);
826 	ctrl_info(ctrl, "  Device ID            : 0x%04x\n", pdev->device);
827 	ctrl_info(ctrl, "  Subsystem ID         : 0x%04x\n",
828 		  pdev->subsystem_device);
829 	ctrl_info(ctrl, "  Subsystem Vendor ID  : 0x%04x\n",
830 		  pdev->subsystem_vendor);
831 	ctrl_info(ctrl, "  PCIe Cap offset      : 0x%02x\n",
832 		  pci_pcie_cap(pdev));
833 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
834 		if (!pci_resource_len(pdev, i))
835 			continue;
836 		ctrl_info(ctrl, "  PCI resource [%d]     : %pR\n",
837 			  i, &pdev->resource[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