1 /*
2  * PCI Express Hot Plug Controller 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/module.h>
31 #include <linux/moduleparam.h>
32 #include <linux/kernel.h>
33 #include <linux/types.h>
34 #include <linux/pci.h>
35 #include "pciehp.h"
36 #include <linux/interrupt.h>
37 #include <linux/time.h>
38 
39 /* Global variables */
40 int pciehp_debug;
41 int pciehp_poll_mode;
42 int pciehp_poll_time;
43 int pciehp_force;
44 struct workqueue_struct *pciehp_wq;
45 
46 #define DRIVER_VERSION	"0.4"
47 #define DRIVER_AUTHOR	"Dan Zink <dan.zink@compaq.com>, Greg Kroah-Hartman <greg@kroah.com>, Dely Sy <dely.l.sy@intel.com>"
48 #define DRIVER_DESC	"PCI Express Hot Plug Controller Driver"
49 
50 MODULE_AUTHOR(DRIVER_AUTHOR);
51 MODULE_DESCRIPTION(DRIVER_DESC);
52 MODULE_LICENSE("GPL");
53 
54 module_param(pciehp_debug, bool, 0644);
55 module_param(pciehp_poll_mode, bool, 0644);
56 module_param(pciehp_poll_time, int, 0644);
57 module_param(pciehp_force, bool, 0644);
58 MODULE_PARM_DESC(pciehp_debug, "Debugging mode enabled or not");
59 MODULE_PARM_DESC(pciehp_poll_mode, "Using polling mechanism for hot-plug events or not");
60 MODULE_PARM_DESC(pciehp_poll_time, "Polling mechanism frequency, in seconds");
61 MODULE_PARM_DESC(pciehp_force, "Force pciehp, even if _OSC and OSHP are missing");
62 
63 #define PCIE_MODULE_NAME "pciehp"
64 
65 static int set_attention_status (struct hotplug_slot *slot, u8 value);
66 static int enable_slot		(struct hotplug_slot *slot);
67 static int disable_slot		(struct hotplug_slot *slot);
68 static int get_power_status	(struct hotplug_slot *slot, u8 *value);
69 static int get_attention_status	(struct hotplug_slot *slot, u8 *value);
70 static int get_latch_status	(struct hotplug_slot *slot, u8 *value);
71 static int get_adapter_status	(struct hotplug_slot *slot, u8 *value);
72 static int get_max_bus_speed	(struct hotplug_slot *slot, enum pci_bus_speed *value);
73 static int get_cur_bus_speed	(struct hotplug_slot *slot, enum pci_bus_speed *value);
74 
75 static struct hotplug_slot_ops pciehp_hotplug_slot_ops = {
76 	.owner =		THIS_MODULE,
77 	.set_attention_status =	set_attention_status,
78 	.enable_slot =		enable_slot,
79 	.disable_slot =		disable_slot,
80 	.get_power_status =	get_power_status,
81 	.get_attention_status =	get_attention_status,
82 	.get_latch_status =	get_latch_status,
83 	.get_adapter_status =	get_adapter_status,
84   	.get_max_bus_speed =	get_max_bus_speed,
85   	.get_cur_bus_speed =	get_cur_bus_speed,
86 };
87 
88 /*
89  * Check the status of the Electro Mechanical Interlock (EMI)
90  */
91 static int get_lock_status(struct hotplug_slot *hotplug_slot, u8 *value)
92 {
93 	struct slot *slot = hotplug_slot->private;
94 	return (slot->hpc_ops->get_emi_status(slot, value));
95 }
96 
97 /*
98  * sysfs interface for the Electro Mechanical Interlock (EMI)
99  * 1 == locked, 0 == unlocked
100  */
101 static ssize_t lock_read_file(struct hotplug_slot *slot, char *buf)
102 {
103 	int retval;
104 	u8 value;
105 
106 	retval = get_lock_status(slot, &value);
107 	if (retval)
108 		goto lock_read_exit;
109 	retval = sprintf (buf, "%d\n", value);
110 
111 lock_read_exit:
112 	return retval;
113 }
114 
115 /*
116  * Change the status of the Electro Mechanical Interlock (EMI)
117  * This is a toggle - in addition there must be at least 1 second
118  * in between toggles.
119  */
120 static int set_lock_status(struct hotplug_slot *hotplug_slot, u8 status)
121 {
122 	struct slot *slot = hotplug_slot->private;
123 	int retval;
124 	u8 value;
125 
126 	mutex_lock(&slot->ctrl->crit_sect);
127 
128 	/* has it been >1 sec since our last toggle? */
129 	if ((get_seconds() - slot->last_emi_toggle) < 1)
130 		return -EINVAL;
131 
132 	/* see what our current state is */
133 	retval = get_lock_status(hotplug_slot, &value);
134 	if (retval || (value == status))
135 		goto set_lock_exit;
136 
137 	slot->hpc_ops->toggle_emi(slot);
138 set_lock_exit:
139 	mutex_unlock(&slot->ctrl->crit_sect);
140 	return 0;
141 }
142 
143 /*
144  * sysfs interface which allows the user to toggle the Electro Mechanical
145  * Interlock.  Valid values are either 0 or 1.  0 == unlock, 1 == lock
146  */
147 static ssize_t lock_write_file(struct hotplug_slot *slot, const char *buf,
148 		size_t count)
149 {
150 	unsigned long llock;
151 	u8 lock;
152 	int retval = 0;
153 
154 	llock = simple_strtoul(buf, NULL, 10);
155 	lock = (u8)(llock & 0xff);
156 
157 	switch (lock) {
158 		case 0:
159 		case 1:
160 			retval = set_lock_status(slot, lock);
161 			break;
162 		default:
163 			err ("%d is an invalid lock value\n", lock);
164 			retval = -EINVAL;
165 	}
166 	if (retval)
167 		return retval;
168 	return count;
169 }
170 
171 static struct hotplug_slot_attribute hotplug_slot_attr_lock = {
172 	.attr = {.name = "lock", .mode = S_IFREG | S_IRUGO | S_IWUSR},
173 	.show = lock_read_file,
174 	.store = lock_write_file
175 };
176 
177 /**
178  * release_slot - free up the memory used by a slot
179  * @hotplug_slot: slot to free
180  */
181 static void release_slot(struct hotplug_slot *hotplug_slot)
182 {
183 	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
184 
185 	kfree(hotplug_slot->info);
186 	kfree(hotplug_slot);
187 }
188 
189 static int init_slots(struct controller *ctrl)
190 {
191 	struct slot *slot;
192 	struct hotplug_slot *hotplug_slot;
193 	struct hotplug_slot_info *info;
194 	int len, dup = 1;
195 	int retval = -ENOMEM;
196 
197 	list_for_each_entry(slot, &ctrl->slot_list, slot_list) {
198 		hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
199 		if (!hotplug_slot)
200 			goto error;
201 
202 		info = kzalloc(sizeof(*info), GFP_KERNEL);
203 		if (!info)
204 			goto error_hpslot;
205 
206 		/* register this slot with the hotplug pci core */
207 		hotplug_slot->info = info;
208 		hotplug_slot->name = slot->name;
209 		hotplug_slot->private = slot;
210 		hotplug_slot->release = &release_slot;
211 		hotplug_slot->ops = &pciehp_hotplug_slot_ops;
212 		get_power_status(hotplug_slot, &info->power_status);
213 		get_attention_status(hotplug_slot, &info->attention_status);
214 		get_latch_status(hotplug_slot, &info->latch_status);
215 		get_adapter_status(hotplug_slot, &info->adapter_status);
216 		slot->hotplug_slot = hotplug_slot;
217 
218 		dbg("Registering bus=%x dev=%x hp_slot=%x sun=%x "
219 		    "slot_device_offset=%x\n", slot->bus, slot->device,
220 		    slot->hp_slot, slot->number, ctrl->slot_device_offset);
221 duplicate_name:
222 		retval = pci_hp_register(hotplug_slot,
223 					 ctrl->pci_dev->subordinate,
224 					 slot->device);
225 		if (retval) {
226 			/*
227 			 * If slot N already exists, we'll try to create
228 			 * slot N-1, N-2 ... N-M, until we overflow.
229 			 */
230 			if (retval == -EEXIST) {
231 				len = snprintf(slot->name, SLOT_NAME_SIZE,
232 					       "%d-%d", slot->number, dup++);
233 				if (len < SLOT_NAME_SIZE)
234 					goto duplicate_name;
235 				else
236 					err("duplicate slot name overflow\n");
237 			}
238 			err("pci_hp_register failed with error %d\n", retval);
239 			goto error_info;
240 		}
241 		/* create additional sysfs entries */
242 		if (EMI(ctrl)) {
243 			retval = sysfs_create_file(&hotplug_slot->pci_slot->kobj,
244 				&hotplug_slot_attr_lock.attr);
245 			if (retval) {
246 				pci_hp_deregister(hotplug_slot);
247 				err("cannot create additional sysfs entries\n");
248 				goto error_info;
249 			}
250 		}
251 	}
252 
253 	return 0;
254 error_info:
255 	kfree(info);
256 error_hpslot:
257 	kfree(hotplug_slot);
258 error:
259 	return retval;
260 }
261 
262 static void cleanup_slots(struct controller *ctrl)
263 {
264 	struct slot *slot;
265 
266 	list_for_each_entry(slot, &ctrl->slot_list, slot_list) {
267 		if (EMI(ctrl))
268 			sysfs_remove_file(&slot->hotplug_slot->pci_slot->kobj,
269 				&hotplug_slot_attr_lock.attr);
270 		pci_hp_deregister(slot->hotplug_slot);
271 	}
272 }
273 
274 /*
275  * set_attention_status - Turns the Amber LED for a slot on, off or blink
276  */
277 static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
278 {
279 	struct slot *slot = hotplug_slot->private;
280 
281 	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
282 
283 	hotplug_slot->info->attention_status = status;
284 
285 	if (ATTN_LED(slot->ctrl))
286 		slot->hpc_ops->set_attention_status(slot, status);
287 
288 	return 0;
289 }
290 
291 
292 static int enable_slot(struct hotplug_slot *hotplug_slot)
293 {
294 	struct slot *slot = hotplug_slot->private;
295 
296 	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
297 
298 	return pciehp_sysfs_enable_slot(slot);
299 }
300 
301 
302 static int disable_slot(struct hotplug_slot *hotplug_slot)
303 {
304 	struct slot *slot = hotplug_slot->private;
305 
306 	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
307 
308 	return pciehp_sysfs_disable_slot(slot);
309 }
310 
311 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
312 {
313 	struct slot *slot = hotplug_slot->private;
314 	int retval;
315 
316 	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
317 
318 	retval = slot->hpc_ops->get_power_status(slot, value);
319 	if (retval < 0)
320 		*value = hotplug_slot->info->power_status;
321 
322 	return 0;
323 }
324 
325 static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
326 {
327 	struct slot *slot = hotplug_slot->private;
328 	int retval;
329 
330 	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
331 
332 	retval = slot->hpc_ops->get_attention_status(slot, value);
333 	if (retval < 0)
334 		*value = hotplug_slot->info->attention_status;
335 
336 	return 0;
337 }
338 
339 static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
340 {
341 	struct slot *slot = hotplug_slot->private;
342 	int retval;
343 
344 	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
345 
346 	retval = slot->hpc_ops->get_latch_status(slot, value);
347 	if (retval < 0)
348 		*value = hotplug_slot->info->latch_status;
349 
350 	return 0;
351 }
352 
353 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
354 {
355 	struct slot *slot = hotplug_slot->private;
356 	int retval;
357 
358 	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
359 
360 	retval = slot->hpc_ops->get_adapter_status(slot, value);
361 	if (retval < 0)
362 		*value = hotplug_slot->info->adapter_status;
363 
364 	return 0;
365 }
366 
367 static int get_max_bus_speed(struct hotplug_slot *hotplug_slot,
368 				enum pci_bus_speed *value)
369 {
370 	struct slot *slot = hotplug_slot->private;
371 	int retval;
372 
373 	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
374 
375 	retval = slot->hpc_ops->get_max_bus_speed(slot, value);
376 	if (retval < 0)
377 		*value = PCI_SPEED_UNKNOWN;
378 
379 	return 0;
380 }
381 
382 static int get_cur_bus_speed(struct hotplug_slot *hotplug_slot, enum pci_bus_speed *value)
383 {
384 	struct slot *slot = hotplug_slot->private;
385 	int retval;
386 
387 	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
388 
389 	retval = slot->hpc_ops->get_cur_bus_speed(slot, value);
390 	if (retval < 0)
391 		*value = PCI_SPEED_UNKNOWN;
392 
393 	return 0;
394 }
395 
396 static int pciehp_probe(struct pcie_device *dev, const struct pcie_port_service_id *id)
397 {
398 	int rc;
399 	struct controller *ctrl;
400 	struct slot *t_slot;
401 	u8 value;
402 	struct pci_dev *pdev = dev->port;
403 
404 	if (pciehp_force)
405 		dbg("Bypassing BIOS check for pciehp use on %s\n",
406 		    pci_name(pdev));
407 	else if (pciehp_get_hp_hw_control_from_firmware(pdev))
408 		goto err_out_none;
409 
410 	ctrl = pcie_init(dev);
411 	if (!ctrl) {
412 		dbg("%s: controller initialization failed\n", PCIE_MODULE_NAME);
413 		goto err_out_none;
414 	}
415 	set_service_data(dev, ctrl);
416 
417 	/* Setup the slot information structures */
418 	rc = init_slots(ctrl);
419 	if (rc) {
420 		if (rc == -EBUSY)
421 			warn("%s: slot already registered by another "
422 				"hotplug driver\n", PCIE_MODULE_NAME);
423 		else
424 			err("%s: slot initialization failed\n",
425 				PCIE_MODULE_NAME);
426 		goto err_out_release_ctlr;
427 	}
428 
429 	t_slot = pciehp_find_slot(ctrl, ctrl->slot_device_offset);
430 
431 	t_slot->hpc_ops->get_adapter_status(t_slot, &value); /* Check if slot is occupied */
432 	if (value && pciehp_force) {
433 		rc = pciehp_enable_slot(t_slot);
434 		if (rc)	/* -ENODEV: shouldn't happen, but deal with it */
435 			value = 0;
436 	}
437 	if ((POWER_CTRL(ctrl)) && !value) {
438 		rc = t_slot->hpc_ops->power_off_slot(t_slot); /* Power off slot if not occupied*/
439 		if (rc)
440 			goto err_out_free_ctrl_slot;
441 	}
442 
443 	return 0;
444 
445 err_out_free_ctrl_slot:
446 	cleanup_slots(ctrl);
447 err_out_release_ctlr:
448 	ctrl->hpc_ops->release_ctlr(ctrl);
449 err_out_none:
450 	return -ENODEV;
451 }
452 
453 static void pciehp_remove (struct pcie_device *dev)
454 {
455 	struct controller *ctrl = get_service_data(dev);
456 
457 	cleanup_slots(ctrl);
458 	ctrl->hpc_ops->release_ctlr(ctrl);
459 }
460 
461 #ifdef CONFIG_PM
462 static int pciehp_suspend (struct pcie_device *dev, pm_message_t state)
463 {
464 	printk("%s ENTRY\n", __func__);
465 	return 0;
466 }
467 
468 static int pciehp_resume (struct pcie_device *dev)
469 {
470 	printk("%s ENTRY\n", __func__);
471 	if (pciehp_force) {
472 		struct controller *ctrl = get_service_data(dev);
473 		struct slot *t_slot;
474 		u8 status;
475 
476 		/* reinitialize the chipset's event detection logic */
477 		pcie_enable_notification(ctrl);
478 
479 		t_slot = pciehp_find_slot(ctrl, ctrl->slot_device_offset);
480 
481 		/* Check if slot is occupied */
482 		t_slot->hpc_ops->get_adapter_status(t_slot, &status);
483 		if (status)
484 			pciehp_enable_slot(t_slot);
485 		else
486 			pciehp_disable_slot(t_slot);
487 	}
488 	return 0;
489 }
490 #endif
491 
492 static struct pcie_port_service_id port_pci_ids[] = { {
493 	.vendor = PCI_ANY_ID,
494 	.device = PCI_ANY_ID,
495 	.port_type = PCIE_ANY_PORT,
496 	.service_type = PCIE_PORT_SERVICE_HP,
497 	.driver_data =	0,
498 	}, { /* end: all zeroes */ }
499 };
500 static const char device_name[] = "hpdriver";
501 
502 static struct pcie_port_service_driver hpdriver_portdrv = {
503 	.name		= (char *)device_name,
504 	.id_table	= &port_pci_ids[0],
505 
506 	.probe		= pciehp_probe,
507 	.remove		= pciehp_remove,
508 
509 #ifdef	CONFIG_PM
510 	.suspend	= pciehp_suspend,
511 	.resume		= pciehp_resume,
512 #endif	/* PM */
513 };
514 
515 static int __init pcied_init(void)
516 {
517 	int retval = 0;
518 
519 	retval = pcie_port_service_register(&hpdriver_portdrv);
520  	dbg("pcie_port_service_register = %d\n", retval);
521   	info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
522  	if (retval)
523 		dbg("%s: Failure to register service\n", __func__);
524 	return retval;
525 }
526 
527 static void __exit pcied_cleanup(void)
528 {
529 	dbg("unload_pciehpd()\n");
530 	pcie_port_service_unregister(&hpdriver_portdrv);
531 	info(DRIVER_DESC " version: " DRIVER_VERSION " unloaded\n");
532 }
533 
534 module_init(pcied_init);
535 module_exit(pcied_cleanup);
536