edac_pci.c 11.7 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509
/*
 * EDAC PCI component
 *
 * Author: Dave Jiang <djiang@mvista.com>
 *
 * 2007 (c) MontaVista Software, Inc. This file is licensed under
 * the terms of the GNU General Public License version 2. This program
 * is licensed "as is" without any warranty of any kind, whether express
 * or implied.
 *
 */
#include <linux/module.h>
#include <linux/types.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/highmem.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/sysdev.h>
#include <linux/ctype.h>
#include <linux/workqueue.h>
#include <asm/uaccess.h>
#include <asm/page.h>

#include "edac_core.h"
#include "edac_module.h"

static DEFINE_MUTEX(edac_pci_ctls_mutex);
static LIST_HEAD(edac_pci_list);
static atomic_t pci_indexes = ATOMIC_INIT(0);

/*
 * edac_pci_alloc_ctl_info
 *
 *	The alloc() function for the 'edac_pci' control info
 *	structure. The chip driver will allocate one of these for each
 *	edac_pci it is going to control/register with the EDAC CORE.
 */
struct edac_pci_ctl_info *edac_pci_alloc_ctl_info(unsigned int sz_pvt,
						const char *edac_pci_name)
{
	struct edac_pci_ctl_info *pci;
	void *pvt;
	unsigned int size;

	debugf1("%s()\n", __func__);

	pci = (struct edac_pci_ctl_info *)0;
	pvt = edac_align_ptr(&pci[1], sz_pvt);
	size = ((unsigned long)pvt) + sz_pvt;

	/* Alloc the needed control struct memory */
	pci = kzalloc(size, GFP_KERNEL);
	if (pci  == NULL)
		return NULL;

	/* Now much private space */
	pvt = sz_pvt ? ((char *)pci) + ((unsigned long)pvt) : NULL;

	pci->pvt_info = pvt;
	pci->op_state = OP_ALLOC;

	snprintf(pci->name, strlen(edac_pci_name) + 1, "%s", edac_pci_name);

	return pci;
}
EXPORT_SYMBOL_GPL(edac_pci_alloc_ctl_info);

/*
 * edac_pci_free_ctl_info()
 *
 *	Last action on the pci control structure.
 *
 *	call the remove sysfs information, which will unregister
 *	this control struct's kobj. When that kobj's ref count
 *	goes to zero, its release function will be call and then
 *	kfree() the memory.
 */
void edac_pci_free_ctl_info(struct edac_pci_ctl_info *pci)
{
	debugf1("%s()\n", __func__);

	edac_pci_remove_sysfs(pci);
}
EXPORT_SYMBOL_GPL(edac_pci_free_ctl_info);

/*
 * find_edac_pci_by_dev()
 * 	scans the edac_pci list for a specific 'struct device *'
 *
 *	return NULL if not found, or return control struct pointer
 */
static struct edac_pci_ctl_info *find_edac_pci_by_dev(struct device *dev)
{
	struct edac_pci_ctl_info *pci;
	struct list_head *item;

	debugf1("%s()\n", __func__);

	list_for_each(item, &edac_pci_list) {
		pci = list_entry(item, struct edac_pci_ctl_info, link);

		if (pci->dev == dev)
			return pci;
	}

	return NULL;
}

/*
 * add_edac_pci_to_global_list
 * 	Before calling this function, caller must assign a unique value to
 * 	edac_dev->pci_idx.
 * 	Return:
 * 		0 on success
 * 		1 on failure
 */
static int add_edac_pci_to_global_list(struct edac_pci_ctl_info *pci)
{
	struct list_head *item, *insert_before;
	struct edac_pci_ctl_info *rover;

	debugf1("%s()\n", __func__);

	insert_before = &edac_pci_list;

	/* Determine if already on the list */
	rover = find_edac_pci_by_dev(pci->dev);
	if (unlikely(rover != NULL))
		goto fail0;

	/* Insert in ascending order by 'pci_idx', so find position */
	list_for_each(item, &edac_pci_list) {
		rover = list_entry(item, struct edac_pci_ctl_info, link);

		if (rover->pci_idx >= pci->pci_idx) {
			if (unlikely(rover->pci_idx == pci->pci_idx))
				goto fail1;

			insert_before = item;
			break;
		}
	}

	list_add_tail_rcu(&pci->link, insert_before);
	return 0;

fail0:
	edac_printk(KERN_WARNING, EDAC_PCI,
		"%s (%s) %s %s already assigned %d\n",
		dev_name(rover->dev), edac_dev_name(rover),
		rover->mod_name, rover->ctl_name, rover->pci_idx);
	return 1;

fail1:
	edac_printk(KERN_WARNING, EDAC_PCI,
		"but in low-level driver: attempt to assign\n"
		"\tduplicate pci_idx %d in %s()\n", rover->pci_idx,
		__func__);
	return 1;
}

/*
 * complete_edac_pci_list_del
 *
 *	RCU completion callback to indicate item is deleted
 */
static void complete_edac_pci_list_del(struct rcu_head *head)
{
	struct edac_pci_ctl_info *pci;

	pci = container_of(head, struct edac_pci_ctl_info, rcu);
	INIT_LIST_HEAD(&pci->link);
}

/*
 * del_edac_pci_from_global_list
 *
 *	remove the PCI control struct from the global list
 */
static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
{
	list_del_rcu(&pci->link);
	call_rcu(&pci->rcu, complete_edac_pci_list_del);
	rcu_barrier();
}

#if 0
/* Older code, but might use in the future */

/*
 * edac_pci_find()
 * 	Search for an edac_pci_ctl_info structure whose index is 'idx'
 *
 * If found, return a pointer to the structure
 * Else return NULL.
 *
 * Caller must hold pci_ctls_mutex.
 */
struct edac_pci_ctl_info *edac_pci_find(int idx)
{
	struct list_head *item;
	struct edac_pci_ctl_info *pci;

	/* Iterage over list, looking for exact match of ID */
	list_for_each(item, &edac_pci_list) {
		pci = list_entry(item, struct edac_pci_ctl_info, link);

		if (pci->pci_idx >= idx) {
			if (pci->pci_idx == idx)
				return pci;

			/* not on list, so terminate early */
			break;
		}
	}

	return NULL;
}
EXPORT_SYMBOL_GPL(edac_pci_find);
#endif

/*
 * edac_pci_workq_function()
 *
 * 	periodic function that performs the operation
 *	scheduled by a workq request, for a given PCI control struct
 */
static void edac_pci_workq_function(struct work_struct *work_req)
{
	struct delayed_work *d_work = to_delayed_work(work_req);
	struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);
	int msec;
	unsigned long delay;

	debugf3("%s() checking\n", __func__);

	mutex_lock(&edac_pci_ctls_mutex);

	if (pci->op_state == OP_RUNNING_POLL) {
		/* we might be in POLL mode, but there may NOT be a poll func
		 */
		if ((pci->edac_check != NULL) && edac_pci_get_check_errors())
			pci->edac_check(pci);

		/* if we are on a one second period, then use round */
		msec = edac_pci_get_poll_msec();
		if (msec == 1000)
			delay = round_jiffies_relative(msecs_to_jiffies(msec));
		else
			delay = msecs_to_jiffies(msec);

		/* Reschedule only if we are in POLL mode */
		queue_delayed_work(edac_workqueue, &pci->work, delay);
	}

	mutex_unlock(&edac_pci_ctls_mutex);
}

/*
 * edac_pci_workq_setup()
 * 	initialize a workq item for this edac_pci instance
 * 	passing in the new delay period in msec
 *
 *	locking model:
 *		called when 'edac_pci_ctls_mutex' is locked
 */
static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci,
				 unsigned int msec)
{
	debugf0("%s()\n", __func__);

	INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
	queue_delayed_work(edac_workqueue, &pci->work,
			msecs_to_jiffies(edac_pci_get_poll_msec()));
}

/*
 * edac_pci_workq_teardown()
 * 	stop the workq processing on this edac_pci instance
 */
static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
{
	int status;

	debugf0("%s()\n", __func__);

	status = cancel_delayed_work(&pci->work);
	if (status == 0)
		flush_workqueue(edac_workqueue);
}

/*
 * edac_pci_reset_delay_period
 *
 *	called with a new period value for the workq period
 *	a) stop current workq timer
 *	b) restart workq timer with new value
 */
void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci,
				 unsigned long value)
{
	debugf0("%s()\n", __func__);

	edac_pci_workq_teardown(pci);

	/* need to lock for the setup */
	mutex_lock(&edac_pci_ctls_mutex);

	edac_pci_workq_setup(pci, value);

	mutex_unlock(&edac_pci_ctls_mutex);
}
EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period);

/*
 * edac_pci_alloc_index: Allocate a unique PCI index number
 *
 * Return:
 *      allocated index number
 *
 */
int edac_pci_alloc_index(void)
{
	return atomic_inc_return(&pci_indexes) - 1;
}
EXPORT_SYMBOL_GPL(edac_pci_alloc_index);

/*
 * edac_pci_add_device: Insert the 'edac_dev' structure into the
 * edac_pci global list and create sysfs entries associated with
 * edac_pci structure.
 * @pci: pointer to the edac_device structure to be added to the list
 * @edac_idx: A unique numeric identifier to be assigned to the
 * 'edac_pci' structure.
 *
 * Return:
 *      0       Success
 *      !0      Failure
 */
int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
{
	debugf0("%s()\n", __func__);

	pci->pci_idx = edac_idx;
	pci->start_time = jiffies;

	mutex_lock(&edac_pci_ctls_mutex);

	if (add_edac_pci_to_global_list(pci))
		goto fail0;

	if (edac_pci_create_sysfs(pci)) {
		edac_pci_printk(pci, KERN_WARNING,
				"failed to create sysfs pci\n");
		goto fail1;
	}

	if (pci->edac_check != NULL) {
		pci->op_state = OP_RUNNING_POLL;

		edac_pci_workq_setup(pci, 1000);
	} else {
		pci->op_state = OP_RUNNING_INTERRUPT;
	}

	edac_pci_printk(pci, KERN_INFO,
			"Giving out device to module '%s' controller '%s':"
			" DEV '%s' (%s)\n",
			pci->mod_name,
			pci->ctl_name,
			edac_dev_name(pci), edac_op_state_to_string(pci->op_state));

	mutex_unlock(&edac_pci_ctls_mutex);
	return 0;

	/* error unwind stack */
fail1:
	del_edac_pci_from_global_list(pci);
fail0:
	mutex_unlock(&edac_pci_ctls_mutex);
	return 1;
}
EXPORT_SYMBOL_GPL(edac_pci_add_device);

/*
 * edac_pci_del_device()
 * 	Remove sysfs entries for specified edac_pci structure and
 * 	then remove edac_pci structure from global list
 *
 * @dev:
 * 	Pointer to 'struct device' representing edac_pci structure
 * 	to remove
 *
 * Return:
 * 	Pointer to removed edac_pci structure,
 * 	or NULL if device not found
 */
struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
{
	struct edac_pci_ctl_info *pci;

	debugf0("%s()\n", __func__);

	mutex_lock(&edac_pci_ctls_mutex);

	/* ensure the control struct is on the global list
	 * if not, then leave
	 */
	pci = find_edac_pci_by_dev(dev);
	if (pci  == NULL) {
		mutex_unlock(&edac_pci_ctls_mutex);
		return NULL;
	}

	pci->op_state = OP_OFFLINE;

	del_edac_pci_from_global_list(pci);

	mutex_unlock(&edac_pci_ctls_mutex);

	/* stop the workq timer */
	edac_pci_workq_teardown(pci);

	edac_printk(KERN_INFO, EDAC_PCI,
		"Removed device %d for %s %s: DEV %s\n",
		pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci));

	return pci;
}
EXPORT_SYMBOL_GPL(edac_pci_del_device);

/*
 * edac_pci_generic_check
 *
 *	a Generic parity check API
 */
static void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
{
	debugf4("%s()\n", __func__);
	edac_pci_do_parity_check();
}

/* free running instance index counter */
static int edac_pci_idx;
#define EDAC_PCI_GENCTL_NAME	"EDAC PCI controller"

struct edac_pci_gen_data {
	int edac_idx;
};

/*
 * edac_pci_create_generic_ctl
 *
 *	A generic constructor for a PCI parity polling device
 *	Some systems have more than one domain of PCI busses.
 *	For systems with one domain, then this API will
 *	provide for a generic poller.
 *
 *	This routine calls the edac_pci_alloc_ctl_info() for
 *	the generic device, with default values
 */
struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
						const char *mod_name)
{
	struct edac_pci_ctl_info *pci;
	struct edac_pci_gen_data *pdata;

	pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
	if (!pci)
		return NULL;

	pdata = pci->pvt_info;
	pci->dev = dev;
	dev_set_drvdata(pci->dev, pci);
	pci->dev_name = pci_name(to_pci_dev(dev));

	pci->mod_name = mod_name;
	pci->ctl_name = EDAC_PCI_GENCTL_NAME;
	pci->edac_check = edac_pci_generic_check;

	pdata->edac_idx = edac_pci_idx++;

	if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
		debugf3("%s(): failed edac_pci_add_device()\n", __func__);
		edac_pci_free_ctl_info(pci);
		return NULL;
	}

	return pci;
}
EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);

/*
 * edac_pci_release_generic_ctl
 *
 *	The release function of a generic EDAC PCI polling device
 */
void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
{
	debugf0("%s() pci mod=%s\n", __func__, pci->mod_name);

	edac_pci_del_device(pci->dev);
	edac_pci_free_ctl_info(pci);
}
EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);