1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  file.c - part of debugfs, a tiny little debug file system
   4 *
   5 *  Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
   6 *  Copyright (C) 2004 IBM Inc.
   7 *
 
 
 
 
   8 *  debugfs is for people to use instead of /proc or /sys.
   9 *  See Documentation/filesystems/ for more details.
 
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/fs.h>
  14#include <linux/seq_file.h>
  15#include <linux/pagemap.h>
  16#include <linux/debugfs.h>
  17#include <linux/io.h>
  18#include <linux/slab.h>
  19#include <linux/atomic.h>
  20#include <linux/device.h>
  21#include <linux/pm_runtime.h>
  22#include <linux/poll.h>
  23#include <linux/security.h>
  24
  25#include "internal.h"
  26
  27struct poll_table_struct;
  28
  29static ssize_t default_read_file(struct file *file, char __user *buf,
  30				 size_t count, loff_t *ppos)
  31{
  32	return 0;
  33}
  34
  35static ssize_t default_write_file(struct file *file, const char __user *buf,
  36				   size_t count, loff_t *ppos)
  37{
  38	return count;
  39}
  40
  41const struct file_operations debugfs_noop_file_operations = {
  42	.read =		default_read_file,
  43	.write =	default_write_file,
  44	.open =		simple_open,
  45	.llseek =	noop_llseek,
  46};
  47
  48#define F_DENTRY(filp) ((filp)->f_path.dentry)
  49
  50const struct file_operations *debugfs_real_fops(const struct file *filp)
  51{
  52	struct debugfs_fsdata *fsd = F_DENTRY(filp)->d_fsdata;
  53
  54	if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT) {
  55		/*
  56		 * Urgh, we've been called w/o a protecting
  57		 * debugfs_file_get().
  58		 */
  59		WARN_ON(1);
  60		return NULL;
  61	}
  62
  63	return fsd->real_fops;
  64}
  65EXPORT_SYMBOL_GPL(debugfs_real_fops);
  66
  67/**
  68 * debugfs_file_get - mark the beginning of file data access
  69 * @dentry: the dentry object whose data is being accessed.
  70 *
  71 * Up to a matching call to debugfs_file_put(), any successive call
  72 * into the file removing functions debugfs_remove() and
  73 * debugfs_remove_recursive() will block. Since associated private
  74 * file data may only get freed after a successful return of any of
  75 * the removal functions, you may safely access it after a successful
  76 * call to debugfs_file_get() without worrying about lifetime issues.
  77 *
  78 * If -%EIO is returned, the file has already been removed and thus,
  79 * it is not safe to access any of its data. If, on the other hand,
  80 * it is allowed to access the file data, zero is returned.
  81 */
  82int debugfs_file_get(struct dentry *dentry)
  83{
  84	struct debugfs_fsdata *fsd;
  85	void *d_fsd;
  86
  87	/*
  88	 * This could only happen if some debugfs user erroneously calls
  89	 * debugfs_file_get() on a dentry that isn't even a file, let
  90	 * them know about it.
  91	 */
  92	if (WARN_ON(!d_is_reg(dentry)))
  93		return -EINVAL;
  94
  95	d_fsd = READ_ONCE(dentry->d_fsdata);
  96	if (!((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) {
  97		fsd = d_fsd;
  98	} else {
  99		fsd = kmalloc(sizeof(*fsd), GFP_KERNEL);
 100		if (!fsd)
 101			return -ENOMEM;
 102
 103		fsd->real_fops = (void *)((unsigned long)d_fsd &
 104					~DEBUGFS_FSDATA_IS_REAL_FOPS_BIT);
 105		refcount_set(&fsd->active_users, 1);
 106		init_completion(&fsd->active_users_drained);
 107		INIT_LIST_HEAD(&fsd->cancellations);
 108		mutex_init(&fsd->cancellations_mtx);
 109
 110		if (cmpxchg(&dentry->d_fsdata, d_fsd, fsd) != d_fsd) {
 111			mutex_destroy(&fsd->cancellations_mtx);
 112			kfree(fsd);
 113			fsd = READ_ONCE(dentry->d_fsdata);
 114		}
 115	}
 116
 117	/*
 118	 * In case of a successful cmpxchg() above, this check is
 119	 * strictly necessary and must follow it, see the comment in
 120	 * __debugfs_remove_file().
 121	 * OTOH, if the cmpxchg() hasn't been executed or wasn't
 122	 * successful, this serves the purpose of not starving
 123	 * removers.
 124	 */
 125	if (d_unlinked(dentry))
 126		return -EIO;
 127
 128	if (!refcount_inc_not_zero(&fsd->active_users))
 129		return -EIO;
 130
 131	return 0;
 132}
 133EXPORT_SYMBOL_GPL(debugfs_file_get);
 134
 135/**
 136 * debugfs_file_put - mark the end of file data access
 137 * @dentry: the dentry object formerly passed to
 138 *          debugfs_file_get().
 139 *
 140 * Allow any ongoing concurrent call into debugfs_remove() or
 141 * debugfs_remove_recursive() blocked by a former call to
 142 * debugfs_file_get() to proceed and return to its caller.
 143 */
 144void debugfs_file_put(struct dentry *dentry)
 145{
 146	struct debugfs_fsdata *fsd = READ_ONCE(dentry->d_fsdata);
 147
 148	if (refcount_dec_and_test(&fsd->active_users))
 149		complete(&fsd->active_users_drained);
 150}
 151EXPORT_SYMBOL_GPL(debugfs_file_put);
 152
 153/**
 154 * debugfs_enter_cancellation - enter a debugfs cancellation
 155 * @file: the file being accessed
 156 * @cancellation: the cancellation object, the cancel callback
 157 *	inside of it must be initialized
 158 *
 159 * When a debugfs file is removed it needs to wait for all active
 160 * operations to complete. However, the operation itself may need
 161 * to wait for hardware or completion of some asynchronous process
 162 * or similar. As such, it may need to be cancelled to avoid long
 163 * waits or even deadlocks.
 164 *
 165 * This function can be used inside a debugfs handler that may
 166 * need to be cancelled. As soon as this function is called, the
 167 * cancellation's 'cancel' callback may be called, at which point
 168 * the caller should proceed to call debugfs_leave_cancellation()
 169 * and leave the debugfs handler function as soon as possible.
 170 * Note that the 'cancel' callback is only ever called in the
 171 * context of some kind of debugfs_remove().
 172 *
 173 * This function must be paired with debugfs_leave_cancellation().
 174 */
 175void debugfs_enter_cancellation(struct file *file,
 176				struct debugfs_cancellation *cancellation)
 177{
 178	struct debugfs_fsdata *fsd;
 179	struct dentry *dentry = F_DENTRY(file);
 180
 181	INIT_LIST_HEAD(&cancellation->list);
 182
 183	if (WARN_ON(!d_is_reg(dentry)))
 184		return;
 185
 186	if (WARN_ON(!cancellation->cancel))
 187		return;
 188
 189	fsd = READ_ONCE(dentry->d_fsdata);
 190	if (WARN_ON(!fsd ||
 191		    ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)))
 192		return;
 193
 194	mutex_lock(&fsd->cancellations_mtx);
 195	list_add(&cancellation->list, &fsd->cancellations);
 196	mutex_unlock(&fsd->cancellations_mtx);
 197
 198	/* if we're already removing wake it up to cancel */
 199	if (d_unlinked(dentry))
 200		complete(&fsd->active_users_drained);
 201}
 202EXPORT_SYMBOL_GPL(debugfs_enter_cancellation);
 203
 204/**
 205 * debugfs_leave_cancellation - leave cancellation section
 206 * @file: the file being accessed
 207 * @cancellation: the cancellation previously registered with
 208 *	debugfs_enter_cancellation()
 209 *
 210 * See the documentation of debugfs_enter_cancellation().
 211 */
 212void debugfs_leave_cancellation(struct file *file,
 213				struct debugfs_cancellation *cancellation)
 214{
 215	struct debugfs_fsdata *fsd;
 216	struct dentry *dentry = F_DENTRY(file);
 217
 218	if (WARN_ON(!d_is_reg(dentry)))
 219		return;
 220
 221	fsd = READ_ONCE(dentry->d_fsdata);
 222	if (WARN_ON(!fsd ||
 223		    ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)))
 224		return;
 225
 226	mutex_lock(&fsd->cancellations_mtx);
 227	if (!list_empty(&cancellation->list))
 228		list_del(&cancellation->list);
 229	mutex_unlock(&fsd->cancellations_mtx);
 230}
 231EXPORT_SYMBOL_GPL(debugfs_leave_cancellation);
 232
 233/*
 234 * Only permit access to world-readable files when the kernel is locked down.
 235 * We also need to exclude any file that has ways to write or alter it as root
 236 * can bypass the permissions check.
 237 */
 238static int debugfs_locked_down(struct inode *inode,
 239			       struct file *filp,
 240			       const struct file_operations *real_fops)
 241{
 242	if ((inode->i_mode & 07777 & ~0444) == 0 &&
 243	    !(filp->f_mode & FMODE_WRITE) &&
 244	    !real_fops->unlocked_ioctl &&
 245	    !real_fops->compat_ioctl &&
 246	    !real_fops->mmap)
 247		return 0;
 248
 249	if (security_locked_down(LOCKDOWN_DEBUGFS))
 250		return -EPERM;
 251
 252	return 0;
 253}
 254
 255static int open_proxy_open(struct inode *inode, struct file *filp)
 256{
 257	struct dentry *dentry = F_DENTRY(filp);
 258	const struct file_operations *real_fops = NULL;
 259	int r;
 260
 261	r = debugfs_file_get(dentry);
 262	if (r)
 263		return r == -EIO ? -ENOENT : r;
 264
 265	real_fops = debugfs_real_fops(filp);
 266
 267	r = debugfs_locked_down(inode, filp, real_fops);
 268	if (r)
 269		goto out;
 270
 271	if (!fops_get(real_fops)) {
 272#ifdef CONFIG_MODULES
 273		if (real_fops->owner &&
 274		    real_fops->owner->state == MODULE_STATE_GOING) {
 275			r = -ENXIO;
 276			goto out;
 277		}
 278#endif
 279
 280		/* Huh? Module did not clean up after itself at exit? */
 281		WARN(1, "debugfs file owner did not clean up at exit: %pd",
 282			dentry);
 283		r = -ENXIO;
 284		goto out;
 285	}
 286	replace_fops(filp, real_fops);
 287
 288	if (real_fops->open)
 289		r = real_fops->open(inode, filp);
 290
 291out:
 292	debugfs_file_put(dentry);
 293	return r;
 294}
 295
 296const struct file_operations debugfs_open_proxy_file_operations = {
 297	.open = open_proxy_open,
 298};
 299
 300#define PROTO(args...) args
 301#define ARGS(args...) args
 302
 303#define FULL_PROXY_FUNC(name, ret_type, filp, proto, args)		\
 304static ret_type full_proxy_ ## name(proto)				\
 305{									\
 306	struct dentry *dentry = F_DENTRY(filp);			\
 307	const struct file_operations *real_fops;			\
 308	ret_type r;							\
 309									\
 310	r = debugfs_file_get(dentry);					\
 311	if (unlikely(r))						\
 312		return r;						\
 313	real_fops = debugfs_real_fops(filp);				\
 314	r = real_fops->name(args);					\
 315	debugfs_file_put(dentry);					\
 316	return r;							\
 317}
 318
 319FULL_PROXY_FUNC(llseek, loff_t, filp,
 320		PROTO(struct file *filp, loff_t offset, int whence),
 321		ARGS(filp, offset, whence));
 322
 323FULL_PROXY_FUNC(read, ssize_t, filp,
 324		PROTO(struct file *filp, char __user *buf, size_t size,
 325			loff_t *ppos),
 326		ARGS(filp, buf, size, ppos));
 327
 328FULL_PROXY_FUNC(write, ssize_t, filp,
 329		PROTO(struct file *filp, const char __user *buf, size_t size,
 330			loff_t *ppos),
 331		ARGS(filp, buf, size, ppos));
 332
 333FULL_PROXY_FUNC(unlocked_ioctl, long, filp,
 334		PROTO(struct file *filp, unsigned int cmd, unsigned long arg),
 335		ARGS(filp, cmd, arg));
 336
 337static __poll_t full_proxy_poll(struct file *filp,
 338				struct poll_table_struct *wait)
 339{
 340	struct dentry *dentry = F_DENTRY(filp);
 341	__poll_t r = 0;
 342	const struct file_operations *real_fops;
 343
 344	if (debugfs_file_get(dentry))
 345		return EPOLLHUP;
 346
 347	real_fops = debugfs_real_fops(filp);
 348	r = real_fops->poll(filp, wait);
 349	debugfs_file_put(dentry);
 350	return r;
 351}
 352
 353static int full_proxy_release(struct inode *inode, struct file *filp)
 354{
 355	const struct dentry *dentry = F_DENTRY(filp);
 356	const struct file_operations *real_fops = debugfs_real_fops(filp);
 357	const struct file_operations *proxy_fops = filp->f_op;
 358	int r = 0;
 359
 360	/*
 361	 * We must not protect this against removal races here: the
 362	 * original releaser should be called unconditionally in order
 363	 * not to leak any resources. Releasers must not assume that
 364	 * ->i_private is still being meaningful here.
 365	 */
 366	if (real_fops->release)
 367		r = real_fops->release(inode, filp);
 368
 369	replace_fops(filp, d_inode(dentry)->i_fop);
 370	kfree(proxy_fops);
 371	fops_put(real_fops);
 372	return r;
 373}
 374
 375static void __full_proxy_fops_init(struct file_operations *proxy_fops,
 376				const struct file_operations *real_fops)
 377{
 378	proxy_fops->release = full_proxy_release;
 379	if (real_fops->llseek)
 380		proxy_fops->llseek = full_proxy_llseek;
 381	if (real_fops->read)
 382		proxy_fops->read = full_proxy_read;
 383	if (real_fops->write)
 384		proxy_fops->write = full_proxy_write;
 385	if (real_fops->poll)
 386		proxy_fops->poll = full_proxy_poll;
 387	if (real_fops->unlocked_ioctl)
 388		proxy_fops->unlocked_ioctl = full_proxy_unlocked_ioctl;
 389}
 390
 391static int full_proxy_open(struct inode *inode, struct file *filp)
 392{
 393	struct dentry *dentry = F_DENTRY(filp);
 394	const struct file_operations *real_fops = NULL;
 395	struct file_operations *proxy_fops = NULL;
 396	int r;
 397
 398	r = debugfs_file_get(dentry);
 399	if (r)
 400		return r == -EIO ? -ENOENT : r;
 401
 402	real_fops = debugfs_real_fops(filp);
 403
 404	r = debugfs_locked_down(inode, filp, real_fops);
 405	if (r)
 406		goto out;
 407
 408	if (!fops_get(real_fops)) {
 409#ifdef CONFIG_MODULES
 410		if (real_fops->owner &&
 411		    real_fops->owner->state == MODULE_STATE_GOING) {
 412			r = -ENXIO;
 413			goto out;
 414		}
 415#endif
 416
 417		/* Huh? Module did not cleanup after itself at exit? */
 418		WARN(1, "debugfs file owner did not clean up at exit: %pd",
 419			dentry);
 420		r = -ENXIO;
 421		goto out;
 422	}
 423
 424	proxy_fops = kzalloc(sizeof(*proxy_fops), GFP_KERNEL);
 425	if (!proxy_fops) {
 426		r = -ENOMEM;
 427		goto free_proxy;
 428	}
 429	__full_proxy_fops_init(proxy_fops, real_fops);
 430	replace_fops(filp, proxy_fops);
 431
 432	if (real_fops->open) {
 433		r = real_fops->open(inode, filp);
 434		if (r) {
 435			replace_fops(filp, d_inode(dentry)->i_fop);
 436			goto free_proxy;
 437		} else if (filp->f_op != proxy_fops) {
 438			/* No protection against file removal anymore. */
 439			WARN(1, "debugfs file owner replaced proxy fops: %pd",
 440				dentry);
 441			goto free_proxy;
 442		}
 443	}
 444
 445	goto out;
 446free_proxy:
 447	kfree(proxy_fops);
 448	fops_put(real_fops);
 449out:
 450	debugfs_file_put(dentry);
 451	return r;
 452}
 453
 454const struct file_operations debugfs_full_proxy_file_operations = {
 455	.open = full_proxy_open,
 456};
 457
 458ssize_t debugfs_attr_read(struct file *file, char __user *buf,
 459			size_t len, loff_t *ppos)
 460{
 461	struct dentry *dentry = F_DENTRY(file);
 462	ssize_t ret;
 463
 464	ret = debugfs_file_get(dentry);
 465	if (unlikely(ret))
 466		return ret;
 467	ret = simple_attr_read(file, buf, len, ppos);
 468	debugfs_file_put(dentry);
 469	return ret;
 470}
 471EXPORT_SYMBOL_GPL(debugfs_attr_read);
 472
 473static ssize_t debugfs_attr_write_xsigned(struct file *file, const char __user *buf,
 474			 size_t len, loff_t *ppos, bool is_signed)
 475{
 476	struct dentry *dentry = F_DENTRY(file);
 477	ssize_t ret;
 478
 479	ret = debugfs_file_get(dentry);
 480	if (unlikely(ret))
 481		return ret;
 482	if (is_signed)
 483		ret = simple_attr_write_signed(file, buf, len, ppos);
 484	else
 485		ret = simple_attr_write(file, buf, len, ppos);
 486	debugfs_file_put(dentry);
 487	return ret;
 488}
 489
 490ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
 491			 size_t len, loff_t *ppos)
 492{
 493	return debugfs_attr_write_xsigned(file, buf, len, ppos, false);
 494}
 495EXPORT_SYMBOL_GPL(debugfs_attr_write);
 496
 497ssize_t debugfs_attr_write_signed(struct file *file, const char __user *buf,
 498			 size_t len, loff_t *ppos)
 499{
 500	return debugfs_attr_write_xsigned(file, buf, len, ppos, true);
 501}
 502EXPORT_SYMBOL_GPL(debugfs_attr_write_signed);
 503
 504static struct dentry *debugfs_create_mode_unsafe(const char *name, umode_t mode,
 505					struct dentry *parent, void *value,
 506					const struct file_operations *fops,
 507					const struct file_operations *fops_ro,
 508					const struct file_operations *fops_wo)
 509{
 510	/* if there are no write bits set, make read only */
 511	if (!(mode & S_IWUGO))
 512		return debugfs_create_file_unsafe(name, mode, parent, value,
 513						fops_ro);
 514	/* if there are no read bits set, make write only */
 515	if (!(mode & S_IRUGO))
 516		return debugfs_create_file_unsafe(name, mode, parent, value,
 517						fops_wo);
 518
 519	return debugfs_create_file_unsafe(name, mode, parent, value, fops);
 520}
 521
 522static int debugfs_u8_set(void *data, u64 val)
 523{
 524	*(u8 *)data = val;
 525	return 0;
 526}
 527static int debugfs_u8_get(void *data, u64 *val)
 528{
 529	*val = *(u8 *)data;
 530	return 0;
 531}
 532DEFINE_DEBUGFS_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
 533DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
 534DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n");
 535
 536/**
 537 * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value
 538 * @name: a pointer to a string containing the name of the file to create.
 539 * @mode: the permission that the file should have
 540 * @parent: a pointer to the parent dentry for this file.  This should be a
 541 *          directory dentry if set.  If this parameter is %NULL, then the
 542 *          file will be created in the root of the debugfs filesystem.
 543 * @value: a pointer to the variable that the file should read to and write
 544 *         from.
 545 *
 546 * This function creates a file in debugfs with the given name that
 547 * contains the value of the variable @value.  If the @mode variable is so
 548 * set, it can be read from, and written to.
 
 
 
 
 
 
 
 
 
 
 549 */
 550void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent,
 551		       u8 *value)
 552{
 553	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8,
 554				   &fops_u8_ro, &fops_u8_wo);
 555}
 556EXPORT_SYMBOL_GPL(debugfs_create_u8);
 557
 558static int debugfs_u16_set(void *data, u64 val)
 559{
 560	*(u16 *)data = val;
 561	return 0;
 562}
 563static int debugfs_u16_get(void *data, u64 *val)
 564{
 565	*val = *(u16 *)data;
 566	return 0;
 567}
 568DEFINE_DEBUGFS_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
 569DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
 570DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n");
 571
 572/**
 573 * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value
 574 * @name: a pointer to a string containing the name of the file to create.
 575 * @mode: the permission that the file should have
 576 * @parent: a pointer to the parent dentry for this file.  This should be a
 577 *          directory dentry if set.  If this parameter is %NULL, then the
 578 *          file will be created in the root of the debugfs filesystem.
 579 * @value: a pointer to the variable that the file should read to and write
 580 *         from.
 581 *
 582 * This function creates a file in debugfs with the given name that
 583 * contains the value of the variable @value.  If the @mode variable is so
 584 * set, it can be read from, and written to.
 
 
 
 
 
 
 
 
 
 
 585 */
 586void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent,
 587			u16 *value)
 588{
 589	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u16,
 590				   &fops_u16_ro, &fops_u16_wo);
 591}
 592EXPORT_SYMBOL_GPL(debugfs_create_u16);
 593
 594static int debugfs_u32_set(void *data, u64 val)
 595{
 596	*(u32 *)data = val;
 597	return 0;
 598}
 599static int debugfs_u32_get(void *data, u64 *val)
 600{
 601	*val = *(u32 *)data;
 602	return 0;
 603}
 604DEFINE_DEBUGFS_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
 605DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
 606DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
 607
 608/**
 609 * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value
 610 * @name: a pointer to a string containing the name of the file to create.
 611 * @mode: the permission that the file should have
 612 * @parent: a pointer to the parent dentry for this file.  This should be a
 613 *          directory dentry if set.  If this parameter is %NULL, then the
 614 *          file will be created in the root of the debugfs filesystem.
 615 * @value: a pointer to the variable that the file should read to and write
 616 *         from.
 617 *
 618 * This function creates a file in debugfs with the given name that
 619 * contains the value of the variable @value.  If the @mode variable is so
 620 * set, it can be read from, and written to.
 
 
 
 
 
 
 
 
 
 
 621 */
 622void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent,
 623			u32 *value)
 624{
 625	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u32,
 626				   &fops_u32_ro, &fops_u32_wo);
 627}
 628EXPORT_SYMBOL_GPL(debugfs_create_u32);
 629
 630static int debugfs_u64_set(void *data, u64 val)
 631{
 632	*(u64 *)data = val;
 633	return 0;
 634}
 635
 636static int debugfs_u64_get(void *data, u64 *val)
 637{
 638	*val = *(u64 *)data;
 639	return 0;
 640}
 641DEFINE_DEBUGFS_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
 642DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
 643DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n");
 644
 645/**
 646 * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value
 647 * @name: a pointer to a string containing the name of the file to create.
 648 * @mode: the permission that the file should have
 649 * @parent: a pointer to the parent dentry for this file.  This should be a
 650 *          directory dentry if set.  If this parameter is %NULL, then the
 651 *          file will be created in the root of the debugfs filesystem.
 652 * @value: a pointer to the variable that the file should read to and write
 653 *         from.
 654 *
 655 * This function creates a file in debugfs with the given name that
 656 * contains the value of the variable @value.  If the @mode variable is so
 657 * set, it can be read from, and written to.
 
 
 
 
 
 
 
 
 
 
 658 */
 659void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent,
 660			u64 *value)
 661{
 662	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u64,
 663				   &fops_u64_ro, &fops_u64_wo);
 664}
 665EXPORT_SYMBOL_GPL(debugfs_create_u64);
 666
 667static int debugfs_ulong_set(void *data, u64 val)
 668{
 669	*(unsigned long *)data = val;
 670	return 0;
 671}
 672
 673static int debugfs_ulong_get(void *data, u64 *val)
 674{
 675	*val = *(unsigned long *)data;
 676	return 0;
 677}
 678DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong, debugfs_ulong_get, debugfs_ulong_set,
 679			"%llu\n");
 680DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_ro, debugfs_ulong_get, NULL, "%llu\n");
 681DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n");
 682
 683/**
 684 * debugfs_create_ulong - create a debugfs file that is used to read and write
 685 * an unsigned long value.
 686 * @name: a pointer to a string containing the name of the file to create.
 687 * @mode: the permission that the file should have
 688 * @parent: a pointer to the parent dentry for this file.  This should be a
 689 *          directory dentry if set.  If this parameter is %NULL, then the
 690 *          file will be created in the root of the debugfs filesystem.
 691 * @value: a pointer to the variable that the file should read to and write
 692 *         from.
 693 *
 694 * This function creates a file in debugfs with the given name that
 695 * contains the value of the variable @value.  If the @mode variable is so
 696 * set, it can be read from, and written to.
 
 
 
 
 
 
 
 
 
 
 697 */
 698void debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent,
 699			  unsigned long *value)
 700{
 701	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_ulong,
 702				   &fops_ulong_ro, &fops_ulong_wo);
 703}
 704EXPORT_SYMBOL_GPL(debugfs_create_ulong);
 705
 706DEFINE_DEBUGFS_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
 707DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
 708DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
 709
 710DEFINE_DEBUGFS_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set,
 711			"0x%04llx\n");
 712DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
 713DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
 714
 715DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set,
 716			"0x%08llx\n");
 717DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
 718DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
 719
 720DEFINE_DEBUGFS_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set,
 721			"0x%016llx\n");
 722DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_ro, debugfs_u64_get, NULL, "0x%016llx\n");
 723DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\n");
 724
 725/*
 726 * debugfs_create_x{8,16,32,64} - create a debugfs file that is used to read and write an unsigned {8,16,32,64}-bit value
 727 *
 728 * These functions are exactly the same as the above functions (but use a hex
 729 * output for the decimal challenged). For details look at the above unsigned
 730 * decimal functions.
 731 */
 732
 733/**
 734 * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value
 735 * @name: a pointer to a string containing the name of the file to create.
 736 * @mode: the permission that the file should have
 737 * @parent: a pointer to the parent dentry for this file.  This should be a
 738 *          directory dentry if set.  If this parameter is %NULL, then the
 739 *          file will be created in the root of the debugfs filesystem.
 740 * @value: a pointer to the variable that the file should read to and write
 741 *         from.
 742 */
 743void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent,
 744		       u8 *value)
 745{
 746	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8,
 747				   &fops_x8_ro, &fops_x8_wo);
 748}
 749EXPORT_SYMBOL_GPL(debugfs_create_x8);
 750
 751/**
 752 * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value
 753 * @name: a pointer to a string containing the name of the file to create.
 754 * @mode: the permission that the file should have
 755 * @parent: a pointer to the parent dentry for this file.  This should be a
 756 *          directory dentry if set.  If this parameter is %NULL, then the
 757 *          file will be created in the root of the debugfs filesystem.
 758 * @value: a pointer to the variable that the file should read to and write
 759 *         from.
 760 */
 761void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent,
 762			u16 *value)
 763{
 764	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x16,
 765				   &fops_x16_ro, &fops_x16_wo);
 766}
 767EXPORT_SYMBOL_GPL(debugfs_create_x16);
 768
 769/**
 770 * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value
 771 * @name: a pointer to a string containing the name of the file to create.
 772 * @mode: the permission that the file should have
 773 * @parent: a pointer to the parent dentry for this file.  This should be a
 774 *          directory dentry if set.  If this parameter is %NULL, then the
 775 *          file will be created in the root of the debugfs filesystem.
 776 * @value: a pointer to the variable that the file should read to and write
 777 *         from.
 778 */
 779void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent,
 780			u32 *value)
 781{
 782	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x32,
 783				   &fops_x32_ro, &fops_x32_wo);
 784}
 785EXPORT_SYMBOL_GPL(debugfs_create_x32);
 786
 787/**
 788 * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value
 789 * @name: a pointer to a string containing the name of the file to create.
 790 * @mode: the permission that the file should have
 791 * @parent: a pointer to the parent dentry for this file.  This should be a
 792 *          directory dentry if set.  If this parameter is %NULL, then the
 793 *          file will be created in the root of the debugfs filesystem.
 794 * @value: a pointer to the variable that the file should read to and write
 795 *         from.
 796 */
 797void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent,
 798			u64 *value)
 799{
 800	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x64,
 801				   &fops_x64_ro, &fops_x64_wo);
 802}
 803EXPORT_SYMBOL_GPL(debugfs_create_x64);
 804
 805
 806static int debugfs_size_t_set(void *data, u64 val)
 807{
 808	*(size_t *)data = val;
 809	return 0;
 810}
 811static int debugfs_size_t_get(void *data, u64 *val)
 812{
 813	*val = *(size_t *)data;
 814	return 0;
 815}
 816DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set,
 817			"%llu\n"); /* %llu and %zu are more or less the same */
 818DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_ro, debugfs_size_t_get, NULL, "%llu\n");
 819DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n");
 820
 821/**
 822 * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value
 823 * @name: a pointer to a string containing the name of the file to create.
 824 * @mode: the permission that the file should have
 825 * @parent: a pointer to the parent dentry for this file.  This should be a
 826 *          directory dentry if set.  If this parameter is %NULL, then the
 827 *          file will be created in the root of the debugfs filesystem.
 828 * @value: a pointer to the variable that the file should read to and write
 829 *         from.
 830 */
 831void debugfs_create_size_t(const char *name, umode_t mode,
 832			   struct dentry *parent, size_t *value)
 833{
 834	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_size_t,
 835				   &fops_size_t_ro, &fops_size_t_wo);
 836}
 837EXPORT_SYMBOL_GPL(debugfs_create_size_t);
 838
 839static int debugfs_atomic_t_set(void *data, u64 val)
 840{
 841	atomic_set((atomic_t *)data, val);
 842	return 0;
 843}
 844static int debugfs_atomic_t_get(void *data, u64 *val)
 845{
 846	*val = atomic_read((atomic_t *)data);
 847	return 0;
 848}
 849DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t, debugfs_atomic_t_get,
 850			debugfs_atomic_t_set, "%lld\n");
 851DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_ro, debugfs_atomic_t_get, NULL,
 852			"%lld\n");
 853DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_wo, NULL, debugfs_atomic_t_set,
 854			"%lld\n");
 855
 856/**
 857 * debugfs_create_atomic_t - create a debugfs file that is used to read and
 858 * write an atomic_t value
 859 * @name: a pointer to a string containing the name of the file to create.
 860 * @mode: the permission that the file should have
 861 * @parent: a pointer to the parent dentry for this file.  This should be a
 862 *          directory dentry if set.  If this parameter is %NULL, then the
 863 *          file will be created in the root of the debugfs filesystem.
 864 * @value: a pointer to the variable that the file should read to and write
 865 *         from.
 866 */
 867void debugfs_create_atomic_t(const char *name, umode_t mode,
 868			     struct dentry *parent, atomic_t *value)
 869{
 870	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_atomic_t,
 871				   &fops_atomic_t_ro, &fops_atomic_t_wo);
 872}
 873EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
 874
 875ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
 876			       size_t count, loff_t *ppos)
 877{
 878	char buf[2];
 879	bool val;
 880	int r;
 881	struct dentry *dentry = F_DENTRY(file);
 882
 883	r = debugfs_file_get(dentry);
 884	if (unlikely(r))
 885		return r;
 886	val = *(bool *)file->private_data;
 887	debugfs_file_put(dentry);
 888
 889	if (val)
 890		buf[0] = 'Y';
 891	else
 892		buf[0] = 'N';
 893	buf[1] = '\n';
 
 894	return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
 895}
 896EXPORT_SYMBOL_GPL(debugfs_read_file_bool);
 897
 898ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
 899				size_t count, loff_t *ppos)
 900{
 
 
 901	bool bv;
 902	int r;
 903	bool *val = file->private_data;
 904	struct dentry *dentry = F_DENTRY(file);
 905
 906	r = kstrtobool_from_user(user_buf, count, &bv);
 907	if (!r) {
 908		r = debugfs_file_get(dentry);
 909		if (unlikely(r))
 910			return r;
 
 911		*val = bv;
 912		debugfs_file_put(dentry);
 913	}
 914
 915	return count;
 916}
 917EXPORT_SYMBOL_GPL(debugfs_write_file_bool);
 918
 919static const struct file_operations fops_bool = {
 920	.read =		debugfs_read_file_bool,
 921	.write =	debugfs_write_file_bool,
 922	.open =		simple_open,
 923	.llseek =	default_llseek,
 924};
 925
 926static const struct file_operations fops_bool_ro = {
 927	.read =		debugfs_read_file_bool,
 928	.open =		simple_open,
 929	.llseek =	default_llseek,
 930};
 931
 932static const struct file_operations fops_bool_wo = {
 933	.write =	debugfs_write_file_bool,
 934	.open =		simple_open,
 935	.llseek =	default_llseek,
 936};
 937
 938/**
 939 * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value
 940 * @name: a pointer to a string containing the name of the file to create.
 941 * @mode: the permission that the file should have
 942 * @parent: a pointer to the parent dentry for this file.  This should be a
 943 *          directory dentry if set.  If this parameter is %NULL, then the
 944 *          file will be created in the root of the debugfs filesystem.
 945 * @value: a pointer to the variable that the file should read to and write
 946 *         from.
 947 *
 948 * This function creates a file in debugfs with the given name that
 949 * contains the value of the variable @value.  If the @mode variable is so
 950 * set, it can be read from, and written to.
 
 
 
 
 
 
 
 
 
 
 951 */
 952void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent,
 953			 bool *value)
 954{
 955	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_bool,
 956				   &fops_bool_ro, &fops_bool_wo);
 957}
 958EXPORT_SYMBOL_GPL(debugfs_create_bool);
 959
 960ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf,
 961			      size_t count, loff_t *ppos)
 962{
 963	struct dentry *dentry = F_DENTRY(file);
 964	char *str, *copy = NULL;
 965	int copy_len, len;
 966	ssize_t ret;
 967
 968	ret = debugfs_file_get(dentry);
 969	if (unlikely(ret))
 970		return ret;
 971
 972	str = *(char **)file->private_data;
 973	len = strlen(str) + 1;
 974	copy = kmalloc(len, GFP_KERNEL);
 975	if (!copy) {
 976		debugfs_file_put(dentry);
 977		return -ENOMEM;
 978	}
 979
 980	copy_len = strscpy(copy, str, len);
 981	debugfs_file_put(dentry);
 982	if (copy_len < 0) {
 983		kfree(copy);
 984		return copy_len;
 985	}
 986
 987	copy[copy_len] = '\n';
 988
 989	ret = simple_read_from_buffer(user_buf, count, ppos, copy, len);
 990	kfree(copy);
 991
 992	return ret;
 993}
 994EXPORT_SYMBOL_GPL(debugfs_create_str);
 995
 996static ssize_t debugfs_write_file_str(struct file *file, const char __user *user_buf,
 997				      size_t count, loff_t *ppos)
 998{
 999	struct dentry *dentry = F_DENTRY(file);
1000	char *old, *new = NULL;
1001	int pos = *ppos;
1002	int r;
1003
1004	r = debugfs_file_get(dentry);
1005	if (unlikely(r))
1006		return r;
1007
1008	old = *(char **)file->private_data;
1009
1010	/* only allow strict concatenation */
1011	r = -EINVAL;
1012	if (pos && pos != strlen(old))
1013		goto error;
1014
1015	r = -E2BIG;
1016	if (pos + count + 1 > PAGE_SIZE)
1017		goto error;
1018
1019	r = -ENOMEM;
1020	new = kmalloc(pos + count + 1, GFP_KERNEL);
1021	if (!new)
1022		goto error;
1023
1024	if (pos)
1025		memcpy(new, old, pos);
1026
1027	r = -EFAULT;
1028	if (copy_from_user(new + pos, user_buf, count))
1029		goto error;
1030
1031	new[pos + count] = '\0';
1032	strim(new);
1033
1034	rcu_assign_pointer(*(char __rcu **)file->private_data, new);
1035	synchronize_rcu();
1036	kfree(old);
1037
1038	debugfs_file_put(dentry);
1039	return count;
1040
1041error:
1042	kfree(new);
1043	debugfs_file_put(dentry);
1044	return r;
1045}
1046
1047static const struct file_operations fops_str = {
1048	.read =		debugfs_read_file_str,
1049	.write =	debugfs_write_file_str,
1050	.open =		simple_open,
1051	.llseek =	default_llseek,
1052};
1053
1054static const struct file_operations fops_str_ro = {
1055	.read =		debugfs_read_file_str,
1056	.open =		simple_open,
1057	.llseek =	default_llseek,
1058};
1059
1060static const struct file_operations fops_str_wo = {
1061	.write =	debugfs_write_file_str,
1062	.open =		simple_open,
1063	.llseek =	default_llseek,
1064};
1065
1066/**
1067 * debugfs_create_str - create a debugfs file that is used to read and write a string value
1068 * @name: a pointer to a string containing the name of the file to create.
1069 * @mode: the permission that the file should have
1070 * @parent: a pointer to the parent dentry for this file.  This should be a
1071 *          directory dentry if set.  If this parameter is %NULL, then the
1072 *          file will be created in the root of the debugfs filesystem.
1073 * @value: a pointer to the variable that the file should read to and write
1074 *         from.
1075 *
1076 * This function creates a file in debugfs with the given name that
1077 * contains the value of the variable @value.  If the @mode variable is so
1078 * set, it can be read from, and written to.
1079 */
1080void debugfs_create_str(const char *name, umode_t mode,
1081			struct dentry *parent, char **value)
1082{
1083	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_str,
1084				   &fops_str_ro, &fops_str_wo);
1085}
1086
1087static ssize_t read_file_blob(struct file *file, char __user *user_buf,
1088			      size_t count, loff_t *ppos)
1089{
1090	struct debugfs_blob_wrapper *blob = file->private_data;
1091	struct dentry *dentry = F_DENTRY(file);
1092	ssize_t r;
1093
1094	r = debugfs_file_get(dentry);
1095	if (unlikely(r))
1096		return r;
1097	r = simple_read_from_buffer(user_buf, count, ppos, blob->data,
1098				blob->size);
1099	debugfs_file_put(dentry);
1100	return r;
1101}
1102
1103static ssize_t write_file_blob(struct file *file, const char __user *user_buf,
1104			       size_t count, loff_t *ppos)
1105{
1106	struct debugfs_blob_wrapper *blob = file->private_data;
1107	struct dentry *dentry = F_DENTRY(file);
1108	ssize_t r;
1109
1110	r = debugfs_file_get(dentry);
1111	if (unlikely(r))
1112		return r;
1113	r = simple_write_to_buffer(blob->data, blob->size, ppos, user_buf,
1114				   count);
1115
1116	debugfs_file_put(dentry);
1117	return r;
1118}
1119
1120static const struct file_operations fops_blob = {
1121	.read =		read_file_blob,
1122	.write =	write_file_blob,
1123	.open =		simple_open,
1124	.llseek =	default_llseek,
1125};
1126
1127/**
1128 * debugfs_create_blob - create a debugfs file that is used to read and write
1129 * a binary blob
1130 * @name: a pointer to a string containing the name of the file to create.
1131 * @mode: the permission that the file should have
1132 * @parent: a pointer to the parent dentry for this file.  This should be a
1133 *          directory dentry if set.  If this parameter is %NULL, then the
1134 *          file will be created in the root of the debugfs filesystem.
1135 * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer
1136 *        to the blob data and the size of the data.
1137 *
1138 * This function creates a file in debugfs with the given name that exports
1139 * @blob->data as a binary blob. If the @mode variable is so set it can be
1140 * read from and written to.
1141 *
1142 * This function will return a pointer to a dentry if it succeeds.  This
1143 * pointer must be passed to the debugfs_remove() function when the file is
1144 * to be removed (no automatic cleanup happens if your module is unloaded,
1145 * you are responsible here.)  If an error occurs, ERR_PTR(-ERROR) will be
1146 * returned.
1147 *
1148 * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV) will
1149 * be returned.
 
 
1150 */
1151struct dentry *debugfs_create_blob(const char *name, umode_t mode,
1152				   struct dentry *parent,
1153				   struct debugfs_blob_wrapper *blob)
1154{
1155	return debugfs_create_file_unsafe(name, mode & 0644, parent, blob, &fops_blob);
1156}
1157EXPORT_SYMBOL_GPL(debugfs_create_blob);
1158
 
 
 
 
 
1159static size_t u32_format_array(char *buf, size_t bufsize,
1160			       u32 *array, int array_size)
1161{
1162	size_t ret = 0;
1163
1164	while (--array_size >= 0) {
1165		size_t len;
1166		char term = array_size ? ' ' : '\n';
1167
1168		len = snprintf(buf, bufsize, "%u%c", *array++, term);
1169		ret += len;
1170
1171		buf += len;
1172		bufsize -= len;
1173	}
1174	return ret;
1175}
1176
1177static int u32_array_open(struct inode *inode, struct file *file)
1178{
1179	struct debugfs_u32_array *data = inode->i_private;
1180	int size, elements = data->n_elements;
1181	char *buf;
1182
1183	/*
1184	 * Max size:
1185	 *  - 10 digits + ' '/'\n' = 11 bytes per number
1186	 *  - terminating NUL character
1187	 */
1188	size = elements*11;
1189	buf = kmalloc(size+1, GFP_KERNEL);
1190	if (!buf)
1191		return -ENOMEM;
1192	buf[size] = 0;
1193
1194	file->private_data = buf;
1195	u32_format_array(buf, size, data->array, data->n_elements);
1196
1197	return nonseekable_open(inode, file);
1198}
1199
1200static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len,
1201			      loff_t *ppos)
1202{
1203	size_t size = strlen(file->private_data);
1204
1205	return simple_read_from_buffer(buf, len, ppos,
1206					file->private_data, size);
1207}
1208
1209static int u32_array_release(struct inode *inode, struct file *file)
1210{
1211	kfree(file->private_data);
1212
1213	return 0;
1214}
1215
1216static const struct file_operations u32_array_fops = {
1217	.owner	 = THIS_MODULE,
1218	.open	 = u32_array_open,
1219	.release = u32_array_release,
1220	.read	 = u32_array_read,
1221	.llseek  = no_llseek,
1222};
1223
1224/**
1225 * debugfs_create_u32_array - create a debugfs file that is used to read u32
1226 * array.
1227 * @name: a pointer to a string containing the name of the file to create.
1228 * @mode: the permission that the file should have.
1229 * @parent: a pointer to the parent dentry for this file.  This should be a
1230 *          directory dentry if set.  If this parameter is %NULL, then the
1231 *          file will be created in the root of the debugfs filesystem.
1232 * @array: wrapper struct containing data pointer and size of the array.
 
1233 *
1234 * This function creates a file in debugfs with the given name that exports
1235 * @array as data. If the @mode variable is so set it can be read from.
1236 * Writing is not supported. Seek within the file is also not supported.
1237 * Once array is created its size can not be changed.
 
 
 
1238 */
1239void debugfs_create_u32_array(const char *name, umode_t mode,
1240			      struct dentry *parent,
1241			      struct debugfs_u32_array *array)
1242{
1243	debugfs_create_file_unsafe(name, mode, parent, array, &u32_array_fops);
 
 
 
 
 
 
 
 
1244}
1245EXPORT_SYMBOL_GPL(debugfs_create_u32_array);
1246
1247#ifdef CONFIG_HAS_IOMEM
1248
1249/*
1250 * The regset32 stuff is used to print 32-bit registers using the
1251 * seq_file utilities. We offer printing a register set in an already-opened
1252 * sequential file or create a debugfs file that only prints a regset32.
1253 */
1254
1255/**
1256 * debugfs_print_regs32 - use seq_print to describe a set of registers
1257 * @s: the seq_file structure being used to generate output
1258 * @regs: an array if struct debugfs_reg32 structures
1259 * @nregs: the length of the above array
1260 * @base: the base address to be used in reading the registers
1261 * @prefix: a string to be prefixed to every output line
1262 *
1263 * This function outputs a text block describing the current values of
1264 * some 32-bit hardware registers. It is meant to be used within debugfs
1265 * files based on seq_file that need to show registers, intermixed with other
1266 * information. The prefix argument may be used to specify a leading string,
1267 * because some peripherals have several blocks of identical registers,
1268 * for example configuration of dma channels
1269 */
1270void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
1271			  int nregs, void __iomem *base, char *prefix)
1272{
1273	int i;
1274
1275	for (i = 0; i < nregs; i++, regs++) {
1276		if (prefix)
1277			seq_printf(s, "%s", prefix);
1278		seq_printf(s, "%s = 0x%08x\n", regs->name,
1279			   readl(base + regs->offset));
1280		if (seq_has_overflowed(s))
1281			break;
1282	}
1283}
1284EXPORT_SYMBOL_GPL(debugfs_print_regs32);
1285
1286static int debugfs_regset32_show(struct seq_file *s, void *data)
1287{
1288	struct debugfs_regset32 *regset = s->private;
1289
1290	if (regset->dev)
1291		pm_runtime_get_sync(regset->dev);
1292
1293	debugfs_print_regs32(s, regset->regs, regset->nregs, regset->base, "");
1294
1295	if (regset->dev)
1296		pm_runtime_put(regset->dev);
1297
1298	return 0;
1299}
1300
1301DEFINE_SHOW_ATTRIBUTE(debugfs_regset32);
 
 
 
 
 
 
 
 
 
 
1302
1303/**
1304 * debugfs_create_regset32 - create a debugfs file that returns register values
1305 * @name: a pointer to a string containing the name of the file to create.
1306 * @mode: the permission that the file should have
1307 * @parent: a pointer to the parent dentry for this file.  This should be a
1308 *          directory dentry if set.  If this parameter is %NULL, then the
1309 *          file will be created in the root of the debugfs filesystem.
1310 * @regset: a pointer to a struct debugfs_regset32, which contains a pointer
1311 *          to an array of register definitions, the array size and the base
1312 *          address where the register bank is to be found.
1313 *
1314 * This function creates a file in debugfs with the given name that reports
1315 * the names and values of a set of 32-bit registers. If the @mode variable
1316 * is so set it can be read from. Writing is not supported.
1317 */
1318void debugfs_create_regset32(const char *name, umode_t mode,
1319			     struct dentry *parent,
1320			     struct debugfs_regset32 *regset)
 
 
 
 
 
 
 
 
 
 
1321{
1322	debugfs_create_file(name, mode, parent, regset, &debugfs_regset32_fops);
1323}
1324EXPORT_SYMBOL_GPL(debugfs_create_regset32);
1325
1326#endif /* CONFIG_HAS_IOMEM */
1327
1328struct debugfs_devm_entry {
1329	int (*read)(struct seq_file *seq, void *data);
1330	struct device *dev;
1331};
1332
1333static int debugfs_devm_entry_open(struct inode *inode, struct file *f)
1334{
1335	struct debugfs_devm_entry *entry = inode->i_private;
1336
1337	return single_open(f, entry->read, entry->dev);
1338}
1339
1340static const struct file_operations debugfs_devm_entry_ops = {
1341	.owner = THIS_MODULE,
1342	.open = debugfs_devm_entry_open,
1343	.release = single_release,
1344	.read = seq_read,
1345	.llseek = seq_lseek
1346};
1347
1348/**
1349 * debugfs_create_devm_seqfile - create a debugfs file that is bound to device.
1350 *
1351 * @dev: device related to this debugfs file.
1352 * @name: name of the debugfs file.
1353 * @parent: a pointer to the parent dentry for this file.  This should be a
1354 *	directory dentry if set.  If this parameter is %NULL, then the
1355 *	file will be created in the root of the debugfs filesystem.
1356 * @read_fn: function pointer called to print the seq_file content.
1357 */
1358void debugfs_create_devm_seqfile(struct device *dev, const char *name,
1359				 struct dentry *parent,
1360				 int (*read_fn)(struct seq_file *s, void *data))
 
1361{
1362	struct debugfs_devm_entry *entry;
1363
1364	if (IS_ERR(parent))
1365		return;
1366
1367	entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL);
1368	if (!entry)
1369		return;
1370
1371	entry->read = read_fn;
1372	entry->dev = dev;
1373
1374	debugfs_create_file(name, S_IRUGO, parent, entry,
1375			    &debugfs_devm_entry_ops);
1376}
1377EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile);