litmus-rt.git - The LITMUS^RT kernel.

index : litmus-rt.git

The LITMUS^RT kernel.

Bjoern Brandenburg

about summary refs log tree commit diff stats

path: root/arch/x86/kernel/apic/numaq_32.c

diff options

Diffstat (limited to 'arch/x86/kernel/apic/numaq_32.c')

0 files changed, 0 insertions, 0 deletions

id='n178' href='#n178'>178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529

/*
 * Oct 15, 2000 Matt Domsch <Matt_Domsch@dell.com>
 * Nicer crc32 functions/docs submitted by linux@horizon.com.  Thanks!
 * Code was from the public domain, copyright abandoned.  Code was
 * subsequently included in the kernel, thus was re-licensed under the
 * GNU GPL v2.
 *
 * Oct 12, 2000 Matt Domsch <Matt_Domsch@dell.com>
 * Same crc32 function was used in 5 other places in the kernel.
 * I made one version, and deleted the others.
 * There are various incantations of crc32().  Some use a seed of 0 or ~0.
 * Some xor at the end with ~0.  The generic crc32() function takes
 * seed as an argument, and doesn't xor at the end.  Then individual
 * users can do whatever they need.
 *   drivers/net/smc9194.c uses seed ~0, doesn't xor with ~0.
 *   fs/jffs2 uses seed 0, doesn't xor with ~0.
 *   fs/partitions/efi.c uses seed ~0, xor's with ~0.
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2.  See the file COPYING for more details.
 */

#include <linux/crc32.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/compiler.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <asm/atomic.h>
#include "crc32defs.h"
#if CRC_LE_BITS == 8
#define tole(x) __constant_cpu_to_le32(x)
#define tobe(x) __constant_cpu_to_be32(x)
#else
#define tole(x) (x)
#define tobe(x) (x)
#endif
#include "crc32table.h"

MODULE_AUTHOR("Matt Domsch <Matt_Domsch@dell.com>");
MODULE_DESCRIPTION("Ethernet CRC32 calculations");
MODULE_LICENSE("GPL");

#if CRC_LE_BITS == 1
/*
 * In fact, the table-based code will work in this case, but it can be
 * simplified by inlining the table in ?: form.
 */

/**
 * crc32_le() - Calculate bitwise little-endian Ethernet AUTODIN II CRC32
 * @crc - seed value for computation.  ~0 for Ethernet, sometimes 0 for
 *        other uses, or the previous crc32 value if computing incrementally.
 * @p   - pointer to buffer over which CRC is run
 * @len - length of buffer @p
 * 
 */
u32 __attribute_pure__ crc32_le(u32 crc, unsigned char const *p, size_t len)
{
	int i;
	while (len--) {
		crc ^= *p++;
		for (i = 0; i < 8; i++)
			crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
	}
	return crc;
}
#else				/* Table-based approach */

/**
 * crc32_le() - Calculate bitwise little-endian Ethernet AUTODIN II CRC32
 * @crc - seed value for computation.  ~0 for Ethernet, sometimes 0 for
 *        other uses, or the previous crc32 value if computing incrementally.
 * @p   - pointer to buffer over which CRC is run
 * @len - length of buffer @p
 * 
 */
u32 __attribute_pure__ crc32_le(u32 crc, unsigned char const *p, size_t len)
{
# if CRC_LE_BITS == 8
	const u32      *b =(u32 *)p;
	const u32      *tab = crc32table_le;

# ifdef __LITTLE_ENDIAN
#  define DO_CRC(x) crc = tab[ (crc ^ (x)) & 255 ] ^ (crc>>8)
# else
#  define DO_CRC(x) crc = tab[ ((crc >> 24) ^ (x)) & 255] ^ (crc<<8)
# endif

	crc = __cpu_to_le32(crc);
	/* Align it */
	if(unlikely(((long)b)&3 && len)){
		do {
			u8 *p = (u8 *)b;
			DO_CRC(*p++);
			b = (void *)p;
		} while ((--len) && ((long)b)&3 );
	}
	if(likely(len >= 4)){
		/* load data 32 bits wide, xor data 32 bits wide. */
		size_t save_len = len & 3;
	        len = len >> 2;
		--b; /* use pre increment below(*++b) for speed */
		do {
			crc ^= *++b;
			DO_CRC(0);
			DO_CRC(0);
			DO_CRC(0);
			DO_CRC(0);
		} while (--len);
		b++; /* point to next byte(s) */
		len = save_len;
	}
	/* And the last few bytes */
	if(len){
		do {
			u8 *p = (u8 *)b;
			DO_CRC(*p++);
			b = (void *)p;
		} while (--len);
	}

	return __le32_to_cpu(crc);
#undef ENDIAN_SHIFT
#undef DO_CRC

# elif CRC_LE_BITS == 4
	while (len--) {
		crc ^= *p++;
		crc = (crc >> 4) ^ crc32table_le[crc & 15];
		crc = (crc >> 4) ^ crc32table_le[crc & 15];
	}
	return crc;
# elif CRC_LE_BITS == 2
	while (len--) {
		crc ^= *p++;
		crc = (crc >> 2) ^ crc32table_le[crc & 3];
		crc = (crc >> 2) ^ crc32table_le[crc & 3];
		crc = (crc >> 2) ^ crc32table_le[crc & 3];
		crc = (crc >> 2) ^ crc32table_le[crc & 3];
	}
	return crc;
# endif
}
#endif

#if CRC_BE_BITS == 1
/*
 * In fact, the table-based code will work in this case, but it can be
 * simplified by inlining the table in ?: form.
 */

/**
 * crc32_be() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32
 * @crc - seed value for computation.  ~0 for Ethernet, sometimes 0 for
 *        other uses, or the previous crc32 value if computing incrementally.
 * @p   - pointer to buffer over which CRC is run
 * @len - length of buffer @p
 * 
 */
u32 __attribute_pure__ crc32_be(u32 crc, unsigned char const *p, size_t len)
{
	int i;
	while (len--) {
		crc ^= *p++ << 24;
		for (i = 0; i < 8; i++)
			crc =
			    (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE :
					  0);
	}
	return crc;
}

#else				/* Table-based approach */
/**
 * crc32_be() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32
 * @crc - seed value for computation.  ~0 for Ethernet, sometimes 0 for
 *        other uses, or the previous crc32 value if computing incrementally.
 * @p   - pointer to buffer over which CRC is run
 * @len - length of buffer @p
 * 
 */
u32 __attribute_pure__ crc32_be(u32 crc, unsigned char const *p, size_t len)
{
# if CRC_BE_BITS == 8
	const u32      *b =(u32 *)p;
	const u32      *tab = crc32table_be;

# ifdef __LITTLE_ENDIAN
#  define DO_CRC(x) crc = tab[ (crc ^ (x)) & 255 ] ^ (crc>>8)
# else
#  define DO_CRC(x) crc = tab[ ((crc >> 24) ^ (x)) & 255] ^ (crc<<8)
# endif

	crc = __cpu_to_be32(crc);
	/* Align it */
	if(unlikely(((long)b)&3 && len)){
		do {
			u8 *p = (u8 *)b;
			DO_CRC(*p++);
			b = (u32 *)p;
		} while ((--len) && ((long)b)&3 );
	}
	if(likely(len >= 4)){
		/* load data 32 bits wide, xor data 32 bits wide. */
		size_t save_len = len & 3;
	        len = len >> 2;
		--b; /* use pre increment below(*++b) for speed */
		do {
			crc ^= *++b;
			DO_CRC(0);
			DO_CRC(0);
			DO_CRC(0);
			DO_CRC(0);
		} while (--len);
		b++; /* point to next byte(s) */
		len = save_len;


context:
space:
mode: