5  * This file is a "template" that generates a CRC function optimized using the
7  * file must define the following parameters to specify the type of CRC:
9  *	crc_t: the data type of the CRC, e.g. u32 for a 32-bit CRC
10  *	LSB_CRC: 0 for a msb (most-significant-bit) first CRC, i.e. natural
12  *	         1 for a lsb (least-significant-bit) first CRC, i.e. reflected
59  * polynomial whose bit order matches the CRC's bit order.
75 /* XOR @crc into the end of @msgpoly that represents the high-order terms. */
77 crc_clmul_prep(crc_t crc, unsigned long msgpoly)  in crc_clmul_prep()  argument
80 	return msgpoly ^ crc;  in crc_clmul_prep()
82 	return msgpoly ^ ((unsigned long)crc << (BITS_PER_LONG - CRC_BITS));  in crc_clmul_prep()
88  * modulo the generator polynomial G.  This gives the CRC of @msgpoly.
126 	 *    crc := (msgpoly * x^n) + (G * floor((msgpoly * x^n) / G))  in crc_clmul_long()
133 	 *    crc := ((G - x^n) * floor((msgpoly * x^n) / G)) mod x^n  in crc_clmul_long()
136 	 * a shift, as the crc ends up in the physically low n bits from clmulr:  in crc_clmul_long()
139 	 *    crc := floor(product / x^(BITS_PER_LONG + 1 - n)) mod x^n  in crc_clmul_long()
152 /* Update @crc with the data from @msgpoly. */
154 crc_clmul_update_long(crc_t crc, unsigned long msgpoly,  in crc_clmul_update_long()  argument
157 	return crc_clmul_long(crc_clmul_prep(crc, msgpoly), consts);  in crc_clmul_update_long()
160 /* Update @crc with 1 <= @len < sizeof(unsigned long) bytes of data. */
162 crc_clmul_update_partial(crc_t crc, const u8 *p, size_t len,  in crc_clmul_update_partial()  argument
180 		msgpoly ^= (unsigned long)crc << (BITS_PER_LONG - 8*len);  in crc_clmul_update_partial()
182 		msgpoly ^= (unsigned long)crc << (8*len - CRC_BITS);  in crc_clmul_update_partial()
187 	msgpoly ^= (unsigned long)crc << (BITS_PER_LONG - 8*len);  in crc_clmul_update_partial()
188 	return crc_clmul_long(msgpoly, consts) ^ (crc >> (8*len));  in crc_clmul_update_partial()
190 	msgpoly ^= crc >> (CRC_BITS - 8*len);  in crc_clmul_update_partial()
191 	return crc_clmul_long(msgpoly, consts) ^ (crc << (8*len));  in crc_clmul_update_partial()
196 crc_clmul(crc_t crc, const void *p, size_t len,  in crc_clmul()  argument
201 	/* This implementation assumes that the CRC fits in an unsigned long. */  in crc_clmul()
208 		crc = crc_clmul_update_partial(crc, p, align, consts);  in crc_clmul()
216 		m0 = crc_clmul_prep(crc, crc_load_long(p));  in crc_clmul()
251 		crc = crc_clmul_long(m0, consts);  in crc_clmul()
252 		crc = crc_clmul_update_long(crc, m1, consts);  in crc_clmul()
256 		crc = crc_clmul_update_long(crc, crc_load_long(p), consts);  in crc_clmul()
262 		crc = crc_clmul_update_partial(crc, p, len, consts);  in crc_clmul()
264 	return crc;  in crc_clmul()