3  * Unit tests and benchmarks for the CRC library functions
12 #include <linux/crc-t10dif.h>
28  * struct crc_variant - describes a CRC variant
29  * @bits: Number of bits in the CRC, 1 <= @bits <= 64.
30  * @le: true if it's a "little endian" CRC (reversed mapping between bits and
31  *	polynomial coefficients in each byte), false if it's a "big endian" CRC
35  * @func: The function to compute a CRC.  The type signature uses u64 so that it
36  *	  can fit any CRC up to CRC-64.  The CRC is passed in, and is expected
38  *	  function is expected to *not* invert the CRC at the beginning and end.
45 	u64 (*func)(u64 crc, const u8 *p, size_t len);
66 /* Reference implementation of any CRC variant */
68 		   u64 crc, const u8 *p, size_t len)  in crc_ref()
75 				crc ^= (p[i] >> j) & 1;  in crc_ref()
76 				crc = (crc >> 1) ^ ((crc & 1) ? v->poly : 0);  in crc_ref()
78 				crc ^= (u64)((p[i] >> (7 - j)) & 1) <<  in crc_ref()
80 				if (crc & (1ULL << (v->bits - 1)))  in crc_ref()
81 					crc = ((crc << 1) ^ v->poly) &  in crc_ref()
84 					crc <<= 1;  in crc_ref()
88 	return crc;  in crc_ref()
114 /* Generate a random initial CRC. */
176 		 * Compute the CRC, and verify that it equals the CRC computed  in crc_main_test()
191 /* Test that CRC(concat(A, B)) == combine_CRCs(CRC(A), CRC(B), len(B)). */
208 				    "CRC combination gave wrong result with len1=%zu len2=%zu\n",  in crc_combine_test()
222 	      u64 (*crc_func)(u64 crc, const u8 *p, size_t len))  in crc_benchmark()  argument
229 	 * The CRC value that this function computes in a series of calls to  in crc_benchmark()
233 	volatile u64 crc = 0;  in crc_benchmark()  local
241 		crc = crc_func(crc, test_buffer, CRC_KUNIT_MAX_LEN);  in crc_benchmark()
250 			crc = crc_func(crc, test_buffer, len);  in crc_benchmark()
260 static u64 crc7_be_wrapper(u64 crc, const u8 *p, size_t len)  in crc7_be_wrapper()  argument
263 	 * crc7_be() left-aligns the 7-bit CRC in a u8, whereas the test wants a  in crc7_be_wrapper()
264 	 * right-aligned CRC (in a u64).  Convert between the conventions.  in crc7_be_wrapper()
266 	return crc7_be(crc << 1, p, len) >> 1;  in crc7_be_wrapper()
287 static u64 crc16_wrapper(u64 crc, const u8 *p, size_t len)  in crc16_wrapper()  argument
289 	return crc16(crc, p, len);  in crc16_wrapper()
311 static u64 crc_t10dif_wrapper(u64 crc, const u8 *p, size_t len)  in crc_t10dif_wrapper()  argument
313 	return crc_t10dif_update(crc, p, len);  in crc_t10dif_wrapper()
335 static u64 crc32_le_wrapper(u64 crc, const u8 *p, size_t len)  in crc32_le_wrapper()  argument
337 	return crc32_le(crc, p, len);  in crc32_le_wrapper()
365 static u64 crc32_be_wrapper(u64 crc, const u8 *p, size_t len)  in crc32_be_wrapper()  argument
367 	return crc32_be(crc, p, len);  in crc32_be_wrapper()
389 static u64 crc32c_wrapper(u64 crc, const u8 *p, size_t len)  in crc32c_wrapper()  argument
391 	return crc32c(crc, p, len);  in crc32c_wrapper()
419 static u64 crc64_be_wrapper(u64 crc, const u8 *p, size_t len)  in crc64_be_wrapper()  argument
421 	return crc64_be(crc, p, len);  in crc64_be_wrapper()
443 static u64 crc64_nvme_wrapper(u64 crc, const u8 *p, size_t len)  in crc64_nvme_wrapper()  argument
446 	return ~crc64_nvme(~crc, p, len);  in crc64_nvme_wrapper()
487 	.name = "crc",
494 MODULE_DESCRIPTION("Unit tests and benchmarks for the CRC library functions");