3  * Unit tests and benchmarks for the CRC library functions
11 #include <linux/crc-t10dif.h>
27  * struct crc_variant - describes a CRC variant
28  * @bits: Number of bits in the CRC, 1 <= @bits <= 64.
29  * @le: true if it's a "little endian" CRC (reversed mapping between bits and
30  *	polynomial coefficients in each byte), false if it's a "big endian" CRC
34  * @func: The function to compute a CRC.  The type signature uses u64 so that it
35  *	  can fit any CRC up to CRC-64.
42 	u64 (*func)(u64 crc, const u8 *p, size_t len);
63 /* Reference implementation of any CRC variant */
65 		   u64 crc, const u8 *p, size_t len)  in crc_ref()
72 				crc ^= (p[i] >> j) & 1;  in crc_ref()
73 				crc = (crc >> 1) ^ ((crc & 1) ? v->poly : 0);  in crc_ref()
75 				crc ^= (u64)((p[i] >> (7 - j)) & 1) <<  in crc_ref()
77 				if (crc & (1ULL << (v->bits - 1)))  in crc_ref()
78 					crc = ((crc << 1) ^ v->poly) &  in crc_ref()
81 					crc <<= 1;  in crc_ref()
85 	return crc;  in crc_ref()
111 /* Generate a random initial CRC. */
173 		 * Compute the CRC, and verify that it equals the CRC computed  in crc_main_test()
188 /* Test that CRC(concat(A, B)) == combine_CRCs(CRC(A), CRC(B), len(B)). */
205 				    "CRC combination gave wrong result with len1=%zu len2=%zu\n",  in crc_combine_test()
219 	      u64 (*crc_func)(u64 crc, const u8 *p, size_t len))  in crc_benchmark()  argument
226 	 * Some of the CRC library functions are marked as __pure, so use  in crc_benchmark()
229 	volatile u64 crc = 0;  in crc_benchmark()  local
237 		crc = crc_func(crc, test_buffer, CRC_KUNIT_MAX_LEN);  in crc_benchmark()
246 			crc = crc_func(crc, test_buffer, len);  in crc_benchmark()
256 static u64 crc16_wrapper(u64 crc, const u8 *p, size_t len)  in crc16_wrapper()  argument
258 	return crc16(crc, p, len);  in crc16_wrapper()
280 static u64 crc_t10dif_wrapper(u64 crc, const u8 *p, size_t len)  in crc_t10dif_wrapper()  argument
282 	return crc_t10dif_update(crc, p, len);  in crc_t10dif_wrapper()
304 static u64 crc32_le_wrapper(u64 crc, const u8 *p, size_t len)  in crc32_le_wrapper()  argument
306 	return crc32_le(crc, p, len);  in crc32_le_wrapper()
334 static u64 crc32_be_wrapper(u64 crc, const u8 *p, size_t len)  in crc32_be_wrapper()  argument
336 	return crc32_be(crc, p, len);  in crc32_be_wrapper()
358 static u64 crc32c_wrapper(u64 crc, const u8 *p, size_t len)  in crc32c_wrapper()  argument
360 	return crc32c(crc, p, len);  in crc32c_wrapper()
388 static u64 crc64_be_wrapper(u64 crc, const u8 *p, size_t len)  in crc64_be_wrapper()  argument
390 	return crc64_be(crc, p, len);  in crc64_be_wrapper()
427 	.name = "crc",
434 MODULE_DESCRIPTION("Unit tests and benchmarks for the CRC library functions");