3  * Unit tests and benchmarks for the CRC library functions
13 #include <linux/crc-t10dif.h>
29  * struct crc_variant - describes a CRC variant
30  * @bits: Number of bits in the CRC, 1 <= @bits <= 64.
31  * @le: true if it's a "little endian" CRC (reversed mapping between bits and
32  *	polynomial coefficients in each byte), false if it's a "big endian" CRC
36  * @func: The function to compute a CRC.  The type signature uses u64 so that it
37  *	  can fit any CRC up to CRC-64.  The CRC is passed in, and is expected
39  *	  function is expected to *not* invert the CRC at the beginning and end.
45 	u64 (*func)(u64 crc, const u8 *p, size_t len);
65 /* Reference implementation of any CRC variant */
67 		   u64 crc, const u8 *p, size_t len)  in crc_ref()
74 				crc ^= (p[i] >> j) & 1;  in crc_ref()
75 				crc = (crc >> 1) ^ ((crc & 1) ? v->poly : 0);  in crc_ref()
77 				crc ^= (u64)((p[i] >> (7 - j)) & 1) <<  in crc_ref()
79 				if (crc & (1ULL << (v->bits - 1)))  in crc_ref()
80 					crc = ((crc << 1) ^ v->poly) &  in crc_ref()
83 					crc <<= 1;  in crc_ref()
87 	return crc;  in crc_ref()
113 /* Generate a random initial CRC. */
156  * Compute the CRC of one of the test messages and verify that it matches the
157  * expected CRC from @state->expected_crcs.  To increase the chance of detecting
220 		 * Compute the CRC, and verify that it equals the CRC computed  in crc_test()
235 	      u64 (*crc_func)(u64 crc, const u8 *p, size_t len))  in crc_benchmark()  argument
242 	 * The CRC value that this function computes in a series of calls to  in crc_benchmark()
246 	volatile u64 crc = 0;  in crc_benchmark()  local
254 		crc = crc_func(crc, test_buffer, CRC_KUNIT_MAX_LEN);  in crc_benchmark()
263 			crc = crc_func(crc, test_buffer, len);  in crc_benchmark()
273 static u64 crc7_be_wrapper(u64 crc, const u8 *p, size_t len)  in crc7_be_wrapper()  argument
276 	 * crc7_be() left-aligns the 7-bit CRC in a u8, whereas the test wants a  in crc7_be_wrapper()
277 	 * right-aligned CRC (in a u64).  Convert between the conventions.  in crc7_be_wrapper()
279 	return crc7_be(crc << 1, p, len) >> 1;  in crc7_be_wrapper()
300 static u64 crc16_wrapper(u64 crc, const u8 *p, size_t len)  in crc16_wrapper()  argument
302 	return crc16(crc, p, len);  in crc16_wrapper()
324 static u64 crc_t10dif_wrapper(u64 crc, const u8 *p, size_t len)  in crc_t10dif_wrapper()  argument
326 	return crc_t10dif_update(crc, p, len);  in crc_t10dif_wrapper()
348 static u64 crc32_le_wrapper(u64 crc, const u8 *p, size_t len)  in crc32_le_wrapper()  argument
350 	return crc32_le(crc, p, len);  in crc32_le_wrapper()
372 static u64 crc32_be_wrapper(u64 crc, const u8 *p, size_t len)  in crc32_be_wrapper()  argument
374 	return crc32_be(crc, p, len);  in crc32_be_wrapper()
396 static u64 crc32c_wrapper(u64 crc, const u8 *p, size_t len)  in crc32c_wrapper()  argument
398 	return crc32c(crc, p, len);  in crc32c_wrapper()
420 static u64 crc64_be_wrapper(u64 crc, const u8 *p, size_t len)  in crc64_be_wrapper()  argument
422 	return crc64_be(crc, p, len);  in crc64_be_wrapper()
444 static u64 crc64_nvme_wrapper(u64 crc, const u8 *p, size_t len)  in crc64_nvme_wrapper()  argument
447 	return ~crc64_nvme(~crc, p, len);  in crc64_nvme_wrapper()
488 	.name = "crc",
495 MODULE_DESCRIPTION("Unit tests and benchmarks for the CRC library functions");