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-rw-r--r--include/linux/crc32.h40
1 files changed, 40 insertions, 0 deletions
diff --git a/include/linux/crc32.h b/include/linux/crc32.h
index 68267b64bb98..7d275c4fc011 100644
--- a/include/linux/crc32.h
+++ b/include/linux/crc32.h
@@ -11,8 +11,48 @@
extern u32 crc32_le(u32 crc, unsigned char const *p, size_t len);
extern u32 crc32_be(u32 crc, unsigned char const *p, size_t len);
+/**
+ * crc32_le_combine - Combine two crc32 check values into one. For two
+ * sequences of bytes, seq1 and seq2 with lengths len1
+ * and len2, crc32_le() check values were calculated
+ * for each, crc1 and crc2.
+ *
+ * @crc1: crc32 of the first block
+ * @crc2: crc32 of the second block
+ * @len2: length of the second block
+ *
+ * Return: The crc32_le() check value of seq1 and seq2 concatenated,
+ * requiring only crc1, crc2, and len2. Note: If seq_full denotes
+ * the concatenated memory area of seq1 with seq2, and crc_full
+ * the crc32_le() value of seq_full, then crc_full ==
+ * crc32_le_combine(crc1, crc2, len2) when crc_full was seeded
+ * with the same initializer as crc1, and crc2 seed was 0. See
+ * also crc32_combine_test().
+ */
+extern u32 crc32_le_combine(u32 crc1, u32 crc2, size_t len2);
+
extern u32 __crc32c_le(u32 crc, unsigned char const *p, size_t len);
+/**
+ * __crc32c_le_combine - Combine two crc32c check values into one. For two
+ * sequences of bytes, seq1 and seq2 with lengths len1
+ * and len2, __crc32c_le() check values were calculated
+ * for each, crc1 and crc2.
+ *
+ * @crc1: crc32c of the first block
+ * @crc2: crc32c of the second block
+ * @len2: length of the second block
+ *
+ * Return: The __crc32c_le() check value of seq1 and seq2 concatenated,
+ * requiring only crc1, crc2, and len2. Note: If seq_full denotes
+ * the concatenated memory area of seq1 with seq2, and crc_full
+ * the __crc32c_le() value of seq_full, then crc_full ==
+ * __crc32c_le_combine(crc1, crc2, len2) when crc_full was
+ * seeded with the same initializer as crc1, and crc2 seed
+ * was 0. See also crc32c_combine_test().
+ */
+extern u32 __crc32c_le_combine(u32 crc1, u32 crc2, size_t len2);
+
#define crc32(seed, data, length) crc32_le(seed, (unsigned char const *)(data), length)
/*