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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /include/linux/crc32.h
Initial import
Diffstat (limited to 'include/linux/crc32.h')
-rw-r--r--include/linux/crc32.h79
1 files changed, 79 insertions, 0 deletions
diff --git a/include/linux/crc32.h b/include/linux/crc32.h
new file mode 100644
index 000000000..9e8a032c1
--- /dev/null
+++ b/include/linux/crc32.h
@@ -0,0 +1,79 @@
+/*
+ * crc32.h
+ * See linux/lib/crc32.c for license and changes
+ */
+#ifndef _LINUX_CRC32_H
+#define _LINUX_CRC32_H
+
+#include <linux/types.h>
+#include <linux/bitrev.h>
+
+u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len);
+u32 __pure 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().
+ */
+u32 __attribute_const__ crc32_le_shift(u32 crc, size_t len);
+
+static inline u32 crc32_le_combine(u32 crc1, u32 crc2, size_t len2)
+{
+ return crc32_le_shift(crc1, len2) ^ crc2;
+}
+
+u32 __pure __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().
+ */
+u32 __attribute_const__ __crc32c_le_shift(u32 crc, size_t len);
+
+static inline u32 __crc32c_le_combine(u32 crc1, u32 crc2, size_t len2)
+{
+ return __crc32c_le_shift(crc1, len2) ^ crc2;
+}
+
+#define crc32(seed, data, length) crc32_le(seed, (unsigned char const *)(data), length)
+
+/*
+ * Helpers for hash table generation of ethernet nics:
+ *
+ * Ethernet sends the least significant bit of a byte first, thus crc32_le
+ * is used. The output of crc32_le is bit reversed [most significant bit
+ * is in bit nr 0], thus it must be reversed before use. Except for
+ * nics that bit swap the result internally...
+ */
+#define ether_crc(length, data) bitrev32(crc32_le(~0, data, length))
+#define ether_crc_le(length, data) crc32_le(~0, data, length)
+
+#endif /* _LINUX_CRC32_H */