Move c_src dirs back to toplevel

[bcachefs-tools-debian] / include / linux / siphash.h

diff --git a/include/linux/siphash.h b/include/linux/siphash.h
new file mode 100644 (file)
index 0000000..bf21591
--- /dev/null
+++ b/include/linux/siphash.h
@@ -0,0 +1,145 @@
+/* Copyright (C) 2016 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ *
+ * This file is provided under a dual BSD/GPLv2 license.
+ *
+ * SipHash: a fast short-input PRF
+ * https://131002.net/siphash/
+ *
+ * This implementation is specifically for SipHash2-4 for a secure PRF
+ * and HalfSipHash1-3/SipHash1-3 for an insecure PRF only suitable for
+ * hashtables.
+ */
+
+#ifndef _LINUX_SIPHASH_H
+#define _LINUX_SIPHASH_H
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+
+#define SIPHASH_ALIGNMENT __alignof__(u64)
+typedef struct {
+       u64 key[2];
+} siphash_key_t;
+
+static inline bool siphash_key_is_zero(const siphash_key_t *key)
+{
+       return !(key->key[0] | key->key[1]);
+}
+
+u64 __siphash_aligned(const void *data, size_t len, const siphash_key_t *key);
+#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+u64 __siphash_unaligned(const void *data, size_t len, const siphash_key_t *key);
+#endif
+
+u64 siphash_1u64(const u64 a, const siphash_key_t *key);
+u64 siphash_2u64(const u64 a, const u64 b, const siphash_key_t *key);
+u64 siphash_3u64(const u64 a, const u64 b, const u64 c,
+                const siphash_key_t *key);
+u64 siphash_4u64(const u64 a, const u64 b, const u64 c, const u64 d,
+                const siphash_key_t *key);
+u64 siphash_1u32(const u32 a, const siphash_key_t *key);
+u64 siphash_3u32(const u32 a, const u32 b, const u32 c,
+                const siphash_key_t *key);
+
+static inline u64 siphash_2u32(const u32 a, const u32 b,
+                              const siphash_key_t *key)
+{
+       return siphash_1u64((u64)b << 32 | a, key);
+}
+static inline u64 siphash_4u32(const u32 a, const u32 b, const u32 c,
+                              const u32 d, const siphash_key_t *key)
+{
+       return siphash_2u64((u64)b << 32 | a, (u64)d << 32 | c, key);
+}
+
+
+static inline u64 ___siphash_aligned(const __le64 *data, size_t len,
+                                    const siphash_key_t *key)
+{
+       if (__builtin_constant_p(len) && len == 4)
+               return siphash_1u32(le32_to_cpup((const __le32 *)data), key);
+       if (__builtin_constant_p(len) && len == 8)
+               return siphash_1u64(le64_to_cpu(data[0]), key);
+       if (__builtin_constant_p(len) && len == 16)
+               return siphash_2u64(le64_to_cpu(data[0]), le64_to_cpu(data[1]),
+                                   key);
+       if (__builtin_constant_p(len) && len == 24)
+               return siphash_3u64(le64_to_cpu(data[0]), le64_to_cpu(data[1]),
+                                   le64_to_cpu(data[2]), key);
+       if (__builtin_constant_p(len) && len == 32)
+               return siphash_4u64(le64_to_cpu(data[0]), le64_to_cpu(data[1]),
+                                   le64_to_cpu(data[2]), le64_to_cpu(data[3]),
+                                   key);
+       return __siphash_aligned(data, len, key);
+}
+
+/**
+ * siphash - compute 64-bit siphash PRF value
+ * @data: buffer to hash
+ * @size: size of @data
+ * @key: the siphash key
+ */
+static inline u64 siphash(const void *data, size_t len,
+                         const siphash_key_t *key)
+{
+#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+       if (!IS_ALIGNED((unsigned long)data, SIPHASH_ALIGNMENT))
+               return __siphash_unaligned(data, len, key);
+#endif
+       return ___siphash_aligned(data, len, key);
+}
+
+#define HSIPHASH_ALIGNMENT __alignof__(unsigned long)
+typedef struct {
+       unsigned long key[2];
+} hsiphash_key_t;
+
+u32 __hsiphash_aligned(const void *data, size_t len,
+                      const hsiphash_key_t *key);
+#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+u32 __hsiphash_unaligned(const void *data, size_t len,
+                        const hsiphash_key_t *key);
+#endif
+
+u32 hsiphash_1u32(const u32 a, const hsiphash_key_t *key);
+u32 hsiphash_2u32(const u32 a, const u32 b, const hsiphash_key_t *key);
+u32 hsiphash_3u32(const u32 a, const u32 b, const u32 c,
+                 const hsiphash_key_t *key);
+u32 hsiphash_4u32(const u32 a, const u32 b, const u32 c, const u32 d,
+                 const hsiphash_key_t *key);
+
+static inline u32 ___hsiphash_aligned(const __le32 *data, size_t len,
+                                     const hsiphash_key_t *key)
+{
+       if (__builtin_constant_p(len) && len == 4)
+               return hsiphash_1u32(le32_to_cpu(data[0]), key);
+       if (__builtin_constant_p(len) && len == 8)
+               return hsiphash_2u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]),
+                                    key);
+       if (__builtin_constant_p(len) && len == 12)
+               return hsiphash_3u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]),
+                                    le32_to_cpu(data[2]), key);
+       if (__builtin_constant_p(len) && len == 16)
+               return hsiphash_4u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]),
+                                    le32_to_cpu(data[2]), le32_to_cpu(data[3]),
+                                    key);
+       return __hsiphash_aligned(data, len, key);
+}
+
+/**
+ * hsiphash - compute 32-bit hsiphash PRF value
+ * @data: buffer to hash
+ * @size: size of @data
+ * @key: the hsiphash key
+ */
+static inline u32 hsiphash(const void *data, size_t len,
+                          const hsiphash_key_t *key)
+{
+#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+       if (!IS_ALIGNED((unsigned long)data, HSIPHASH_ALIGNMENT))
+               return __hsiphash_unaligned(data, len, key);
+#endif
+       return ___hsiphash_aligned(data, len, key);
+}
+
+#endif /* _LINUX_SIPHASH_H */