fs/btrfs: add dependency on BLAKE2 hash

Now btrfs can utilize the newly intorudced BLAKE2 hash.

Signed-off-by: Qu Wenruo <wqu@suse.com>
diff --git a/fs/btrfs/crypto/hash.c b/fs/btrfs/crypto/hash.c
index fb51f63..891a297 100644
--- a/fs/btrfs/crypto/hash.c
+++ b/fs/btrfs/crypto/hash.c
@@ -4,6 +4,7 @@
 #include <linux/unaligned/access_ok.h>
 #include <linux/types.h>
 #include <u-boot/sha256.h>
+#include <u-boot/blake2.h>
 #include <u-boot/crc.h>
 
 static u32 btrfs_crc32c_table[256];
@@ -39,6 +40,19 @@
 	return 0;
 }
 
+/* We use the full CSUM_SIZE(32) for BLAKE2B */
+#define BTRFS_BLAKE2_HASH_SIZE	32
+int hash_blake2(const u8 *buf, size_t length, u8 *out)
+{
+	blake2b_state S;
+
+	blake2b_init(&S, BTRFS_BLAKE2_HASH_SIZE);
+	blake2b_update(&S, buf, length);
+	blake2b_final(&S, out, BTRFS_BLAKE2_HASH_SIZE);
+
+	return 0;
+}
+
 int hash_crc32c(const u8 *buf, size_t length, u8 *out)
 {
 	u32 crc;
diff --git a/fs/btrfs/crypto/hash.h b/fs/btrfs/crypto/hash.h
index d1ba1fa..f984603 100644
--- a/fs/btrfs/crypto/hash.h
+++ b/fs/btrfs/crypto/hash.h
@@ -9,6 +9,7 @@
 int hash_crc32c(const u8 *buf, size_t length, u8 *out);
 int hash_xxhash(const u8 *buf, size_t length, u8 *out);
 int hash_sha256(const u8 *buf, size_t length, u8 *out);
+int hash_blake2(const u8 *buf, size_t length, u8 *out);
 
 u32 crc32c(u32 seed, const void * data, size_t len);