[PATCH 1/2] libcrc32c: Add crc32c_impl function

[Nikolay Borisov]

This function returns a string with the currently in-use implementation
of the crc32c algorithm, i.e crc32c-generic (for unoptimised, generic
implementation) or crc32c-intel for the sse optimised version. This
will be used by btrfs.

Signed-off-by: Nikolay Borisov <nborisov@xxxxxxxx>
---
 include/linux/crc32c.h | 1 +
 lib/libcrc32c.c        | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/include/linux/crc32c.h b/include/linux/crc32c.h
index 357ae4611a45..bd21af828ff6 100644
--- a/include/linux/crc32c.h
+++ b/include/linux/crc32c.h
@@ -5,6 +5,7 @@
 #include <linux/types.h>
 
 extern u32 crc32c(u32 crc, const void *address, unsigned int length);
+extern const char *crc32c_impl(void);
 
 /* This macro exists for backwards-compatibility. */
 #define crc32c_le crc32c
diff --git a/lib/libcrc32c.c b/lib/libcrc32c.c
index 9f79547d1b97..eaf71e0e04be 100644
--- a/lib/libcrc32c.c
+++ b/lib/libcrc32c.c
@@ -71,6 +71,12 @@ static void __exit libcrc32c_mod_fini(void)
 	crypto_free_shash(tfm);
 }
 
+const char *crc32c_impl(void)
+{
+	return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
+}
+EXPORT_SYMBOL(crc32c_impl);
+
 module_init(libcrc32c_mod_init);
 module_exit(libcrc32c_mod_fini);
 
-- 
2.7.4