[PATCH v16 22/38] lib/crypto: Add SHA512 support for pre-boot environments

[Ross Philipson <ross.philipson@gmail.com>]

Allow the SHA512 library code in lib/crypto/sha512.c to be used in
pre-boot environments. Use the __DISABLE_EXPORTS macro to disable
function exports and define the proper values for that environment
as was done earlier for SHA256.

Signed-off-by: Ross Philipson <ross.philipson@gmail.com>
---
 lib/crypto/sha512.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/crypto/sha512.c b/lib/crypto/sha512.c
index 605eab51aabd..160e81d86da6 100644
--- a/lib/crypto/sha512.c
+++ b/lib/crypto/sha512.c
@@ -133,7 +133,7 @@ sha512_blocks_generic(struct sha512_block_state *state,
 	} while (--nblocks);
 }
 
-#ifdef CONFIG_CRYPTO_LIB_SHA512_ARCH
+#if defined(CONFIG_CRYPTO_LIB_SHA512_ARCH) && !defined(__DISABLE_EXPORTS)
 #include "sha512.h" /* $(SRCARCH)/sha512.h */
 #else
 #define sha512_blocks sha512_blocks_generic
@@ -250,6 +250,12 @@ void sha512(const u8 *data, size_t len, u8 out[SHA512_DIGEST_SIZE])
 }
 EXPORT_SYMBOL_GPL(sha512);
 
+/*
+ * Pre-boot environments (as indicated by __DISABLE_EXPORTS being defined)
+ * don't need the SHA2 HMAC support code.
+ */
+#ifndef __DISABLE_EXPORTS
+
 static void __hmac_sha512_preparekey(struct sha512_block_state *istate,
 				     struct sha512_block_state *ostate,
 				     const u8 *raw_key, size_t raw_key_len,
@@ -406,6 +412,8 @@ void hmac_sha512_usingrawkey(const u8 *raw_key, size_t raw_key_len,
 }
 EXPORT_SYMBOL_GPL(hmac_sha512_usingrawkey);
 
+#endif /* !__DISABLE_EXPORTS */
+
 #if defined(sha512_mod_init_arch) || defined(CONFIG_CRYPTO_FIPS)
 static int __init sha512_mod_init(void)
 {
-- 
2.47.3