crypto: powerpc/poly1305 - Add poly1305_emit_arch wrapper

Add poly1305_emit_arch with fallback instead of calling assembly
directly. This is because the state format differs between p10
and that of the generic implementation.

Reported-by: Venkat Rao Bagalkote <[e-mail]>
Reported-by: Eric Biggers <[e-mail]>
Fixes: 14d31979145d ("crypto: powerpc/poly1305 - Add block-only interface")
Signed-off-by: Herbert Xu <[e-mail]>

arch/powerpc/lib/crypto/poly1305-p10-glue.c

···
 
 asmlinkage void poly1305_p10le_4blocks(struct poly1305_block_state *state, const u8 *m, u32 mlen);
 asmlinkage void poly1305_64s(struct poly1305_block_state *state, const u8 *m, u32 mlen, int highbit);
-asmlinkage void poly1305_emit_arch(const struct poly1305_state *state,
-				   u8 digest[POLY1305_DIGEST_SIZE],
-				   const u32 nonce[4]);
-EXPORT_SYMBOL_GPL(poly1305_emit_arch);
+asmlinkage void poly1305_emit_64(const struct poly1305_state *state, const u32 nonce[4], u8 digest[POLY1305_DIGEST_SIZE]);
 
 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_p10);
 
···
 	vsx_end();
 }
 EXPORT_SYMBOL_GPL(poly1305_blocks_arch);
+
+void poly1305_emit_arch(const struct poly1305_state *state,
+			u8 digest[POLY1305_DIGEST_SIZE],
+			const u32 nonce[4])
+{
+	if (!static_key_enabled(&have_p10))
+		return poly1305_emit_generic(state, digest, nonce);
+	poly1305_emit_64(state, nonce, digest);
+}
+EXPORT_SYMBOL_GPL(poly1305_emit_arch);
 
 bool poly1305_is_arch_optimized(void)
 {

arch/powerpc/lib/crypto/poly1305-p10le_64.S

···
 # Input: r3 = h, r4 = s, r5 = mac
 # mac = h + s
 #
-SYM_FUNC_START(poly1305_emit_arch)
+SYM_FUNC_START(poly1305_emit_64)
 	ld	10, 0(3)
 	ld	11, 8(3)
 	ld	12, 16(3)
···
 	std	10, 0(5)
 	std	11, 8(5)
 	blr
-SYM_FUNC_END(poly1305_emit_arch)
+SYM_FUNC_END(poly1305_emit_64)
 
 SYM_DATA_START_LOCAL(RMASK)
 .align 5