From 7905a1f5dff38cc30af873461f083f30893adcbe Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Tue, 18 Sep 2018 02:18:47 +0200
Subject: crypto: allow for disabling simd in zinc modules

---
 src/crypto/zinc/poly1305/poly1305-x86_64-glue.h | 15 +++++++++++----
 src/crypto/zinc/poly1305/poly1305.c             |  6 +++++-
 2 files changed, 16 insertions(+), 5 deletions(-)

(limited to 'src/crypto/zinc/poly1305')

diff --git a/src/crypto/zinc/poly1305/poly1305-x86_64-glue.h b/src/crypto/zinc/poly1305/poly1305-x86_64-glue.h
index 0ca3485..2158863 100644
--- a/src/crypto/zinc/poly1305/poly1305-x86_64-glue.h
+++ b/src/crypto/zinc/poly1305/poly1305-x86_64-glue.h
@@ -71,7 +71,8 @@ static inline bool poly1305_blocks_arch(void *ctx, const u8 *inp,
 {
 	struct poly1305_arch_internal *state = ctx;
 
-	if ((len < (POLY1305_BLOCK_SIZE * 18) && !state->simd_is_engaged) ||
+	if (!poly1305_use_avx ||
+	    (len < (POLY1305_BLOCK_SIZE * 18) && !state->simd_is_engaged) ||
 	    !simd_use(simd_context))
 	    poly1305_blocks_x86_64(ctx, inp, len, padbit);
 	else
@@ -98,18 +99,24 @@ static inline bool poly1305_emit_arch(void *ctx, u8 mac[POLY1305_MAC_SIZE],
 				      const u32 nonce[4],
 				      simd_context_t *simd_context)
 {
+	struct poly1305_arch_internal *state = ctx;
+
+	if (!poly1305_use_avx || !state->simd_is_engaged ||
+	    !simd_use(simd_context))
+		poly1305_emit_x86_64(ctx, mac, nonce);
+	else
 #ifdef CONFIG_AS_AVX512
-	if (poly1305_use_avx512 && simd_use(simd_context))
+	if (poly1305_use_avx512)
 		poly1305_emit_avx(ctx, mac, nonce);
 	else
 #endif
 #ifdef CONFIG_AS_AVX2
-	if (poly1305_use_avx2 && simd_use(simd_context))
+	if (poly1305_use_avx2)
 		poly1305_emit_avx(ctx, mac, nonce);
 	else
 #endif
 #ifdef CONFIG_AS_AVX
-	if (poly1305_use_avx && simd_use(simd_context))
+	if (poly1305_use_avx)
 		poly1305_emit_avx(ctx, mac, nonce);
 	else
 #endif
diff --git a/src/crypto/zinc/poly1305/poly1305.c b/src/crypto/zinc/poly1305/poly1305.c
index 5377721..2add7aa 100644
--- a/src/crypto/zinc/poly1305/poly1305.c
+++ b/src/crypto/zinc/poly1305/poly1305.c
@@ -136,13 +136,16 @@ EXPORT_SYMBOL(poly1305_final);
 
 #include "../selftest/poly1305.h"
 
+static bool nosimd __initdata = false;
+
 #ifndef COMPAT_ZINC_IS_A_MODULE
 int __init poly1305_mod_init(void)
 #else
 static int __init mod_init(void)
 #endif
 {
-	poly1305_fpu_init();
+	if (!nosimd)
+		poly1305_fpu_init();
 #ifdef DEBUG
 	if (!poly1305_selftest())
 		return -ENOTRECOVERABLE;
@@ -155,6 +158,7 @@ static void __exit mod_exit(void)
 {
 }
 
+module_param(nosimd, bool, 0);
 module_init(mod_init);
 module_exit(mod_exit);
 MODULE_LICENSE("GPL v2");
-- 
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