summaryrefslogtreecommitdiff
path: root/arch/x86/crypto/chacha20_glue.c
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
commit8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be (patch)
treee9891aa6c295060d065adffd610c4f49ecf884f3 /arch/x86/crypto/chacha20_glue.c
parenta71852147516bc1cb5b0b3cbd13639bfd4022dc8 (diff)
Linux-libre 4.3.2-gnu
Diffstat (limited to 'arch/x86/crypto/chacha20_glue.c')
-rw-r--r--arch/x86/crypto/chacha20_glue.c150
1 files changed, 150 insertions, 0 deletions
diff --git a/arch/x86/crypto/chacha20_glue.c b/arch/x86/crypto/chacha20_glue.c
new file mode 100644
index 000000000..effe2160b
--- /dev/null
+++ b/arch/x86/crypto/chacha20_glue.c
@@ -0,0 +1,150 @@
+/*
+ * ChaCha20 256-bit cipher algorithm, RFC7539, SIMD glue code
+ *
+ * Copyright (C) 2015 Martin Willi
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <crypto/algapi.h>
+#include <crypto/chacha20.h>
+#include <linux/crypto.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/fpu/api.h>
+#include <asm/simd.h>
+
+#define CHACHA20_STATE_ALIGN 16
+
+asmlinkage void chacha20_block_xor_ssse3(u32 *state, u8 *dst, const u8 *src);
+asmlinkage void chacha20_4block_xor_ssse3(u32 *state, u8 *dst, const u8 *src);
+#ifdef CONFIG_AS_AVX2
+asmlinkage void chacha20_8block_xor_avx2(u32 *state, u8 *dst, const u8 *src);
+static bool chacha20_use_avx2;
+#endif
+
+static void chacha20_dosimd(u32 *state, u8 *dst, const u8 *src,
+ unsigned int bytes)
+{
+ u8 buf[CHACHA20_BLOCK_SIZE];
+
+#ifdef CONFIG_AS_AVX2
+ if (chacha20_use_avx2) {
+ while (bytes >= CHACHA20_BLOCK_SIZE * 8) {
+ chacha20_8block_xor_avx2(state, dst, src);
+ bytes -= CHACHA20_BLOCK_SIZE * 8;
+ src += CHACHA20_BLOCK_SIZE * 8;
+ dst += CHACHA20_BLOCK_SIZE * 8;
+ state[12] += 8;
+ }
+ }
+#endif
+ while (bytes >= CHACHA20_BLOCK_SIZE * 4) {
+ chacha20_4block_xor_ssse3(state, dst, src);
+ bytes -= CHACHA20_BLOCK_SIZE * 4;
+ src += CHACHA20_BLOCK_SIZE * 4;
+ dst += CHACHA20_BLOCK_SIZE * 4;
+ state[12] += 4;
+ }
+ while (bytes >= CHACHA20_BLOCK_SIZE) {
+ chacha20_block_xor_ssse3(state, dst, src);
+ bytes -= CHACHA20_BLOCK_SIZE;
+ src += CHACHA20_BLOCK_SIZE;
+ dst += CHACHA20_BLOCK_SIZE;
+ state[12]++;
+ }
+ if (bytes) {
+ memcpy(buf, src, bytes);
+ chacha20_block_xor_ssse3(state, buf, buf);
+ memcpy(dst, buf, bytes);
+ }
+}
+
+static int chacha20_simd(struct blkcipher_desc *desc, struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes)
+{
+ u32 *state, state_buf[16 + (CHACHA20_STATE_ALIGN / sizeof(u32)) - 1];
+ struct blkcipher_walk walk;
+ int err;
+
+ if (!may_use_simd())
+ return crypto_chacha20_crypt(desc, dst, src, nbytes);
+
+ state = (u32 *)roundup((uintptr_t)state_buf, CHACHA20_STATE_ALIGN);
+
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+ err = blkcipher_walk_virt_block(desc, &walk, CHACHA20_BLOCK_SIZE);
+
+ crypto_chacha20_init(state, crypto_blkcipher_ctx(desc->tfm), walk.iv);
+
+ kernel_fpu_begin();
+
+ while (walk.nbytes >= CHACHA20_BLOCK_SIZE) {
+ chacha20_dosimd(state, walk.dst.virt.addr, walk.src.virt.addr,
+ rounddown(walk.nbytes, CHACHA20_BLOCK_SIZE));
+ err = blkcipher_walk_done(desc, &walk,
+ walk.nbytes % CHACHA20_BLOCK_SIZE);
+ }
+
+ if (walk.nbytes) {
+ chacha20_dosimd(state, walk.dst.virt.addr, walk.src.virt.addr,
+ walk.nbytes);
+ err = blkcipher_walk_done(desc, &walk, 0);
+ }
+
+ kernel_fpu_end();
+
+ return err;
+}
+
+static struct crypto_alg alg = {
+ .cra_name = "chacha20",
+ .cra_driver_name = "chacha20-simd",
+ .cra_priority = 300,
+ .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
+ .cra_blocksize = 1,
+ .cra_type = &crypto_blkcipher_type,
+ .cra_ctxsize = sizeof(struct chacha20_ctx),
+ .cra_alignmask = sizeof(u32) - 1,
+ .cra_module = THIS_MODULE,
+ .cra_u = {
+ .blkcipher = {
+ .min_keysize = CHACHA20_KEY_SIZE,
+ .max_keysize = CHACHA20_KEY_SIZE,
+ .ivsize = CHACHA20_IV_SIZE,
+ .geniv = "seqiv",
+ .setkey = crypto_chacha20_setkey,
+ .encrypt = chacha20_simd,
+ .decrypt = chacha20_simd,
+ },
+ },
+};
+
+static int __init chacha20_simd_mod_init(void)
+{
+ if (!cpu_has_ssse3)
+ return -ENODEV;
+
+#ifdef CONFIG_AS_AVX2
+ chacha20_use_avx2 = cpu_has_avx && cpu_has_avx2 &&
+ cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, NULL);
+#endif
+ return crypto_register_alg(&alg);
+}
+
+static void __exit chacha20_simd_mod_fini(void)
+{
+ crypto_unregister_alg(&alg);
+}
+
+module_init(chacha20_simd_mod_init);
+module_exit(chacha20_simd_mod_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
+MODULE_DESCRIPTION("chacha20 cipher algorithm, SIMD accelerated");
+MODULE_ALIAS_CRYPTO("chacha20");
+MODULE_ALIAS_CRYPTO("chacha20-simd");