crypto: sha256 - Create module providing optimized SHA256 routines using SSSE3, AVX or AVX2 instructions.
We added glue code and config options to create crypto
module that uses SSE/AVX/AVX2 optimized SHA256 x86_64 assembly routines.
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/arch/x86/crypto/sha256_ssse3_glue.c b/arch/x86/crypto/sha256_ssse3_glue.c
new file mode 100644
index 0000000..597d4da
--- /dev/null
+++ b/arch/x86/crypto/sha256_ssse3_glue.c
@@ -0,0 +1,275 @@
+/*
+ * Cryptographic API.
+ *
+ * Glue code for the SHA256 Secure Hash Algorithm assembler
+ * implementation using supplemental SSE3 / AVX / AVX2 instructions.
+ *
+ * This file is based on sha256_generic.c
+ *
+ * Copyright (C) 2013 Intel Corporation.
+ *
+ * Author:
+ * Tim Chen <tim.c.chen@linux.intel.com>
+ *
+ * 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.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <crypto/internal/hash.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/cryptohash.h>
+#include <linux/types.h>
+#include <crypto/sha.h>
+#include <asm/byteorder.h>
+#include <asm/i387.h>
+#include <asm/xcr.h>
+#include <asm/xsave.h>
+#include <linux/string.h>
+
+asmlinkage void sha256_transform_ssse3(const char *data, u32 *digest,
+ u64 rounds);
+#ifdef CONFIG_AS_AVX
+asmlinkage void sha256_transform_avx(const char *data, u32 *digest,
+ u64 rounds);
+#endif
+#ifdef CONFIG_AS_AVX2
+asmlinkage void sha256_transform_rorx(const char *data, u32 *digest,
+ u64 rounds);
+#endif
+
+static asmlinkage void (*sha256_transform_asm)(const char *, u32 *, u64);
+
+
+static int sha256_ssse3_init(struct shash_desc *desc)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+
+ sctx->state[0] = SHA256_H0;
+ sctx->state[1] = SHA256_H1;
+ sctx->state[2] = SHA256_H2;
+ sctx->state[3] = SHA256_H3;
+ sctx->state[4] = SHA256_H4;
+ sctx->state[5] = SHA256_H5;
+ sctx->state[6] = SHA256_H6;
+ sctx->state[7] = SHA256_H7;
+ sctx->count = 0;
+
+ return 0;
+}
+
+static int __sha256_ssse3_update(struct shash_desc *desc, const u8 *data,
+ unsigned int len, unsigned int partial)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+ unsigned int done = 0;
+
+ sctx->count += len;
+
+ if (partial) {
+ done = SHA256_BLOCK_SIZE - partial;
+ memcpy(sctx->buf + partial, data, done);
+ sha256_transform_asm(sctx->buf, sctx->state, 1);
+ }
+
+ if (len - done >= SHA256_BLOCK_SIZE) {
+ const unsigned int rounds = (len - done) / SHA256_BLOCK_SIZE;
+
+ sha256_transform_asm(data + done, sctx->state, (u64) rounds);
+
+ done += rounds * SHA256_BLOCK_SIZE;
+ }
+
+ memcpy(sctx->buf, data + done, len - done);
+
+ return 0;
+}
+
+static int sha256_ssse3_update(struct shash_desc *desc, const u8 *data,
+ unsigned int len)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+ unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
+ int res;
+
+ /* Handle the fast case right here */
+ if (partial + len < SHA256_BLOCK_SIZE) {
+ sctx->count += len;
+ memcpy(sctx->buf + partial, data, len);
+
+ return 0;
+ }
+
+ if (!irq_fpu_usable()) {
+ res = crypto_sha256_update(desc, data, len);
+ } else {
+ kernel_fpu_begin();
+ res = __sha256_ssse3_update(desc, data, len, partial);
+ kernel_fpu_end();
+ }
+
+ return res;
+}
+
+
+/* Add padding and return the message digest. */
+static int sha256_ssse3_final(struct shash_desc *desc, u8 *out)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+ unsigned int i, index, padlen;
+ __be32 *dst = (__be32 *)out;
+ __be64 bits;
+ static const u8 padding[SHA256_BLOCK_SIZE] = { 0x80, };
+
+ bits = cpu_to_be64(sctx->count << 3);
+
+ /* Pad out to 56 mod 64 and append length */
+ index = sctx->count % SHA256_BLOCK_SIZE;
+ padlen = (index < 56) ? (56 - index) : ((SHA256_BLOCK_SIZE+56)-index);
+
+ if (!irq_fpu_usable()) {
+ crypto_sha256_update(desc, padding, padlen);
+ crypto_sha256_update(desc, (const u8 *)&bits, sizeof(bits));
+ } else {
+ kernel_fpu_begin();
+ /* We need to fill a whole block for __sha256_ssse3_update() */
+ if (padlen <= 56) {
+ sctx->count += padlen;
+ memcpy(sctx->buf + index, padding, padlen);
+ } else {
+ __sha256_ssse3_update(desc, padding, padlen, index);
+ }
+ __sha256_ssse3_update(desc, (const u8 *)&bits,
+ sizeof(bits), 56);
+ kernel_fpu_end();
+ }
+
+ /* Store state in digest */
+ for (i = 0; i < 8; i++)
+ dst[i] = cpu_to_be32(sctx->state[i]);
+
+ /* Wipe context */
+ memset(sctx, 0, sizeof(*sctx));
+
+ return 0;
+}
+
+static int sha256_ssse3_export(struct shash_desc *desc, void *out)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+
+ memcpy(out, sctx, sizeof(*sctx));
+
+ return 0;
+}
+
+static int sha256_ssse3_import(struct shash_desc *desc, const void *in)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+
+ memcpy(sctx, in, sizeof(*sctx));
+
+ return 0;
+}
+
+static struct shash_alg alg = {
+ .digestsize = SHA256_DIGEST_SIZE,
+ .init = sha256_ssse3_init,
+ .update = sha256_ssse3_update,
+ .final = sha256_ssse3_final,
+ .export = sha256_ssse3_export,
+ .import = sha256_ssse3_import,
+ .descsize = sizeof(struct sha256_state),
+ .statesize = sizeof(struct sha256_state),
+ .base = {
+ .cra_name = "sha256",
+ .cra_driver_name = "sha256-ssse3",
+ .cra_priority = 150,
+ .cra_flags = CRYPTO_ALG_TYPE_SHASH,
+ .cra_blocksize = SHA256_BLOCK_SIZE,
+ .cra_module = THIS_MODULE,
+ }
+};
+
+#ifdef CONFIG_AS_AVX
+static bool __init avx_usable(void)
+{
+ u64 xcr0;
+
+ if (!cpu_has_avx || !cpu_has_osxsave)
+ return false;
+
+ xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
+ pr_info("AVX detected but unusable.\n");
+
+ return false;
+ }
+
+ return true;
+}
+#endif
+
+static int __init sha256_ssse3_mod_init(void)
+{
+ /* test for SSE3 first */
+ if (cpu_has_ssse3)
+ sha256_transform_asm = sha256_transform_ssse3;
+
+#ifdef CONFIG_AS_AVX
+ /* allow AVX to override SSSE3, it's a little faster */
+ if (avx_usable()) {
+#ifdef CONFIG_AS_AVX2
+ if (boot_cpu_has(X86_FEATURE_AVX2))
+ sha256_transform_asm = sha256_transform_rorx;
+ else
+#endif
+ sha256_transform_asm = sha256_transform_avx;
+ }
+#endif
+
+ if (sha256_transform_asm) {
+#ifdef CONFIG_AS_AVX
+ if (sha256_transform_asm == sha256_transform_avx)
+ pr_info("Using AVX optimized SHA-256 implementation\n");
+#ifdef CONFIG_AS_AVX2
+ else if (sha256_transform_asm == sha256_transform_rorx)
+ pr_info("Using AVX2 optimized SHA-256 implementation\n");
+#endif
+ else
+#endif
+ pr_info("Using SSSE3 optimized SHA-256 implementation\n");
+ return crypto_register_shash(&alg);
+ }
+ pr_info("Neither AVX nor SSSE3 is available/usable.\n");
+
+ return -ENODEV;
+}
+
+static void __exit sha256_ssse3_mod_fini(void)
+{
+ crypto_unregister_shash(&alg);
+}
+
+module_init(sha256_ssse3_mod_init);
+module_exit(sha256_ssse3_mod_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SHA256 Secure Hash Algorithm, Supplemental SSE3 accelerated");
+
+MODULE_ALIAS("sha256");