crypto: create generic version of ablk_helper

Create a generic version of ablk_helper so it can be reused
by other architectures.

Change-Id: I3bc45cde3c736b82e752ae8a9ea6a2f9465963fc
Acked-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Git-commit: 0df9ee0ee0dd0f50f1c0c03f14f44dc76ad7dd60
Git-repo: https://android.googlesource.com/kernel/common/
Signed-off-by: Samir Mehta <samirn@codeaurora.org>

crypto/Kconfig

@@ -100,6 +100,10 @@ config CRYPTO_MANAGER2
 	select CRYPTO_BLKCIPHER2
 	select CRYPTO_PCOMP2
 
+config CRYPTO_ABLK_HELPER
+	tristate
+	select CRYPTO_CRYPTD
+
 config CRYPTO_USER
 	tristate "Userspace cryptographic algorithm configuration"
 	depends on NET

crypto/Makefile

@@ -96,3 +96,4 @@ obj-$(CONFIG_CRYPTO_USER_API_SKCIPHER) += algif_skcipher.o
 #
 obj-$(CONFIG_XOR_BLOCKS) += xor.o
 obj-$(CONFIG_ASYNC_CORE) += async_tx/
+obj-$(CONFIG_CRYPTO_ABLK_HELPER) += ablk_helper.o

crypto/ablk_helper.c

@@ -0,0 +1,150 @@
+/*
+ * Shared async block cipher helpers
+ *
+ * Copyright (c) 2012 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
+ *
+ * Based on aesni-intel_glue.c by:
+ *  Copyright (C) 2008, Intel Corp.
+ *    Author: Huang Ying <ying.huang@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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
+ * USA
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/crypto.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/hardirq.h>
+#include <crypto/algapi.h>
+#include <crypto/cryptd.h>
+#include <crypto/ablk_helper.h>
+#include <asm/simd.h>
+
+int ablk_set_key(struct crypto_ablkcipher *tfm, const u8 *key,
+		 unsigned int key_len)
+{
+	struct async_helper_ctx *ctx = crypto_ablkcipher_ctx(tfm);
+	struct crypto_ablkcipher *child = &ctx->cryptd_tfm->base;
+	int err;
+
+	crypto_ablkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
+	crypto_ablkcipher_set_flags(child, crypto_ablkcipher_get_flags(tfm)
+				    & CRYPTO_TFM_REQ_MASK);
+	err = crypto_ablkcipher_setkey(child, key, key_len);
+	crypto_ablkcipher_set_flags(tfm, crypto_ablkcipher_get_flags(child)
+				    & CRYPTO_TFM_RES_MASK);
+	return err;
+}
+EXPORT_SYMBOL_GPL(ablk_set_key);
+
+int __ablk_encrypt(struct ablkcipher_request *req)
+{
+	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
+	struct async_helper_ctx *ctx = crypto_ablkcipher_ctx(tfm);
+	struct blkcipher_desc desc;
+
+	desc.tfm = cryptd_ablkcipher_child(ctx->cryptd_tfm);
+	desc.info = req->info;
+	desc.flags = 0;
+
+	return crypto_blkcipher_crt(desc.tfm)->encrypt(
+		&desc, req->dst, req->src, req->nbytes);
+}
+EXPORT_SYMBOL_GPL(__ablk_encrypt);
+
+int ablk_encrypt(struct ablkcipher_request *req)
+{
+	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
+	struct async_helper_ctx *ctx = crypto_ablkcipher_ctx(tfm);
+
+	if (!may_use_simd()) {
+		struct ablkcipher_request *cryptd_req =
+			ablkcipher_request_ctx(req);
+
+		memcpy(cryptd_req, req, sizeof(*req));
+		ablkcipher_request_set_tfm(cryptd_req, &ctx->cryptd_tfm->base);
+
+		return crypto_ablkcipher_encrypt(cryptd_req);
+	} else {
+		return __ablk_encrypt(req);
+	}
+}
+EXPORT_SYMBOL_GPL(ablk_encrypt);
+
+int ablk_decrypt(struct ablkcipher_request *req)
+{
+	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
+	struct async_helper_ctx *ctx = crypto_ablkcipher_ctx(tfm);
+
+	if (!may_use_simd()) {
+		struct ablkcipher_request *cryptd_req =
+			ablkcipher_request_ctx(req);
+
+		memcpy(cryptd_req, req, sizeof(*req));
+		ablkcipher_request_set_tfm(cryptd_req, &ctx->cryptd_tfm->base);
+
+		return crypto_ablkcipher_decrypt(cryptd_req);
+	} else {
+		struct blkcipher_desc desc;
+
+		desc.tfm = cryptd_ablkcipher_child(ctx->cryptd_tfm);
+		desc.info = req->info;
+		desc.flags = 0;
+
+		return crypto_blkcipher_crt(desc.tfm)->decrypt(
+			&desc, req->dst, req->src, req->nbytes);
+	}
+}
+EXPORT_SYMBOL_GPL(ablk_decrypt);
+
+void ablk_exit(struct crypto_tfm *tfm)
+{
+	struct async_helper_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	cryptd_free_ablkcipher(ctx->cryptd_tfm);
+}
+EXPORT_SYMBOL_GPL(ablk_exit);
+
+int ablk_init_common(struct crypto_tfm *tfm, const char *drv_name)
+{
+	struct async_helper_ctx *ctx = crypto_tfm_ctx(tfm);
+	struct cryptd_ablkcipher *cryptd_tfm;
+
+	cryptd_tfm = cryptd_alloc_ablkcipher(drv_name, 0, 0);
+	if (IS_ERR(cryptd_tfm))
+		return PTR_ERR(cryptd_tfm);
+
+	ctx->cryptd_tfm = cryptd_tfm;
+	tfm->crt_ablkcipher.reqsize = sizeof(struct ablkcipher_request) +
+		crypto_ablkcipher_reqsize(&cryptd_tfm->base);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ablk_init_common);
+
+int ablk_init(struct crypto_tfm *tfm)
+{
+	char drv_name[CRYPTO_MAX_ALG_NAME];
+
+	snprintf(drv_name, sizeof(drv_name), "__driver-%s",
+					crypto_tfm_alg_driver_name(tfm));
+
+	return ablk_init_common(tfm, drv_name);
+}
+EXPORT_SYMBOL_GPL(ablk_init);
+
+MODULE_LICENSE("GPL");

include/asm-generic/simd.h

@@ -0,0 +1,14 @@
+
+#include <linux/hardirq.h>
+
+/*
+ * may_use_simd - whether it is allowable at this time to issue SIMD
+ *                instructions or access the SIMD register file
+ *
+ * As architectures typically don't preserve the SIMD register file when
+ * taking an interrupt, !in_interrupt() should be a reasonable default.
+ */
+static __must_check inline bool may_use_simd(void)
+{
+	return !in_interrupt();
+}

include/crypto/ablk_helper.h

@@ -0,0 +1,31 @@
+/*
+ * Shared async block cipher helpers
+ */
+
+#ifndef _CRYPTO_ABLK_HELPER_H
+#define _CRYPTO_ABLK_HELPER_H
+
+#include <linux/crypto.h>
+#include <linux/kernel.h>
+#include <crypto/cryptd.h>
+
+struct async_helper_ctx {
+	struct cryptd_ablkcipher *cryptd_tfm;
+};
+
+extern int ablk_set_key(struct crypto_ablkcipher *tfm, const u8 *key,
+			unsigned int key_len);
+
+extern int __ablk_encrypt(struct ablkcipher_request *req);
+
+extern int ablk_encrypt(struct ablkcipher_request *req);
+
+extern int ablk_decrypt(struct ablkcipher_request *req);
+
+extern void ablk_exit(struct crypto_tfm *tfm);
+
+extern int ablk_init_common(struct crypto_tfm *tfm, const char *drv_name);
+
+extern int ablk_init(struct crypto_tfm *tfm);
+
+#endif /* _CRYPTO_ABLK_HELPER_H */