1 files changed, 149 insertions, 0 deletions
diff --git a/arch/powerpc/crypto/aes_ctr.c b/arch/powerpc/crypto/aes_ctr.c
new file mode 100644
index 0000000000..9a3da8cd62
--- /dev/null
+++ b/arch/powerpc/crypto/aes_ctr.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AES CTR routines supporting VMX instructions on the Power 8
+ *
+ * Copyright (C) 2015 International Business Machines Inc.
+ *
+ * Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
+ */
+
+#include <asm/simd.h>
+#include <asm/switch_to.h>
+#include <crypto/aes.h>
+#include <crypto/internal/simd.h>
+#include <crypto/internal/skcipher.h>
+
+#include "aesp8-ppc.h"
+
+struct p8_aes_ctr_ctx {
+	struct crypto_skcipher *fallback;
+	struct aes_key enc_key;
+};
+
+static int p8_aes_ctr_init(struct crypto_skcipher *tfm)
+{
+	struct p8_aes_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
+	struct crypto_skcipher *fallback;
+
+	fallback = crypto_alloc_skcipher("ctr(aes)", 0,
+					 CRYPTO_ALG_NEED_FALLBACK |
+					 CRYPTO_ALG_ASYNC);
+	if (IS_ERR(fallback)) {
+		pr_err("Failed to allocate ctr(aes) fallback: %ld\n",
+		       PTR_ERR(fallback));
+		return PTR_ERR(fallback);
+	}
+
+	crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
+				    crypto_skcipher_reqsize(fallback));
+	ctx->fallback = fallback;
+	return 0;
+}
+
+static void p8_aes_ctr_exit(struct crypto_skcipher *tfm)
+{
+	struct p8_aes_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
+
+	crypto_free_skcipher(ctx->fallback);
+}
+
+static int p8_aes_ctr_setkey(struct crypto_skcipher *tfm, const u8 *key,
+			     unsigned int keylen)
+{
+	struct p8_aes_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
+	int ret;
+
+	preempt_disable();
+	pagefault_disable();
+	enable_kernel_vsx();
+	ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
+	disable_kernel_vsx();
+	pagefault_enable();
+	preempt_enable();
+
+	ret |= crypto_skcipher_setkey(ctx->fallback, key, keylen);
+
+	return ret ? -EINVAL : 0;
+}
+
+static void p8_aes_ctr_final(const struct p8_aes_ctr_ctx *ctx,
+			     struct skcipher_walk *walk)
+{
+	u8 *ctrblk = walk->iv;
+	u8 keystream[AES_BLOCK_SIZE];
+	u8 *src = walk->src.virt.addr;
+	u8 *dst = walk->dst.virt.addr;
+	unsigned int nbytes = walk->nbytes;
+
+	preempt_disable();
+	pagefault_disable();
+	enable_kernel_vsx();
+	aes_p8_encrypt(ctrblk, keystream, &ctx->enc_key);
+	disable_kernel_vsx();
+	pagefault_enable();
+	preempt_enable();
+
+	crypto_xor_cpy(dst, keystream, src, nbytes);
+	crypto_inc(ctrblk, AES_BLOCK_SIZE);
+}
+
+static int p8_aes_ctr_crypt(struct skcipher_request *req)
+{
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	const struct p8_aes_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
+	struct skcipher_walk walk;
+	unsigned int nbytes;
+	int ret;
+
+	if (!crypto_simd_usable()) {
+		struct skcipher_request *subreq = skcipher_request_ctx(req);
+
+		*subreq = *req;
+		skcipher_request_set_tfm(subreq, ctx->fallback);
+		return crypto_skcipher_encrypt(subreq);
+	}
+
+	ret = skcipher_walk_virt(&walk, req, false);
+	while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
+		preempt_disable();
+		pagefault_disable();
+		enable_kernel_vsx();
+		aes_p8_ctr32_encrypt_blocks(walk.src.virt.addr,
+					    walk.dst.virt.addr,
+					    nbytes / AES_BLOCK_SIZE,
+					    &ctx->enc_key, walk.iv);
+		disable_kernel_vsx();
+		pagefault_enable();
+		preempt_enable();
+
+		do {
+			crypto_inc(walk.iv, AES_BLOCK_SIZE);
+		} while ((nbytes -= AES_BLOCK_SIZE) >= AES_BLOCK_SIZE);
+
+		ret = skcipher_walk_done(&walk, nbytes);
+	}
+	if (nbytes) {
+		p8_aes_ctr_final(ctx, &walk);
+		ret = skcipher_walk_done(&walk, 0);
+	}
+	return ret;
+}
+
+struct skcipher_alg p8_aes_ctr_alg = {
+	.base.cra_name = "ctr(aes)",
+	.base.cra_driver_name = "p8_aes_ctr",
+	.base.cra_module = THIS_MODULE,
+	.base.cra_priority = 2000,
+	.base.cra_flags = CRYPTO_ALG_NEED_FALLBACK,
+	.base.cra_blocksize = 1,
+	.base.cra_ctxsize = sizeof(struct p8_aes_ctr_ctx),
+	.setkey = p8_aes_ctr_setkey,
+	.encrypt = p8_aes_ctr_crypt,
+	.decrypt = p8_aes_ctr_crypt,
+	.init = p8_aes_ctr_init,
+	.exit = p8_aes_ctr_exit,
+	.min_keysize = AES_MIN_KEY_SIZE,
+	.max_keysize = AES_MAX_KEY_SIZE,
+	.ivsize = AES_BLOCK_SIZE,
+	.chunksize = AES_BLOCK_SIZE,
+};