crypto: ccp - Enable support for AES GCM on v5 CCPs

A version 5 device provides the primitive commands
required for AES GCM. This patch adds support for
en/decryption.

Signed-off-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 252 insertions, 0 deletions

diff --git a/drivers/crypto/ccp/ccp-crypto-aes-galois.c b/drivers/crypto/ccp/ccp-crypto-aes-galois.c
new file mode 100644
index 000000000000..38ee6f348ea9
--- /dev/null
+++ b/drivers/crypto/ccp/ccp-crypto-aes-galois.c
@@ -0,0 +1,252 @@
+/*
+ * AMD Cryptographic Coprocessor (CCP) AES GCM crypto API support
+ *
+ * Copyright (C) 2016 Advanced Micro Devices, Inc.
+ *
+ * Author: Gary R Hook <gary.hook@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/scatterlist.h>
+#include <linux/crypto.h>
+#include <crypto/internal/aead.h>
+#include <crypto/algapi.h>
+#include <crypto/aes.h>
+#include <crypto/ctr.h>
+#include <crypto/scatterwalk.h>
+#include <linux/delay.h>
+
+#include "ccp-crypto.h"
+
+#define	AES_GCM_IVSIZE	12
+
+static int ccp_aes_gcm_complete(struct crypto_async_request *async_req, int ret)
+{
+	return ret;
+}
+
+static int ccp_aes_gcm_setkey(struct crypto_aead *tfm, const u8 *key,
+			      unsigned int key_len)
+{
+	struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
+
+	switch (key_len) {
+	case AES_KEYSIZE_128:
+		ctx->u.aes.type = CCP_AES_TYPE_128;
+		break;
+	case AES_KEYSIZE_192:
+		ctx->u.aes.type = CCP_AES_TYPE_192;
+		break;
+	case AES_KEYSIZE_256:
+		ctx->u.aes.type = CCP_AES_TYPE_256;
+		break;
+	default:
+		crypto_aead_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+
+	ctx->u.aes.mode = CCP_AES_MODE_GCM;
+	ctx->u.aes.key_len = key_len;
+
+	memcpy(ctx->u.aes.key, key, key_len);
+	sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
+
+	return 0;
+}
+
+static int ccp_aes_gcm_setauthsize(struct crypto_aead *tfm,
+				   unsigned int authsize)
+{
+	return 0;
+}
+
+static int ccp_aes_gcm_crypt(struct aead_request *req, bool encrypt)
+{
+	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
+	struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
+	struct ccp_aes_req_ctx *rctx = aead_request_ctx(req);
+	struct scatterlist *iv_sg = NULL;
+	unsigned int iv_len = 0;
+	int i;
+	int ret = 0;
+
+	if (!ctx->u.aes.key_len)
+		return -EINVAL;
+
+	if (ctx->u.aes.mode != CCP_AES_MODE_GCM)
+		return -EINVAL;
+
+	if (!req->iv)
+		return -EINVAL;
+
+	/*
+	 * 5 parts:
+	 *   plaintext/ciphertext input
+	 *   AAD
+	 *   key
+	 *   IV
+	 *   Destination+tag buffer
+	 */
+
+	/* Prepare the IV: 12 bytes + an integer (counter) */
+	memcpy(rctx->iv, req->iv, AES_GCM_IVSIZE);
+	for (i = 0; i < 3; i++)
+		rctx->iv[i + AES_GCM_IVSIZE] = 0;
+	rctx->iv[AES_BLOCK_SIZE - 1] = 1;
+
+	/* Set up a scatterlist for the IV */
+	iv_sg = &rctx->iv_sg;
+	iv_len = AES_BLOCK_SIZE;
+	sg_init_one(iv_sg, rctx->iv, iv_len);
+
+	/* The AAD + plaintext are concatenated in the src buffer */
+	memset(&rctx->cmd, 0, sizeof(rctx->cmd));
+	INIT_LIST_HEAD(&rctx->cmd.entry);
+	rctx->cmd.engine = CCP_ENGINE_AES;
+	rctx->cmd.u.aes.type = ctx->u.aes.type;
+	rctx->cmd.u.aes.mode = ctx->u.aes.mode;
+	rctx->cmd.u.aes.action = encrypt;
+	rctx->cmd.u.aes.key = &ctx->u.aes.key_sg;
+	rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
+	rctx->cmd.u.aes.iv = iv_sg;
+	rctx->cmd.u.aes.iv_len = iv_len;
+	rctx->cmd.u.aes.src = req->src;
+	rctx->cmd.u.aes.src_len = req->cryptlen;
+	rctx->cmd.u.aes.aad_len = req->assoclen;
+
+	/* The cipher text + the tag are in the dst buffer */
+	rctx->cmd.u.aes.dst = req->dst;
+
+	ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
+
+	return ret;
+}
+
+static int ccp_aes_gcm_encrypt(struct aead_request *req)
+{
+	return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_ENCRYPT);
+}
+
+static int ccp_aes_gcm_decrypt(struct aead_request *req)
+{
+	return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_DECRYPT);
+}
+
+static int ccp_aes_gcm_cra_init(struct crypto_aead *tfm)
+{
+	struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
+
+	ctx->complete = ccp_aes_gcm_complete;
+	ctx->u.aes.key_len = 0;
+
+	crypto_aead_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx));
+
+	return 0;
+}
+
+static void ccp_aes_gcm_cra_exit(struct crypto_tfm *tfm)
+{
+}
+
+static struct aead_alg ccp_aes_gcm_defaults = {
+	.setkey = ccp_aes_gcm_setkey,
+	.setauthsize = ccp_aes_gcm_setauthsize,
+	.encrypt = ccp_aes_gcm_encrypt,
+	.decrypt = ccp_aes_gcm_decrypt,
+	.init = ccp_aes_gcm_cra_init,
+	.ivsize = AES_GCM_IVSIZE,
+	.maxauthsize = AES_BLOCK_SIZE,
+	.base = {
+		.cra_flags	= CRYPTO_ALG_TYPE_ABLKCIPHER |
+				  CRYPTO_ALG_ASYNC |
+				  CRYPTO_ALG_KERN_DRIVER_ONLY |
+				  CRYPTO_ALG_NEED_FALLBACK,
+		.cra_blocksize	= AES_BLOCK_SIZE,
+		.cra_ctxsize	= sizeof(struct ccp_ctx),
+		.cra_priority	= CCP_CRA_PRIORITY,
+		.cra_type	= &crypto_ablkcipher_type,
+		.cra_exit	= ccp_aes_gcm_cra_exit,
+		.cra_module	= THIS_MODULE,
+	},
+};
+
+struct ccp_aes_aead_def {
+	enum ccp_aes_mode mode;
+	unsigned int version;
+	const char *name;
+	const char *driver_name;
+	unsigned int blocksize;
+	unsigned int ivsize;
+	struct aead_alg *alg_defaults;
+};
+
+static struct ccp_aes_aead_def aes_aead_algs[] = {
+	{
+		.mode		= CCP_AES_MODE_GHASH,
+		.version	= CCP_VERSION(5, 0),
+		.name		= "gcm(aes)",
+		.driver_name	= "gcm-aes-ccp",
+		.blocksize	= 1,
+		.ivsize		= AES_BLOCK_SIZE,
+		.alg_defaults	= &ccp_aes_gcm_defaults,
+	},
+};
+
+static int ccp_register_aes_aead(struct list_head *head,
+				 const struct ccp_aes_aead_def *def)
+{
+	struct ccp_crypto_aead *ccp_aead;
+	struct aead_alg *alg;
+	int ret;
+
+	ccp_aead = kzalloc(sizeof(*ccp_aead), GFP_KERNEL);
+	if (!ccp_aead)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&ccp_aead->entry);
+
+	ccp_aead->mode = def->mode;
+
+	/* Copy the defaults and override as necessary */
+	alg = &ccp_aead->alg;
+	*alg = *def->alg_defaults;
+	snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
+	snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
+		 def->driver_name);
+	alg->base.cra_blocksize = def->blocksize;
+	alg->base.cra_ablkcipher.ivsize = def->ivsize;
+
+	ret = crypto_register_aead(alg);
+	if (ret) {
+		pr_err("%s ablkcipher algorithm registration error (%d)\n",
+		       alg->base.cra_name, ret);
+		kfree(ccp_aead);
+		return ret;
+	}
+
+	list_add(&ccp_aead->entry, head);
+
+	return 0;
+}
+
+int ccp_register_aes_aeads(struct list_head *head)
+{
+	int i, ret;
+	unsigned int ccpversion = ccp_version();
+
+	for (i = 0; i < ARRAY_SIZE(aes_aead_algs); i++) {
+		if (aes_aead_algs[i].version > ccpversion)
+			continue;
+		ret = ccp_register_aes_aead(head, &aes_aead_algs[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}