1 files changed, 291 insertions, 0 deletions
diff --git a/drivers/crypto/ccp/ccp-crypto-aes-xts.c b/drivers/crypto/ccp/ccp-crypto-aes-xts.c
new file mode 100644
index 000000000..94b5bcf5b
--- /dev/null
+++ b/drivers/crypto/ccp/ccp-crypto-aes-xts.c
@@ -0,0 +1,291 @@
+/*
+ * AMD Cryptographic Coprocessor (CCP) AES XTS crypto API support
+ *
+ * Copyright (C) 2013,2017 Advanced Micro Devices, Inc.
+ *
+ * Author: Gary R Hook <gary.hook@amd.com>
+ * Author: Tom Lendacky <thomas.lendacky@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 <crypto/aes.h>
+#include <crypto/xts.h>
+#include <crypto/internal/skcipher.h>
+#include <crypto/scatterwalk.h>
+
+#include "ccp-crypto.h"
+
+struct ccp_aes_xts_def {
+	const char *name;
+	const char *drv_name;
+};
+
+static struct ccp_aes_xts_def aes_xts_algs[] = {
+	{
+		.name		= "xts(aes)",
+		.drv_name	= "xts-aes-ccp",
+	},
+};
+
+struct ccp_unit_size_map {
+	unsigned int size;
+	u32 value;
+};
+
+static struct ccp_unit_size_map xts_unit_sizes[] = {
+	{
+		.size   = 16,
+		.value	= CCP_XTS_AES_UNIT_SIZE_16,
+	},
+	{
+		.size   = 512,
+		.value	= CCP_XTS_AES_UNIT_SIZE_512,
+	},
+	{
+		.size   = 1024,
+		.value	= CCP_XTS_AES_UNIT_SIZE_1024,
+	},
+	{
+		.size   = 2048,
+		.value	= CCP_XTS_AES_UNIT_SIZE_2048,
+	},
+	{
+		.size   = 4096,
+		.value	= CCP_XTS_AES_UNIT_SIZE_4096,
+	},
+};
+
+static int ccp_aes_xts_complete(struct crypto_async_request *async_req, int ret)
+{
+	struct ablkcipher_request *req = ablkcipher_request_cast(async_req);
+	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
+
+	if (ret)
+		return ret;
+
+	memcpy(req->info, rctx->iv, AES_BLOCK_SIZE);
+
+	return 0;
+}
+
+static int ccp_aes_xts_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
+			      unsigned int key_len)
+{
+	struct crypto_tfm *xfm = crypto_ablkcipher_tfm(tfm);
+	struct ccp_ctx *ctx = crypto_tfm_ctx(xfm);
+	unsigned int ccpversion = ccp_version();
+	int ret;
+
+	ret = xts_check_key(xfm, key, key_len);
+	if (ret)
+		return ret;
+
+	/* Version 3 devices support 128-bit keys; version 5 devices can
+	 * accommodate 128- and 256-bit keys.
+	 */
+	switch (key_len) {
+	case AES_KEYSIZE_128 * 2:
+		memcpy(ctx->u.aes.key, key, key_len);
+		break;
+	case AES_KEYSIZE_256 * 2:
+		if (ccpversion > CCP_VERSION(3, 0))
+			memcpy(ctx->u.aes.key, key, key_len);
+		break;
+	}
+	ctx->u.aes.key_len = key_len / 2;
+	sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
+
+	return crypto_skcipher_setkey(ctx->u.aes.tfm_skcipher, key, key_len);
+}
+
+static int ccp_aes_xts_crypt(struct ablkcipher_request *req,
+			     unsigned int encrypt)
+{
+	struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
+	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
+	unsigned int ccpversion = ccp_version();
+	unsigned int fallback = 0;
+	unsigned int unit;
+	u32 unit_size;
+	int ret;
+
+	if (!ctx->u.aes.key_len)
+		return -EINVAL;
+
+	if (req->nbytes & (AES_BLOCK_SIZE - 1))
+		return -EINVAL;
+
+	if (!req->info)
+		return -EINVAL;
+
+	/* Check conditions under which the CCP can fulfill a request. The
+	 * device can handle input plaintext of a length that is a multiple
+	 * of the unit_size, bug the crypto implementation only supports
+	 * the unit_size being equal to the input length. This limits the
+	 * number of scenarios we can handle.
+	 */
+	unit_size = CCP_XTS_AES_UNIT_SIZE__LAST;
+	for (unit = 0; unit < ARRAY_SIZE(xts_unit_sizes); unit++) {
+		if (req->nbytes == xts_unit_sizes[unit].size) {
+			unit_size = unit;
+			break;
+		}
+	}
+	/* The CCP has restrictions on block sizes. Also, a version 3 device
+	 * only supports AES-128 operations; version 5 CCPs support both
+	 * AES-128 and -256 operations.
+	 */
+	if (unit_size == CCP_XTS_AES_UNIT_SIZE__LAST)
+		fallback = 1;
+	if ((ccpversion < CCP_VERSION(5, 0)) &&
+	    (ctx->u.aes.key_len != AES_KEYSIZE_128))
+		fallback = 1;
+	if ((ctx->u.aes.key_len != AES_KEYSIZE_128) &&
+	    (ctx->u.aes.key_len != AES_KEYSIZE_256))
+		fallback = 1;
+	if (fallback) {
+		SKCIPHER_REQUEST_ON_STACK(subreq, ctx->u.aes.tfm_skcipher);
+
+		/* Use the fallback to process the request for any
+		 * unsupported unit sizes or key sizes
+		 */
+		skcipher_request_set_tfm(subreq, ctx->u.aes.tfm_skcipher);
+		skcipher_request_set_callback(subreq, req->base.flags,
+					      NULL, NULL);
+		skcipher_request_set_crypt(subreq, req->src, req->dst,
+					   req->nbytes, req->info);
+		ret = encrypt ? crypto_skcipher_encrypt(subreq) :
+				crypto_skcipher_decrypt(subreq);
+		skcipher_request_zero(subreq);
+		return ret;
+	}
+
+	memcpy(rctx->iv, req->info, AES_BLOCK_SIZE);
+	sg_init_one(&rctx->iv_sg, rctx->iv, AES_BLOCK_SIZE);
+
+	memset(&rctx->cmd, 0, sizeof(rctx->cmd));
+	INIT_LIST_HEAD(&rctx->cmd.entry);
+	rctx->cmd.engine = CCP_ENGINE_XTS_AES_128;
+	rctx->cmd.u.xts.type = CCP_AES_TYPE_128;
+	rctx->cmd.u.xts.action = (encrypt) ? CCP_AES_ACTION_ENCRYPT
+					   : CCP_AES_ACTION_DECRYPT;
+	rctx->cmd.u.xts.unit_size = unit_size;
+	rctx->cmd.u.xts.key = &ctx->u.aes.key_sg;
+	rctx->cmd.u.xts.key_len = ctx->u.aes.key_len;
+	rctx->cmd.u.xts.iv = &rctx->iv_sg;
+	rctx->cmd.u.xts.iv_len = AES_BLOCK_SIZE;
+	rctx->cmd.u.xts.src = req->src;
+	rctx->cmd.u.xts.src_len = req->nbytes;
+	rctx->cmd.u.xts.dst = req->dst;
+
+	ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
+
+	return ret;
+}
+
+static int ccp_aes_xts_encrypt(struct ablkcipher_request *req)
+{
+	return ccp_aes_xts_crypt(req, 1);
+}
+
+static int ccp_aes_xts_decrypt(struct ablkcipher_request *req)
+{
+	return ccp_aes_xts_crypt(req, 0);
+}
+
+static int ccp_aes_xts_cra_init(struct crypto_tfm *tfm)
+{
+	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
+	struct crypto_skcipher *fallback_tfm;
+
+	ctx->complete = ccp_aes_xts_complete;
+	ctx->u.aes.key_len = 0;
+
+	fallback_tfm = crypto_alloc_skcipher("xts(aes)", 0,
+					     CRYPTO_ALG_ASYNC |
+					     CRYPTO_ALG_NEED_FALLBACK);
+	if (IS_ERR(fallback_tfm)) {
+		pr_warn("could not load fallback driver xts(aes)\n");
+		return PTR_ERR(fallback_tfm);
+	}
+	ctx->u.aes.tfm_skcipher = fallback_tfm;
+
+	tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx);
+
+	return 0;
+}
+
+static void ccp_aes_xts_cra_exit(struct crypto_tfm *tfm)
+{
+	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	crypto_free_skcipher(ctx->u.aes.tfm_skcipher);
+}
+
+static int ccp_register_aes_xts_alg(struct list_head *head,
+				    const struct ccp_aes_xts_def *def)
+{
+	struct ccp_crypto_ablkcipher_alg *ccp_alg;
+	struct crypto_alg *alg;
+	int ret;
+
+	ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
+	if (!ccp_alg)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&ccp_alg->entry);
+
+	alg = &ccp_alg->alg;
+
+	snprintf(alg->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
+	snprintf(alg->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
+		 def->drv_name);
+	alg->cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC |
+			 CRYPTO_ALG_KERN_DRIVER_ONLY |
+			 CRYPTO_ALG_NEED_FALLBACK;
+	alg->cra_blocksize = AES_BLOCK_SIZE;
+	alg->cra_ctxsize = sizeof(struct ccp_ctx);
+	alg->cra_priority = CCP_CRA_PRIORITY;
+	alg->cra_type = &crypto_ablkcipher_type;
+	alg->cra_ablkcipher.setkey = ccp_aes_xts_setkey;
+	alg->cra_ablkcipher.encrypt = ccp_aes_xts_encrypt;
+	alg->cra_ablkcipher.decrypt = ccp_aes_xts_decrypt;
+	alg->cra_ablkcipher.min_keysize = AES_MIN_KEY_SIZE * 2;
+	alg->cra_ablkcipher.max_keysize = AES_MAX_KEY_SIZE * 2;
+	alg->cra_ablkcipher.ivsize = AES_BLOCK_SIZE;
+	alg->cra_init = ccp_aes_xts_cra_init;
+	alg->cra_exit = ccp_aes_xts_cra_exit;
+	alg->cra_module = THIS_MODULE;
+
+	ret = crypto_register_alg(alg);
+	if (ret) {
+		pr_err("%s ablkcipher algorithm registration error (%d)\n",
+		       alg->cra_name, ret);
+		kfree(ccp_alg);
+		return ret;
+	}
+
+	list_add(&ccp_alg->entry, head);
+
+	return 0;
+}
+
+int ccp_register_aes_xts_algs(struct list_head *head)
+{
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(aes_xts_algs); i++) {
+		ret = ccp_register_aes_xts_alg(head, &aes_xts_algs[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}