crypto: keembay - Add Keem Bay OCS HCU driver

Add support for the Hashing Control Unit (HCU) included in the Offload
Crypto Subsystem (OCS) of the Intel Keem Bay SoC, thus enabling
hardware-accelerated hashing on the Keem Bay SoC for the following
algorithms:
- sha256
- sha384
- sha512
- sm3

The driver is composed of two files:

- 'ocs-hcu.c' which interacts with the hardware and abstracts it by
  providing an API following the usual paradigm used in hashing drivers
  / libraries (e.g., hash_init(), hash_update(), hash_final(), etc.).
  NOTE: this API can block and sleep, since completions are used to wait
  for the HW to complete the hashing.

- 'keembay-ocs-hcu-core.c' which exports the functionality provided by
  'ocs-hcu.c' as a ahash crypto driver. The crypto engine is used to
  provide asynchronous behavior. 'keembay-ocs-hcu-core.c' also takes
  care of the DMA mapping of the input sg list.

The driver passes crypto manager self-tests, including the extra tests
(CRYPTO_MANAGER_EXTRA_TESTS=y).
Signed-off-by: Declan Murphy <declan.murphy@intel.com>
Co-developed-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
Signed-off-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
Acked-by: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/keembay/Kconfig

@@ -38,3 +38,20 @@ config CRYPTO_DEV_KEEMBAY_OCS_AES_SM4_CTS
 	  Provides OCS version of cts(cbc(aes)) and cts(cbc(sm4)).
 
 	  Intel does not recommend use of CTS mode with AES/SM4.
+
+config CRYPTO_DEV_KEEMBAY_OCS_HCU
+	tristate "Support for Intel Keem Bay OCS HCU HW acceleration"
+	select CRYPTO_HASH
+	select CRYPTO_ENGINE
+	depends on OF || COMPILE_TEST
+	help
+	  Support for Intel Keem Bay Offload and Crypto Subsystem (OCS) Hash
+	  Control Unit (HCU) hardware acceleration for use with Crypto API.
+
+	  Provides OCS HCU hardware acceleration of sha256, sha384, sha512, and
+	  sm3.
+
+	  Say Y or M if you're building for the Intel Keem Bay SoC. If compiled
+	  as a module, the module will be called keembay-ocs-hcu.
+
+	  If unsure, say N.

drivers/crypto/keembay/Makefile

@@ -3,3 +3,6 @@
 #
 obj-$(CONFIG_CRYPTO_DEV_KEEMBAY_OCS_AES_SM4) += keembay-ocs-aes.o
 keembay-ocs-aes-objs := keembay-ocs-aes-core.o ocs-aes.o
+
+obj-$(CONFIG_CRYPTO_DEV_KEEMBAY_OCS_HCU) += keembay-ocs-hcu.o
+keembay-ocs-hcu-objs := keembay-ocs-hcu-core.o ocs-hcu.o

drivers/crypto/keembay/ocs-hcu.h

+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Intel Keem Bay OCS HCU Crypto Driver.
+ *
+ * Copyright (C) 2018-2020 Intel Corporation
+ */
+
+#include <linux/dma-mapping.h>
+
+#ifndef _CRYPTO_OCS_HCU_H
+#define _CRYPTO_OCS_HCU_H
+
+#define OCS_HCU_DMA_BIT_MASK		DMA_BIT_MASK(32)
+
+#define OCS_HCU_HW_KEY_LEN		64
+
+struct ocs_hcu_dma_list;
+
+enum ocs_hcu_algo {
+	OCS_HCU_ALGO_SHA256 = 2,
+	OCS_HCU_ALGO_SHA224 = 3,
+	OCS_HCU_ALGO_SHA384 = 4,
+	OCS_HCU_ALGO_SHA512 = 5,
+	OCS_HCU_ALGO_SM3    = 6,
+};
+
+/**
+ * struct ocs_hcu_dev - OCS HCU device context.
+ * @list:	List of device contexts.
+ * @dev:	OCS HCU device.
+ * @io_base:	Base address of OCS HCU registers.
+ * @engine:	Crypto engine for the device.
+ * @irq:	IRQ number.
+ * @irq_done:	Completion for IRQ.
+ * @irq_err:	Flag indicating an IRQ error has happened.
+ */
+struct ocs_hcu_dev {
+	struct list_head list;
+	struct device *dev;
+	void __iomem *io_base;
+	struct crypto_engine *engine;
+	int irq;
+	struct completion irq_done;
+	bool irq_err;
+};
+
+/**
+ * struct ocs_hcu_idata - Intermediate data generated by the HCU.
+ * @msg_len_lo: Length of data the HCU has operated on in bits, low 32b.
+ * @msg_len_hi: Length of data the HCU has operated on in bits, high 32b.
+ * @digest: The digest read from the HCU. If the HCU is terminated, it will
+ *	    contain the actual hash digest. Otherwise it is the intermediate
+ *	    state.
+ */
+struct ocs_hcu_idata {
+	u32 msg_len_lo;
+	u32 msg_len_hi;
+	u8  digest[SHA512_DIGEST_SIZE];
+};
+
+/**
+ * struct ocs_hcu_hash_ctx - Context for OCS HCU hashing operation.
+ * @algo:	The hashing algorithm being used.
+ * @idata:	The current intermediate data.
+ */
+struct ocs_hcu_hash_ctx {
+	enum ocs_hcu_algo	algo;
+	struct ocs_hcu_idata	idata;
+};
+
+irqreturn_t ocs_hcu_irq_handler(int irq, void *dev_id);
+
+struct ocs_hcu_dma_list *ocs_hcu_dma_list_alloc(struct ocs_hcu_dev *hcu_dev,
+						int max_nents);
+
+void ocs_hcu_dma_list_free(struct ocs_hcu_dev *hcu_dev,
+			   struct ocs_hcu_dma_list *dma_list);
+
+int ocs_hcu_dma_list_add_tail(struct ocs_hcu_dev *hcu_dev,
+			      struct ocs_hcu_dma_list *dma_list,
+			      dma_addr_t addr, u32 len);
+
+int ocs_hcu_hash_init(struct ocs_hcu_hash_ctx *ctx, enum ocs_hcu_algo algo);
+
+int ocs_hcu_hash_update(struct ocs_hcu_dev *hcu_dev,
+			struct ocs_hcu_hash_ctx *ctx,
+			const struct ocs_hcu_dma_list *dma_list);
+
+int ocs_hcu_hash_finup(struct ocs_hcu_dev *hcu_dev,
+		       const struct ocs_hcu_hash_ctx *ctx,
+		       const struct ocs_hcu_dma_list *dma_list,
+		       u8 *dgst, size_t dgst_len);
+
+int ocs_hcu_hash_final(struct ocs_hcu_dev *hcu_dev,
+		       const struct ocs_hcu_hash_ctx *ctx, u8 *dgst,
+		       size_t dgst_len);
+
+#endif /* _CRYPTO_OCS_HCU_H */