Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 840 insertions, 0 deletions

diff --git a/drivers/crypto/keembay/ocs-hcu.c b/drivers/crypto/keembay/ocs-hcu.c
new file mode 100644
index 000000000..deb9bd460
--- /dev/null
+++ b/drivers/crypto/keembay/ocs-hcu.c
@@ -0,0 +1,840 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel Keem Bay OCS HCU Crypto Driver.
+ *
+ * Copyright (C) 2018-2020 Intel Corporation
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/iopoll.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+
+#include <crypto/sha2.h>
+
+#include "ocs-hcu.h"
+
+/* Registers. */
+#define OCS_HCU_MODE			0x00
+#define OCS_HCU_CHAIN			0x04
+#define OCS_HCU_OPERATION		0x08
+#define OCS_HCU_KEY_0			0x0C
+#define OCS_HCU_ISR			0x50
+#define OCS_HCU_IER			0x54
+#define OCS_HCU_STATUS			0x58
+#define OCS_HCU_MSG_LEN_LO		0x60
+#define OCS_HCU_MSG_LEN_HI		0x64
+#define OCS_HCU_KEY_BYTE_ORDER_CFG	0x80
+#define OCS_HCU_DMA_SRC_ADDR		0x400
+#define OCS_HCU_DMA_SRC_SIZE		0x408
+#define OCS_HCU_DMA_DST_SIZE		0x40C
+#define OCS_HCU_DMA_DMA_MODE		0x410
+#define OCS_HCU_DMA_NEXT_SRC_DESCR	0x418
+#define OCS_HCU_DMA_MSI_ISR		0x480
+#define OCS_HCU_DMA_MSI_IER		0x484
+#define OCS_HCU_DMA_MSI_MASK		0x488
+
+/* Register bit definitions. */
+#define HCU_MODE_ALGO_SHIFT		16
+#define HCU_MODE_HMAC_SHIFT		22
+
+#define HCU_STATUS_BUSY			BIT(0)
+
+#define HCU_BYTE_ORDER_SWAP		BIT(0)
+
+#define HCU_IRQ_HASH_DONE		BIT(2)
+#define HCU_IRQ_HASH_ERR_MASK		(BIT(3) | BIT(1) | BIT(0))
+
+#define HCU_DMA_IRQ_SRC_DONE		BIT(0)
+#define HCU_DMA_IRQ_SAI_ERR		BIT(2)
+#define HCU_DMA_IRQ_BAD_COMP_ERR	BIT(3)
+#define HCU_DMA_IRQ_INBUF_RD_ERR	BIT(4)
+#define HCU_DMA_IRQ_INBUF_WD_ERR	BIT(5)
+#define HCU_DMA_IRQ_OUTBUF_WR_ERR	BIT(6)
+#define HCU_DMA_IRQ_OUTBUF_RD_ERR	BIT(7)
+#define HCU_DMA_IRQ_CRD_ERR		BIT(8)
+#define HCU_DMA_IRQ_ERR_MASK		(HCU_DMA_IRQ_SAI_ERR | \
+					 HCU_DMA_IRQ_BAD_COMP_ERR | \
+					 HCU_DMA_IRQ_INBUF_RD_ERR | \
+					 HCU_DMA_IRQ_INBUF_WD_ERR | \
+					 HCU_DMA_IRQ_OUTBUF_WR_ERR | \
+					 HCU_DMA_IRQ_OUTBUF_RD_ERR | \
+					 HCU_DMA_IRQ_CRD_ERR)
+
+#define HCU_DMA_SNOOP_MASK		(0x7 << 28)
+#define HCU_DMA_SRC_LL_EN		BIT(25)
+#define HCU_DMA_EN			BIT(31)
+
+#define OCS_HCU_ENDIANNESS_VALUE	0x2A
+
+#define HCU_DMA_MSI_UNMASK		BIT(0)
+#define HCU_DMA_MSI_DISABLE		0
+#define HCU_IRQ_DISABLE			0
+
+#define OCS_HCU_START			BIT(0)
+#define OCS_HCU_TERMINATE		BIT(1)
+
+#define OCS_LL_DMA_FLAG_TERMINATE	BIT(31)
+
+#define OCS_HCU_HW_KEY_LEN_U32		(OCS_HCU_HW_KEY_LEN / sizeof(u32))
+
+#define HCU_DATA_WRITE_ENDIANNESS_OFFSET	26
+
+#define OCS_HCU_NUM_CHAINS_SHA256_224_SM3	(SHA256_DIGEST_SIZE / sizeof(u32))
+#define OCS_HCU_NUM_CHAINS_SHA384_512		(SHA512_DIGEST_SIZE / sizeof(u32))
+
+/*
+ * While polling on a busy HCU, wait maximum 200us between one check and the
+ * other.
+ */
+#define OCS_HCU_WAIT_BUSY_RETRY_DELAY_US	200
+/* Wait on a busy HCU for maximum 1 second. */
+#define OCS_HCU_WAIT_BUSY_TIMEOUT_US		1000000
+
+/**
+ * struct ocs_hcu_dma_entry - An entry in an OCS DMA linked list.
+ * @src_addr:  Source address of the data.
+ * @src_len:   Length of data to be fetched.
+ * @nxt_desc:  Next descriptor to fetch.
+ * @ll_flags:  Flags (Freeze @ terminate) for the DMA engine.
+ */
+struct ocs_hcu_dma_entry {
+	u32 src_addr;
+	u32 src_len;
+	u32 nxt_desc;
+	u32 ll_flags;
+};
+
+/**
+ * struct ocs_hcu_dma_list - OCS-specific DMA linked list.
+ * @head:	The head of the list (points to the array backing the list).
+ * @tail:	The current tail of the list; NULL if the list is empty.
+ * @dma_addr:	The DMA address of @head (i.e., the DMA address of the backing
+ *		array).
+ * @max_nents:	Maximum number of entries in the list (i.e., number of elements
+ *		in the backing array).
+ *
+ * The OCS DMA list is an array-backed list of OCS DMA descriptors. The array
+ * backing the list is allocated with dma_alloc_coherent() and pointed by
+ * @head.
+ */
+struct ocs_hcu_dma_list {
+	struct ocs_hcu_dma_entry	*head;
+	struct ocs_hcu_dma_entry	*tail;
+	dma_addr_t			dma_addr;
+	size_t				max_nents;
+};
+
+static inline u32 ocs_hcu_num_chains(enum ocs_hcu_algo algo)
+{
+	switch (algo) {
+	case OCS_HCU_ALGO_SHA224:
+	case OCS_HCU_ALGO_SHA256:
+	case OCS_HCU_ALGO_SM3:
+		return OCS_HCU_NUM_CHAINS_SHA256_224_SM3;
+	case OCS_HCU_ALGO_SHA384:
+	case OCS_HCU_ALGO_SHA512:
+		return OCS_HCU_NUM_CHAINS_SHA384_512;
+	default:
+		return 0;
+	};
+}
+
+static inline u32 ocs_hcu_digest_size(enum ocs_hcu_algo algo)
+{
+	switch (algo) {
+	case OCS_HCU_ALGO_SHA224:
+		return SHA224_DIGEST_SIZE;
+	case OCS_HCU_ALGO_SHA256:
+	case OCS_HCU_ALGO_SM3:
+		/* SM3 shares the same block size. */
+		return SHA256_DIGEST_SIZE;
+	case OCS_HCU_ALGO_SHA384:
+		return SHA384_DIGEST_SIZE;
+	case OCS_HCU_ALGO_SHA512:
+		return SHA512_DIGEST_SIZE;
+	default:
+		return 0;
+	}
+}
+
+/**
+ * ocs_hcu_wait_busy() - Wait for HCU OCS hardware to became usable.
+ * @hcu_dev:	OCS HCU device to wait for.
+ *
+ * Return: 0 if device free, -ETIMEOUT if device busy and internal timeout has
+ *	   expired.
+ */
+static int ocs_hcu_wait_busy(struct ocs_hcu_dev *hcu_dev)
+{
+	long val;
+
+	return readl_poll_timeout(hcu_dev->io_base + OCS_HCU_STATUS, val,
+				  !(val & HCU_STATUS_BUSY),
+				  OCS_HCU_WAIT_BUSY_RETRY_DELAY_US,
+				  OCS_HCU_WAIT_BUSY_TIMEOUT_US);
+}
+
+static void ocs_hcu_done_irq_en(struct ocs_hcu_dev *hcu_dev)
+{
+	/* Clear any pending interrupts. */
+	writel(0xFFFFFFFF, hcu_dev->io_base + OCS_HCU_ISR);
+	hcu_dev->irq_err = false;
+	/* Enable error and HCU done interrupts. */
+	writel(HCU_IRQ_HASH_DONE | HCU_IRQ_HASH_ERR_MASK,
+	       hcu_dev->io_base + OCS_HCU_IER);
+}
+
+static void ocs_hcu_dma_irq_en(struct ocs_hcu_dev *hcu_dev)
+{
+	/* Clear any pending interrupts. */
+	writel(0xFFFFFFFF, hcu_dev->io_base + OCS_HCU_DMA_MSI_ISR);
+	hcu_dev->irq_err = false;
+	/* Only operating on DMA source completion and error interrupts. */
+	writel(HCU_DMA_IRQ_ERR_MASK | HCU_DMA_IRQ_SRC_DONE,
+	       hcu_dev->io_base + OCS_HCU_DMA_MSI_IER);
+	/* Unmask */
+	writel(HCU_DMA_MSI_UNMASK, hcu_dev->io_base + OCS_HCU_DMA_MSI_MASK);
+}
+
+static void ocs_hcu_irq_dis(struct ocs_hcu_dev *hcu_dev)
+{
+	writel(HCU_IRQ_DISABLE, hcu_dev->io_base + OCS_HCU_IER);
+	writel(HCU_DMA_MSI_DISABLE, hcu_dev->io_base + OCS_HCU_DMA_MSI_IER);
+}
+
+static int ocs_hcu_wait_and_disable_irq(struct ocs_hcu_dev *hcu_dev)
+{
+	int rc;
+
+	rc = wait_for_completion_interruptible(&hcu_dev->irq_done);
+	if (rc)
+		goto exit;
+
+	if (hcu_dev->irq_err) {
+		/* Unset flag and return error. */
+		hcu_dev->irq_err = false;
+		rc = -EIO;
+		goto exit;
+	}
+
+exit:
+	ocs_hcu_irq_dis(hcu_dev);
+
+	return rc;
+}
+
+/**
+ * ocs_hcu_get_intermediate_data() - Get intermediate data.
+ * @hcu_dev:	The target HCU device.
+ * @data:	Where to store the intermediate.
+ * @algo:	The algorithm being used.
+ *
+ * This function is used to save the current hashing process state in order to
+ * continue it in the future.
+ *
+ * Note: once all data has been processed, the intermediate data actually
+ * contains the hashing result. So this function is also used to retrieve the
+ * final result of a hashing process.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+static int ocs_hcu_get_intermediate_data(struct ocs_hcu_dev *hcu_dev,
+					 struct ocs_hcu_idata *data,
+					 enum ocs_hcu_algo algo)
+{
+	const int n = ocs_hcu_num_chains(algo);
+	u32 *chain;
+	int rc;
+	int i;
+
+	/* Data not requested. */
+	if (!data)
+		return -EINVAL;
+
+	chain = (u32 *)data->digest;
+
+	/* Ensure that the OCS is no longer busy before reading the chains. */
+	rc = ocs_hcu_wait_busy(hcu_dev);
+	if (rc)
+		return rc;
+
+	/*
+	 * This loops is safe because data->digest is an array of
+	 * SHA512_DIGEST_SIZE bytes and the maximum value returned by
+	 * ocs_hcu_num_chains() is OCS_HCU_NUM_CHAINS_SHA384_512 which is equal
+	 * to SHA512_DIGEST_SIZE / sizeof(u32).
+	 */
+	for (i = 0; i < n; i++)
+		chain[i] = readl(hcu_dev->io_base + OCS_HCU_CHAIN);
+
+	data->msg_len_lo = readl(hcu_dev->io_base + OCS_HCU_MSG_LEN_LO);
+	data->msg_len_hi = readl(hcu_dev->io_base + OCS_HCU_MSG_LEN_HI);
+
+	return 0;
+}
+
+/**
+ * ocs_hcu_set_intermediate_data() - Set intermediate data.
+ * @hcu_dev:	The target HCU device.
+ * @data:	The intermediate data to be set.
+ * @algo:	The algorithm being used.
+ *
+ * This function is used to continue a previous hashing process.
+ */
+static void ocs_hcu_set_intermediate_data(struct ocs_hcu_dev *hcu_dev,
+					  const struct ocs_hcu_idata *data,
+					  enum ocs_hcu_algo algo)
+{
+	const int n = ocs_hcu_num_chains(algo);
+	u32 *chain = (u32 *)data->digest;
+	int i;
+
+	/*
+	 * This loops is safe because data->digest is an array of
+	 * SHA512_DIGEST_SIZE bytes and the maximum value returned by
+	 * ocs_hcu_num_chains() is OCS_HCU_NUM_CHAINS_SHA384_512 which is equal
+	 * to SHA512_DIGEST_SIZE / sizeof(u32).
+	 */
+	for (i = 0; i < n; i++)
+		writel(chain[i], hcu_dev->io_base + OCS_HCU_CHAIN);
+
+	writel(data->msg_len_lo, hcu_dev->io_base + OCS_HCU_MSG_LEN_LO);
+	writel(data->msg_len_hi, hcu_dev->io_base + OCS_HCU_MSG_LEN_HI);
+}
+
+static int ocs_hcu_get_digest(struct ocs_hcu_dev *hcu_dev,
+			      enum ocs_hcu_algo algo, u8 *dgst, size_t dgst_len)
+{
+	u32 *chain;
+	int rc;
+	int i;
+
+	if (!dgst)
+		return -EINVAL;
+
+	/* Length of the output buffer must match the algo digest size. */
+	if (dgst_len != ocs_hcu_digest_size(algo))
+		return -EINVAL;
+
+	/* Ensure that the OCS is no longer busy before reading the chains. */
+	rc = ocs_hcu_wait_busy(hcu_dev);
+	if (rc)
+		return rc;
+
+	chain = (u32 *)dgst;
+	for (i = 0; i < dgst_len / sizeof(u32); i++)
+		chain[i] = readl(hcu_dev->io_base + OCS_HCU_CHAIN);
+
+	return 0;
+}
+
+/**
+ * ocs_hcu_hw_cfg() - Configure the HCU hardware.
+ * @hcu_dev:	The HCU device to configure.
+ * @algo:	The algorithm to be used by the HCU device.
+ * @use_hmac:	Whether or not HW HMAC should be used.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+static int ocs_hcu_hw_cfg(struct ocs_hcu_dev *hcu_dev, enum ocs_hcu_algo algo,
+			  bool use_hmac)
+{
+	u32 cfg;
+	int rc;
+
+	if (algo != OCS_HCU_ALGO_SHA256 && algo != OCS_HCU_ALGO_SHA224 &&
+	    algo != OCS_HCU_ALGO_SHA384 && algo != OCS_HCU_ALGO_SHA512 &&
+	    algo != OCS_HCU_ALGO_SM3)
+		return -EINVAL;
+
+	rc = ocs_hcu_wait_busy(hcu_dev);
+	if (rc)
+		return rc;
+
+	/* Ensure interrupts are disabled. */
+	ocs_hcu_irq_dis(hcu_dev);
+
+	/* Configure endianness, hashing algorithm and HW HMAC (if needed) */
+	cfg = OCS_HCU_ENDIANNESS_VALUE << HCU_DATA_WRITE_ENDIANNESS_OFFSET;
+	cfg |= algo << HCU_MODE_ALGO_SHIFT;
+	if (use_hmac)
+		cfg |= BIT(HCU_MODE_HMAC_SHIFT);
+
+	writel(cfg, hcu_dev->io_base + OCS_HCU_MODE);
+
+	return 0;
+}
+
+/**
+ * ocs_hcu_clear_key() - Clear key stored in OCS HMAC KEY registers.
+ * @hcu_dev:	The OCS HCU device whose key registers should be cleared.
+ */
+static void ocs_hcu_clear_key(struct ocs_hcu_dev *hcu_dev)
+{
+	int reg_off;
+
+	/* Clear OCS_HCU_KEY_[0..15] */
+	for (reg_off = 0; reg_off < OCS_HCU_HW_KEY_LEN; reg_off += sizeof(u32))
+		writel(0, hcu_dev->io_base + OCS_HCU_KEY_0 + reg_off);
+}
+
+/**
+ * ocs_hcu_write_key() - Write key to OCS HMAC KEY registers.
+ * @hcu_dev:	The OCS HCU device the key should be written to.
+ * @key:	The key to be written.
+ * @len:	The size of the key to write. It must be OCS_HCU_HW_KEY_LEN.
+ *
+ * Return:	0 on success, negative error code otherwise.
+ */
+static int ocs_hcu_write_key(struct ocs_hcu_dev *hcu_dev, const u8 *key, size_t len)
+{
+	u32 key_u32[OCS_HCU_HW_KEY_LEN_U32];
+	int i;
+
+	if (len > OCS_HCU_HW_KEY_LEN)
+		return -EINVAL;
+
+	/* Copy key into temporary u32 array. */
+	memcpy(key_u32, key, len);
+
+	/*
+	 * Hardware requires all the bytes of the HW Key vector to be
+	 * written. So pad with zero until we reach OCS_HCU_HW_KEY_LEN.
+	 */
+	memzero_explicit((u8 *)key_u32 + len, OCS_HCU_HW_KEY_LEN - len);
+
+	/*
+	 * OCS hardware expects the MSB of the key to be written at the highest
+	 * address of the HCU Key vector; in other word, the key must be
+	 * written in reverse order.
+	 *
+	 * Therefore, we first enable byte swapping for the HCU key vector;
+	 * so that bytes of 32-bit word written to OCS_HCU_KEY_[0..15] will be
+	 * swapped:
+	 * 3 <---> 0, 2 <---> 1.
+	 */
+	writel(HCU_BYTE_ORDER_SWAP,
+	       hcu_dev->io_base + OCS_HCU_KEY_BYTE_ORDER_CFG);
+	/*
+	 * And then we write the 32-bit words composing the key starting from
+	 * the end of the key.
+	 */
+	for (i = 0; i < OCS_HCU_HW_KEY_LEN_U32; i++)
+		writel(key_u32[OCS_HCU_HW_KEY_LEN_U32 - 1 - i],
+		       hcu_dev->io_base + OCS_HCU_KEY_0 + (sizeof(u32) * i));
+
+	memzero_explicit(key_u32, OCS_HCU_HW_KEY_LEN);
+
+	return 0;
+}
+
+/**
+ * ocs_hcu_ll_dma_start() - Start OCS HCU hashing via DMA
+ * @hcu_dev:	The OCS HCU device to use.
+ * @dma_list:	The OCS DMA list mapping the data to hash.
+ * @finalize:	Whether or not this is the last hashing operation and therefore
+ *		the final hash should be compute even if data is not
+ *		block-aligned.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+static int ocs_hcu_ll_dma_start(struct ocs_hcu_dev *hcu_dev,
+				const struct ocs_hcu_dma_list *dma_list,
+				bool finalize)
+{
+	u32 cfg = HCU_DMA_SNOOP_MASK | HCU_DMA_SRC_LL_EN | HCU_DMA_EN;
+	int rc;
+
+	if (!dma_list)
+		return -EINVAL;
+
+	/*
+	 * For final requests we use HCU_DONE IRQ to be notified when all input
+	 * data has been processed by the HCU; however, we cannot do so for
+	 * non-final requests, because we don't get a HCU_DONE IRQ when we
+	 * don't terminate the operation.
+	 *
+	 * Therefore, for non-final requests, we use the DMA IRQ, which
+	 * triggers when DMA has finishing feeding all the input data to the
+	 * HCU, but the HCU may still be processing it. This is fine, since we
+	 * will wait for the HCU processing to be completed when we try to read
+	 * intermediate results, in ocs_hcu_get_intermediate_data().
+	 */
+	if (finalize)
+		ocs_hcu_done_irq_en(hcu_dev);
+	else
+		ocs_hcu_dma_irq_en(hcu_dev);
+
+	reinit_completion(&hcu_dev->irq_done);
+	writel(dma_list->dma_addr, hcu_dev->io_base + OCS_HCU_DMA_NEXT_SRC_DESCR);
+	writel(0, hcu_dev->io_base + OCS_HCU_DMA_SRC_SIZE);
+	writel(0, hcu_dev->io_base + OCS_HCU_DMA_DST_SIZE);
+
+	writel(OCS_HCU_START, hcu_dev->io_base + OCS_HCU_OPERATION);
+
+	writel(cfg, hcu_dev->io_base + OCS_HCU_DMA_DMA_MODE);
+
+	if (finalize)
+		writel(OCS_HCU_TERMINATE, hcu_dev->io_base + OCS_HCU_OPERATION);
+
+	rc = ocs_hcu_wait_and_disable_irq(hcu_dev);
+	if (rc)
+		return rc;
+
+	return 0;
+}
+
+struct ocs_hcu_dma_list *ocs_hcu_dma_list_alloc(struct ocs_hcu_dev *hcu_dev,
+						int max_nents)
+{
+	struct ocs_hcu_dma_list *dma_list;
+
+	dma_list = kmalloc(sizeof(*dma_list), GFP_KERNEL);
+	if (!dma_list)
+		return NULL;
+
+	/* Total size of the DMA list to allocate. */
+	dma_list->head = dma_alloc_coherent(hcu_dev->dev,
+					    sizeof(*dma_list->head) * max_nents,
+					    &dma_list->dma_addr, GFP_KERNEL);
+	if (!dma_list->head) {
+		kfree(dma_list);
+		return NULL;
+	}
+	dma_list->max_nents = max_nents;
+	dma_list->tail = NULL;
+
+	return dma_list;
+}
+
+void ocs_hcu_dma_list_free(struct ocs_hcu_dev *hcu_dev,
+			   struct ocs_hcu_dma_list *dma_list)
+{
+	if (!dma_list)
+		return;
+
+	dma_free_coherent(hcu_dev->dev,
+			  sizeof(*dma_list->head) * dma_list->max_nents,
+			  dma_list->head, dma_list->dma_addr);
+
+	kfree(dma_list);
+}
+
+/* Add a new DMA entry at the end of the OCS 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)
+{
+	struct device *dev = hcu_dev->dev;
+	struct ocs_hcu_dma_entry *old_tail;
+	struct ocs_hcu_dma_entry *new_tail;
+
+	if (!len)
+		return 0;
+
+	if (!dma_list)
+		return -EINVAL;
+
+	if (addr & ~OCS_HCU_DMA_BIT_MASK) {
+		dev_err(dev,
+			"Unexpected error: Invalid DMA address for OCS HCU\n");
+		return -EINVAL;
+	}
+
+	old_tail = dma_list->tail;
+	new_tail = old_tail ? old_tail + 1 : dma_list->head;
+
+	/* Check if list is full. */
+	if (new_tail - dma_list->head >= dma_list->max_nents)
+		return -ENOMEM;
+
+	/*
+	 * If there was an old tail (i.e., this is not the first element we are
+	 * adding), un-terminate the old tail and make it point to the new one.
+	 */
+	if (old_tail) {
+		old_tail->ll_flags &= ~OCS_LL_DMA_FLAG_TERMINATE;
+		/*
+		 * The old tail 'nxt_desc' must point to the DMA address of the
+		 * new tail.
+		 */
+		old_tail->nxt_desc = dma_list->dma_addr +
+				     sizeof(*dma_list->tail) * (new_tail -
+								dma_list->head);
+	}
+
+	new_tail->src_addr = (u32)addr;
+	new_tail->src_len = (u32)len;
+	new_tail->ll_flags = OCS_LL_DMA_FLAG_TERMINATE;
+	new_tail->nxt_desc = 0;
+
+	/* Update list tail with new tail. */
+	dma_list->tail = new_tail;
+
+	return 0;
+}
+
+/**
+ * ocs_hcu_hash_init() - Initialize hash operation context.
+ * @ctx:	The context to initialize.
+ * @algo:	The hashing algorithm to use.
+ *
+ * Return:	0 on success, negative error code otherwise.
+ */
+int ocs_hcu_hash_init(struct ocs_hcu_hash_ctx *ctx, enum ocs_hcu_algo algo)
+{
+	if (!ctx)
+		return -EINVAL;
+
+	ctx->algo = algo;
+	ctx->idata.msg_len_lo = 0;
+	ctx->idata.msg_len_hi = 0;
+	/* No need to set idata.digest to 0. */
+
+	return 0;
+}
+
+/**
+ * ocs_hcu_hash_update() - Perform a hashing iteration.
+ * @hcu_dev:	The OCS HCU device to use.
+ * @ctx:	The OCS HCU hashing context.
+ * @dma_list:	The OCS DMA list mapping the input data to process.
+ *
+ * Return: 0 on success; negative error code otherwise.
+ */
+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 rc;
+
+	if (!hcu_dev || !ctx)
+		return -EINVAL;
+
+	/* Configure the hardware for the current request. */
+	rc = ocs_hcu_hw_cfg(hcu_dev, ctx->algo, false);
+	if (rc)
+		return rc;
+
+	/* If we already processed some data, idata needs to be set. */
+	if (ctx->idata.msg_len_lo || ctx->idata.msg_len_hi)
+		ocs_hcu_set_intermediate_data(hcu_dev, &ctx->idata, ctx->algo);
+
+	/* Start linked-list DMA hashing. */
+	rc = ocs_hcu_ll_dma_start(hcu_dev, dma_list, false);
+	if (rc)
+		return rc;
+
+	/* Update idata and return. */
+	return ocs_hcu_get_intermediate_data(hcu_dev, &ctx->idata, ctx->algo);
+}
+
+/**
+ * ocs_hcu_hash_finup() - Update and finalize hash computation.
+ * @hcu_dev:	The OCS HCU device to use.
+ * @ctx:	The OCS HCU hashing context.
+ * @dma_list:	The OCS DMA list mapping the input data to process.
+ * @dgst:	The buffer where to save the computed digest.
+ * @dgst_len:	The length of @dgst.
+ *
+ * Return: 0 on success; negative error code otherwise.
+ */
+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 rc;
+
+	if (!hcu_dev || !ctx)
+		return -EINVAL;
+
+	/* Configure the hardware for the current request. */
+	rc = ocs_hcu_hw_cfg(hcu_dev, ctx->algo, false);
+	if (rc)
+		return rc;
+
+	/* If we already processed some data, idata needs to be set. */
+	if (ctx->idata.msg_len_lo || ctx->idata.msg_len_hi)
+		ocs_hcu_set_intermediate_data(hcu_dev, &ctx->idata, ctx->algo);
+
+	/* Start linked-list DMA hashing. */
+	rc = ocs_hcu_ll_dma_start(hcu_dev, dma_list, true);
+	if (rc)
+		return rc;
+
+	/* Get digest and return. */
+	return ocs_hcu_get_digest(hcu_dev, ctx->algo, dgst, dgst_len);
+}
+
+/**
+ * ocs_hcu_hash_final() - Finalize hash computation.
+ * @hcu_dev:		The OCS HCU device to use.
+ * @ctx:		The OCS HCU hashing context.
+ * @dgst:		The buffer where to save the computed digest.
+ * @dgst_len:		The length of @dgst.
+ *
+ * Return: 0 on success; negative error code otherwise.
+ */
+int ocs_hcu_hash_final(struct ocs_hcu_dev *hcu_dev,
+		       const struct ocs_hcu_hash_ctx *ctx, u8 *dgst,
+		       size_t dgst_len)
+{
+	int rc;
+
+	if (!hcu_dev || !ctx)
+		return -EINVAL;
+
+	/* Configure the hardware for the current request. */
+	rc = ocs_hcu_hw_cfg(hcu_dev, ctx->algo, false);
+	if (rc)
+		return rc;
+
+	/* If we already processed some data, idata needs to be set. */
+	if (ctx->idata.msg_len_lo || ctx->idata.msg_len_hi)
+		ocs_hcu_set_intermediate_data(hcu_dev, &ctx->idata, ctx->algo);
+
+	/*
+	 * Enable HCU interrupts, so that HCU_DONE will be triggered once the
+	 * final hash is computed.
+	 */
+	ocs_hcu_done_irq_en(hcu_dev);
+	reinit_completion(&hcu_dev->irq_done);
+	writel(OCS_HCU_TERMINATE, hcu_dev->io_base + OCS_HCU_OPERATION);
+
+	rc = ocs_hcu_wait_and_disable_irq(hcu_dev);
+	if (rc)
+		return rc;
+
+	/* Get digest and return. */
+	return ocs_hcu_get_digest(hcu_dev, ctx->algo, dgst, dgst_len);
+}
+
+/**
+ * ocs_hcu_digest() - Compute hash digest.
+ * @hcu_dev:		The OCS HCU device to use.
+ * @algo:		The hash algorithm to use.
+ * @data:		The input data to process.
+ * @data_len:		The length of @data.
+ * @dgst:		The buffer where to save the computed digest.
+ * @dgst_len:		The length of @dgst.
+ *
+ * Return: 0 on success; negative error code otherwise.
+ */
+int ocs_hcu_digest(struct ocs_hcu_dev *hcu_dev, enum ocs_hcu_algo algo,
+		   void *data, size_t data_len, u8 *dgst, size_t dgst_len)
+{
+	struct device *dev = hcu_dev->dev;
+	dma_addr_t dma_handle;
+	u32 reg;
+	int rc;
+
+	/* Configure the hardware for the current request. */
+	rc = ocs_hcu_hw_cfg(hcu_dev, algo, false);
+	if (rc)
+		return rc;
+
+	dma_handle = dma_map_single(dev, data, data_len, DMA_TO_DEVICE);
+	if (dma_mapping_error(dev, dma_handle))
+		return -EIO;
+
+	reg = HCU_DMA_SNOOP_MASK | HCU_DMA_EN;
+
+	ocs_hcu_done_irq_en(hcu_dev);
+
+	reinit_completion(&hcu_dev->irq_done);
+
+	writel(dma_handle, hcu_dev->io_base + OCS_HCU_DMA_SRC_ADDR);
+	writel(data_len, hcu_dev->io_base + OCS_HCU_DMA_SRC_SIZE);
+	writel(OCS_HCU_START, hcu_dev->io_base + OCS_HCU_OPERATION);
+	writel(reg, hcu_dev->io_base + OCS_HCU_DMA_DMA_MODE);
+
+	writel(OCS_HCU_TERMINATE, hcu_dev->io_base + OCS_HCU_OPERATION);
+
+	rc = ocs_hcu_wait_and_disable_irq(hcu_dev);
+	if (rc)
+		return rc;
+
+	dma_unmap_single(dev, dma_handle, data_len, DMA_TO_DEVICE);
+
+	return ocs_hcu_get_digest(hcu_dev, algo, dgst, dgst_len);
+}
+
+/**
+ * ocs_hcu_hmac() - Compute HMAC.
+ * @hcu_dev:		The OCS HCU device to use.
+ * @algo:		The hash algorithm to use with HMAC.
+ * @key:		The key to use.
+ * @dma_list:	The OCS DMA list mapping the input data to process.
+ * @key_len:		The length of @key.
+ * @dgst:		The buffer where to save the computed HMAC.
+ * @dgst_len:		The length of @dgst.
+ *
+ * Return: 0 on success; negative error code otherwise.
+ */
+int ocs_hcu_hmac(struct ocs_hcu_dev *hcu_dev, enum ocs_hcu_algo algo,
+		 const u8 *key, size_t key_len,
+		 const struct ocs_hcu_dma_list *dma_list,
+		 u8 *dgst, size_t dgst_len)
+{
+	int rc;
+
+	/* Ensure 'key' is not NULL. */
+	if (!key || key_len == 0)
+		return -EINVAL;
+
+	/* Configure the hardware for the current request. */
+	rc = ocs_hcu_hw_cfg(hcu_dev, algo, true);
+	if (rc)
+		return rc;
+
+	rc = ocs_hcu_write_key(hcu_dev, key, key_len);
+	if (rc)
+		return rc;
+
+	rc = ocs_hcu_ll_dma_start(hcu_dev, dma_list, true);
+
+	/* Clear HW key before processing return code. */
+	ocs_hcu_clear_key(hcu_dev);
+
+	if (rc)
+		return rc;
+
+	return ocs_hcu_get_digest(hcu_dev, algo, dgst, dgst_len);
+}
+
+irqreturn_t ocs_hcu_irq_handler(int irq, void *dev_id)
+{
+	struct ocs_hcu_dev *hcu_dev = dev_id;
+	u32 hcu_irq;
+	u32 dma_irq;
+
+	/* Read and clear the HCU interrupt. */
+	hcu_irq = readl(hcu_dev->io_base + OCS_HCU_ISR);
+	writel(hcu_irq, hcu_dev->io_base + OCS_HCU_ISR);
+
+	/* Read and clear the HCU DMA interrupt. */
+	dma_irq = readl(hcu_dev->io_base + OCS_HCU_DMA_MSI_ISR);
+	writel(dma_irq, hcu_dev->io_base + OCS_HCU_DMA_MSI_ISR);
+
+	/* Check for errors. */
+	if (hcu_irq & HCU_IRQ_HASH_ERR_MASK || dma_irq & HCU_DMA_IRQ_ERR_MASK) {
+		hcu_dev->irq_err = true;
+		goto complete;
+	}
+
+	/* Check for DONE IRQs. */
+	if (hcu_irq & HCU_IRQ_HASH_DONE || dma_irq & HCU_DMA_IRQ_SRC_DONE)
+		goto complete;
+
+	return IRQ_NONE;
+
+complete:
+	complete(&hcu_dev->irq_done);
+
+	return IRQ_HANDLED;
+}
+
+MODULE_LICENSE("GPL");