Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 1009 insertions, 0 deletions

diff --git a/drivers/crypto/intel/keembay/keembay-ocs-ecc.c b/drivers/crypto/intel/keembay/keembay-ocs-ecc.c
new file mode 100644
index 0000000000..fb95deed90
--- /dev/null
+++ b/drivers/crypto/intel/keembay/keembay-ocs-ecc.c
@@ -0,0 +1,1009 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel Keem Bay OCS ECC Crypto Driver.
+ *
+ * Copyright (C) 2019-2021 Intel Corporation
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <crypto/ecc_curve.h>
+#include <crypto/ecdh.h>
+#include <crypto/engine.h>
+#include <crypto/internal/ecc.h>
+#include <crypto/internal/kpp.h>
+#include <crypto/kpp.h>
+#include <crypto/rng.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/err.h>
+#include <linux/fips.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/scatterlist.h>
+#include <linux/string.h>
+
+#define DRV_NAME			"keembay-ocs-ecc"
+
+#define KMB_OCS_ECC_PRIORITY		350
+
+#define HW_OFFS_OCS_ECC_COMMAND		0x00000000
+#define HW_OFFS_OCS_ECC_STATUS		0x00000004
+#define HW_OFFS_OCS_ECC_DATA_IN		0x00000080
+#define HW_OFFS_OCS_ECC_CX_DATA_OUT	0x00000100
+#define HW_OFFS_OCS_ECC_CY_DATA_OUT	0x00000180
+#define HW_OFFS_OCS_ECC_ISR		0x00000400
+#define HW_OFFS_OCS_ECC_IER		0x00000404
+
+#define HW_OCS_ECC_ISR_INT_STATUS_DONE	BIT(0)
+#define HW_OCS_ECC_COMMAND_INS_BP	BIT(0)
+
+#define HW_OCS_ECC_COMMAND_START_VAL	BIT(0)
+
+#define OCS_ECC_OP_SIZE_384		BIT(8)
+#define OCS_ECC_OP_SIZE_256		0
+
+/* ECC Instruction : for ECC_COMMAND */
+#define OCS_ECC_INST_WRITE_AX		(0x1 << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_WRITE_AY		(0x2 << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_WRITE_BX_D		(0x3 << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_WRITE_BY_L		(0x4 << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_WRITE_P		(0x5 << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_WRITE_A		(0x6 << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_CALC_D_IDX_A	(0x8 << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_CALC_A_POW_B_MODP	(0xB << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_CALC_A_MUL_B_MODP	(0xC  << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_CALC_A_ADD_B_MODP	(0xD << HW_OCS_ECC_COMMAND_INS_BP)
+
+#define ECC_ENABLE_INTR			1
+
+#define POLL_USEC			100
+#define TIMEOUT_USEC			10000
+
+#define KMB_ECC_VLI_MAX_DIGITS		ECC_CURVE_NIST_P384_DIGITS
+#define KMB_ECC_VLI_MAX_BYTES		(KMB_ECC_VLI_MAX_DIGITS \
+					 << ECC_DIGITS_TO_BYTES_SHIFT)
+
+#define POW_CUBE			3
+
+/**
+ * struct ocs_ecc_dev - ECC device context
+ * @list: List of device contexts
+ * @dev: OCS ECC device
+ * @base_reg: IO base address of OCS ECC
+ * @engine: Crypto engine for the device
+ * @irq_done: IRQ done completion.
+ * @irq: IRQ number
+ */
+struct ocs_ecc_dev {
+	struct list_head list;
+	struct device *dev;
+	void __iomem *base_reg;
+	struct crypto_engine *engine;
+	struct completion irq_done;
+	int irq;
+};
+
+/**
+ * struct ocs_ecc_ctx - Transformation context.
+ * @ecc_dev:	 The ECC driver associated with this context.
+ * @curve:	 The elliptic curve used by this transformation.
+ * @private_key: The private key.
+ */
+struct ocs_ecc_ctx {
+	struct ocs_ecc_dev *ecc_dev;
+	const struct ecc_curve *curve;
+	u64 private_key[KMB_ECC_VLI_MAX_DIGITS];
+};
+
+/* Driver data. */
+struct ocs_ecc_drv {
+	struct list_head dev_list;
+	spinlock_t lock;	/* Protects dev_list. */
+};
+
+/* Global variable holding the list of OCS ECC devices (only one expected). */
+static struct ocs_ecc_drv ocs_ecc = {
+	.dev_list = LIST_HEAD_INIT(ocs_ecc.dev_list),
+	.lock = __SPIN_LOCK_UNLOCKED(ocs_ecc.lock),
+};
+
+/* Get OCS ECC tfm context from kpp_request. */
+static inline struct ocs_ecc_ctx *kmb_ocs_ecc_tctx(struct kpp_request *req)
+{
+	return kpp_tfm_ctx(crypto_kpp_reqtfm(req));
+}
+
+/* Converts number of digits to number of bytes. */
+static inline unsigned int digits_to_bytes(unsigned int n)
+{
+	return n << ECC_DIGITS_TO_BYTES_SHIFT;
+}
+
+/*
+ * Wait for ECC idle i.e when an operation (other than write operations)
+ * is done.
+ */
+static inline int ocs_ecc_wait_idle(struct ocs_ecc_dev *dev)
+{
+	u32 value;
+
+	return readl_poll_timeout((dev->base_reg + HW_OFFS_OCS_ECC_STATUS),
+				  value,
+				  !(value & HW_OCS_ECC_ISR_INT_STATUS_DONE),
+				  POLL_USEC, TIMEOUT_USEC);
+}
+
+static void ocs_ecc_cmd_start(struct ocs_ecc_dev *ecc_dev, u32 op_size)
+{
+	iowrite32(op_size | HW_OCS_ECC_COMMAND_START_VAL,
+		  ecc_dev->base_reg + HW_OFFS_OCS_ECC_COMMAND);
+}
+
+/* Direct write of u32 buffer to ECC engine with associated instruction. */
+static void ocs_ecc_write_cmd_and_data(struct ocs_ecc_dev *dev,
+				       u32 op_size,
+				       u32 inst,
+				       const void *data_in,
+				       size_t data_size)
+{
+	iowrite32(op_size | inst, dev->base_reg + HW_OFFS_OCS_ECC_COMMAND);
+
+	/* MMIO Write src uint32 to dst. */
+	memcpy_toio(dev->base_reg + HW_OFFS_OCS_ECC_DATA_IN, data_in,
+		    data_size);
+}
+
+/* Start OCS ECC operation and wait for its completion. */
+static int ocs_ecc_trigger_op(struct ocs_ecc_dev *ecc_dev, u32 op_size,
+			      u32 inst)
+{
+	reinit_completion(&ecc_dev->irq_done);
+
+	iowrite32(ECC_ENABLE_INTR, ecc_dev->base_reg + HW_OFFS_OCS_ECC_IER);
+	iowrite32(op_size | inst, ecc_dev->base_reg + HW_OFFS_OCS_ECC_COMMAND);
+
+	return wait_for_completion_interruptible(&ecc_dev->irq_done);
+}
+
+/**
+ * ocs_ecc_read_cx_out() - Read the CX data output buffer.
+ * @dev:	The OCS ECC device to read from.
+ * @cx_out:	The buffer where to store the CX value. Must be at least
+ *		@byte_count byte long.
+ * @byte_count:	The amount of data to read.
+ */
+static inline void ocs_ecc_read_cx_out(struct ocs_ecc_dev *dev, void *cx_out,
+				       size_t byte_count)
+{
+	memcpy_fromio(cx_out, dev->base_reg + HW_OFFS_OCS_ECC_CX_DATA_OUT,
+		      byte_count);
+}
+
+/**
+ * ocs_ecc_read_cy_out() - Read the CX data output buffer.
+ * @dev:	The OCS ECC device to read from.
+ * @cy_out:	The buffer where to store the CY value. Must be at least
+ *		@byte_count byte long.
+ * @byte_count:	The amount of data to read.
+ */
+static inline void ocs_ecc_read_cy_out(struct ocs_ecc_dev *dev, void *cy_out,
+				       size_t byte_count)
+{
+	memcpy_fromio(cy_out, dev->base_reg + HW_OFFS_OCS_ECC_CY_DATA_OUT,
+		      byte_count);
+}
+
+static struct ocs_ecc_dev *kmb_ocs_ecc_find_dev(struct ocs_ecc_ctx *tctx)
+{
+	if (tctx->ecc_dev)
+		return tctx->ecc_dev;
+
+	spin_lock(&ocs_ecc.lock);
+
+	/* Only a single OCS device available. */
+	tctx->ecc_dev = list_first_entry(&ocs_ecc.dev_list, struct ocs_ecc_dev,
+					 list);
+
+	spin_unlock(&ocs_ecc.lock);
+
+	return tctx->ecc_dev;
+}
+
+/* Do point multiplication using OCS ECC HW. */
+static int kmb_ecc_point_mult(struct ocs_ecc_dev *ecc_dev,
+			      struct ecc_point *result,
+			      const struct ecc_point *point,
+			      u64 *scalar,
+			      const struct ecc_curve *curve)
+{
+	u8 sca[KMB_ECC_VLI_MAX_BYTES]; /* Use the maximum data size. */
+	u32 op_size = (curve->g.ndigits > ECC_CURVE_NIST_P256_DIGITS) ?
+		      OCS_ECC_OP_SIZE_384 : OCS_ECC_OP_SIZE_256;
+	size_t nbytes = digits_to_bytes(curve->g.ndigits);
+	int rc = 0;
+
+	/* Generate random nbytes for Simple and Differential SCA protection. */
+	rc = crypto_get_default_rng();
+	if (rc)
+		return rc;
+
+	rc = crypto_rng_get_bytes(crypto_default_rng, sca, nbytes);
+	crypto_put_default_rng();
+	if (rc)
+		return rc;
+
+	/* Wait engine to be idle before starting new operation. */
+	rc = ocs_ecc_wait_idle(ecc_dev);
+	if (rc)
+		return rc;
+
+	/* Send ecc_start pulse as well as indicating operation size. */
+	ocs_ecc_cmd_start(ecc_dev, op_size);
+
+	/* Write ax param; Base point (Gx). */
+	ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_AX,
+				   point->x, nbytes);
+
+	/* Write ay param; Base point (Gy). */
+	ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_AY,
+				   point->y, nbytes);
+
+	/*
+	 * Write the private key into DATA_IN reg.
+	 *
+	 * Since DATA_IN register is used to write different values during the
+	 * computation private Key value is overwritten with
+	 * side-channel-resistance value.
+	 */
+	ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_BX_D,
+				   scalar, nbytes);
+
+	/* Write operand by/l. */
+	ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_BY_L,
+				   sca, nbytes);
+	memzero_explicit(sca, sizeof(sca));
+
+	/* Write p = curve prime(GF modulus). */
+	ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_P,
+				   curve->p, nbytes);
+
+	/* Write a = curve coefficient. */
+	ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_A,
+				   curve->a, nbytes);
+
+	/* Make hardware perform the multiplication. */
+	rc = ocs_ecc_trigger_op(ecc_dev, op_size, OCS_ECC_INST_CALC_D_IDX_A);
+	if (rc)
+		return rc;
+
+	/* Read result. */
+	ocs_ecc_read_cx_out(ecc_dev, result->x, nbytes);
+	ocs_ecc_read_cy_out(ecc_dev, result->y, nbytes);
+
+	return 0;
+}
+
+/**
+ * kmb_ecc_do_scalar_op() - Perform Scalar operation using OCS ECC HW.
+ * @ecc_dev:	The OCS ECC device to use.
+ * @scalar_out:	Where to store the output scalar.
+ * @scalar_a:	Input scalar operand 'a'.
+ * @scalar_b:	Input scalar operand 'b'
+ * @curve:	The curve on which the operation is performed.
+ * @ndigits:	The size of the operands (in digits).
+ * @inst:	The operation to perform (as an OCS ECC instruction).
+ *
+ * Return:	0 on success, negative error code otherwise.
+ */
+static int kmb_ecc_do_scalar_op(struct ocs_ecc_dev *ecc_dev, u64 *scalar_out,
+				const u64 *scalar_a, const u64 *scalar_b,
+				const struct ecc_curve *curve,
+				unsigned int ndigits, const u32 inst)
+{
+	u32 op_size = (ndigits > ECC_CURVE_NIST_P256_DIGITS) ?
+		      OCS_ECC_OP_SIZE_384 : OCS_ECC_OP_SIZE_256;
+	size_t nbytes = digits_to_bytes(ndigits);
+	int rc;
+
+	/* Wait engine to be idle before starting new operation. */
+	rc = ocs_ecc_wait_idle(ecc_dev);
+	if (rc)
+		return rc;
+
+	/* Send ecc_start pulse as well as indicating operation size. */
+	ocs_ecc_cmd_start(ecc_dev, op_size);
+
+	/* Write ax param (Base point (Gx).*/
+	ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_AX,
+				   scalar_a, nbytes);
+
+	/* Write ay param Base point (Gy).*/
+	ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_AY,
+				   scalar_b, nbytes);
+
+	/* Write p = curve prime(GF modulus).*/
+	ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_P,
+				   curve->p, nbytes);
+
+	/* Give instruction A.B or A+B to ECC engine. */
+	rc = ocs_ecc_trigger_op(ecc_dev, op_size, inst);
+	if (rc)
+		return rc;
+
+	ocs_ecc_read_cx_out(ecc_dev, scalar_out, nbytes);
+
+	if (vli_is_zero(scalar_out, ndigits))
+		return -EINVAL;
+
+	return 0;
+}
+
+/* SP800-56A section 5.6.2.3.4 partial verification: ephemeral keys only */
+static int kmb_ocs_ecc_is_pubkey_valid_partial(struct ocs_ecc_dev *ecc_dev,
+					       const struct ecc_curve *curve,
+					       struct ecc_point *pk)
+{
+	u64 xxx[KMB_ECC_VLI_MAX_DIGITS] = { 0 };
+	u64 yy[KMB_ECC_VLI_MAX_DIGITS] = { 0 };
+	u64 w[KMB_ECC_VLI_MAX_DIGITS] = { 0 };
+	int rc;
+
+	if (WARN_ON(pk->ndigits != curve->g.ndigits))
+		return -EINVAL;
+
+	/* Check 1: Verify key is not the zero point. */
+	if (ecc_point_is_zero(pk))
+		return -EINVAL;
+
+	/* Check 2: Verify key is in the range [0, p-1]. */
+	if (vli_cmp(curve->p, pk->x, pk->ndigits) != 1)
+		return -EINVAL;
+
+	if (vli_cmp(curve->p, pk->y, pk->ndigits) != 1)
+		return -EINVAL;
+
+	/* Check 3: Verify that y^2 == (x^3 + a·x + b) mod p */
+
+	 /* y^2 */
+	/* Compute y^2 -> store in yy */
+	rc = kmb_ecc_do_scalar_op(ecc_dev, yy, pk->y, pk->y, curve, pk->ndigits,
+				  OCS_ECC_INST_CALC_A_MUL_B_MODP);
+	if (rc)
+		goto exit;
+
+	/* x^3 */
+	/* Assigning w = 3, used for calculating x^3. */
+	w[0] = POW_CUBE;
+	/* Load the next stage.*/
+	rc = kmb_ecc_do_scalar_op(ecc_dev, xxx, pk->x, w, curve, pk->ndigits,
+				  OCS_ECC_INST_CALC_A_POW_B_MODP);
+	if (rc)
+		goto exit;
+
+	/* Do a*x -> store in w. */
+	rc = kmb_ecc_do_scalar_op(ecc_dev, w, curve->a, pk->x, curve,
+				  pk->ndigits,
+				  OCS_ECC_INST_CALC_A_MUL_B_MODP);
+	if (rc)
+		goto exit;
+
+	/* Do ax + b == w + b; store in w. */
+	rc = kmb_ecc_do_scalar_op(ecc_dev, w, w, curve->b, curve,
+				  pk->ndigits,
+				  OCS_ECC_INST_CALC_A_ADD_B_MODP);
+	if (rc)
+		goto exit;
+
+	/* x^3 + ax + b == x^3 + w -> store in w. */
+	rc = kmb_ecc_do_scalar_op(ecc_dev, w, xxx, w, curve, pk->ndigits,
+				  OCS_ECC_INST_CALC_A_ADD_B_MODP);
+	if (rc)
+		goto exit;
+
+	/* Compare y^2 == x^3 + a·x + b. */
+	rc = vli_cmp(yy, w, pk->ndigits);
+	if (rc)
+		rc = -EINVAL;
+
+exit:
+	memzero_explicit(xxx, sizeof(xxx));
+	memzero_explicit(yy, sizeof(yy));
+	memzero_explicit(w, sizeof(w));
+
+	return rc;
+}
+
+/* SP800-56A section 5.6.2.3.3 full verification */
+static int kmb_ocs_ecc_is_pubkey_valid_full(struct ocs_ecc_dev *ecc_dev,
+					    const struct ecc_curve *curve,
+					    struct ecc_point *pk)
+{
+	struct ecc_point *nQ;
+	int rc;
+
+	/* Checks 1 through 3 */
+	rc = kmb_ocs_ecc_is_pubkey_valid_partial(ecc_dev, curve, pk);
+	if (rc)
+		return rc;
+
+	/* Check 4: Verify that nQ is the zero point. */
+	nQ = ecc_alloc_point(pk->ndigits);
+	if (!nQ)
+		return -ENOMEM;
+
+	rc = kmb_ecc_point_mult(ecc_dev, nQ, pk, curve->n, curve);
+	if (rc)
+		goto exit;
+
+	if (!ecc_point_is_zero(nQ))
+		rc = -EINVAL;
+
+exit:
+	ecc_free_point(nQ);
+
+	return rc;
+}
+
+static int kmb_ecc_is_key_valid(const struct ecc_curve *curve,
+				const u64 *private_key, size_t private_key_len)
+{
+	size_t ndigits = curve->g.ndigits;
+	u64 one[KMB_ECC_VLI_MAX_DIGITS] = {1};
+	u64 res[KMB_ECC_VLI_MAX_DIGITS];
+
+	if (private_key_len != digits_to_bytes(ndigits))
+		return -EINVAL;
+
+	if (!private_key)
+		return -EINVAL;
+
+	/* Make sure the private key is in the range [2, n-3]. */
+	if (vli_cmp(one, private_key, ndigits) != -1)
+		return -EINVAL;
+
+	vli_sub(res, curve->n, one, ndigits);
+	vli_sub(res, res, one, ndigits);
+	if (vli_cmp(res, private_key, ndigits) != 1)
+		return -EINVAL;
+
+	return 0;
+}
+
+/*
+ * ECC private keys are generated using the method of extra random bits,
+ * equivalent to that described in FIPS 186-4, Appendix B.4.1.
+ *
+ * d = (c mod(n–1)) + 1    where c is a string of random bits, 64 bits longer
+ *                         than requested
+ * 0 <= c mod(n-1) <= n-2  and implies that
+ * 1 <= d <= n-1
+ *
+ * This method generates a private key uniformly distributed in the range
+ * [1, n-1].
+ */
+static int kmb_ecc_gen_privkey(const struct ecc_curve *curve, u64 *privkey)
+{
+	size_t nbytes = digits_to_bytes(curve->g.ndigits);
+	u64 priv[KMB_ECC_VLI_MAX_DIGITS];
+	size_t nbits;
+	int rc;
+
+	nbits = vli_num_bits(curve->n, curve->g.ndigits);
+
+	/* Check that N is included in Table 1 of FIPS 186-4, section 6.1.1 */
+	if (nbits < 160 || curve->g.ndigits > ARRAY_SIZE(priv))
+		return -EINVAL;
+
+	/*
+	 * FIPS 186-4 recommends that the private key should be obtained from a
+	 * RBG with a security strength equal to or greater than the security
+	 * strength associated with N.
+	 *
+	 * The maximum security strength identified by NIST SP800-57pt1r4 for
+	 * ECC is 256 (N >= 512).
+	 *
+	 * This condition is met by the default RNG because it selects a favored
+	 * DRBG with a security strength of 256.
+	 */
+	if (crypto_get_default_rng())
+		return -EFAULT;
+
+	rc = crypto_rng_get_bytes(crypto_default_rng, (u8 *)priv, nbytes);
+	crypto_put_default_rng();
+	if (rc)
+		goto cleanup;
+
+	rc = kmb_ecc_is_key_valid(curve, priv, nbytes);
+	if (rc)
+		goto cleanup;
+
+	ecc_swap_digits(priv, privkey, curve->g.ndigits);
+
+cleanup:
+	memzero_explicit(&priv, sizeof(priv));
+
+	return rc;
+}
+
+static int kmb_ocs_ecdh_set_secret(struct crypto_kpp *tfm, const void *buf,
+				   unsigned int len)
+{
+	struct ocs_ecc_ctx *tctx = kpp_tfm_ctx(tfm);
+	struct ecdh params;
+	int rc = 0;
+
+	rc = crypto_ecdh_decode_key(buf, len, &params);
+	if (rc)
+		goto cleanup;
+
+	/* Ensure key size is not bigger then expected. */
+	if (params.key_size > digits_to_bytes(tctx->curve->g.ndigits)) {
+		rc = -EINVAL;
+		goto cleanup;
+	}
+
+	/* Auto-generate private key is not provided. */
+	if (!params.key || !params.key_size) {
+		rc = kmb_ecc_gen_privkey(tctx->curve, tctx->private_key);
+		goto cleanup;
+	}
+
+	rc = kmb_ecc_is_key_valid(tctx->curve, (const u64 *)params.key,
+				  params.key_size);
+	if (rc)
+		goto cleanup;
+
+	ecc_swap_digits((const u64 *)params.key, tctx->private_key,
+			tctx->curve->g.ndigits);
+cleanup:
+	memzero_explicit(&params, sizeof(params));
+
+	if (rc)
+		tctx->curve = NULL;
+
+	return rc;
+}
+
+/* Compute shared secret. */
+static int kmb_ecc_do_shared_secret(struct ocs_ecc_ctx *tctx,
+				    struct kpp_request *req)
+{
+	struct ocs_ecc_dev *ecc_dev = tctx->ecc_dev;
+	const struct ecc_curve *curve = tctx->curve;
+	u64 shared_secret[KMB_ECC_VLI_MAX_DIGITS];
+	u64 pubk_buf[KMB_ECC_VLI_MAX_DIGITS * 2];
+	size_t copied, nbytes, pubk_len;
+	struct ecc_point *pk, *result;
+	int rc;
+
+	nbytes = digits_to_bytes(curve->g.ndigits);
+
+	/* Public key is a point, thus it has two coordinates */
+	pubk_len = 2 * nbytes;
+
+	/* Copy public key from SG list to pubk_buf. */
+	copied = sg_copy_to_buffer(req->src,
+				   sg_nents_for_len(req->src, pubk_len),
+				   pubk_buf, pubk_len);
+	if (copied != pubk_len)
+		return -EINVAL;
+
+	/* Allocate and initialize public key point. */
+	pk = ecc_alloc_point(curve->g.ndigits);
+	if (!pk)
+		return -ENOMEM;
+
+	ecc_swap_digits(pubk_buf, pk->x, curve->g.ndigits);
+	ecc_swap_digits(&pubk_buf[curve->g.ndigits], pk->y, curve->g.ndigits);
+
+	/*
+	 * Check the public key for following
+	 * Check 1: Verify key is not the zero point.
+	 * Check 2: Verify key is in the range [1, p-1].
+	 * Check 3: Verify that y^2 == (x^3 + a·x + b) mod p
+	 */
+	rc = kmb_ocs_ecc_is_pubkey_valid_partial(ecc_dev, curve, pk);
+	if (rc)
+		goto exit_free_pk;
+
+	/* Allocate point for storing computed shared secret. */
+	result = ecc_alloc_point(pk->ndigits);
+	if (!result) {
+		rc = -ENOMEM;
+		goto exit_free_pk;
+	}
+
+	/* Calculate the shared secret.*/
+	rc = kmb_ecc_point_mult(ecc_dev, result, pk, tctx->private_key, curve);
+	if (rc)
+		goto exit_free_result;
+
+	if (ecc_point_is_zero(result)) {
+		rc = -EFAULT;
+		goto exit_free_result;
+	}
+
+	/* Copy shared secret from point to buffer. */
+	ecc_swap_digits(result->x, shared_secret, result->ndigits);
+
+	/* Request might ask for less bytes than what we have. */
+	nbytes = min_t(size_t, nbytes, req->dst_len);
+
+	copied = sg_copy_from_buffer(req->dst,
+				     sg_nents_for_len(req->dst, nbytes),
+				     shared_secret, nbytes);
+
+	if (copied != nbytes)
+		rc = -EINVAL;
+
+	memzero_explicit(shared_secret, sizeof(shared_secret));
+
+exit_free_result:
+	ecc_free_point(result);
+
+exit_free_pk:
+	ecc_free_point(pk);
+
+	return rc;
+}
+
+/* Compute public key. */
+static int kmb_ecc_do_public_key(struct ocs_ecc_ctx *tctx,
+				 struct kpp_request *req)
+{
+	const struct ecc_curve *curve = tctx->curve;
+	u64 pubk_buf[KMB_ECC_VLI_MAX_DIGITS * 2];
+	struct ecc_point *pk;
+	size_t pubk_len;
+	size_t copied;
+	int rc;
+
+	/* Public key is a point, so it has double the digits. */
+	pubk_len = 2 * digits_to_bytes(curve->g.ndigits);
+
+	pk = ecc_alloc_point(curve->g.ndigits);
+	if (!pk)
+		return -ENOMEM;
+
+	/* Public Key(pk) = priv * G. */
+	rc = kmb_ecc_point_mult(tctx->ecc_dev, pk, &curve->g, tctx->private_key,
+				curve);
+	if (rc)
+		goto exit;
+
+	/* SP800-56A rev 3 5.6.2.1.3 key check */
+	if (kmb_ocs_ecc_is_pubkey_valid_full(tctx->ecc_dev, curve, pk)) {
+		rc = -EAGAIN;
+		goto exit;
+	}
+
+	/* Copy public key from point to buffer. */
+	ecc_swap_digits(pk->x, pubk_buf, pk->ndigits);
+	ecc_swap_digits(pk->y, &pubk_buf[pk->ndigits], pk->ndigits);
+
+	/* Copy public key to req->dst. */
+	copied = sg_copy_from_buffer(req->dst,
+				     sg_nents_for_len(req->dst, pubk_len),
+				     pubk_buf, pubk_len);
+
+	if (copied != pubk_len)
+		rc = -EINVAL;
+
+exit:
+	ecc_free_point(pk);
+
+	return rc;
+}
+
+static int kmb_ocs_ecc_do_one_request(struct crypto_engine *engine,
+				      void *areq)
+{
+	struct kpp_request *req = container_of(areq, struct kpp_request, base);
+	struct ocs_ecc_ctx *tctx = kmb_ocs_ecc_tctx(req);
+	struct ocs_ecc_dev *ecc_dev = tctx->ecc_dev;
+	int rc;
+
+	if (req->src)
+		rc = kmb_ecc_do_shared_secret(tctx, req);
+	else
+		rc = kmb_ecc_do_public_key(tctx, req);
+
+	crypto_finalize_kpp_request(ecc_dev->engine, req, rc);
+
+	return 0;
+}
+
+static int kmb_ocs_ecdh_generate_public_key(struct kpp_request *req)
+{
+	struct ocs_ecc_ctx *tctx = kmb_ocs_ecc_tctx(req);
+	const struct ecc_curve *curve = tctx->curve;
+
+	/* Ensure kmb_ocs_ecdh_set_secret() has been successfully called. */
+	if (!tctx->curve)
+		return -EINVAL;
+
+	/* Ensure dst is present. */
+	if (!req->dst)
+		return -EINVAL;
+
+	/* Check the request dst is big enough to hold the public key. */
+	if (req->dst_len < (2 * digits_to_bytes(curve->g.ndigits)))
+		return -EINVAL;
+
+	/* 'src' is not supposed to be present when generate pubk is called. */
+	if (req->src)
+		return -EINVAL;
+
+	return crypto_transfer_kpp_request_to_engine(tctx->ecc_dev->engine,
+						     req);
+}
+
+static int kmb_ocs_ecdh_compute_shared_secret(struct kpp_request *req)
+{
+	struct ocs_ecc_ctx *tctx = kmb_ocs_ecc_tctx(req);
+	const struct ecc_curve *curve = tctx->curve;
+
+	/* Ensure kmb_ocs_ecdh_set_secret() has been successfully called. */
+	if (!tctx->curve)
+		return -EINVAL;
+
+	/* Ensure dst is present. */
+	if (!req->dst)
+		return -EINVAL;
+
+	/* Ensure src is present. */
+	if (!req->src)
+		return -EINVAL;
+
+	/*
+	 * req->src is expected to the (other-side) public key, so its length
+	 * must be 2 * coordinate size (in bytes).
+	 */
+	if (req->src_len != 2 * digits_to_bytes(curve->g.ndigits))
+		return -EINVAL;
+
+	return crypto_transfer_kpp_request_to_engine(tctx->ecc_dev->engine,
+						     req);
+}
+
+static int kmb_ecc_tctx_init(struct ocs_ecc_ctx *tctx, unsigned int curve_id)
+{
+	memset(tctx, 0, sizeof(*tctx));
+
+	tctx->ecc_dev = kmb_ocs_ecc_find_dev(tctx);
+
+	if (IS_ERR(tctx->ecc_dev)) {
+		pr_err("Failed to find the device : %ld\n",
+		       PTR_ERR(tctx->ecc_dev));
+		return PTR_ERR(tctx->ecc_dev);
+	}
+
+	tctx->curve = ecc_get_curve(curve_id);
+	if (!tctx->curve)
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+
+static int kmb_ocs_ecdh_nist_p256_init_tfm(struct crypto_kpp *tfm)
+{
+	struct ocs_ecc_ctx *tctx = kpp_tfm_ctx(tfm);
+
+	return kmb_ecc_tctx_init(tctx, ECC_CURVE_NIST_P256);
+}
+
+static int kmb_ocs_ecdh_nist_p384_init_tfm(struct crypto_kpp *tfm)
+{
+	struct ocs_ecc_ctx *tctx = kpp_tfm_ctx(tfm);
+
+	return kmb_ecc_tctx_init(tctx, ECC_CURVE_NIST_P384);
+}
+
+static void kmb_ocs_ecdh_exit_tfm(struct crypto_kpp *tfm)
+{
+	struct ocs_ecc_ctx *tctx = kpp_tfm_ctx(tfm);
+
+	memzero_explicit(tctx->private_key, sizeof(*tctx->private_key));
+}
+
+static unsigned int kmb_ocs_ecdh_max_size(struct crypto_kpp *tfm)
+{
+	struct ocs_ecc_ctx *tctx = kpp_tfm_ctx(tfm);
+
+	/* Public key is made of two coordinates, so double the digits. */
+	return digits_to_bytes(tctx->curve->g.ndigits) * 2;
+}
+
+static struct kpp_engine_alg ocs_ecdh_p256 = {
+	.base.set_secret = kmb_ocs_ecdh_set_secret,
+	.base.generate_public_key = kmb_ocs_ecdh_generate_public_key,
+	.base.compute_shared_secret = kmb_ocs_ecdh_compute_shared_secret,
+	.base.init = kmb_ocs_ecdh_nist_p256_init_tfm,
+	.base.exit = kmb_ocs_ecdh_exit_tfm,
+	.base.max_size = kmb_ocs_ecdh_max_size,
+	.base.base = {
+		.cra_name = "ecdh-nist-p256",
+		.cra_driver_name = "ecdh-nist-p256-keembay-ocs",
+		.cra_priority = KMB_OCS_ECC_PRIORITY,
+		.cra_module = THIS_MODULE,
+		.cra_ctxsize = sizeof(struct ocs_ecc_ctx),
+	},
+	.op.do_one_request = kmb_ocs_ecc_do_one_request,
+};
+
+static struct kpp_engine_alg ocs_ecdh_p384 = {
+	.base.set_secret = kmb_ocs_ecdh_set_secret,
+	.base.generate_public_key = kmb_ocs_ecdh_generate_public_key,
+	.base.compute_shared_secret = kmb_ocs_ecdh_compute_shared_secret,
+	.base.init = kmb_ocs_ecdh_nist_p384_init_tfm,
+	.base.exit = kmb_ocs_ecdh_exit_tfm,
+	.base.max_size = kmb_ocs_ecdh_max_size,
+	.base.base = {
+		.cra_name = "ecdh-nist-p384",
+		.cra_driver_name = "ecdh-nist-p384-keembay-ocs",
+		.cra_priority = KMB_OCS_ECC_PRIORITY,
+		.cra_module = THIS_MODULE,
+		.cra_ctxsize = sizeof(struct ocs_ecc_ctx),
+	},
+	.op.do_one_request = kmb_ocs_ecc_do_one_request,
+};
+
+static irqreturn_t ocs_ecc_irq_handler(int irq, void *dev_id)
+{
+	struct ocs_ecc_dev *ecc_dev = dev_id;
+	u32 status;
+
+	/*
+	 * Read the status register and write it back to clear the
+	 * DONE_INT_STATUS bit.
+	 */
+	status = ioread32(ecc_dev->base_reg + HW_OFFS_OCS_ECC_ISR);
+	iowrite32(status, ecc_dev->base_reg + HW_OFFS_OCS_ECC_ISR);
+
+	if (!(status & HW_OCS_ECC_ISR_INT_STATUS_DONE))
+		return IRQ_NONE;
+
+	complete(&ecc_dev->irq_done);
+
+	return IRQ_HANDLED;
+}
+
+static int kmb_ocs_ecc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ocs_ecc_dev *ecc_dev;
+	int rc;
+
+	ecc_dev = devm_kzalloc(dev, sizeof(*ecc_dev), GFP_KERNEL);
+	if (!ecc_dev)
+		return -ENOMEM;
+
+	ecc_dev->dev = dev;
+
+	platform_set_drvdata(pdev, ecc_dev);
+
+	INIT_LIST_HEAD(&ecc_dev->list);
+	init_completion(&ecc_dev->irq_done);
+
+	/* Get base register address. */
+	ecc_dev->base_reg = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ecc_dev->base_reg)) {
+		dev_err(dev, "Failed to get base address\n");
+		rc = PTR_ERR(ecc_dev->base_reg);
+		goto list_del;
+	}
+
+	/* Get and request IRQ */
+	ecc_dev->irq = platform_get_irq(pdev, 0);
+	if (ecc_dev->irq < 0) {
+		rc = ecc_dev->irq;
+		goto list_del;
+	}
+
+	rc = devm_request_threaded_irq(dev, ecc_dev->irq, ocs_ecc_irq_handler,
+				       NULL, 0, "keembay-ocs-ecc", ecc_dev);
+	if (rc < 0) {
+		dev_err(dev, "Could not request IRQ\n");
+		goto list_del;
+	}
+
+	/* Add device to the list of OCS ECC devices. */
+	spin_lock(&ocs_ecc.lock);
+	list_add_tail(&ecc_dev->list, &ocs_ecc.dev_list);
+	spin_unlock(&ocs_ecc.lock);
+
+	/* Initialize crypto engine. */
+	ecc_dev->engine = crypto_engine_alloc_init(dev, 1);
+	if (!ecc_dev->engine) {
+		dev_err(dev, "Could not allocate crypto engine\n");
+		rc = -ENOMEM;
+		goto list_del;
+	}
+
+	rc = crypto_engine_start(ecc_dev->engine);
+	if (rc) {
+		dev_err(dev, "Could not start crypto engine\n");
+		goto cleanup;
+	}
+
+	/* Register the KPP algo. */
+	rc = crypto_engine_register_kpp(&ocs_ecdh_p256);
+	if (rc) {
+		dev_err(dev,
+			"Could not register OCS algorithms with Crypto API\n");
+		goto cleanup;
+	}
+
+	rc = crypto_engine_register_kpp(&ocs_ecdh_p384);
+	if (rc) {
+		dev_err(dev,
+			"Could not register OCS algorithms with Crypto API\n");
+		goto ocs_ecdh_p384_error;
+	}
+
+	return 0;
+
+ocs_ecdh_p384_error:
+	crypto_engine_unregister_kpp(&ocs_ecdh_p256);
+
+cleanup:
+	crypto_engine_exit(ecc_dev->engine);
+
+list_del:
+	spin_lock(&ocs_ecc.lock);
+	list_del(&ecc_dev->list);
+	spin_unlock(&ocs_ecc.lock);
+
+	return rc;
+}
+
+static int kmb_ocs_ecc_remove(struct platform_device *pdev)
+{
+	struct ocs_ecc_dev *ecc_dev;
+
+	ecc_dev = platform_get_drvdata(pdev);
+
+	crypto_engine_unregister_kpp(&ocs_ecdh_p384);
+	crypto_engine_unregister_kpp(&ocs_ecdh_p256);
+
+	spin_lock(&ocs_ecc.lock);
+	list_del(&ecc_dev->list);
+	spin_unlock(&ocs_ecc.lock);
+
+	crypto_engine_exit(ecc_dev->engine);
+
+	return 0;
+}
+
+/* Device tree driver match. */
+static const struct of_device_id kmb_ocs_ecc_of_match[] = {
+	{
+		.compatible = "intel,keembay-ocs-ecc",
+	},
+	{}
+};
+
+/* The OCS driver is a platform device. */
+static struct platform_driver kmb_ocs_ecc_driver = {
+	.probe = kmb_ocs_ecc_probe,
+	.remove = kmb_ocs_ecc_remove,
+	.driver = {
+			.name = DRV_NAME,
+			.of_match_table = kmb_ocs_ecc_of_match,
+		},
+};
+module_platform_driver(kmb_ocs_ecc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Intel Keem Bay OCS ECC Driver");
+MODULE_ALIAS_CRYPTO("ecdh-nist-p256");
+MODULE_ALIAS_CRYPTO("ecdh-nist-p384");
+MODULE_ALIAS_CRYPTO("ecdh-nist-p256-keembay-ocs");
+MODULE_ALIAS_CRYPTO("ecdh-nist-p384-keembay-ocs");