// SPDX-License-Identifier: GPL-2.0-only
/*
 * SHA-512 routines supporting the Power 7+ Nest Accelerators driver
 *
 * Copyright (C) 2011-2012 International Business Machines Inc.
 *
 * Author: Kent Yoder <yoder1@us.ibm.com>
 */

#include <crypto/internal/hash.h>
#include <crypto/sha2.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/unaligned.h>

#include "nx_csbcpb.h"
#include "nx.h"

struct sha512_state_be {
	__be64 state[SHA512_DIGEST_SIZE / 8];
	u64 count[2];
};

static int nx_crypto_ctx_sha512_init(struct crypto_shash *tfm)
{
	struct nx_crypto_ctx *nx_ctx = crypto_shash_ctx(tfm);
	int err;

	err = nx_crypto_ctx_sha_init(tfm);
	if (err)
		return err;

	nx_ctx_init(nx_ctx, HCOP_FC_SHA);

	nx_ctx->ap = &nx_ctx->props[NX_PROPS_SHA512];

	NX_CPB_SET_DIGEST_SIZE(nx_ctx->csbcpb, NX_DS_SHA512);

	return 0;
}

static int nx_sha512_init(struct shash_desc *desc)
{
	struct sha512_state_be *sctx = shash_desc_ctx(desc);

	sctx->state[0] = __cpu_to_be64(SHA512_H0);
	sctx->state[1] = __cpu_to_be64(SHA512_H1);
	sctx->state[2] = __cpu_to_be64(SHA512_H2);
	sctx->state[3] = __cpu_to_be64(SHA512_H3);
	sctx->state[4] = __cpu_to_be64(SHA512_H4);
	sctx->state[5] = __cpu_to_be64(SHA512_H5);
	sctx->state[6] = __cpu_to_be64(SHA512_H6);
	sctx->state[7] = __cpu_to_be64(SHA512_H7);
	sctx->count[0] = 0;
	sctx->count[1] = 0;

	return 0;
}

static int nx_sha512_update(struct shash_desc *desc, const u8 *data,
			    unsigned int len)
{
	struct nx_crypto_ctx *nx_ctx = crypto_shash_ctx(desc->tfm);
	struct sha512_state_be *sctx = shash_desc_ctx(desc);
	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
	u64 to_process, leftover, total = len;
	struct nx_sg *out_sg;
	unsigned long irq_flags;
	int rc = 0;
	int data_len;
	u32 max_sg_len;

	spin_lock_irqsave(&nx_ctx->lock, irq_flags);

	memcpy(csbcpb->cpb.sha512.message_digest, sctx->state, SHA512_DIGEST_SIZE);
	NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
	NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;

	max_sg_len = min_t(u64, nx_ctx->ap->sglen,
			nx_driver.of.max_sg_len/sizeof(struct nx_sg));
	max_sg_len = min_t(u64, max_sg_len,
			nx_ctx->ap->databytelen/NX_PAGE_SIZE);

	data_len = SHA512_DIGEST_SIZE;
	out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *)sctx->state,
				  &data_len, max_sg_len);
	nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);

	if (data_len != SHA512_DIGEST_SIZE) {
		rc = -EINVAL;
		goto out;
	}

	do {
		struct nx_sg *in_sg = nx_ctx->in_sg;

		to_process = total & ~(SHA512_BLOCK_SIZE - 1);

		data_len = to_process;
		in_sg = nx_build_sg_list(in_sg, (u8 *) data,
					 &data_len, max_sg_len);

		nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);

		to_process = data_len;
		leftover = total - to_process;

		/*
		 * we've hit the nx chip previously and we're updating
		 * again, so copy over the partial digest.
		 */
		memcpy(csbcpb->cpb.sha512.input_partial_digest,
			       csbcpb->cpb.sha512.message_digest,
			       SHA512_DIGEST_SIZE);

		if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
			rc = -EINVAL;
			goto out;
		}

		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 0);
		if (rc)
			goto out;

		atomic_inc(&(nx_ctx->stats->sha512_ops));

		total -= to_process;
		data += to_process;
		sctx->count[0] += to_process;
		if (sctx->count[0] < to_process)
			sctx->count[1]++;
	} while (leftover >= SHA512_BLOCK_SIZE);

	rc = leftover;
	memcpy(sctx->state, csbcpb->cpb.sha512.message_digest, SHA512_DIGEST_SIZE);
out:
	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
	return rc;
}

static int nx_sha512_finup(struct shash_desc *desc, const u8 *src,
			   unsigned int nbytes, u8 *out)
{
	struct sha512_state_be *sctx = shash_desc_ctx(desc);
	struct nx_crypto_ctx *nx_ctx = crypto_shash_ctx(desc->tfm);
	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
	struct nx_sg *in_sg, *out_sg;
	u32 max_sg_len;
	unsigned long irq_flags;
	u64 count0, count1;
	int rc = 0;
	int len;

	spin_lock_irqsave(&nx_ctx->lock, irq_flags);

	max_sg_len = min_t(u64, nx_ctx->ap->sglen,
			nx_driver.of.max_sg_len/sizeof(struct nx_sg));
	max_sg_len = min_t(u64, max_sg_len,
			nx_ctx->ap->databytelen/NX_PAGE_SIZE);

	/* final is represented by continuing the operation and indicating that
	 * this is not an intermediate operation
	 * copy over the partial digest */
	memcpy(csbcpb->cpb.sha512.input_partial_digest, sctx->state, SHA512_DIGEST_SIZE);
	NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
	NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;

	count0 = sctx->count[0] + nbytes;
	count1 = sctx->count[1];

	csbcpb->cpb.sha512.message_bit_length_lo = count0 << 3;
	csbcpb->cpb.sha512.message_bit_length_hi = (count1 << 3) |
						   (count0 >> 61);

	len = nbytes;
	in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *)src, &len, max_sg_len);

	if (len != nbytes) {
		rc = -EINVAL;
		goto out;
	}

	len = SHA512_DIGEST_SIZE;
	out_sg = nx_build_sg_list(nx_ctx->out_sg, out, &len,
				 max_sg_len);

	nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
	nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);

	if (!nx_ctx->op.outlen) {
		rc = -EINVAL;
		goto out;
	}

	rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 0);
	if (rc)
		goto out;

	atomic_inc(&(nx_ctx->stats->sha512_ops));
	atomic64_add(count0, &(nx_ctx->stats->sha512_bytes));

	memcpy(out, csbcpb->cpb.sha512.message_digest, SHA512_DIGEST_SIZE);
out:
	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
	return rc;
}

static int nx_sha512_export(struct shash_desc *desc, void *out)
{
	struct sha512_state_be *sctx = shash_desc_ctx(desc);
	union {
		u8 *u8;
		u64 *u64;
	} p = { .u8 = out };
	int i;

	for (i = 0; i < SHA512_DIGEST_SIZE / sizeof(*p.u64); i++)
		put_unaligned(be64_to_cpu(sctx->state[i]), p.u64++);

	put_unaligned(sctx->count[0], p.u64++);
	put_unaligned(sctx->count[1], p.u64++);
	return 0;
}

static int nx_sha512_import(struct shash_desc *desc, const void *in)
{
	struct sha512_state_be *sctx = shash_desc_ctx(desc);
	union {
		const u8 *u8;
		const u64 *u64;
	} p = { .u8 = in };
	int i;

	for (i = 0; i < SHA512_DIGEST_SIZE / sizeof(*p.u64); i++)
		sctx->state[i] = cpu_to_be64(get_unaligned(p.u64++));

	sctx->count[0] = get_unaligned(p.u64++);
	sctx->count[1] = get_unaligned(p.u64++);
	return 0;
}

struct shash_alg nx_shash_sha512_alg = {
	.digestsize = SHA512_DIGEST_SIZE,
	.init       = nx_sha512_init,
	.update     = nx_sha512_update,
	.finup      = nx_sha512_finup,
	.export     = nx_sha512_export,
	.import     = nx_sha512_import,
	.init_tfm   = nx_crypto_ctx_sha512_init,
	.exit_tfm   = nx_crypto_ctx_shash_exit,
	.descsize   = sizeof(struct sha512_state_be),
	.statesize  = sizeof(struct sha512_state_be),
	.base       = {
		.cra_name        = "sha512",
		.cra_driver_name = "sha512-nx",
		.cra_priority    = 300,
		.cra_flags	 = CRYPTO_AHASH_ALG_BLOCK_ONLY,
		.cra_blocksize   = SHA512_BLOCK_SIZE,
		.cra_module      = THIS_MODULE,
		.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
	}
};