powerpc/crypto: SHA256 hash routines for nx encryption

These routines add support for SHA-256 hashing on the Power7+ CPU's
in-Nest accelerator driver.
Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

drivers/crypto/nx/nx-sha256.c

+/**
+ * SHA-256 routines supporting the Power 7+ Nest Accelerators driver
+ *
+ * Copyright (C) 2011-2012 International Business Machines Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 only.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Author: Kent Yoder <yoder1@us.ibm.com>
+ */
+
+#include <crypto/internal/hash.h>
+#include <crypto/sha.h>
+#include <linux/module.h>
+#include <asm/vio.h>
+
+#include "nx_csbcpb.h"
+#include "nx.h"
+
+
+static int nx_sha256_init(struct shash_desc *desc)
+{
+	struct sha256_state *sctx = shash_desc_ctx(desc);
+	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
+	struct nx_sg *out_sg;
+
+	nx_ctx_init(nx_ctx, HCOP_FC_SHA);
+
+	memset(sctx, 0, sizeof *sctx);
+
+	nx_ctx->ap = &nx_ctx->props[NX_PROPS_SHA256];
+
+	NX_CPB_SET_DIGEST_SIZE(nx_ctx->csbcpb, NX_DS_SHA256);
+	out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *)sctx->state,
+				  SHA256_DIGEST_SIZE, nx_ctx->ap->sglen);
+	nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
+
+	return 0;
+}
+
+static int nx_sha256_update(struct shash_desc *desc, const u8 *data,
+			    unsigned int len)
+{
+	struct sha256_state *sctx = shash_desc_ctx(desc);
+	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
+	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
+	struct nx_sg *in_sg;
+	u64 to_process, leftover;
+	int rc = 0;
+
+	if (NX_CPB_FDM(csbcpb) & NX_FDM_CONTINUATION) {
+		/* we've hit the nx chip previously and we're updating again,
+		 * so copy over the partial digest */
+		memcpy(csbcpb->cpb.sha256.input_partial_digest,
+		       csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
+	}
+
+	/* 2 cases for total data len:
+	 *  1: <= SHA256_BLOCK_SIZE: copy into state, return 0
+	 *  2: > SHA256_BLOCK_SIZE: process X blocks, copy in leftover
+	 */
+	if (len + sctx->count <= SHA256_BLOCK_SIZE) {
+		memcpy(sctx->buf + sctx->count, data, len);
+		sctx->count += len;
+		goto out;
+	}
+
+	/* to_process: the SHA256_BLOCK_SIZE data chunk to process in this
+	 * update */
+	to_process = (sctx->count + len) & ~(SHA256_BLOCK_SIZE - 1);
+	leftover = (sctx->count + len) & (SHA256_BLOCK_SIZE - 1);
+
+	if (sctx->count) {
+		in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *)sctx->buf,
+					 sctx->count, nx_ctx->ap->sglen);
+		in_sg = nx_build_sg_list(in_sg, (u8 *)data,
+					 to_process - sctx->count,
+					 nx_ctx->ap->sglen);
+		nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) *
+					sizeof(struct nx_sg);
+	} else {
+		in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *)data,
+					 to_process, nx_ctx->ap->sglen);
+		nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) *
+					sizeof(struct nx_sg);
+	}
+
+	NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
+
+	if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+	rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
+			   desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
+	if (rc)
+		goto out;
+
+	atomic_inc(&(nx_ctx->stats->sha256_ops));
+
+	/* copy the leftover back into the state struct */
+	memcpy(sctx->buf, data + len - leftover, leftover);
+	sctx->count = leftover;
+
+	csbcpb->cpb.sha256.message_bit_length += (u64)
+		(csbcpb->cpb.sha256.spbc * 8);
+
+	/* everything after the first update is continuation */
+	NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
+out:
+	return rc;
+}
+
+static int nx_sha256_final(struct shash_desc *desc, u8 *out)
+{
+	struct sha256_state *sctx = shash_desc_ctx(desc);
+	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
+	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
+	struct nx_sg *in_sg, *out_sg;
+	int rc;
+
+	if (NX_CPB_FDM(csbcpb) & NX_FDM_CONTINUATION) {
+		/* we've hit the nx chip previously, now we're finalizing,
+		 * so copy over the partial digest */
+		memcpy(csbcpb->cpb.sha256.input_partial_digest,
+		       csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
+	}
+
+	/* final is represented by continuing the operation and indicating that
+	 * this is not an intermediate operation */
+	NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
+
+	csbcpb->cpb.sha256.message_bit_length += (u64)(sctx->count * 8);
+
+	in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *)sctx->buf,
+				 sctx->count, nx_ctx->ap->sglen);
+	out_sg = nx_build_sg_list(nx_ctx->out_sg, out, SHA256_DIGEST_SIZE,
+				  nx_ctx->ap->sglen);
+	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,
+			   desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
+	if (rc)
+		goto out;
+
+	atomic_inc(&(nx_ctx->stats->sha256_ops));
+
+	atomic64_add(csbcpb->cpb.sha256.message_bit_length,
+		     &(nx_ctx->stats->sha256_bytes));
+	memcpy(out, csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
+out:
+	return rc;
+}
+
+static int nx_sha256_export(struct shash_desc *desc, void *out)
+{
+	struct sha256_state *sctx = shash_desc_ctx(desc);
+	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
+	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
+	struct sha256_state *octx = out;
+
+	octx->count = sctx->count +
+		      (csbcpb->cpb.sha256.message_bit_length / 8);
+	memcpy(octx->buf, sctx->buf, sizeof(octx->buf));
+
+	/* if no data has been processed yet, we need to export SHA256's
+	 * initial data, in case this context gets imported into a software
+	 * context */
+	if (csbcpb->cpb.sha256.message_bit_length)
+		memcpy(octx->state, csbcpb->cpb.sha256.message_digest,
+		       SHA256_DIGEST_SIZE);
+	else {
+		octx->state[0] = SHA256_H0;
+		octx->state[1] = SHA256_H1;
+		octx->state[2] = SHA256_H2;
+		octx->state[3] = SHA256_H3;
+		octx->state[4] = SHA256_H4;
+		octx->state[5] = SHA256_H5;
+		octx->state[6] = SHA256_H6;
+		octx->state[7] = SHA256_H7;
+	}
+
+	return 0;
+}
+
+static int nx_sha256_import(struct shash_desc *desc, const void *in)
+{
+	struct sha256_state *sctx = shash_desc_ctx(desc);
+	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
+	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
+	const struct sha256_state *ictx = in;
+
+	memcpy(sctx->buf, ictx->buf, sizeof(ictx->buf));
+
+	sctx->count = ictx->count & 0x3f;
+	csbcpb->cpb.sha256.message_bit_length = (ictx->count & ~0x3f) * 8;
+
+	if (csbcpb->cpb.sha256.message_bit_length) {
+		memcpy(csbcpb->cpb.sha256.message_digest, ictx->state,
+		       SHA256_DIGEST_SIZE);
+
+		NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
+		NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
+	}
+
+	return 0;
+}
+
+struct shash_alg nx_shash_sha256_alg = {
+	.digestsize = SHA256_DIGEST_SIZE,
+	.init       = nx_sha256_init,
+	.update     = nx_sha256_update,
+	.final      = nx_sha256_final,
+	.export     = nx_sha256_export,
+	.import     = nx_sha256_import,
+	.descsize   = sizeof(struct sha256_state),
+	.statesize  = sizeof(struct sha256_state),
+	.base       = {
+		.cra_name        = "sha256",
+		.cra_driver_name = "sha256-nx",
+		.cra_priority    = 300,
+		.cra_flags       = CRYPTO_ALG_TYPE_SHASH,
+		.cra_blocksize   = SHA256_BLOCK_SIZE,
+		.cra_module      = THIS_MODULE,
+		.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
+		.cra_init        = nx_crypto_ctx_sha_init,
+		.cra_exit        = nx_crypto_ctx_exit,
+	}
+};