1 files changed, 527 insertions, 0 deletions

diff --git a/drivers/crypto/sunxi-ss/sun4i-ss-hash.c b/drivers/crypto/sunxi-ss/sun4i-ss-hash.c
new file mode 100644
index 000000000..2d178e013
--- /dev/null
+++ b/drivers/crypto/sunxi-ss/sun4i-ss-hash.c
@@ -0,0 +1,527 @@
+/*
+ * sun4i-ss-hash.c - hardware cryptographic accelerator for Allwinner A20 SoC
+ *
+ * Copyright (C) 2013-2015 Corentin LABBE <clabbe.montjoie@gmail.com>
+ *
+ * This file add support for MD5 and SHA1.
+ *
+ * You could find the datasheet in Documentation/arm/sunxi/README
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#include "sun4i-ss.h"
+#include <linux/scatterlist.h>
+
+/* This is a totally arbitrary value */
+#define SS_TIMEOUT 100
+
+int sun4i_hash_crainit(struct crypto_tfm *tfm)
+{
+	struct sun4i_tfm_ctx *op = crypto_tfm_ctx(tfm);
+	struct ahash_alg *alg = __crypto_ahash_alg(tfm->__crt_alg);
+	struct sun4i_ss_alg_template *algt;
+
+	memset(op, 0, sizeof(struct sun4i_tfm_ctx));
+
+	algt = container_of(alg, struct sun4i_ss_alg_template, alg.hash);
+	op->ss = algt->ss;
+
+	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
+				 sizeof(struct sun4i_req_ctx));
+	return 0;
+}
+
+/* sun4i_hash_init: initialize request context */
+int sun4i_hash_init(struct ahash_request *areq)
+{
+	struct sun4i_req_ctx *op = ahash_request_ctx(areq);
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
+	struct ahash_alg *alg = __crypto_ahash_alg(tfm->base.__crt_alg);
+	struct sun4i_ss_alg_template *algt;
+
+	memset(op, 0, sizeof(struct sun4i_req_ctx));
+
+	algt = container_of(alg, struct sun4i_ss_alg_template, alg.hash);
+	op->mode = algt->mode;
+
+	return 0;
+}
+
+int sun4i_hash_export_md5(struct ahash_request *areq, void *out)
+{
+	struct sun4i_req_ctx *op = ahash_request_ctx(areq);
+	struct md5_state *octx = out;
+	int i;
+
+	octx->byte_count = op->byte_count + op->len;
+
+	memcpy(octx->block, op->buf, op->len);
+
+	if (op->byte_count) {
+		for (i = 0; i < 4; i++)
+			octx->hash[i] = op->hash[i];
+	} else {
+		octx->hash[0] = SHA1_H0;
+		octx->hash[1] = SHA1_H1;
+		octx->hash[2] = SHA1_H2;
+		octx->hash[3] = SHA1_H3;
+	}
+
+	return 0;
+}
+
+int sun4i_hash_import_md5(struct ahash_request *areq, const void *in)
+{
+	struct sun4i_req_ctx *op = ahash_request_ctx(areq);
+	const struct md5_state *ictx = in;
+	int i;
+
+	sun4i_hash_init(areq);
+
+	op->byte_count = ictx->byte_count & ~0x3F;
+	op->len = ictx->byte_count & 0x3F;
+
+	memcpy(op->buf, ictx->block, op->len);
+
+	for (i = 0; i < 4; i++)
+		op->hash[i] = ictx->hash[i];
+
+	return 0;
+}
+
+int sun4i_hash_export_sha1(struct ahash_request *areq, void *out)
+{
+	struct sun4i_req_ctx *op = ahash_request_ctx(areq);
+	struct sha1_state *octx = out;
+	int i;
+
+	octx->count = op->byte_count + op->len;
+
+	memcpy(octx->buffer, op->buf, op->len);
+
+	if (op->byte_count) {
+		for (i = 0; i < 5; i++)
+			octx->state[i] = op->hash[i];
+	} else {
+		octx->state[0] = SHA1_H0;
+		octx->state[1] = SHA1_H1;
+		octx->state[2] = SHA1_H2;
+		octx->state[3] = SHA1_H3;
+		octx->state[4] = SHA1_H4;
+	}
+
+	return 0;
+}
+
+int sun4i_hash_import_sha1(struct ahash_request *areq, const void *in)
+{
+	struct sun4i_req_ctx *op = ahash_request_ctx(areq);
+	const struct sha1_state *ictx = in;
+	int i;
+
+	sun4i_hash_init(areq);
+
+	op->byte_count = ictx->count & ~0x3F;
+	op->len = ictx->count & 0x3F;
+
+	memcpy(op->buf, ictx->buffer, op->len);
+
+	for (i = 0; i < 5; i++)
+		op->hash[i] = ictx->state[i];
+
+	return 0;
+}
+
+#define SS_HASH_UPDATE 1
+#define SS_HASH_FINAL 2
+
+/*
+ * sun4i_hash_update: update hash engine
+ *
+ * Could be used for both SHA1 and MD5
+ * Write data by step of 32bits and put then in the SS.
+ *
+ * Since we cannot leave partial data and hash state in the engine,
+ * we need to get the hash state at the end of this function.
+ * We can get the hash state every 64 bytes
+ *
+ * So the first work is to get the number of bytes to write to SS modulo 64
+ * The extra bytes will go to a temporary buffer op->buf storing op->len bytes
+ *
+ * So at the begin of update()
+ * if op->len + areq->nbytes < 64
+ * => all data will be written to wait buffer (op->buf) and end=0
+ * if not, write all data from op->buf to the device and position end to
+ * complete to 64bytes
+ *
+ * example 1:
+ * update1 60o => op->len=60
+ * update2 60o => need one more word to have 64 bytes
+ * end=4
+ * so write all data from op->buf and one word of SGs
+ * write remaining data in op->buf
+ * final state op->len=56
+ */
+static int sun4i_hash(struct ahash_request *areq)
+{
+	/*
+	 * i is the total bytes read from SGs, to be compared to areq->nbytes
+	 * i is important because we cannot rely on SG length since the sum of
+	 * SG->length could be greater than areq->nbytes
+	 *
+	 * end is the position when we need to stop writing to the device,
+	 * to be compared to i
+	 *
+	 * in_i: advancement in the current SG
+	 */
+	unsigned int i = 0, end, fill, min_fill, nwait, nbw = 0, j = 0, todo;
+	unsigned int in_i = 0;
+	u32 spaces, rx_cnt = SS_RX_DEFAULT, bf[32] = {0}, v, ivmode = 0;
+	struct sun4i_req_ctx *op = ahash_request_ctx(areq);
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
+	struct sun4i_tfm_ctx *tfmctx = crypto_ahash_ctx(tfm);
+	struct sun4i_ss_ctx *ss = tfmctx->ss;
+	struct scatterlist *in_sg = areq->src;
+	struct sg_mapping_iter mi;
+	int in_r, err = 0;
+	size_t copied = 0;
+	__le32 wb = 0;
+
+	dev_dbg(ss->dev, "%s %s bc=%llu len=%u mode=%x wl=%u h0=%0x",
+		__func__, crypto_tfm_alg_name(areq->base.tfm),
+		op->byte_count, areq->nbytes, op->mode,
+		op->len, op->hash[0]);
+
+	if (unlikely(!areq->nbytes) && !(op->flags & SS_HASH_FINAL))
+		return 0;
+
+	/* protect against overflow */
+	if (unlikely(areq->nbytes > UINT_MAX - op->len)) {
+		dev_err(ss->dev, "Cannot process too large request\n");
+		return -EINVAL;
+	}
+
+	if (op->len + areq->nbytes < 64 && !(op->flags & SS_HASH_FINAL)) {
+		/* linearize data to op->buf */
+		copied = sg_pcopy_to_buffer(areq->src, sg_nents(areq->src),
+					    op->buf + op->len, areq->nbytes, 0);
+		op->len += copied;
+		return 0;
+	}
+
+	spin_lock_bh(&ss->slock);
+
+	/*
+	 * if some data have been processed before,
+	 * we need to restore the partial hash state
+	 */
+	if (op->byte_count) {
+		ivmode = SS_IV_ARBITRARY;
+		for (i = 0; i < 5; i++)
+			writel(op->hash[i], ss->base + SS_IV0 + i * 4);
+	}
+	/* Enable the device */
+	writel(op->mode | SS_ENABLED | ivmode, ss->base + SS_CTL);
+
+	if (!(op->flags & SS_HASH_UPDATE))
+		goto hash_final;
+
+	/* start of handling data */
+	if (!(op->flags & SS_HASH_FINAL)) {
+		end = ((areq->nbytes + op->len) / 64) * 64 - op->len;
+
+		if (end > areq->nbytes || areq->nbytes - end > 63) {
+			dev_err(ss->dev, "ERROR: Bound error %u %u\n",
+				end, areq->nbytes);
+			err = -EINVAL;
+			goto release_ss;
+		}
+	} else {
+		/* Since we have the flag final, we can go up to modulo 4 */
+		if (areq->nbytes < 4)
+			end = 0;
+		else
+			end = ((areq->nbytes + op->len) / 4) * 4 - op->len;
+	}
+
+	/* TODO if SGlen % 4 and !op->len then DMA */
+	i = 1;
+	while (in_sg && i == 1) {
+		if (in_sg->length % 4)
+			i = 0;
+		in_sg = sg_next(in_sg);
+	}
+	if (i == 1 && !op->len && areq->nbytes)
+		dev_dbg(ss->dev, "We can DMA\n");
+
+	i = 0;
+	sg_miter_start(&mi, areq->src, sg_nents(areq->src),
+		       SG_MITER_FROM_SG | SG_MITER_ATOMIC);
+	sg_miter_next(&mi);
+	in_i = 0;
+
+	do {
+		/*
+		 * we need to linearize in two case:
+		 * - the buffer is already used
+		 * - the SG does not have enough byte remaining ( < 4)
+		 */
+		if (op->len || (mi.length - in_i) < 4) {
+			/*
+			 * if we have entered here we have two reason to stop
+			 * - the buffer is full
+			 * - reach the end
+			 */
+			while (op->len < 64 && i < end) {
+				/* how many bytes we can read from current SG */
+				in_r = min(end - i, 64 - op->len);
+				in_r = min_t(size_t, mi.length - in_i, in_r);
+				memcpy(op->buf + op->len, mi.addr + in_i, in_r);
+				op->len += in_r;
+				i += in_r;
+				in_i += in_r;
+				if (in_i == mi.length) {
+					sg_miter_next(&mi);
+					in_i = 0;
+				}
+			}
+			if (op->len > 3 && !(op->len % 4)) {
+				/* write buf to the device */
+				writesl(ss->base + SS_RXFIFO, op->buf,
+					op->len / 4);
+				op->byte_count += op->len;
+				op->len = 0;
+			}
+		}
+		if (mi.length - in_i > 3 && i < end) {
+			/* how many bytes we can read from current SG */
+			in_r = min_t(size_t, mi.length - in_i, areq->nbytes - i);
+			in_r = min_t(size_t, ((mi.length - in_i) / 4) * 4, in_r);
+			/* how many bytes we can write in the device*/
+			todo = min3((u32)(end - i) / 4, rx_cnt, (u32)in_r / 4);
+			writesl(ss->base + SS_RXFIFO, mi.addr + in_i, todo);
+			op->byte_count += todo * 4;
+			i += todo * 4;
+			in_i += todo * 4;
+			rx_cnt -= todo;
+			if (!rx_cnt) {
+				spaces = readl(ss->base + SS_FCSR);
+				rx_cnt = SS_RXFIFO_SPACES(spaces);
+			}
+			if (in_i == mi.length) {
+				sg_miter_next(&mi);
+				in_i = 0;
+			}
+		}
+	} while (i < end);
+
+	/*
+	 * Now we have written to the device all that we can,
+	 * store the remaining bytes in op->buf
+	 */
+	if ((areq->nbytes - i) < 64) {
+		while (i < areq->nbytes && in_i < mi.length && op->len < 64) {
+			/* how many bytes we can read from current SG */
+			in_r = min(areq->nbytes - i, 64 - op->len);
+			in_r = min_t(size_t, mi.length - in_i, in_r);
+			memcpy(op->buf + op->len, mi.addr + in_i, in_r);
+			op->len += in_r;
+			i += in_r;
+			in_i += in_r;
+			if (in_i == mi.length) {
+				sg_miter_next(&mi);
+				in_i = 0;
+			}
+		}
+	}
+
+	sg_miter_stop(&mi);
+
+	/*
+	 * End of data process
+	 * Now if we have the flag final go to finalize part
+	 * If not, store the partial hash
+	 */
+	if (op->flags & SS_HASH_FINAL)
+		goto hash_final;
+
+	writel(op->mode | SS_ENABLED | SS_DATA_END, ss->base + SS_CTL);
+	i = 0;
+	do {
+		v = readl(ss->base + SS_CTL);
+		i++;
+	} while (i < SS_TIMEOUT && (v & SS_DATA_END));
+	if (unlikely(i >= SS_TIMEOUT)) {
+		dev_err_ratelimited(ss->dev,
+				    "ERROR: hash end timeout %d>%d ctl=%x len=%u\n",
+				    i, SS_TIMEOUT, v, areq->nbytes);
+		err = -EIO;
+		goto release_ss;
+	}
+
+	/*
+	 * The datasheet isn't very clear about when to retrieve the digest. The
+	 * bit SS_DATA_END is cleared when the engine has processed the data and
+	 * when the digest is computed *but* it doesn't mean the digest is
+	 * available in the digest registers. Hence the delay to be sure we can
+	 * read it.
+	 */
+	ndelay(1);
+
+	for (i = 0; i < crypto_ahash_digestsize(tfm) / 4; i++)
+		op->hash[i] = readl(ss->base + SS_MD0 + i * 4);
+
+	goto release_ss;
+
+/*
+ * hash_final: finalize hashing operation
+ *
+ * If we have some remaining bytes, we write them.
+ * Then ask the SS for finalizing the hashing operation
+ *
+ * I do not check RX FIFO size in this function since the size is 32
+ * after each enabling and this function neither write more than 32 words.
+ * If we come from the update part, we cannot have more than
+ * 3 remaining bytes to write and SS is fast enough to not care about it.
+ */
+
+hash_final:
+
+	/* write the remaining words of the wait buffer */
+	if (op->len) {
+		nwait = op->len / 4;
+		if (nwait) {
+			writesl(ss->base + SS_RXFIFO, op->buf, nwait);
+			op->byte_count += 4 * nwait;
+		}
+
+		nbw = op->len - 4 * nwait;
+		if (nbw) {
+			wb = cpu_to_le32(*(u32 *)(op->buf + nwait * 4));
+			wb &= GENMASK((nbw * 8) - 1, 0);
+
+			op->byte_count += nbw;
+		}
+	}
+
+	/* write the remaining bytes of the nbw buffer */
+	wb |= ((1 << 7) << (nbw * 8));
+	bf[j++] = le32_to_cpu(wb);
+
+	/*
+	 * number of space to pad to obtain 64o minus 8(size) minus 4 (final 1)
+	 * I take the operations from other MD5/SHA1 implementations
+	 */
+
+	/* last block size */
+	fill = 64 - (op->byte_count % 64);
+	min_fill = 2 * sizeof(u32) + (nbw ? 0 : sizeof(u32));
+
+	/* if we can't fill all data, jump to the next 64 block */
+	if (fill < min_fill)
+		fill += 64;
+
+	j += (fill - min_fill) / sizeof(u32);
+
+	/* write the length of data */
+	if (op->mode == SS_OP_SHA1) {
+		__be64 *bits = (__be64 *)&bf[j];
+		*bits = cpu_to_be64(op->byte_count << 3);
+		j += 2;
+	} else {
+		__le64 *bits = (__le64 *)&bf[j];
+		*bits = cpu_to_le64(op->byte_count << 3);
+		j += 2;
+	}
+	writesl(ss->base + SS_RXFIFO, bf, j);
+
+	/* Tell the SS to stop the hashing */
+	writel(op->mode | SS_ENABLED | SS_DATA_END, ss->base + SS_CTL);
+
+	/*
+	 * Wait for SS to finish the hash.
+	 * The timeout could happen only in case of bad overclocking
+	 * or driver bug.
+	 */
+	i = 0;
+	do {
+		v = readl(ss->base + SS_CTL);
+		i++;
+	} while (i < SS_TIMEOUT && (v & SS_DATA_END));
+	if (unlikely(i >= SS_TIMEOUT)) {
+		dev_err_ratelimited(ss->dev,
+				    "ERROR: hash end timeout %d>%d ctl=%x len=%u\n",
+				    i, SS_TIMEOUT, v, areq->nbytes);
+		err = -EIO;
+		goto release_ss;
+	}
+
+	/*
+	 * The datasheet isn't very clear about when to retrieve the digest. The
+	 * bit SS_DATA_END is cleared when the engine has processed the data and
+	 * when the digest is computed *but* it doesn't mean the digest is
+	 * available in the digest registers. Hence the delay to be sure we can
+	 * read it.
+	 */
+	ndelay(1);
+
+	/* Get the hash from the device */
+	if (op->mode == SS_OP_SHA1) {
+		for (i = 0; i < 5; i++) {
+			v = cpu_to_be32(readl(ss->base + SS_MD0 + i * 4));
+			memcpy(areq->result + i * 4, &v, 4);
+		}
+	} else {
+		for (i = 0; i < 4; i++) {
+			v = cpu_to_le32(readl(ss->base + SS_MD0 + i * 4));
+			memcpy(areq->result + i * 4, &v, 4);
+		}
+	}
+
+release_ss:
+	writel(0, ss->base + SS_CTL);
+	spin_unlock_bh(&ss->slock);
+	return err;
+}
+
+int sun4i_hash_final(struct ahash_request *areq)
+{
+	struct sun4i_req_ctx *op = ahash_request_ctx(areq);
+
+	op->flags = SS_HASH_FINAL;
+	return sun4i_hash(areq);
+}
+
+int sun4i_hash_update(struct ahash_request *areq)
+{
+	struct sun4i_req_ctx *op = ahash_request_ctx(areq);
+
+	op->flags = SS_HASH_UPDATE;
+	return sun4i_hash(areq);
+}
+
+/* sun4i_hash_finup: finalize hashing operation after an update */
+int sun4i_hash_finup(struct ahash_request *areq)
+{
+	struct sun4i_req_ctx *op = ahash_request_ctx(areq);
+
+	op->flags = SS_HASH_UPDATE | SS_HASH_FINAL;
+	return sun4i_hash(areq);
+}
+
+/* combo of init/update/final functions */
+int sun4i_hash_digest(struct ahash_request *areq)
+{
+	int err;
+	struct sun4i_req_ctx *op = ahash_request_ctx(areq);
+
+	err = sun4i_hash_init(areq);
+	if (err)
+		return err;
+
+	op->flags = SS_HASH_UPDATE | SS_HASH_FINAL;
+	return sun4i_hash(areq);
+}