in allwinner/sun4i-ss/sun4i-ss-hash.c [177:506]
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 ahash_alg *alg = __crypto_ahash_alg(tfm->base.__crt_alg);
struct sun4i_tfm_ctx *tfmctx = crypto_ahash_ctx(tfm);
struct sun4i_ss_ctx *ss = tfmctx->ss;
struct sun4i_ss_alg_template *algt;
struct scatterlist *in_sg = areq->src;
struct sg_mapping_iter mi;
int in_r, err = 0;
size_t copied = 0;
u32 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 < crypto_ahash_digestsize(tfm) / 4; 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:
if (IS_ENABLED(CONFIG_CRYPTO_DEV_SUN4I_SS_DEBUG)) {
algt = container_of(alg, struct sun4i_ss_alg_template, alg.hash);
algt->stat_req++;
}
/* 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 = le32_to_cpup((__le32 *)(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));
((__le32 *)bf)[j++] = cpu_to_le32(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 = readl(ss->base + SS_MD0 + i * 4);
if (ss->variant->sha1_in_be)
put_unaligned_le32(v, areq->result + i * 4);
else
put_unaligned_be32(v, areq->result + i * 4);
}
} else {
for (i = 0; i < 4; i++) {
v = readl(ss->base + SS_MD0 + i * 4);
put_unaligned_le32(v, areq->result + i * 4);
}
}
release_ss:
writel(0, ss->base + SS_CTL);
spin_unlock_bh(&ss->slock);
return err;
}