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crypto: sun4i-ss - fix kmap usage
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[ Upstream commit 9bc3dd2 ]

With the recent kmap change, some tests which were conditional on
CONFIG_DEBUG_HIGHMEM now are enabled by default.
This permit to detect a problem in sun4i-ss usage of kmap.

sun4i-ss uses two kmap via sg_miter (one for input, one for output), but
using two kmap at the same time is hard:
"the ordering has to be correct and with sg_miter that's probably hard to get
right." (quoting Tlgx)

So the easiest solution is to never have two sg_miter/kmap open at the same time.
After each use of sg_miter, I store the current index, for being able to
resume sg_miter to the right place.

Fixes: 6298e94 ("crypto: sunxi-ss - Add Allwinner Security System crypto accelerator")
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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@montjoie @gregkh
montjoie authored and gregkh committed Mar 4, 2021
1 parent 99e9cb7 commit 2f7287f
Showing 1 changed file with 65 additions and 44 deletions.
109 changes: 65 additions & 44 deletions drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
View file
Expand Up @@ -30,6 +30,8 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq)
unsigned int ileft = areq->cryptlen;
unsigned int oleft = areq->cryptlen;
unsigned int todo;
unsigned long pi = 0, po = 0; /* progress for in and out */
bool miter_err;
struct sg_mapping_iter mi, mo;
unsigned int oi, oo; /* offset for in and out */
unsigned long flags;
Expand All @@ -55,39 +57,51 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq)
}
writel(mode, ss->base + SS_CTL);

sg_miter_start(&mi, areq->src, sg_nents(areq->src),
SG_MITER_FROM_SG | SG_MITER_ATOMIC);
sg_miter_start(&mo, areq->dst, sg_nents(areq->dst),
SG_MITER_TO_SG | SG_MITER_ATOMIC);
sg_miter_next(&mi);
sg_miter_next(&mo);
if (!mi.addr || !mo.addr) {
dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
err = -EINVAL;
goto release_ss;
}

ileft = areq->cryptlen / 4;
oleft = areq->cryptlen / 4;
oi = 0;
oo = 0;
do {
todo = min(rx_cnt, ileft);
todo = min_t(size_t, todo, (mi.length - oi) / 4);
if (todo) {
ileft -= todo;
writesl(ss->base + SS_RXFIFO, mi.addr + oi, todo);
oi += todo * 4;
}
if (oi == mi.length) {
sg_miter_next(&mi);
oi = 0;
if (ileft) {
sg_miter_start(&mi, areq->src, sg_nents(areq->src),
SG_MITER_FROM_SG | SG_MITER_ATOMIC);
if (pi)
sg_miter_skip(&mi, pi);
miter_err = sg_miter_next(&mi);
if (!miter_err || !mi.addr) {
dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
err = -EINVAL;
goto release_ss;
}
todo = min(rx_cnt, ileft);
todo = min_t(size_t, todo, (mi.length - oi) / 4);
if (todo) {
ileft -= todo;
writesl(ss->base + SS_RXFIFO, mi.addr + oi, todo);
oi += todo * 4;
}
if (oi == mi.length) {
pi += mi.length;
oi = 0;
}
sg_miter_stop(&mi);
}

spaces = readl(ss->base + SS_FCSR);
rx_cnt = SS_RXFIFO_SPACES(spaces);
tx_cnt = SS_TXFIFO_SPACES(spaces);

sg_miter_start(&mo, areq->dst, sg_nents(areq->dst),
SG_MITER_TO_SG | SG_MITER_ATOMIC);
if (po)
sg_miter_skip(&mo, po);
miter_err = sg_miter_next(&mo);
if (!miter_err || !mo.addr) {
dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
err = -EINVAL;
goto release_ss;
}
todo = min(tx_cnt, oleft);
todo = min_t(size_t, todo, (mo.length - oo) / 4);
if (todo) {
Expand All @@ -96,9 +110,10 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq)
oo += todo * 4;
}
if (oo == mo.length) {
sg_miter_next(&mo);
oo = 0;
po += mo.length;
}
sg_miter_stop(&mo);
} while (oleft);

if (areq->iv) {
Expand All @@ -109,8 +124,6 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq)
}

release_ss:
sg_miter_stop(&mi);
sg_miter_stop(&mo);
writel(0, ss->base + SS_CTL);
spin_unlock_irqrestore(&ss->slock, flags);
return err;
Expand Down Expand Up @@ -162,6 +175,8 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
unsigned int oleft = areq->cryptlen;
unsigned int todo;
struct sg_mapping_iter mi, mo;
unsigned long pi = 0, po = 0; /* progress for in and out */
bool miter_err;
unsigned int oi, oo; /* offset for in and out */
unsigned int ob = 0; /* offset in buf */
unsigned int obo = 0; /* offset in bufo*/
Expand Down Expand Up @@ -215,24 +230,23 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
}
writel(mode, ss->base + SS_CTL);

sg_miter_start(&mi, areq->src, sg_nents(areq->src),
SG_MITER_FROM_SG | SG_MITER_ATOMIC);
sg_miter_start(&mo, areq->dst, sg_nents(areq->dst),
SG_MITER_TO_SG | SG_MITER_ATOMIC);
sg_miter_next(&mi);
sg_miter_next(&mo);
if (!mi.addr || !mo.addr) {
dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
err = -EINVAL;
goto release_ss;
}
ileft = areq->cryptlen;
oleft = areq->cryptlen;
oi = 0;
oo = 0;

while (oleft) {
if (ileft) {
sg_miter_start(&mi, areq->src, sg_nents(areq->src),
SG_MITER_FROM_SG | SG_MITER_ATOMIC);
if (pi)
sg_miter_skip(&mi, pi);
miter_err = sg_miter_next(&mi);
if (!miter_err || !mi.addr) {
dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
err = -EINVAL;
goto release_ss;
}
/*
* todo is the number of consecutive 4byte word that we
* can read from current SG
Expand Down Expand Up @@ -265,31 +279,38 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
}
}
if (oi == mi.length) {
sg_miter_next(&mi);
pi += mi.length;
oi = 0;
}
sg_miter_stop(&mi);
}

spaces = readl(ss->base + SS_FCSR);
rx_cnt = SS_RXFIFO_SPACES(spaces);
tx_cnt = SS_TXFIFO_SPACES(spaces);
dev_dbg(ss->dev,
"%x %u/%zu %u/%u cnt=%u %u/%zu %u/%u cnt=%u %u\n",
mode,
oi, mi.length, ileft, areq->cryptlen, rx_cnt,
oo, mo.length, oleft, areq->cryptlen, tx_cnt, ob);

if (!tx_cnt)
continue;
sg_miter_start(&mo, areq->dst, sg_nents(areq->dst),
SG_MITER_TO_SG | SG_MITER_ATOMIC);
if (po)
sg_miter_skip(&mo, po);
miter_err = sg_miter_next(&mo);
if (!miter_err || !mo.addr) {
dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
err = -EINVAL;
goto release_ss;
}
/* todo in 4bytes word */
todo = min(tx_cnt, oleft / 4);
todo = min_t(size_t, todo, (mo.length - oo) / 4);

if (todo) {
readsl(ss->base + SS_TXFIFO, mo.addr + oo, todo);
oleft -= todo * 4;
oo += todo * 4;
if (oo == mo.length) {
sg_miter_next(&mo);
po += mo.length;
oo = 0;
}
} else {
Expand All @@ -314,12 +335,14 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
obo += todo;
oo += todo;
if (oo == mo.length) {
po += mo.length;
sg_miter_next(&mo);
oo = 0;
}
} while (obo < obl);
/* bufo must be fully used here */
}
sg_miter_stop(&mo);
}
if (areq->iv) {
for (i = 0; i < 4 && i < ivsize / 4; i++) {
Expand All @@ -329,8 +352,6 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
}

release_ss:
sg_miter_stop(&mi);
sg_miter_stop(&mo);
writel(0, ss->base + SS_CTL);
spin_unlock_irqrestore(&ss->slock, flags);

Expand Down

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