alistair23-linux/drivers/crypto/sunxi-ss/sun4i-ss-prng.c
Artem Savkov 2e7d1d61ea crypto: sun4i_ss_prng - convert lock to _bh in sun4i_ss_prng_generate
Lockdep detects a possible deadlock in sun4i_ss_prng_generate() and
throws an "inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage" warning.
Disabling softirqs to fix this.

Fixes: b8ae5c7387 ("crypto: sun4i-ss - support the Security System PRNG")
Signed-off-by: Artem Savkov <artem.savkov@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-02-08 22:38:14 +11:00

57 lines
1.3 KiB
C

#include "sun4i-ss.h"
int sun4i_ss_prng_seed(struct crypto_rng *tfm, const u8 *seed,
unsigned int slen)
{
struct sun4i_ss_alg_template *algt;
struct rng_alg *alg = crypto_rng_alg(tfm);
algt = container_of(alg, struct sun4i_ss_alg_template, alg.rng);
memcpy(algt->ss->seed, seed, slen);
return 0;
}
int sun4i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int dlen)
{
struct sun4i_ss_alg_template *algt;
struct rng_alg *alg = crypto_rng_alg(tfm);
int i;
u32 v;
u32 *data = (u32 *)dst;
const u32 mode = SS_OP_PRNG | SS_PRNG_CONTINUE | SS_ENABLED;
size_t len;
struct sun4i_ss_ctx *ss;
unsigned int todo = (dlen / 4) * 4;
algt = container_of(alg, struct sun4i_ss_alg_template, alg.rng);
ss = algt->ss;
spin_lock_bh(&ss->slock);
writel(mode, ss->base + SS_CTL);
while (todo > 0) {
/* write the seed */
for (i = 0; i < SS_SEED_LEN / BITS_PER_LONG; i++)
writel(ss->seed[i], ss->base + SS_KEY0 + i * 4);
/* Read the random data */
len = min_t(size_t, SS_DATA_LEN / BITS_PER_BYTE, todo);
readsl(ss->base + SS_TXFIFO, data, len / 4);
data += len / 4;
todo -= len;
/* Update the seed */
for (i = 0; i < SS_SEED_LEN / BITS_PER_LONG; i++) {
v = readl(ss->base + SS_KEY0 + i * 4);
ss->seed[i] = v;
}
}
writel(0, ss->base + SS_CTL);
spin_unlock_bh(&ss->slock);
return 0;
}