Don't disable bottom half while the crypto engine is in use, as it
should be unnecessary: All kernel crypto engine usage is wrapped with
crypto engine state save/restore, so if we get interrupted by softirq
that uses crypto they should save and restore our context.
This actually fixes an issue when running OCTEON MD5 with interrupts
disabled (tcrypt mode=302). There's a WARNING because the module is
trying to enable the bottom half with irqs disabled:
[   52.656610] ------------[ cut here ]------------
[   52.661439] WARNING: CPU: 1 PID: 428 at /home/aaro/git/linux/kernel/softirq.c:150 __local_bh_enable_ip+0x9c/0xd8()
[   52.671780] Modules linked in: tcrypt(+)
[...]
[   52.763539] [<
ffffffff8114082c>] warn_slowpath_common+0x94/0xd8
[   52.769465] [<
ffffffff81144614>] __local_bh_enable_ip+0x9c/0xd8
[   52.775390] [<
ffffffff81119574>] octeon_md5_final+0x12c/0x1e8
[   52.781144] [<
ffffffff81337050>] shash_compat_digest+0xd0/0x1b0
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9490/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
 
        memcpy((char *)mctx->block + (sizeof(mctx->block) - avail), data,
               avail);
 
-       local_bh_disable();
        preempt_disable();
        flags = octeon_crypto_enable(&state);
        octeon_md5_store_hash(mctx);
        octeon_md5_read_hash(mctx);
        octeon_crypto_disable(&state, flags);
        preempt_enable();
-       local_bh_enable();
 
        memcpy(mctx->block, data, len);
 
 
        *p++ = 0x80;
 
-       local_bh_disable();
        preempt_disable();
        flags = octeon_crypto_enable(&state);
        octeon_md5_store_hash(mctx);
        octeon_md5_read_hash(mctx);
        octeon_crypto_disable(&state, flags);
        preempt_enable();
-       local_bh_enable();
 
        memcpy(out, mctx->hash, sizeof(mctx->hash));
        memset(mctx, 0, sizeof(*mctx));