padata: make padata_do_parallel find alternate callback CPU

padata_do_parallel currently returns -EINVAL if the callback CPU isn't
in the callback cpumask.

pcrypt tries to prevent this situation by keeping its own callback
cpumask in sync with padata's and checks that the callback CPU it passes
to padata is valid.  Make padata handle this instead.

padata_do_parallel now takes a pointer to the callback CPU and updates
it for the caller if an alternate CPU is used.  Overall behavior in
terms of which callback CPUs are chosen stays the same.

Prepares for removal of the padata cpumask notifier in pcrypt, which
will fix a lockdep complaint about nested acquisition of the CPU hotplug
lock later in the series.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 2 insertions, 31 deletions

diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c
index d6729306..efca962a 100644
--- a/crypto/pcrypt.c
+++ b/crypto/pcrypt.c
@@ -57,35 +57,6 @@ struct pcrypt_aead_ctx {
 	unsigned int cb_cpu;
 };
 
-static int pcrypt_do_parallel(struct padata_priv *padata, unsigned int *cb_cpu,
-			      struct padata_pcrypt *pcrypt)
-{
-	unsigned int cpu_index, cpu, i;
-	struct pcrypt_cpumask *cpumask;
-
-	cpu = *cb_cpu;
-
-	rcu_read_lock_bh();
-	cpumask = rcu_dereference_bh(pcrypt->cb_cpumask);
-	if (cpumask_test_cpu(cpu, cpumask->mask))
-			goto out;
-
-	if (!cpumask_weight(cpumask->mask))
-			goto out;
-
-	cpu_index = cpu % cpumask_weight(cpumask->mask);
-
-	cpu = cpumask_first(cpumask->mask);
-	for (i = 0; i < cpu_index; i++)
-		cpu = cpumask_next(cpu, cpumask->mask);
-
-	*cb_cpu = cpu;
-
-out:
-	rcu_read_unlock_bh();
-	return padata_do_parallel(pcrypt->pinst, padata, cpu);
-}
-
 static int pcrypt_aead_setkey(struct crypto_aead *parent,
 			      const u8 *key, unsigned int keylen)
 {
@@ -157,7 +128,7 @@ static int pcrypt_aead_encrypt(struct aead_request *req)
 			       req->cryptlen, req->iv);
 	aead_request_set_ad(creq, req->assoclen);
 
-	err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pencrypt);
+	err = padata_do_parallel(pencrypt.pinst, padata, &ctx->cb_cpu);
 	if (!err)
 		return -EINPROGRESS;
 
@@ -199,7 +170,7 @@ static int pcrypt_aead_decrypt(struct aead_request *req)
 			       req->cryptlen, req->iv);
 	aead_request_set_ad(creq, req->assoclen);
 
-	err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pdecrypt);
+	err = padata_do_parallel(pdecrypt.pinst, padata, &ctx->cb_cpu);
 	if (!err)
 		return -EINPROGRESS;