padata: allocate workqueue internally

Move workqueue allocation inside of padata to prepare for further
changes to how padata uses workqueues.

Guarantees the workqueue is created with max_active=1, which padata
relies on to work correctly.  No functional change.

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: Jonathan Corbet <corbet@lwn.net>
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-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 15 insertions, 9 deletions

diff --git a/kernel/padata.c b/kernel/padata.c
index b60cc3dcee58..58728cd7f40c 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -805,6 +805,7 @@ static void __padata_free(struct padata_instance *pinst)
 	padata_free_pd(pinst->pd);
 	free_cpumask_var(pinst->cpumask.pcpu);
 	free_cpumask_var(pinst->cpumask.cbcpu);
+	destroy_workqueue(pinst->wq);
 	kfree(pinst);
 }
 
@@ -938,13 +939,13 @@ static struct kobj_type padata_attr_type = {
  * padata_alloc - allocate and initialize a padata instance and specify
  *                cpumasks for serial and parallel workers.
  *
- * @wq: workqueue to use for the allocated padata instance
+ * @name: used to identify the instance
  * @pcpumask: cpumask that will be used for padata parallelization
  * @cbcpumask: cpumask that will be used for padata serialization
  *
  * Must be called from a cpus_read_lock() protected region
  */
-static struct padata_instance *padata_alloc(struct workqueue_struct *wq,
+static struct padata_instance *padata_alloc(const char *name,
 					    const struct cpumask *pcpumask,
 					    const struct cpumask *cbcpumask)
 {
@@ -955,11 +956,16 @@ static struct padata_instance *padata_alloc(struct workqueue_struct *wq,
 	if (!pinst)
 		goto err;
 
-	if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL))
+	pinst->wq = alloc_workqueue("%s", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE,
+				    1, name);
+	if (!pinst->wq)
 		goto err_free_inst;
+
+	if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL))
+		goto err_free_wq;
 	if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) {
 		free_cpumask_var(pinst->cpumask.pcpu);
-		goto err_free_inst;
+		goto err_free_wq;
 	}
 	if (!padata_validate_cpumask(pinst, pcpumask) ||
 	    !padata_validate_cpumask(pinst, cbcpumask))
@@ -971,8 +977,6 @@ static struct padata_instance *padata_alloc(struct workqueue_struct *wq,
 
 	rcu_assign_pointer(pinst->pd, pd);
 
-	pinst->wq = wq;
-
 	cpumask_copy(pinst->cpumask.pcpu, pcpumask);
 	cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
 
@@ -990,6 +994,8 @@ static struct padata_instance *padata_alloc(struct workqueue_struct *wq,
 err_free_masks:
 	free_cpumask_var(pinst->cpumask.pcpu);
 	free_cpumask_var(pinst->cpumask.cbcpu);
+err_free_wq:
+	destroy_workqueue(pinst->wq);
 err_free_inst:
 	kfree(pinst);
 err:
@@ -1001,14 +1007,14 @@ err:
  *                         Use the cpu_possible_mask for serial and
  *                         parallel workers.
  *
- * @wq: workqueue to use for the allocated padata instance
+ * @name: used to identify the instance
  *
  * Must be called from a cpus_read_lock() protected region
  */
-struct padata_instance *padata_alloc_possible(struct workqueue_struct *wq)
+struct padata_instance *padata_alloc_possible(const char *name)
 {
 	lockdep_assert_cpus_held();
-	return padata_alloc(wq, cpu_possible_mask, cpu_possible_mask);
+	return padata_alloc(name, cpu_possible_mask, cpu_possible_mask);
 }
 EXPORT_SYMBOL(padata_alloc_possible);