padata: remove cpumask change notifier

Since commit 63d35788 ("crypto: pcrypt - remove padata cpumask
notifier") this feature is unused, so get rid of it.
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
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>

Documentation/padata.txt

@@ -75,30 +75,6 @@ To simply add or remove one CPU from a certain cpumask the functions
 padata_add_cpu/padata_remove_cpu are used. cpu specifies the CPU to add or
 remove and mask is one of PADATA_CPU_SERIAL, PADATA_CPU_PARALLEL.
 
-If a user is interested in padata cpumask changes, he can register to
-the padata cpumask change notifier::
-
-    int padata_register_cpumask_notifier(struct padata_instance *pinst,
-					 struct notifier_block *nblock);
-
-To unregister from that notifier::
-
-    int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
-					   struct notifier_block *nblock);
-
-The padata cpumask change notifier notifies about changes of the usable
-cpumasks, i.e. the subset of active CPUs in the user supplied cpumask.
-
-Padata calls the notifier chain with::
-
-    blocking_notifier_call_chain(&pinst->cpumask_change_notifier,
-				 notification_mask,
-				 &pd_new->cpumask);
-
-Here cpumask_change_notifier is registered notifier, notification_mask
-is one of PADATA_CPU_SERIAL, PADATA_CPU_PARALLEL and cpumask is a pointer
-to a struct padata_cpumask that contains the new cpumask information.
-
 Actually submitting work to the padata instance requires the creation of a
 padata_priv structure::
 

crypto/pcrypt.c

@@ -13,7 +13,6 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/slab.h>
-#include <linux/notifier.h>
 #include <linux/kobject.h>
 #include <linux/cpu.h>
 #include <crypto/pcrypt.h>

include/linux/padata.h

@@ -13,7 +13,6 @@
 #include <linux/workqueue.h>
 #include <linux/spinlock.h>
 #include <linux/list.h>
-#include <linux/notifier.h>
 #include <linux/kobject.h>
 
 #define PADATA_CPU_SERIAL   0x01
@@ -151,10 +150,6 @@ struct padata_shell {
  * @pslist: List of padata_shell objects attached to this instance.
  * @cpumask: User supplied cpumasks for parallel and serial works.
  * @rcpumask: Actual cpumasks based on user cpumask and cpu_online_mask.
- * @omask: Temporary storage used to compute the notification mask.
- * @cpumask_change_notifier: Notifiers chain for user-defined notify
- *            callbacks that will be called when either @pcpu or @cbcpu
- *            or both cpumasks change.
  * @kobj: padata instance kernel object.
  * @lock: padata instance lock.
  * @flags: padata flags.
@@ -166,8 +161,6 @@ struct padata_instance {
 	struct list_head		pslist;
 	struct padata_cpumask		cpumask;
 	struct padata_cpumask		rcpumask;
-	cpumask_var_t			omask;
-	struct blocking_notifier_head	 cpumask_change_notifier;
 	struct kobject                   kobj;
 	struct mutex			 lock;
 	u8				 flags;
@@ -187,8 +180,4 @@ extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
 			      cpumask_var_t cpumask);
 extern int padata_start(struct padata_instance *pinst);
 extern void padata_stop(struct padata_instance *pinst);
-extern int padata_register_cpumask_notifier(struct padata_instance *pinst,
-					    struct notifier_block *nblock);
-extern int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
-					      struct notifier_block *nblock);
 #endif

kernel/padata.c

@@ -514,23 +514,16 @@ static int padata_replace_one(struct padata_shell *ps)
 
 static int padata_replace(struct padata_instance *pinst)
 {
-	int notification_mask = 0;
 	struct padata_shell *ps;
 	int err;
 
 	pinst->flags |= PADATA_RESET;
 
-	cpumask_copy(pinst->omask, pinst->rcpumask.pcpu);
 	cpumask_and(pinst->rcpumask.pcpu, pinst->cpumask.pcpu,
 		    cpu_online_mask);
-	if (!cpumask_equal(pinst->omask, pinst->rcpumask.pcpu))
-		notification_mask |= PADATA_CPU_PARALLEL;
 
-	cpumask_copy(pinst->omask, pinst->rcpumask.cbcpu);
 	cpumask_and(pinst->rcpumask.cbcpu, pinst->cpumask.cbcpu,
 		    cpu_online_mask);
-	if (!cpumask_equal(pinst->omask, pinst->rcpumask.cbcpu))
-		notification_mask |= PADATA_CPU_SERIAL;
 
 	list_for_each_entry(ps, &pinst->pslist, list) {
 		err = padata_replace_one(ps);
@@ -544,48 +537,11 @@ static int padata_replace(struct padata_instance *pinst)
 		if (atomic_dec_and_test(&ps->opd->refcnt))
 			padata_free_pd(ps->opd);
 
-	if (notification_mask)
-		blocking_notifier_call_chain(&pinst->cpumask_change_notifier,
-					     notification_mask,
-					     &pinst->cpumask);
-
 	pinst->flags &= ~PADATA_RESET;
 
 	return err;
 }
 
-/**
- * padata_register_cpumask_notifier - Registers a notifier that will be called
- *                             if either pcpu or cbcpu or both cpumasks change.
- *
- * @pinst: A poineter to padata instance
- * @nblock: A pointer to notifier block.
- */
-int padata_register_cpumask_notifier(struct padata_instance *pinst,
-				     struct notifier_block *nblock)
-{
-	return blocking_notifier_chain_register(&pinst->cpumask_change_notifier,
-						nblock);
-}
-EXPORT_SYMBOL(padata_register_cpumask_notifier);
-
-/**
- * padata_unregister_cpumask_notifier - Unregisters cpumask notifier
- *        registered earlier  using padata_register_cpumask_notifier
- *
- * @pinst: A pointer to data instance.
- * @nlock: A pointer to notifier block.
- */
-int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
-				       struct notifier_block *nblock)
-{
-	return blocking_notifier_chain_unregister(
-		&pinst->cpumask_change_notifier,
-		nblock);
-}
-EXPORT_SYMBOL(padata_unregister_cpumask_notifier);
-
-
 /* If cpumask contains no active cpu, we mark the instance as invalid. */
 static bool padata_validate_cpumask(struct padata_instance *pinst,
 				    const struct cpumask *cpumask)
@@ -785,7 +741,6 @@ static void __padata_free(struct padata_instance *pinst)
 	WARN_ON(!list_empty(&pinst->pslist));
 
 	padata_stop(pinst);
-	free_cpumask_var(pinst->omask);
 	free_cpumask_var(pinst->rcpumask.cbcpu);
 	free_cpumask_var(pinst->rcpumask.pcpu);
 	free_cpumask_var(pinst->cpumask.pcpu);
@@ -965,8 +920,6 @@ static struct padata_instance *padata_alloc(const char *name,
 		goto err_free_masks;
 	if (!alloc_cpumask_var(&pinst->rcpumask.cbcpu, GFP_KERNEL))
 		goto err_free_rcpumask_pcpu;
-	if (!alloc_cpumask_var(&pinst->omask, GFP_KERNEL))
-		goto err_free_rcpumask_cbcpu;
 
 	INIT_LIST_HEAD(&pinst->pslist);
 
@@ -976,11 +929,10 @@ static struct padata_instance *padata_alloc(const char *name,
 	cpumask_and(pinst->rcpumask.cbcpu, cbcpumask, cpu_online_mask);
 
 	if (padata_setup_cpumasks(pinst))
-		goto err_free_omask;
+		goto err_free_rcpumask_cbcpu;
 
 	pinst->flags = 0;
 
-	BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier);
 	kobject_init(&pinst->kobj, &padata_attr_type);
 	mutex_init(&pinst->lock);
 
@@ -994,8 +946,6 @@ static struct padata_instance *padata_alloc(const char *name,
 
 	return pinst;
 
-err_free_omask:
-	free_cpumask_var(pinst->omask);
 err_free_rcpumask_cbcpu:
 	free_cpumask_var(pinst->rcpumask.cbcpu);
 err_free_rcpumask_pcpu: