1 files changed, 165 insertions, 71 deletions

diff --git a/kernel/padata.c b/kernel/padata.c
index fc00f7e64133..8c8755f170ca 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -89,7 +89,7 @@ static void padata_parallel_worker(struct work_struct *parallel_work)
 /**
  * padata_do_parallel - padata parallelization function
  *
- * @pinst: padata instance
+ * @ps: padatashell
  * @padata: object to be parallelized
  * @cb_cpu: pointer to the CPU that the serialization callback function should
  *          run on.  If it's not in the serial cpumask of @pinst
@@ -100,16 +100,17 @@ static void padata_parallel_worker(struct work_struct *parallel_work)
  * Note: Every object which is parallelized by padata_do_parallel
  * must be seen by padata_do_serial.
  */
-int padata_do_parallel(struct padata_instance *pinst,
+int padata_do_parallel(struct padata_shell *ps,
 		       struct padata_priv *padata, int *cb_cpu)
 {
+	struct padata_instance *pinst = ps->pinst;
 	int i, cpu, cpu_index, target_cpu, err;
 	struct padata_parallel_queue *queue;
 	struct parallel_data *pd;
 
 	rcu_read_lock_bh();
 
-	pd = rcu_dereference_bh(pinst->pd);
+	pd = rcu_dereference_bh(ps->pd);
 
 	err = -EINVAL;
 	if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID)
@@ -212,10 +213,10 @@ static struct padata_priv *padata_find_next(struct parallel_data *pd,
 
 static void padata_reorder(struct parallel_data *pd)
 {
+	struct padata_instance *pinst = pd->ps->pinst;
 	int cb_cpu;
 	struct padata_priv *padata;
 	struct padata_serial_queue *squeue;
-	struct padata_instance *pinst = pd->pinst;
 	struct padata_parallel_queue *next_queue;
 
 	/*
@@ -349,36 +350,39 @@ void padata_do_serial(struct padata_priv *padata)
 }
 EXPORT_SYMBOL(padata_do_serial);
 
-static int padata_setup_cpumasks(struct parallel_data *pd,
-				 const struct cpumask *pcpumask,
-				 const struct cpumask *cbcpumask)
+static int padata_setup_cpumasks(struct padata_instance *pinst)
 {
 	struct workqueue_attrs *attrs;
+	int err;
+
+	attrs = alloc_workqueue_attrs();
+	if (!attrs)
+		return -ENOMEM;
+
+	/* Restrict parallel_wq workers to pd->cpumask.pcpu. */
+	cpumask_copy(attrs->cpumask, pinst->cpumask.pcpu);
+	err = apply_workqueue_attrs(pinst->parallel_wq, attrs);
+	free_workqueue_attrs(attrs);
+
+	return err;
+}
+
+static int pd_setup_cpumasks(struct parallel_data *pd,
+			     const struct cpumask *pcpumask,
+			     const struct cpumask *cbcpumask)
+{
 	int err = -ENOMEM;
 
 	if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL))
 		goto out;
-	cpumask_and(pd->cpumask.pcpu, pcpumask, cpu_online_mask);
-
 	if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL))
 		goto free_pcpu_mask;
-	cpumask_and(pd->cpumask.cbcpu, cbcpumask, cpu_online_mask);
 
-	attrs = alloc_workqueue_attrs();
-	if (!attrs)
-		goto free_cbcpu_mask;
-
-	/* Restrict parallel_wq workers to pd->cpumask.pcpu. */
-	cpumask_copy(attrs->cpumask, pd->cpumask.pcpu);
-	err = apply_workqueue_attrs(pd->pinst->parallel_wq, attrs);
-	free_workqueue_attrs(attrs);
-	if (err < 0)
-		goto free_cbcpu_mask;
+	cpumask_copy(pd->cpumask.pcpu, pcpumask);
+	cpumask_copy(pd->cpumask.cbcpu, cbcpumask);
 
 	return 0;
 
-free_cbcpu_mask:
-	free_cpumask_var(pd->cpumask.cbcpu);
 free_pcpu_mask:
 	free_cpumask_var(pd->cpumask.pcpu);
 out:
@@ -422,12 +426,16 @@ static void padata_init_pqueues(struct parallel_data *pd)
 }
 
 /* Allocate and initialize the internal cpumask dependend resources. */
-static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst,
-					     const struct cpumask *pcpumask,
-					     const struct cpumask *cbcpumask)
+static struct parallel_data *padata_alloc_pd(struct padata_shell *ps)
 {
+	struct padata_instance *pinst = ps->pinst;
+	const struct cpumask *cbcpumask;
+	const struct cpumask *pcpumask;
 	struct parallel_data *pd;
 
+	cbcpumask = pinst->rcpumask.cbcpu;
+	pcpumask = pinst->rcpumask.pcpu;
+
 	pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL);
 	if (!pd)
 		goto err;
@@ -440,8 +448,8 @@ static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst,
 	if (!pd->squeue)
 		goto err_free_pqueue;
 
-	pd->pinst = pinst;
-	if (padata_setup_cpumasks(pd, pcpumask, cbcpumask) < 0)
+	pd->ps = ps;
+	if (pd_setup_cpumasks(pd, pcpumask, cbcpumask))
 		goto err_free_squeue;
 
 	padata_init_pqueues(pd);
@@ -490,32 +498,64 @@ static void __padata_stop(struct padata_instance *pinst)
 }
 
 /* Replace the internal control structure with a new one. */
-static void padata_replace(struct padata_instance *pinst,
-			   struct parallel_data *pd_new)
+static int padata_replace_one(struct padata_shell *ps)
 {
-	struct parallel_data *pd_old = pinst->pd;
-	int notification_mask = 0;
+	struct parallel_data *pd_new;
 
-	pinst->flags |= PADATA_RESET;
+	pd_new = padata_alloc_pd(ps);
+	if (!pd_new)
+		return -ENOMEM;
 
-	rcu_assign_pointer(pinst->pd, pd_new);
+	ps->opd = rcu_dereference_protected(ps->pd, 1);
+	rcu_assign_pointer(ps->pd, pd_new);
 
-	synchronize_rcu();
+	return 0;
+}
+
+static int padata_replace(struct padata_instance *pinst, int cpu)
+{
+	int notification_mask = 0;
+	struct padata_shell *ps;
+	int err;
+
+	pinst->flags |= PADATA_RESET;
 
-	if (!cpumask_equal(pd_old->cpumask.pcpu, pd_new->cpumask.pcpu))
+	cpumask_copy(pinst->omask, pinst->rcpumask.pcpu);
+	cpumask_and(pinst->rcpumask.pcpu, pinst->cpumask.pcpu,
+		    cpu_online_mask);
+	if (cpu >= 0)
+		cpumask_clear_cpu(cpu, pinst->rcpumask.pcpu);
+	if (!cpumask_equal(pinst->omask, pinst->rcpumask.pcpu))
 		notification_mask |= PADATA_CPU_PARALLEL;
-	if (!cpumask_equal(pd_old->cpumask.cbcpu, pd_new->cpumask.cbcpu))
+
+	cpumask_copy(pinst->omask, pinst->rcpumask.cbcpu);
+	cpumask_and(pinst->rcpumask.cbcpu, pinst->cpumask.cbcpu,
+		    cpu_online_mask);
+	if (cpu >= 0)
+		cpumask_clear_cpu(cpu, pinst->rcpumask.cbcpu);
+	if (!cpumask_equal(pinst->omask, pinst->rcpumask.cbcpu))
 		notification_mask |= PADATA_CPU_SERIAL;
 
-	if (atomic_dec_and_test(&pd_old->refcnt))
-		padata_free_pd(pd_old);
+	list_for_each_entry(ps, &pinst->pslist, list) {
+		err = padata_replace_one(ps);
+		if (err)
+			break;
+	}
+
+	synchronize_rcu();
+
+	list_for_each_entry_continue_reverse(ps, &pinst->pslist, list)
+		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,
-					     &pd_new->cpumask);
+					     &pinst->cpumask);
 
 	pinst->flags &= ~PADATA_RESET;
+
+	return err;
 }
 
 /**
@@ -568,7 +608,7 @@ static int __padata_set_cpumasks(struct padata_instance *pinst,
 				 cpumask_var_t cbcpumask)
 {
 	int valid;
-	struct parallel_data *pd;
+	int err;
 
 	valid = padata_validate_cpumask(pinst, pcpumask);
 	if (!valid) {
@@ -581,19 +621,15 @@ static int __padata_set_cpumasks(struct padata_instance *pinst,
 		__padata_stop(pinst);
 
 out_replace:
-	pd = padata_alloc_pd(pinst, pcpumask, cbcpumask);
-	if (!pd)
-		return -ENOMEM;
-
 	cpumask_copy(pinst->cpumask.pcpu, pcpumask);
 	cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
 
-	padata_replace(pinst, pd);
+	err = padata_setup_cpumasks(pinst) ?: padata_replace(pinst, -1);
 
 	if (valid)
 		__padata_start(pinst);
 
-	return 0;
+	return err;
 }
 
 /**
@@ -676,46 +712,32 @@ EXPORT_SYMBOL(padata_stop);
 
 static int __padata_add_cpu(struct padata_instance *pinst, int cpu)
 {
-	struct parallel_data *pd;
+	int err = 0;
 
 	if (cpumask_test_cpu(cpu, cpu_online_mask)) {
-		pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu,
-				     pinst->cpumask.cbcpu);
-		if (!pd)
-			return -ENOMEM;
-
-		padata_replace(pinst, pd);
+		err = padata_replace(pinst, -1);
 
 		if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) &&
 		    padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
 			__padata_start(pinst);
 	}
 
-	return 0;
+	return err;
 }
 
 static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
 {
-	struct parallel_data *pd = NULL;
+	int err = 0;
 
 	if (cpumask_test_cpu(cpu, cpu_online_mask)) {
-
 		if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu) ||
 		    !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
 			__padata_stop(pinst);
 
-		pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu,
-				     pinst->cpumask.cbcpu);
-		if (!pd)
-			return -ENOMEM;
-
-		padata_replace(pinst, pd);
-
-		cpumask_clear_cpu(cpu, pd->cpumask.cbcpu);
-		cpumask_clear_cpu(cpu, pd->cpumask.pcpu);
+		err = padata_replace(pinst, cpu);
 	}
 
-	return 0;
+	return err;
 }
 
 static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu)
@@ -763,8 +785,12 @@ static void __padata_free(struct padata_instance *pinst)
 	cpuhp_state_remove_instance_nocalls(hp_online, &pinst->node);
 #endif
 
+	WARN_ON(!list_empty(&pinst->pslist));
+
 	padata_stop(pinst);
-	padata_free_pd(pinst->pd);
+	free_cpumask_var(pinst->omask);
+	free_cpumask_var(pinst->rcpumask.cbcpu);
+	free_cpumask_var(pinst->rcpumask.pcpu);
 	free_cpumask_var(pinst->cpumask.pcpu);
 	free_cpumask_var(pinst->cpumask.cbcpu);
 	destroy_workqueue(pinst->serial_wq);
@@ -911,7 +937,6 @@ static struct padata_instance *padata_alloc(const char *name,
 					    const struct cpumask *cbcpumask)
 {
 	struct padata_instance *pinst;
-	struct parallel_data *pd = NULL;
 
 	pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL);
 	if (!pinst)
@@ -939,14 +964,22 @@ static struct padata_instance *padata_alloc(const char *name,
 	    !padata_validate_cpumask(pinst, cbcpumask))
 		goto err_free_masks;
 
-	pd = padata_alloc_pd(pinst, pcpumask, cbcpumask);
-	if (!pd)
+	if (!alloc_cpumask_var(&pinst->rcpumask.pcpu, GFP_KERNEL))
 		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;
 
-	rcu_assign_pointer(pinst->pd, pd);
+	INIT_LIST_HEAD(&pinst->pslist);
 
 	cpumask_copy(pinst->cpumask.pcpu, pcpumask);
 	cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
+	cpumask_and(pinst->rcpumask.pcpu, pcpumask, cpu_online_mask);
+	cpumask_and(pinst->rcpumask.cbcpu, cbcpumask, cpu_online_mask);
+
+	if (padata_setup_cpumasks(pinst))
+		goto err_free_omask;
 
 	pinst->flags = 0;
 
@@ -962,6 +995,12 @@ 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:
+	free_cpumask_var(pinst->rcpumask.pcpu);
 err_free_masks:
 	free_cpumask_var(pinst->cpumask.pcpu);
 	free_cpumask_var(pinst->cpumask.cbcpu);
@@ -1000,6 +1039,61 @@ void padata_free(struct padata_instance *pinst)
 }
 EXPORT_SYMBOL(padata_free);
 
+/**
+ * padata_alloc_shell - Allocate and initialize padata shell.
+ *
+ * @pinst: Parent padata_instance object.
+ */
+struct padata_shell *padata_alloc_shell(struct padata_instance *pinst)
+{
+	struct parallel_data *pd;
+	struct padata_shell *ps;
+
+	ps = kzalloc(sizeof(*ps), GFP_KERNEL);
+	if (!ps)
+		goto out;
+
+	ps->pinst = pinst;
+
+	get_online_cpus();
+	pd = padata_alloc_pd(ps);
+	put_online_cpus();
+
+	if (!pd)
+		goto out_free_ps;
+
+	mutex_lock(&pinst->lock);
+	RCU_INIT_POINTER(ps->pd, pd);
+	list_add(&ps->list, &pinst->pslist);
+	mutex_unlock(&pinst->lock);
+
+	return ps;
+
+out_free_ps:
+	kfree(ps);
+out:
+	return NULL;
+}
+EXPORT_SYMBOL(padata_alloc_shell);
+
+/**
+ * padata_free_shell - free a padata shell
+ *
+ * @ps: padata shell to free
+ */
+void padata_free_shell(struct padata_shell *ps)
+{
+	struct padata_instance *pinst = ps->pinst;
+
+	mutex_lock(&pinst->lock);
+	list_del(&ps->list);
+	padata_free_pd(rcu_dereference_protected(ps->pd, 1));
+	mutex_unlock(&pinst->lock);
+
+	kfree(ps);
+}
+EXPORT_SYMBOL(padata_free_shell);
+
 #ifdef CONFIG_HOTPLUG_CPU
 
 static __init int padata_driver_init(void)