From: Robin Murphy <robin.murphy@arm.com>
Date: Fri, 17 Dec 2021 15:31:01 +0000
Subject: iommu/iova: Consolidate flush queue code
Git-commit: ea4d71bb5e3fc5c2b7b856bc7506439298f47a23
Patch-mainline: v5.17-rc1
References: bsc#1205701

Squash and simplify some of the freeing code, and move the init
and free routines down into the rest of the flush queue code to
obviate the forward declarations.

Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/b0dd4565e6646b6489599d7a1eaa362c75f53c95.1639753638.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/iova.c | 131 +++++++++++++++++++++++----------------------------
 1 file changed, 58 insertions(+), 73 deletions(-)

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 962614c7afbb..e368fd3da0d2 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -24,8 +24,6 @@ static unsigned long iova_rcache_get(struct iova_domain *iovad,
 static void init_iova_rcaches(struct iova_domain *iovad);
 static void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad);
 static void free_iova_rcaches(struct iova_domain *iovad);
-static void fq_destroy_all_entries(struct iova_domain *iovad);
-static void fq_flush_timeout(struct timer_list *t);
 
 static int iova_cpuhp_dead(unsigned int cpu, struct hlist_node *node)
 {
@@ -73,60 +71,6 @@ init_iova_domain(struct iova_domain *iovad, unsigned long granule,
 }
 EXPORT_SYMBOL_GPL(init_iova_domain);
 
-static bool has_iova_flush_queue(struct iova_domain *iovad)
-{
-	return !!iovad->fq;
-}
-
-static void free_iova_flush_queue(struct iova_domain *iovad)
-{
-	if (!has_iova_flush_queue(iovad))
-		return;
-
-	del_timer_sync(&iovad->fq_timer);
-
-	fq_destroy_all_entries(iovad);
-
-	free_percpu(iovad->fq);
-
-	iovad->fq         = NULL;
-	iovad->fq_domain  = NULL;
-}
-
-int init_iova_flush_queue(struct iova_domain *iovad, struct iommu_domain *fq_domain)
-{
-	struct iova_fq __percpu *queue;
-	int i, cpu;
-
-	atomic64_set(&iovad->fq_flush_start_cnt,  0);
-	atomic64_set(&iovad->fq_flush_finish_cnt, 0);
-
-	queue = alloc_percpu(struct iova_fq);
-	if (!queue)
-		return -ENOMEM;
-
-	for_each_possible_cpu(cpu) {
-		struct iova_fq *fq;
-
-		fq = per_cpu_ptr(queue, cpu);
-		fq->head = 0;
-		fq->tail = 0;
-
-		spin_lock_init(&fq->lock);
-
-		for (i = 0; i < IOVA_FQ_SIZE; i++)
-			INIT_LIST_HEAD(&fq->entries[i].freelist);
-	}
-
-	iovad->fq_domain = fq_domain;
-	iovad->fq = queue;
-
-	timer_setup(&iovad->fq_timer, fq_flush_timeout, 0);
-	atomic_set(&iovad->fq_timer_on, 0);
-
-	return 0;
-}
-
 static struct rb_node *
 __get_cached_rbnode(struct iova_domain *iovad, unsigned long limit_pfn)
 {
@@ -594,23 +538,6 @@ static void iova_domain_flush(struct iova_domain *iovad)
 	atomic64_inc(&iovad->fq_flush_finish_cnt);
 }
 
-static void fq_destroy_all_entries(struct iova_domain *iovad)
-{
-	int cpu;
-
-	/*
-	 * This code runs when the iova_domain is being detroyed, so don't
-	 * bother to free iovas, just free any remaining pagetable pages.
-	 */
-	for_each_possible_cpu(cpu) {
-		struct iova_fq *fq = per_cpu_ptr(iovad->fq, cpu);
-		int idx;
-
-		fq_ring_for_each(idx, fq)
-			put_pages_list(&fq->entries[idx].freelist);
-	}
-}
-
 static void fq_flush_timeout(struct timer_list *t)
 {
 	struct iova_domain *iovad = from_timer(iovad, t, fq_timer);
@@ -678,6 +605,64 @@ void queue_iova(struct iova_domain *iovad,
 			  jiffies + msecs_to_jiffies(IOVA_FQ_TIMEOUT));
 }
 
+static void free_iova_flush_queue(struct iova_domain *iovad)
+{
+	int cpu, idx;
+
+	if (!iovad->fq)
+		return;
+
+	del_timer_sync(&iovad->fq_timer);
+	/*
+	 * This code runs when the iova_domain is being detroyed, so don't
+	 * bother to free iovas, just free any remaining pagetable pages.
+	 */
+	for_each_possible_cpu(cpu) {
+		struct iova_fq *fq = per_cpu_ptr(iovad->fq, cpu);
+
+		fq_ring_for_each(idx, fq)
+			put_pages_list(&fq->entries[idx].freelist);
+	}
+
+	free_percpu(iovad->fq);
+
+	iovad->fq = NULL;
+	iovad->fq_domain = NULL;
+}
+
+int init_iova_flush_queue(struct iova_domain *iovad, struct iommu_domain *fq_domain)
+{
+	struct iova_fq __percpu *queue;
+	int i, cpu;
+
+	atomic64_set(&iovad->fq_flush_start_cnt,  0);
+	atomic64_set(&iovad->fq_flush_finish_cnt, 0);
+
+	queue = alloc_percpu(struct iova_fq);
+	if (!queue)
+		return -ENOMEM;
+
+	for_each_possible_cpu(cpu) {
+		struct iova_fq *fq = per_cpu_ptr(queue, cpu);
+
+		fq->head = 0;
+		fq->tail = 0;
+
+		spin_lock_init(&fq->lock);
+
+		for (i = 0; i < IOVA_FQ_SIZE; i++)
+			INIT_LIST_HEAD(&fq->entries[i].freelist);
+	}
+
+	iovad->fq_domain = fq_domain;
+	iovad->fq = queue;
+
+	timer_setup(&iovad->fq_timer, fq_flush_timeout, 0);
+	atomic_set(&iovad->fq_timer_on, 0);
+
+	return 0;
+}
+
 /**
  * put_iova_domain - destroys the iova domain
  * @iovad: - iova domain in question.