iommu/iova: Add flush-queue data structures

This patch adds the basic data-structures to implement
flush-queues in the generic IOVA code. It also adds the
initialization and destroy routines for these data
structures.

The initialization routine is designed so that the use of
this feature is optional for the users of IOVA code.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 39 insertions, 0 deletions

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 246f14c..b9f6ce0 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -50,10 +50,48 @@ init_iova_domain(struct iova_domain *iovad, unsigned long granule,
 	iovad->granule = granule;
 	iovad->start_pfn = start_pfn;
 	iovad->dma_32bit_pfn = pfn_32bit + 1;
+	iovad->flush_cb = NULL;
+	iovad->fq = NULL;
 	init_iova_rcaches(iovad);
 }
 EXPORT_SYMBOL_GPL(init_iova_domain);
 
+static void free_iova_flush_queue(struct iova_domain *iovad)
+{
+	if (!iovad->fq)
+		return;
+
+	free_percpu(iovad->fq);
+
+	iovad->fq         = NULL;
+	iovad->flush_cb   = NULL;
+	iovad->entry_dtor = NULL;
+}
+
+int init_iova_flush_queue(struct iova_domain *iovad,
+			  iova_flush_cb flush_cb, iova_entry_dtor entry_dtor)
+{
+	int cpu;
+
+	iovad->fq = alloc_percpu(struct iova_fq);
+	if (!iovad->fq)
+		return -ENOMEM;
+
+	iovad->flush_cb   = flush_cb;
+	iovad->entry_dtor = entry_dtor;
+
+	for_each_possible_cpu(cpu) {
+		struct iova_fq *fq;
+
+		fq = per_cpu_ptr(iovad->fq, cpu);
+		fq->head = 0;
+		fq->tail = 0;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(init_iova_flush_queue);
+
 static struct rb_node *
 __get_cached_rbnode(struct iova_domain *iovad, unsigned long *limit_pfn)
 {
@@ -433,6 +471,7 @@ void put_iova_domain(struct iova_domain *iovad)
 	struct rb_node *node;
 	unsigned long flags;
 
+	free_iova_flush_queue(iovad);
 	free_iova_rcaches(iovad);
 	spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
 	node = rb_first(&iovad->rbroot);