From c5b5da9c79bb2d88fa3c5163ccf1a7a9e89cfa49 Mon Sep 17 00:00:00 2001
From: Joerg Roedel <jroedel@suse.de>
Date: Wed, 6 Jul 2016 11:55:37 +0200
Subject: iommu/amd: Set up data structures for flush queue

The flush queue is the equivalent to defered-flushing in the
Intel VT-d driver. This patch sets up the data structures
needed for this.

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

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index d218e35..38f8a5e 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -89,6 +89,22 @@ LIST_HEAD(ioapic_map);
 LIST_HEAD(hpet_map);
 LIST_HEAD(acpihid_map);
 
+#define FLUSH_QUEUE_SIZE 256
+
+struct flush_queue_entry {
+	unsigned long iova_pfn;
+	unsigned long pages;
+	struct dma_ops_domain *dma_dom;
+};
+
+struct flush_queue {
+	spinlock_t lock;
+	unsigned next;
+	struct flush_queue_entry *entries;
+};
+
+DEFINE_PER_CPU(struct flush_queue, flush_queue);
+
 /*
  * Domain for untranslated devices - only allocated
  * if iommu=pt passed on kernel cmd line.
@@ -2508,7 +2524,7 @@ static int init_reserved_iova_ranges(void)
 
 int __init amd_iommu_init_api(void)
 {
-	int ret, err = 0;
+	int ret, cpu, err = 0;
 
 	ret = iova_cache_get();
 	if (ret)
@@ -2518,6 +2534,18 @@ int __init amd_iommu_init_api(void)
 	if (ret)
 		return ret;
 
+	for_each_possible_cpu(cpu) {
+		struct flush_queue *queue = per_cpu_ptr(&flush_queue, cpu);
+
+		queue->entries = kzalloc(FLUSH_QUEUE_SIZE *
+					 sizeof(*queue->entries),
+					 GFP_KERNEL);
+		if (!queue->entries)
+			goto out_put_iova;
+
+		spin_lock_init(&queue->lock);
+	}
+
 	err = bus_set_iommu(&pci_bus_type, &amd_iommu_ops);
 	if (err)
 		return err;
@@ -2530,6 +2558,15 @@ int __init amd_iommu_init_api(void)
 	if (err)
 		return err;
 	return 0;
+
+out_put_iova:
+	for_each_possible_cpu(cpu) {
+		struct flush_queue *queue = per_cpu_ptr(&flush_queue, cpu);
+
+		kfree(queue->entries);
+	}
+
+	return -ENOMEM;
 }
 
 int __init amd_iommu_init_dma_ops(void)
@@ -2552,6 +2589,7 @@ int __init amd_iommu_init_dma_ops(void)
 		pr_info("AMD-Vi: Lazy IO/TLB flushing enabled\n");
 
 	return 0;
+
 }
 
 /*****************************************************************************
-- 
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