iommu/iova: Free global iova rcache on iova alloc failure

When ever an iova alloc request fails we free the iova
ranges present in the percpu iova rcaches and then retry
but the global iova rcache is not freed as a result we could
still see iova alloc failure even after retry as global
rcache is holding the iova's which can cause fragmentation.
So, free the global iova rcache as well and then go for the
retry.

Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: John Garry <john.garry@huaqwei.com>
Link: https://lore.kernel.org/r/1601451864-5956-2-git-send-email-vjitta@codeaurora.org
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index c3a1a8e6f2c1da547ae4c6d61d59743d12e61ed9..ea04a88c673d3e38e301485a8448ffb29aa8479f 100644 (file)
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -25,6 +25,7 @@ static void init_iova_rcaches(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 void free_global_cached_iovas(struct iova_domain *iovad);
 
 void
 init_iova_domain(struct iova_domain *iovad, unsigned long granule,
@@ -442,6 +443,7 @@ retry:
                flush_rcache = false;
                for_each_online_cpu(cpu)
                        free_cpu_cached_iovas(cpu, iovad);
+               free_global_cached_iovas(iovad);
                goto retry;
        }
 
@@ -1057,5 +1059,25 @@ void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad)
        }
 }
 
+/*
+ * free all the IOVA ranges of global cache
+ */
+static void free_global_cached_iovas(struct iova_domain *iovad)
+{
+       struct iova_rcache *rcache;
+       unsigned long flags;
+       int i, j;
+
+       for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
+               rcache = &iovad->rcaches[i];
+               spin_lock_irqsave(&rcache->lock, flags);
+               for (j = 0; j < rcache->depot_size; ++j) {
+                       iova_magazine_free_pfns(rcache->depot[j], iovad);
+                       iova_magazine_free(rcache->depot[j]);
+               }
+               rcache->depot_size = 0;
+               spin_unlock_irqrestore(&rcache->lock, flags);
+       }
+}
 MODULE_AUTHOR("Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>");
 MODULE_LICENSE("GPL");