On 2020-08-20 13:49, vji...@codeaurora.org wrote:
From: Vijayanand Jitta <vji...@codeaurora.org>

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 <vji...@codeaurora.org>
---
  drivers/iommu/iova.c | 23 +++++++++++++++++++++++
  include/linux/iova.h |  6 ++++++
  2 files changed, 29 insertions(+)

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 4e77116..5836c87 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -442,6 +442,7 @@ struct iova *find_iova(struct iova_domain *iovad, unsigned 
long pfn)
                flush_rcache = false;
                for_each_online_cpu(cpu)
                        free_cpu_cached_iovas(cpu, iovad);
+               free_global_cached_iovas(iovad);
                goto retry;
        }
@@ -1055,5 +1056,27 @@ void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad)
        }
  }
+/*
+ * free all the IOVA ranges of global cache
+ */
+void free_global_cached_iovas(struct iova_domain *iovad)

As John pointed out last time, this should be static and the header changes dropped.

(TBH we should probably register our own hotplug notifier instance for a flush queue, so that external code has no need to poke at the per-CPU caches either)

Robin.

+{
+       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[j] = NULL;
+               }
+               rcache->depot_size = 0;
+               spin_unlock_irqrestore(&rcache->lock, flags);
+       }
+}
+
  MODULE_AUTHOR("Anil S Keshavamurthy <anil.s.keshavamur...@intel.com>");
  MODULE_LICENSE("GPL");
diff --git a/include/linux/iova.h b/include/linux/iova.h
index a0637ab..a905726 100644
--- a/include/linux/iova.h
+++ b/include/linux/iova.h
@@ -163,6 +163,7 @@ int init_iova_flush_queue(struct iova_domain *iovad,
  struct iova *split_and_remove_iova(struct iova_domain *iovad,
        struct iova *iova, unsigned long pfn_lo, unsigned long pfn_hi);
  void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad);
+void free_global_cached_iovas(struct iova_domain *iovad);
  #else
  static inline int iova_cache_get(void)
  {
@@ -270,6 +271,11 @@ static inline void free_cpu_cached_iovas(unsigned int cpu,
                                         struct iova_domain *iovad)
  {
  }
+
+static inline void free_global_cached_iovas(struct iova_domain *iovad)
+{
+}
+
  #endif
#endif

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Reply via email to