Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Sender: vjitta=codeaurora.org@mg.codeaurora.org
DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 9DE51C433CA
From:   vjitta@codeaurora.org
To:     joro@8bytes.org, iommu@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
Cc:     vinmenon@codeaurora.org, kernel-team@android.com,
        vjitta@codeaurora.org, robin.murphy@arm.com
Subject: [PATCH v4 2/2] iommu/iova: Free global iova rcache on iova alloc failure
Date:   Wed, 30 Sep 2020 11:17:21 +0530
Message-Id: <1601444841-12267-2-git-send-email-vjitta@codeaurora.org>
In-Reply-To: <1601444841-12267-1-git-send-email-vjitta@codeaurora.org>
References: <1601444841-12267-1-git-send-email-vjitta@codeaurora.org>
Precedence: bulk

From: Vijayanand Jitta <vjitta@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 <vjitta@codeaurora.org>
---
 drivers/iommu/iova.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index c3a1a8e..64ce082 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -442,6 +442,7 @@ alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
 		flush_rcache = false;
 		for_each_online_cpu(cpu)
 			free_cpu_cached_iovas(cpu, iovad);
+		free_global_cached_iovas(iovad);
 		goto retry;
 	}
 
@@ -1057,5 +1058,26 @@ 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[j] = NULL;
+		}
+		rcache->depot_size = 0;
+		spin_unlock_irqrestore(&rcache->lock, flags);
+	}
+}
 MODULE_AUTHOR("Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>");
 MODULE_LICENSE("GPL");
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
2.7.4