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From:   John Garry <john.garry@huawei.com>
To:     <robin.murphy@arm.com>, <joro@8bytes.org>, <will@kernel.org>
CC:     <iommu@lists.linux.dev>, <linux-kernel@vger.kernel.org>,
        <linuxarm@huawei.com>, <jsnitsel@redhat.com>,
        <haifeng.zhao@linux.intel.com>, John Garry <john.garry@huawei.com>
Subject: [PATCH v4 3/3] iova: Remove iovad->rcaches check in iova_rcache_get()
Date:   Wed, 7 Sep 2022 21:34:41 +0800
Message-ID: <1662557681-145906-4-git-send-email-john.garry@huawei.com>
In-Reply-To: <1662557681-145906-1-git-send-email-john.garry@huawei.com>
References: <1662557681-145906-1-git-send-email-john.garry@huawei.com>
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The iovad->rcaches check in iova_rcache_get() is pretty much useless
without the same check in iova_rcache_insert().

Instead of adding this symmetric check to fastpath iova_rcache_insert(),
drop the check in iova_rcache_get() in favour of making the IOVA domain
rcache init more robust to failure in future.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/iommu/iova.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 8aece052ce72..a44ad92fc5eb 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -875,7 +875,7 @@ static unsigned long iova_rcache_get(struct iova_domain *iovad,
 {
 	unsigned int log_size = order_base_2(size);
 
-	if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE || !iovad->rcaches)
+	if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE)
 		return 0;
 
 	return __iova_rcache_get(&iovad->rcaches[log_size], limit_pfn - size);
-- 
2.25.1