[PATCH v4 22/24] iommu: Only log strictness for DMA domains

Robin Murphy robin.murphy at arm.com
Wed Aug 11 05:21:36 PDT 2021


When passthrough is enabled, the default strictness policy becomes
irrelevant, since any subsequent runtime override to a DMA domain type
now embodies an explicit choice of strictness as well. Save on noise by
only logging the default policy when it is meaningfully in effect.

Reviewed-by: John Garry <john.garry at huawei.com>
Reviewed-by: Lu Baolu <baolu.lu at linux.intel.com>
Signed-off-by: Robin Murphy <robin.murphy at arm.com>
---
 drivers/iommu/iommu.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index b141161d5bbc..63face36fc49 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -144,10 +144,11 @@ static int __init iommu_subsys_init(void)
 		(iommu_cmd_line & IOMMU_CMD_LINE_DMA_API) ?
 			"(set via kernel command line)" : "");
 
-	pr_info("DMA domain TLB invalidation policy: %s mode %s\n",
-		iommu_dma_strict ? "strict" : "lazy",
-		(iommu_cmd_line & IOMMU_CMD_LINE_STRICT) ?
-			"(set via kernel command line)" : "");
+	if (!iommu_default_passthrough())
+		pr_info("DMA domain TLB invalidation policy: %s mode %s\n",
+			iommu_dma_strict ? "strict" : "lazy",
+			(iommu_cmd_line & IOMMU_CMD_LINE_STRICT) ?
+				"(set via kernel command line)" : "");
 
 	return 0;
 }
-- 
2.25.1




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