linux-kernel - [PATCH v2 24/24] iommu: Only log strictness for DMA domains

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Message-Id: <b2da9ba999b54acded9198cf92cf9b7d0fce1b45.1627468310.git.robin.murphy@arm.com>
Date:   Wed, 28 Jul 2021 16:58:45 +0100
From:   Robin Murphy <robin.murphy@....com>
To:     joro@...tes.org, will@...nel.org
Cc:     iommu@...ts.linux-foundation.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        suravee.suthikulpanit@....com, baolu.lu@...ux.intel.com,
        john.garry@...wei.com, dianders@...omium.org
Subject: [PATCH v2 24/24] iommu: Only log strictness for DMA domains

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.

Signed-off-by: Robin Murphy <robin.murphy@....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 be399d630953..87d7b299436e 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