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From:   John Garry <john.garry@huawei.com>
To:     <joro@8bytes.org>, <will@kernel.org>, <dwmw2@infradead.org>,
        <baolu.lu@linux.intel.com>, <robin.murphy@arm.com>,
        <corbet@lwn.net>
CC:     <linux-kernel@vger.kernel.org>, <iommu@lists.linux-foundation.org>,
        <linuxarm@huawei.com>, <thunder.leizhen@huawei.com>,
        <chenxiang66@hisilicon.com>, <linux-doc@vger.kernel.org>,
        John Garry <john.garry@huawei.com>
Subject: [PATCH v13 2/6] iommu: Print strict or lazy mode at init time
Date:   Wed, 16 Jun 2021 19:03:53 +0800
Message-ID: <1623841437-211832-3-git-send-email-john.garry@huawei.com>
In-Reply-To: <1623841437-211832-1-git-send-email-john.garry@huawei.com>
References: <1623841437-211832-1-git-send-email-john.garry@huawei.com>
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As well as the default domain type, it's useful to know whether strict
or lazy for DMA domains, so add this info in a separate print.

The (stict/lazy) mode may be also set via iommu.strict earlyparm, but
this will be processed prior to iommu_subsys_init(), so that print will be
accurate for drivers which don't set the mode via custom means.

For the drivers which set the mode via custom means - AMD and Intel drivers
- they maintain prints to inform a change in policy or that custom cmdline
methods to change policy are deprecated.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/iommu/iommu.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 5419c4b9f27a..cf58949cc2f3 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -138,6 +138,11 @@ 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)" : "");
+
 	return 0;
 }
 subsys_initcall(iommu_subsys_init);
-- 
2.26.2