[PATCH v14 1/6] iommu: Deprecate Intel and AMD cmdline methods to enable strict mode

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-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	linuxarm@huawei.com, iommu@lists.linux-foundation.org
Subject: [PATCH v14 1/6] iommu: Deprecate Intel and AMD cmdline methods to enable strict mode
Date: Fri, 18 Jun 2021 19:34:13 +0800	[thread overview]
Message-ID: <1624016058-189713-2-git-send-email-john.garry@huawei.com> (raw)
In-Reply-To: <1624016058-189713-1-git-send-email-john.garry@huawei.com>

Now that the x86 drivers support iommu.strict, deprecate the custom
methods.

Signed-off-by: John Garry <john.garry@huawei.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
---
 Documentation/admin-guide/kernel-parameters.txt | 9 ++-------
 drivers/iommu/amd/init.c                        | 4 +++-
 drivers/iommu/intel/iommu.c                     | 1 +
 3 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 30e9dd52464e..673952379900 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -290,10 +290,7 @@
 	amd_iommu=	[HW,X86-64]
 			Pass parameters to the AMD IOMMU driver in the system.
 			Possible values are:
-			fullflush - enable flushing of IO/TLB entries when
-				    they are unmapped. Otherwise they are
-				    flushed before they will be reused, which
-				    is a lot of faster
+			fullflush - Deprecated, equivalent to iommu.strict=1
 			off	  - do not initialize any AMD IOMMU found in
 				    the system
 			force_isolation - Force device isolation for all
@@ -1948,9 +1945,7 @@
 			this case, gfx device will use physical address for
 			DMA.
 		strict [Default Off]
-			With this option on every unmap_single operation will
-			result in a hardware IOTLB flush operation as opposed
-			to batching them for performance.
+			Deprecated, equivalent to iommu.strict=1.
 		sp_off [Default Off]
 			By default, super page will be supported if Intel IOMMU
 			has the capability. With this option, super page will
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 46280e6e1535..3a2fb805f11e 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -3098,8 +3098,10 @@ static int __init parse_amd_iommu_intr(char *str)
 static int __init parse_amd_iommu_options(char *str)
 {
 	for (; *str; ++str) {
-		if (strncmp(str, "fullflush", 9) == 0)
+		if (strncmp(str, "fullflush", 9) == 0) {
+			pr_warn("amd_iommu=fullflush deprecated; use iommu.strict=1 instead\n");
 			amd_iommu_unmap_flush = true;
+		}
 		if (strncmp(str, "force_enable", 12) == 0)
 			amd_iommu_force_enable = true;
 		if (strncmp(str, "off", 3) == 0)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index bd93c7ec879e..29497113d748 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -454,6 +454,7 @@ static int __init intel_iommu_setup(char *str)
 			pr_warn("intel_iommu=forcedac deprecated; use iommu.forcedac instead\n");
 			iommu_dma_forcedac = true;
 		} else if (!strncmp(str, "strict", 6)) {
+			pr_warn("intel_iommu=strict deprecated; use iommu.strict=1 instead\n");
 			pr_info("Disable batched IOTLB flush\n");
 			intel_iommu_strict = 1;
 		} else if (!strncmp(str, "sp_off", 6)) {
-- 
2.26.2

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