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From: Robin Murphy <robin.murphy@arm.com>
To: joro@8bytes.org, will@kernel.org
Cc: iommu@lists.linux-foundation.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, suravee.suthikulpanit@amd.com,
	baolu.lu@linux.intel.com, john.garry@huawei.com,
	dianders@chromium.org
Subject: [PATCH v2 18/24] iommu: Express DMA strictness via the domain type
Date: Wed, 28 Jul 2021 16:58:39 +0100	[thread overview]
Message-ID: <50bee17e9248ccfccb33a10238210d4ff4f4cf4d.1627468309.git.robin.murphy@arm.com> (raw)
In-Reply-To: <cover.1627468308.git.robin.murphy@arm.com>

Eliminate the iommu_get_dma_strict() indirection and pipe the
information through the domain type from the beginning. Besides
the flow simplification this also has several nice side-effects:

 - Automatically implies strict mode for untrusted devices by
   virtue of their IOMMU_DOMAIN_DMA override.
 - Ensures that we only end up using flush queues for drivers
   which are aware of them and can actually benefit.
 - Allows us to handle flush queue init failure by falling back
   to strict mode instead of leaving it to possibly blow up later.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c |  2 +-
 drivers/iommu/arm/arm-smmu/arm-smmu.c       |  2 +-
 drivers/iommu/dma-iommu.c                   |  9 +++++----
 drivers/iommu/iommu.c                       | 12 +++---------
 include/linux/iommu.h                       |  1 -
 5 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index a1f0d83d1eb5..19400826eba7 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2175,7 +2175,7 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain,
 		.iommu_dev	= smmu->dev,
 	};
 
-	if (!iommu_get_dma_strict(domain))
+	if (domain->type == IOMMU_DOMAIN_DMA_FQ)
 		pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT;
 
 	pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 936c5e9d5e82..109e4723f9f5 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -765,7 +765,7 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
 		.iommu_dev	= smmu->dev,
 	};
 
-	if (!iommu_get_dma_strict(domain))
+	if (domain->type == IOMMU_DOMAIN_DMA_FQ)
 		pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT;
 
 	if (smmu->impl && smmu->impl->init_context) {
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 8b3545c01077..7f3968865387 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -363,13 +363,14 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 
 	init_iova_domain(iovad, 1UL << order, base_pfn);
 
-	if (!cookie->fq_domain && !dev_is_untrusted(dev) &&
-	    domain->ops->flush_iotlb_all && !iommu_get_dma_strict(domain)) {
+	if (domain->type == IOMMU_DOMAIN_DMA_FQ && !cookie->fq_domain) {
 		if (init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all,
-					  iommu_dma_entry_dtor))
+					  iommu_dma_entry_dtor)) {
 			pr_warn("iova flush queue initialization failed\n");
-		else
+			domain->type = IOMMU_DOMAIN_DMA;
+		} else {
 			cookie->fq_domain = domain;
+		}
 	}
 
 	return iova_reserve_iommu_regions(dev, domain);
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 982545234cf3..eecb5657de69 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -136,6 +136,9 @@ static int __init iommu_subsys_init(void)
 		}
 	}
 
+	if (!iommu_default_passthrough() && !iommu_dma_strict)
+		iommu_def_domain_type = IOMMU_DOMAIN_DMA_FQ;
+
 	pr_info("Default domain type: %s %s\n",
 		iommu_domain_type_str(iommu_def_domain_type),
 		(iommu_cmd_line & IOMMU_CMD_LINE_DMA_API) ?
@@ -357,15 +360,6 @@ void iommu_set_dma_strict(void)
 	iommu_dma_strict = true;
 }
 
-bool iommu_get_dma_strict(struct iommu_domain *domain)
-{
-	/* only allow lazy flushing for DMA domains */
-	if (domain->type == IOMMU_DOMAIN_DMA)
-		return iommu_dma_strict;
-	return true;
-}
-EXPORT_SYMBOL_GPL(iommu_get_dma_strict);
-
 static ssize_t iommu_group_attr_show(struct kobject *kobj,
 				     struct attribute *__attr, char *buf)
 {
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 046ba4d54cd2..edfe2fdb8368 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -498,7 +498,6 @@ int iommu_set_pgtable_quirks(struct iommu_domain *domain,
 		unsigned long quirks);
 
 void iommu_set_dma_strict(void);
-bool iommu_get_dma_strict(struct iommu_domain *domain);
 
 extern int report_iommu_fault(struct iommu_domain *domain, struct device *dev,
 			      unsigned long iova, int flags);
-- 
2.25.1


  parent reply	other threads:[~2021-07-28 16:00 UTC|newest]

Thread overview: 65+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-28 15:58 [PATCH v2 00/24] iommu: Refactor DMA domain strictness Robin Murphy
2021-07-28 15:58 ` [PATCH v2 01/24] iommu: Pull IOVA cookie management into the core Robin Murphy
2021-07-30  6:06   ` Lu Baolu
2021-07-30  9:32   ` Jean-Philippe Brucker
2021-07-28 15:58 ` [PATCH v2 02/24] iommu/amd: Drop IOVA cookie management Robin Murphy
2021-07-28 15:58 ` [PATCH v2 03/24] iommu/arm-smmu: " Robin Murphy
2021-07-28 15:58 ` [PATCH v2 04/24] iommu/vt-d: " Robin Murphy
2021-07-30  6:07   ` Lu Baolu
2021-07-28 15:58 ` [PATCH v2 05/24] iommu/exynos: " Robin Murphy
2021-07-28 15:58 ` [PATCH v2 06/24] iommu/ipmmu-vmsa: " Robin Murphy
2021-07-28 15:58 ` [PATCH v2 07/24] iommu/mtk: " Robin Murphy
2021-07-28 15:58 ` [PATCH v2 08/24] iommu/rockchip: " Robin Murphy
2021-07-28 15:58 ` [PATCH v2 09/24] iommu/sprd: " Robin Murphy
2021-07-28 15:58 ` [PATCH v2 10/24] iommu/sun50i: " Robin Murphy
2021-07-28 15:58 ` [PATCH v2 11/24] iommu/virtio: " Robin Murphy
2021-07-30  9:20   ` Jean-Philippe Brucker
2021-07-28 15:58 ` [PATCH v2 12/24] iommu/dma: Unexport " Robin Murphy
2021-07-30  6:07   ` Lu Baolu
2021-07-30  9:21   ` Jean-Philippe Brucker
2021-07-28 15:58 ` [PATCH v2 13/24] iommu/dma: Remove redundant "!dev" checks Robin Murphy
2021-07-30  6:08   ` Lu Baolu
2021-07-28 15:58 ` [PATCH v2 14/24] iommu: Introduce explicit type for non-strict DMA domains Robin Murphy
2021-07-30  6:08   ` Lu Baolu
2021-07-30  9:23   ` Jean-Philippe Brucker
2021-07-28 15:58 ` [PATCH v2 15/24] iommu/amd: Prepare for multiple DMA domain types Robin Murphy
2021-07-28 15:58 ` [PATCH v2 16/24] iommu/arm-smmu: " Robin Murphy
2021-07-28 15:58 ` [PATCH v2 17/24] iommu/vt-d: " Robin Murphy
2021-07-30  6:09   ` Lu Baolu
2021-07-28 15:58 ` Robin Murphy [this message]
2021-07-29  7:13   ` [PATCH v2 18/24] iommu: Express DMA strictness via the domain type Lu Baolu
2021-07-29  9:36     ` Robin Murphy
2021-07-29 12:42       ` Lu Baolu
2021-07-30  6:09       ` Lu Baolu
2021-07-28 15:58 ` [PATCH v2 19/24] iommu: Expose DMA domain strictness via sysfs Robin Murphy
2021-07-30  6:10   ` Lu Baolu
2021-07-30  9:28   ` Jean-Philippe Brucker
2021-07-30 10:20   ` John Garry
2021-07-28 15:58 ` [PATCH v2 20/24] iommu: Merge strictness and domain type configs Robin Murphy
2021-07-30  6:10   ` Lu Baolu
2021-07-30  9:29   ` Jean-Philippe Brucker
2021-07-30  9:33   ` John Garry
2021-07-28 15:58 ` [PATCH v2 21/24] iommu/dma: Factor out flush queue init Robin Murphy
2021-07-30  6:11   ` Lu Baolu
2021-07-30  9:20   ` John Garry
2021-07-28 15:58 ` [PATCH v2 22/24] iommu: Allow enabling non-strict mode dynamically Robin Murphy
2021-07-30  6:11   ` Lu Baolu
2021-07-30  9:24   ` John Garry
2021-07-28 15:58 ` [PATCH v2 23/24] iommu/arm-smmu: Allow non-strict in pgtable_quirks interface Robin Murphy
2021-08-02 13:04   ` Will Deacon
2021-08-02 14:15     ` Robin Murphy
2021-08-03 10:36       ` Will Deacon
2021-08-03 12:13         ` Robin Murphy
2021-08-03 12:35           ` Will Deacon
2021-07-28 15:58 ` [PATCH v2 24/24] iommu: Only log strictness for DMA domains Robin Murphy
2021-07-29  9:04   ` John Garry
2021-07-30  6:12   ` Lu Baolu
2021-07-29  2:55 ` [PATCH v2 00/24] iommu: Refactor DMA domain strictness chenxiang (M)
2021-07-29 10:59   ` Robin Murphy
2021-07-30  1:21     ` chenxiang (M)
2021-07-29 15:04 ` Heiko Stübner
2021-07-29 15:43   ` Robin Murphy
2021-07-29 15:53     ` Heiko Stübner
2021-07-29 16:29       ` Robin Murphy
2021-07-29 22:33 ` Doug Anderson
2021-07-30  0:06   ` Doug Anderson

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