[PATCH v6 22/29] iommu: Add ops->domain_alloc_sva()

From: Jason Gunthorpe <jgg@nvidia.com>
To: iommu@lists.linux.dev, Joerg Roedel <joro@8bytes.org>,
	linux-arm-kernel@lists.infradead.org,
	Robin Murphy <robin.murphy@arm.com>,
	Will Deacon <will@kernel.org>
Cc: Lu Baolu <baolu.lu@linux.intel.com>,
	Eric Auger <eric.auger@redhat.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>,
	Joerg Roedel <jroedel@suse.de>, Kevin Tian <kevin.tian@intel.com>,
	kernel test robot <lkp@intel.com>,
	Moritz Fischer <mdf@kernel.org>,
	Moritz Fischer <moritzf@google.com>,
	Michael Shavit <mshavit@google.com>,
	Nicolin Chen <nicolinc@nvidia.com>,
	patches@lists.linux.dev,
	Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>,
	Mostafa Saleh <smostafa@google.com>,
	Tony Zhu <tony.zhu@intel.com>, Yi Liu <yi.l.liu@intel.com>,
	Zhangfei Gao <zhangfei.gao@linaro.org>
Subject: [PATCH v6 22/29] iommu: Add ops->domain_alloc_sva()
Date: Wed, 27 Mar 2024 15:08:08 -0300	[thread overview]
Message-ID: <22-v6-228e7adf25eb+4155-smmuv3_newapi_p2_jgg@nvidia.com> (raw)
In-Reply-To: <0-v6-228e7adf25eb+4155-smmuv3_newapi_p2_jgg@nvidia.com>

Make a new op that receives the device and the mm_struct that the SVA
domain should be created for. Unlike domain_alloc_paging() the dev
argument is never NULL here.

This allows drivers to fully initialize the SVA domain and allocate the
mmu_notifier during allocation. It allows the notifier lifetime to follow
the lifetime of the iommu_domain.

Since we have only one call site, upgrade the new op to return ERR_PTR
instead of NULL.

Change SMMUv3 to use the new op.

Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Michael Shavit <mshavit@google.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 11 +++++++----
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c     |  2 +-
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h     |  6 +++++-
 drivers/iommu/iommu-sva.c                       | 16 +++++++++++-----
 include/linux/iommu.h                           |  3 +++
 5 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index 3e7aad0960bfd2..e337e40ac5de31 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -659,17 +659,20 @@ static const struct iommu_domain_ops arm_smmu_sva_domain_ops = {
 	.free			= arm_smmu_sva_domain_free
 };
 
-struct iommu_domain *arm_smmu_sva_domain_alloc(unsigned type)
+struct iommu_domain *arm_smmu_sva_domain_alloc(struct device *dev,
+					       struct mm_struct *mm)
 {
+	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
+	struct arm_smmu_device *smmu = master->smmu;
 	struct arm_smmu_domain *smmu_domain;
 
-	if (type != IOMMU_DOMAIN_SVA)
-		return ERR_PTR(-EOPNOTSUPP);
-
 	smmu_domain = arm_smmu_domain_alloc();
 	if (IS_ERR(smmu_domain))
 		return ERR_CAST(smmu_domain);
+
+	smmu_domain->domain.type = IOMMU_DOMAIN_SVA;
 	smmu_domain->domain.ops = &arm_smmu_sva_domain_ops;
+	smmu_domain->smmu = smmu;
 
 	return &smmu_domain->domain;
 }
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 3d9109ad60c19c..7b001afda17aa8 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3302,8 +3302,8 @@ static struct iommu_ops arm_smmu_ops = {
 	.identity_domain	= &arm_smmu_identity_domain,
 	.blocked_domain		= &arm_smmu_blocked_domain,
 	.capable		= arm_smmu_capable,
-	.domain_alloc		= arm_smmu_sva_domain_alloc,
 	.domain_alloc_paging    = arm_smmu_domain_alloc_paging,
+	.domain_alloc_sva       = arm_smmu_sva_domain_alloc,
 	.probe_device		= arm_smmu_probe_device,
 	.release_device		= arm_smmu_release_device,
 	.device_group		= arm_smmu_device_group,
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index 9db84d5940466a..107a39f1dfe869 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -791,7 +791,8 @@ int arm_smmu_master_enable_sva(struct arm_smmu_master *master);
 int arm_smmu_master_disable_sva(struct arm_smmu_master *master);
 bool arm_smmu_master_iopf_supported(struct arm_smmu_master *master);
 void arm_smmu_sva_notifier_synchronize(void);
-struct iommu_domain *arm_smmu_sva_domain_alloc(unsigned int type);
+struct iommu_domain *arm_smmu_sva_domain_alloc(struct device *dev,
+					       struct mm_struct *mm);
 void arm_smmu_sva_remove_dev_pasid(struct iommu_domain *domain,
 				   struct device *dev, ioasid_t id);
 #else /* CONFIG_ARM_SMMU_V3_SVA */
@@ -837,5 +838,8 @@ static inline void arm_smmu_sva_remove_dev_pasid(struct iommu_domain *domain,
 						 ioasid_t id)
 {
 }
+
+#define arm_smmu_sva_domain_alloc NULL
+
 #endif /* CONFIG_ARM_SMMU_V3_SVA */
 #endif /* _ARM_SMMU_V3_H */
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index 640acc804e8cdc..18a35e798b729c 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -108,8 +108,8 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm
 
 	/* Allocate a new domain and set it on device pasid. */
 	domain = iommu_sva_domain_alloc(dev, mm);
-	if (!domain) {
-		ret = -ENOMEM;
+	if (IS_ERR(domain)) {
+		ret = PTR_ERR(domain);
 		goto out_free_handle;
 	}
 
@@ -283,9 +283,15 @@ struct iommu_domain *iommu_sva_domain_alloc(struct device *dev,
 	const struct iommu_ops *ops = dev_iommu_ops(dev);
 	struct iommu_domain *domain;
 
-	domain = ops->domain_alloc(IOMMU_DOMAIN_SVA);
-	if (!domain)
-		return NULL;
+	if (ops->domain_alloc_sva) {
+		domain = ops->domain_alloc_sva(dev, mm);
+		if (IS_ERR(domain))
+			return domain;
+	} else {
+		domain = ops->domain_alloc(IOMMU_DOMAIN_SVA);
+		if (!domain)
+			return ERR_PTR(-ENOMEM);
+	}
 
 	domain->type = IOMMU_DOMAIN_SVA;
 	mmgrab(mm);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 2e925b5eba534c..8aabe83af8f266 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -518,6 +518,7 @@ static inline int __iommu_copy_struct_from_user_array(
  *                     Upon failure, ERR_PTR must be returned.
  * @domain_alloc_paging: Allocate an iommu_domain that can be used for
  *                       UNMANAGED, DMA, and DMA_FQ domain types.
+ * @domain_alloc_sva: Allocate an iommu_domain for Shared Virtual Addressing.
  * @probe_device: Add device to iommu driver handling
  * @release_device: Remove device from iommu driver handling
  * @probe_finalize: Do final setup work after the device is added to an IOMMU
@@ -558,6 +559,8 @@ struct iommu_ops {
 		struct device *dev, u32 flags, struct iommu_domain *parent,
 		const struct iommu_user_data *user_data);
 	struct iommu_domain *(*domain_alloc_paging)(struct device *dev);
+	struct iommu_domain *(*domain_alloc_sva)(struct device *dev,
+						 struct mm_struct *mm);
 
 	struct iommu_device *(*probe_device)(struct device *dev);
 	void (*release_device)(struct device *dev);
-- 
2.43.2

