[PATCH v5 3/6] iommu: Introduce mm_get_pasid() helper function
From: Tina Zhang
Date: Sun Sep 24 2023 - 22:39:10 EST
Use the helper function mm_get_pasid() to get a mm assigned pasid
value. The motivation is to replace mm->pasid with an iommu private
data structure that is introduced in a later patch.
The mm_get_pasid() is intended for generic usage of mm's pasid.
Using mm_get_pasid() for shared virtual addressing (SVA) with enqcmd
usage is discouraged. Instead, one should consider using
mm_get_enqcmd_pasid().
Reviewed-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Signed-off-by: Tina Zhang <tina.zhang@xxxxxxxxx>
---
Change in v5:
- Update commit message.
Change in v4:
- Rebase to v6.6-rc1.
Changes in v2:
- Update commit message.
- Let mm_get_enqcmd_pasid() call mm_get_pasid() to get pasid.
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 12 ++++++------
drivers/iommu/iommu-sva.c | 12 ++++++------
include/linux/iommu.h | 10 +++++++++-
3 files changed, 21 insertions(+), 13 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 4d83edc2be99..dbb3af323ede 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
@@ -215,7 +215,7 @@ static void arm_smmu_mm_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
smmu_domain);
}
- arm_smmu_atc_inv_domain(smmu_domain, mm->pasid, start, size);
+ arm_smmu_atc_inv_domain(smmu_domain, mm_get_pasid(mm), start, size);
}
static void arm_smmu_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
@@ -233,10 +233,10 @@ static void arm_smmu_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
* DMA may still be running. Keep the cd valid to avoid C_BAD_CD events,
* but disable translation.
*/
- arm_smmu_write_ctx_desc(smmu_domain, mm->pasid, &quiet_cd);
+ arm_smmu_write_ctx_desc(smmu_domain, mm_get_pasid(mm), &quiet_cd);
arm_smmu_tlb_inv_asid(smmu_domain->smmu, smmu_mn->cd->asid);
- arm_smmu_atc_inv_domain(smmu_domain, mm->pasid, 0, 0);
+ arm_smmu_atc_inv_domain(smmu_domain, mm_get_pasid(mm), 0, 0);
smmu_mn->cleared = true;
mutex_unlock(&sva_lock);
@@ -290,7 +290,7 @@ arm_smmu_mmu_notifier_get(struct arm_smmu_domain *smmu_domain,
goto err_free_cd;
}
- ret = arm_smmu_write_ctx_desc(smmu_domain, mm->pasid, cd);
+ ret = arm_smmu_write_ctx_desc(smmu_domain, mm_get_pasid(mm), cd);
if (ret)
goto err_put_notifier;
@@ -315,7 +315,7 @@ static void arm_smmu_mmu_notifier_put(struct arm_smmu_mmu_notifier *smmu_mn)
return;
list_del(&smmu_mn->list);
- arm_smmu_write_ctx_desc(smmu_domain, mm->pasid, NULL);
+ arm_smmu_write_ctx_desc(smmu_domain, mm_get_pasid(mm), NULL);
/*
* If we went through clear(), we've already invalidated, and no
@@ -323,7 +323,7 @@ static void arm_smmu_mmu_notifier_put(struct arm_smmu_mmu_notifier *smmu_mn)
*/
if (!smmu_mn->cleared) {
arm_smmu_tlb_inv_asid(smmu_domain->smmu, cd->asid);
- arm_smmu_atc_inv_domain(smmu_domain, mm->pasid, 0, 0);
+ arm_smmu_atc_inv_domain(smmu_domain, mm_get_pasid(mm), 0, 0);
}
/* Frees smmu_mn */
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index b78671a8a914..0f956ecd0c9b 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -23,7 +23,7 @@ static int iommu_sva_alloc_pasid(struct mm_struct *mm, struct device *dev)
mutex_lock(&iommu_sva_lock);
/* Is a PASID already associated with this mm? */
if (mm_valid_pasid(mm)) {
- if (mm->pasid >= dev->iommu->max_pasids)
+ if (mm_get_pasid(mm) >= dev->iommu->max_pasids)
ret = -EOVERFLOW;
goto out;
}
@@ -73,7 +73,7 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm
mutex_lock(&iommu_sva_lock);
/* Search for an existing domain. */
- domain = iommu_get_domain_for_dev_pasid(dev, mm->pasid,
+ domain = iommu_get_domain_for_dev_pasid(dev, mm_get_pasid(mm),
IOMMU_DOMAIN_SVA);
if (IS_ERR(domain)) {
ret = PTR_ERR(domain);
@@ -92,7 +92,7 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm
goto out_unlock;
}
- ret = iommu_attach_device_pasid(domain, dev, mm->pasid);
+ ret = iommu_attach_device_pasid(domain, dev, mm_get_pasid(mm));
if (ret)
goto out_free_domain;
domain->users = 1;
@@ -124,7 +124,7 @@ EXPORT_SYMBOL_GPL(iommu_sva_bind_device);
void iommu_sva_unbind_device(struct iommu_sva *handle)
{
struct iommu_domain *domain = handle->domain;
- ioasid_t pasid = domain->mm->pasid;
+ ioasid_t pasid = mm_get_pasid(domain->mm);
struct device *dev = handle->dev;
mutex_lock(&iommu_sva_lock);
@@ -141,7 +141,7 @@ u32 iommu_sva_get_pasid(struct iommu_sva *handle)
{
struct iommu_domain *domain = handle->domain;
- return domain->mm->pasid;
+ return mm_get_pasid(domain->mm);
}
EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
@@ -208,5 +208,5 @@ void mm_pasid_drop(struct mm_struct *mm)
if (likely(!mm_valid_pasid(mm)))
return;
- iommu_free_global_pasid(mm->pasid);
+ iommu_free_global_pasid(mm_get_pasid(mm));
}
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index a4eab6697fe1..db2510da28c1 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -1189,10 +1189,14 @@ static inline bool mm_valid_pasid(struct mm_struct *mm)
{
return mm->pasid != IOMMU_PASID_INVALID;
}
-static inline u32 mm_get_enqcmd_pasid(struct mm_struct *mm)
+static inline u32 mm_get_pasid(struct mm_struct *mm)
{
return mm->pasid;
}
+static inline u32 mm_get_enqcmd_pasid(struct mm_struct *mm)
+{
+ return mm_get_pasid(mm);
+}
void mm_pasid_drop(struct mm_struct *mm);
struct iommu_sva *iommu_sva_bind_device(struct device *dev,
struct mm_struct *mm);
@@ -1215,6 +1219,10 @@ static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle)
}
static inline void mm_pasid_init(struct mm_struct *mm) {}
static inline bool mm_valid_pasid(struct mm_struct *mm) { return false; }
+static inline u32 mm_get_pasid(struct mm_struct *mm)
+{
+ return IOMMU_PASID_INVALID;
+}
static inline u32 mm_get_enqcmd_pasid(struct mm_struct *mm)
{
return IOMMU_PASID_INVALID;
--
2.34.1