diff options
| author | Michael Shavit <mshavit@google.com> | 2023-09-05 19:49:13 +0800 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2023-10-12 18:37:06 +0100 |
| commit | 37ed36448fcd73be197c87ce291d96eeb4d55c00 (patch) | |
| tree | dfe2a31712217d2bf7ee447ee450adde813af6f2 /drivers/iommu/arm | |
| parent | d912aed14fe412038379b1a90d1ae5a02307e830 (diff) | |
iommu/arm-smmu-v3-sva: Remove bond refcount
Always allocate a new arm_smmu_bond in __arm_smmu_sva_bind and remove
the bond refcount since arm_smmu_bond can never be shared across calls
to __arm_smmu_sva_bind.
The iommu framework will not allocate multiple SVA domains for the same
(device/mm) pair, nor will it call set_dev_pasid for a device if a
domain is already attached on the given pasid. There's also a one-to-one
mapping between MM and PASID. __arm_smmu_sva_bind is therefore never
called with the same (device/mm) pair, and so there's no reason to try
and normalize allocations of the arm_smmu_bond struct for a (device/mm)
pair across set_dev_pasid.
Signed-off-by: Michael Shavit <mshavit@google.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230905194849.v1.2.Id3ab7cf665bcead097654937233a645722a4cce3@changeid
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'drivers/iommu/arm')
| -rw-r--r-- | drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 12 |
1 files changed, 1 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 ce895c5ce42e..353248ab18e7 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 @@ -28,7 +28,6 @@ struct arm_smmu_bond { struct mm_struct *mm; struct arm_smmu_mmu_notifier *smmu_mn; struct list_head list; - refcount_t refs; }; #define sva_to_bond(handle) \ @@ -386,20 +385,11 @@ static int __arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm) if (!master || !master->sva_enabled) return -ENODEV; - /* If bind() was already called for this {dev, mm} pair, reuse it. */ - list_for_each_entry(bond, &master->bonds, list) { - if (bond->mm == mm) { - refcount_inc(&bond->refs); - return &bond->sva; - } - } - bond = kzalloc(sizeof(*bond), GFP_KERNEL); if (!bond) return -ENOMEM; bond->mm = mm; - refcount_set(&bond->refs, 1); bond->smmu_mn = arm_smmu_mmu_notifier_get(smmu_domain, mm); if (IS_ERR(bond->smmu_mn)) { @@ -578,7 +568,7 @@ void arm_smmu_sva_remove_dev_pasid(struct iommu_domain *domain, } } - if (!WARN_ON(!bond) && refcount_dec_and_test(&bond->refs)) { + if (!WARN_ON(!bond)) { list_del(&bond->list); arm_smmu_mmu_notifier_put(bond->smmu_mn); kfree(bond); |