diff options
Diffstat (limited to 'drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c')
| -rw-r--r-- | drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 35 |
1 files changed, 33 insertions, 2 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 6c1113059632..ef3fcfa72187 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 @@ -10,10 +10,18 @@ #include "arm-smmu-v3.h" #include "../../io-pgtable-arm.h" +/* + * Check if the CPU ASID is available on the SMMU side. If a private context + * descriptor is using it, try to replace it. + */ static struct arm_smmu_ctx_desc * arm_smmu_share_asid(struct mm_struct *mm, u16 asid) { + int ret; + u32 new_asid; struct arm_smmu_ctx_desc *cd; + struct arm_smmu_device *smmu; + struct arm_smmu_domain *smmu_domain; cd = xa_load(&arm_smmu_asid_xa, asid); if (!cd) @@ -27,8 +35,31 @@ arm_smmu_share_asid(struct mm_struct *mm, u16 asid) return cd; } - /* Ouch, ASID is already in use for a private cd. */ - return ERR_PTR(-EBUSY); + smmu_domain = container_of(cd, struct arm_smmu_domain, s1_cfg.cd); + smmu = smmu_domain->smmu; + + ret = xa_alloc(&arm_smmu_asid_xa, &new_asid, cd, + XA_LIMIT(1, (1 << smmu->asid_bits) - 1), GFP_KERNEL); + if (ret) + return ERR_PTR(-ENOSPC); + /* + * Race with unmap: TLB invalidations will start targeting the new ASID, + * which isn't assigned yet. We'll do an invalidate-all on the old ASID + * later, so it doesn't matter. + */ + cd->asid = new_asid; + /* + * Update ASID and invalidate CD in all associated masters. There will + * be some overlap between use of both ASIDs, until we invalidate the + * TLB. + */ + arm_smmu_write_ctx_desc(smmu_domain, 0, cd); + + /* Invalidate TLB entries previously associated with that context */ + arm_smmu_tlb_inv_asid(smmu, asid); + + xa_erase(&arm_smmu_asid_xa, asid); + return NULL; } __maybe_unused |