From: Robin Murphy <robin.murphy@arm.com> To: Lu Baolu <baolu.lu@linux.intel.com>, joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] iommu: Unify iova_to_phys for identity domains Date: Thu, 15 Jul 2021 09:53:21 +0100 [thread overview] Message-ID: <3c03a3f1-5c9c-be2f-e3bc-9487d662d4f9@arm.com> (raw) In-Reply-To: <eaa44be7-5c83-6d11-5efb-5ba4707b683b@linux.intel.com> On 2021-07-15 02:38, Lu Baolu wrote: > On 7/15/21 1:28 AM, Robin Murphy wrote: >> If people are going to insist on calling iommu_iova_to_phys() >> pointlessly and expecting it to work, we can at least do ourselves a >> favour by handling those cases in the core code, rather than repeatedly >> across an inconsistent handful of drivers. >> >> Signed-off-by: Robin Murphy <robin.murphy@arm.com> >> --- >> drivers/iommu/amd/io_pgtable.c | 3 --- >> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 3 --- >> drivers/iommu/arm/arm-smmu/arm-smmu.c | 3 --- >> drivers/iommu/iommu.c | 6 +++++- >> 4 files changed, 5 insertions(+), 10 deletions(-) >> >> diff --git a/drivers/iommu/amd/io_pgtable.c >> b/drivers/iommu/amd/io_pgtable.c >> index bb0ee5c9fde7..182c93a43efd 100644 >> --- a/drivers/iommu/amd/io_pgtable.c >> +++ b/drivers/iommu/amd/io_pgtable.c >> @@ -493,9 +493,6 @@ static phys_addr_t iommu_v1_iova_to_phys(struct >> io_pgtable_ops *ops, unsigned lo >> unsigned long offset_mask, pte_pgsize; >> u64 *pte, __pte; >> - if (pgtable->mode == PAGE_MODE_NONE) >> - return iova; >> - >> pte = fetch_pte(pgtable, iova, &pte_pgsize); >> if (!pte || !IOMMU_PTE_PRESENT(*pte)) >> 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 3e87a9cf6da3..c9fdd0d097be 100644 >> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c >> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c >> @@ -2481,9 +2481,6 @@ arm_smmu_iova_to_phys(struct iommu_domain >> *domain, dma_addr_t iova) >> { >> struct io_pgtable_ops *ops = to_smmu_domain(domain)->pgtbl_ops; >> - if (domain->type == IOMMU_DOMAIN_IDENTITY) >> - return iova; >> - >> if (!ops) >> return 0; >> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c >> b/drivers/iommu/arm/arm-smmu/arm-smmu.c >> index 0f181f76c31b..0d04eafa3fdb 100644 >> --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c >> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c >> @@ -1317,9 +1317,6 @@ static phys_addr_t arm_smmu_iova_to_phys(struct >> iommu_domain *domain, >> struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); >> struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops; >> - if (domain->type == IOMMU_DOMAIN_IDENTITY) >> - return iova; >> - >> if (!ops) >> return 0; >> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >> index 43a2041d9629..7c16f977b5a6 100644 >> --- a/drivers/iommu/iommu.c >> +++ b/drivers/iommu/iommu.c >> @@ -2371,7 +2371,11 @@ EXPORT_SYMBOL_GPL(iommu_detach_group); >> phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, >> dma_addr_t iova) >> { >> - if (unlikely(domain->ops->iova_to_phys == NULL)) >> + if (domain->type == IOMMU_DOMAIN_IDENTITY) >> + return iova; >> + >> + if (unlikely(domain->ops->iova_to_phys == NULL) || >> + domain->type == IOMMU_DOMAIN_BLOCKED) >> return 0; > > Nit: > Logically we only needs ops->iova_to_phys for DMA and UNMANAGED domains, > so it looks better if we have > > if (domain->type == IOMMU_DOMAIN_BLOCKED || > unlikely(domain->ops->iova_to_phys == NULL)) > return 0; Yeah, I put IOMMU_DOMAIN_BLOCKED last as the least likely condition since it's really just for completeness - I don't think it's possible to see it legitimately used at the moment - but on second look I think ops->iova_to_phys == NULL is equally theoretical now, so maybe I could be removing that and we just make it mandatory for any new drivers? > Anyway, > > Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Thanks! Robin. > > Best regards, > baolu > >> return domain->ops->iova_to_phys(domain, iova); >> _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
WARNING: multiple messages have this Message-ID (diff)
From: Robin Murphy <robin.murphy@arm.com> To: Lu Baolu <baolu.lu@linux.intel.com>, joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] iommu: Unify iova_to_phys for identity domains Date: Thu, 15 Jul 2021 09:53:21 +0100 [thread overview] Message-ID: <3c03a3f1-5c9c-be2f-e3bc-9487d662d4f9@arm.com> (raw) In-Reply-To: <eaa44be7-5c83-6d11-5efb-5ba4707b683b@linux.intel.com> On 2021-07-15 02:38, Lu Baolu wrote: > On 7/15/21 1:28 AM, Robin Murphy wrote: >> If people are going to insist on calling iommu_iova_to_phys() >> pointlessly and expecting it to work, we can at least do ourselves a >> favour by handling those cases in the core code, rather than repeatedly >> across an inconsistent handful of drivers. >> >> Signed-off-by: Robin Murphy <robin.murphy@arm.com> >> --- >> drivers/iommu/amd/io_pgtable.c | 3 --- >> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 3 --- >> drivers/iommu/arm/arm-smmu/arm-smmu.c | 3 --- >> drivers/iommu/iommu.c | 6 +++++- >> 4 files changed, 5 insertions(+), 10 deletions(-) >> >> diff --git a/drivers/iommu/amd/io_pgtable.c >> b/drivers/iommu/amd/io_pgtable.c >> index bb0ee5c9fde7..182c93a43efd 100644 >> --- a/drivers/iommu/amd/io_pgtable.c >> +++ b/drivers/iommu/amd/io_pgtable.c >> @@ -493,9 +493,6 @@ static phys_addr_t iommu_v1_iova_to_phys(struct >> io_pgtable_ops *ops, unsigned lo >> unsigned long offset_mask, pte_pgsize; >> u64 *pte, __pte; >> - if (pgtable->mode == PAGE_MODE_NONE) >> - return iova; >> - >> pte = fetch_pte(pgtable, iova, &pte_pgsize); >> if (!pte || !IOMMU_PTE_PRESENT(*pte)) >> 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 3e87a9cf6da3..c9fdd0d097be 100644 >> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c >> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c >> @@ -2481,9 +2481,6 @@ arm_smmu_iova_to_phys(struct iommu_domain >> *domain, dma_addr_t iova) >> { >> struct io_pgtable_ops *ops = to_smmu_domain(domain)->pgtbl_ops; >> - if (domain->type == IOMMU_DOMAIN_IDENTITY) >> - return iova; >> - >> if (!ops) >> return 0; >> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c >> b/drivers/iommu/arm/arm-smmu/arm-smmu.c >> index 0f181f76c31b..0d04eafa3fdb 100644 >> --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c >> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c >> @@ -1317,9 +1317,6 @@ static phys_addr_t arm_smmu_iova_to_phys(struct >> iommu_domain *domain, >> struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); >> struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops; >> - if (domain->type == IOMMU_DOMAIN_IDENTITY) >> - return iova; >> - >> if (!ops) >> return 0; >> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >> index 43a2041d9629..7c16f977b5a6 100644 >> --- a/drivers/iommu/iommu.c >> +++ b/drivers/iommu/iommu.c >> @@ -2371,7 +2371,11 @@ EXPORT_SYMBOL_GPL(iommu_detach_group); >> phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, >> dma_addr_t iova) >> { >> - if (unlikely(domain->ops->iova_to_phys == NULL)) >> + if (domain->type == IOMMU_DOMAIN_IDENTITY) >> + return iova; >> + >> + if (unlikely(domain->ops->iova_to_phys == NULL) || >> + domain->type == IOMMU_DOMAIN_BLOCKED) >> return 0; > > Nit: > Logically we only needs ops->iova_to_phys for DMA and UNMANAGED domains, > so it looks better if we have > > if (domain->type == IOMMU_DOMAIN_BLOCKED || > unlikely(domain->ops->iova_to_phys == NULL)) > return 0; Yeah, I put IOMMU_DOMAIN_BLOCKED last as the least likely condition since it's really just for completeness - I don't think it's possible to see it legitimately used at the moment - but on second look I think ops->iova_to_phys == NULL is equally theoretical now, so maybe I could be removing that and we just make it mandatory for any new drivers? > Anyway, > > Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Thanks! Robin. > > Best regards, > baolu > >> return domain->ops->iova_to_phys(domain, iova); >> _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-07-15 8:53 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-14 17:28 [PATCH] iommu: Unify iova_to_phys for identity domains Robin Murphy 2021-07-14 17:28 ` Robin Murphy 2021-07-15 1:38 ` Lu Baolu 2021-07-15 1:38 ` Lu Baolu 2021-07-15 8:53 ` Robin Murphy [this message] 2021-07-15 8:53 ` Robin Murphy 2021-07-26 11:34 ` Joerg Roedel 2021-07-26 11:34 ` Joerg Roedel
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=3c03a3f1-5c9c-be2f-e3bc-9487d662d4f9@arm.com \ --to=robin.murphy@arm.com \ --cc=baolu.lu@linux.intel.com \ --cc=iommu@lists.linux-foundation.org \ --cc=joro@8bytes.org \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=will@kernel.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.