Re: [PATCH v9 4/7] iommu/arm-smmu: Add a pointer to the attached device to smmu_domain
From: Will Deacon <will@kernel.org>
Date: 2020-07-13 15:09:09
Also in:
linux-arm-msm, linux-iommu, lkml
On Fri, Jun 26, 2020 at 02:00:38PM -0600, Jordan Crouse wrote:
quoted hunk ↗ jump to hunk
Add a link to the pointer to the struct device that is attached to a domain. This makes it easy to get the pointer if it is needed in the implementation specific code. Signed-off-by: Jordan Crouse <redacted> --- drivers/iommu/arm-smmu.c | 6 ++++-- drivers/iommu/arm-smmu.h | 1 + 2 files changed, 5 insertions(+), 2 deletions(-)diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 048de2681670..060139452c54 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c@@ -668,7 +668,8 @@ static void arm_smmu_write_context_bank(struct arm_smmu_device *smmu, int idx) } static int arm_smmu_init_domain_context(struct iommu_domain *domain, - struct arm_smmu_device *smmu) + struct arm_smmu_device *smmu, + struct device *dev) { int irq, start, ret = 0; unsigned long ias, oas;@@ -801,6 +802,7 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain, cfg->asid = cfg->cbndx; smmu_domain->smmu = smmu; + smmu_domain->dev = dev; pgtbl_cfg = (struct io_pgtable_cfg) { .pgsize_bitmap = smmu->pgsize_bitmap,@@ -1190,7 +1192,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) return ret; /* Ensure that the domain is finalised */ - ret = arm_smmu_init_domain_context(domain, smmu); + ret = arm_smmu_init_domain_context(domain, smmu, dev); if (ret < 0) goto rpm_put;diff --git a/drivers/iommu/arm-smmu.h b/drivers/iommu/arm-smmu.h index 5f2de20e883b..d33cfe26b2f5 100644 --- a/drivers/iommu/arm-smmu.h +++ b/drivers/iommu/arm-smmu.h@@ -345,6 +345,7 @@ struct arm_smmu_domain { struct mutex init_mutex; /* Protects smmu pointer */ spinlock_t cb_lock; /* Serialises ATS1* ops and TLB syncs */ struct iommu_domain domain; + struct device *dev; /* Device attached to this domain */
This really doesn't feel right to me -- you can generally have multiple devices attached to a domain and they can come and go without the domain being destroyed. Perhaps you could instead identify the GPU during cfg_probe() and squirrel that information away somewhere? The rest of the series looks ok to me. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel