Messages in this thread | | | Date | Sat, 1 Apr 2023 21:39:32 +0800 | Subject | Re: [PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API | From | Baolu Lu <> |
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On 2023/4/1 7:11, Jacob Pan wrote: > static void idxd_disable_system_pasid(struct idxd_device *idxd) > { > + struct pci_dev *pdev = idxd->pdev; > + struct device *dev = &pdev->dev; > + struct iommu_domain *domain; > + union gencfg_reg gencfg; > + > + domain = iommu_get_domain_for_dev(dev); > + if (!domain || domain->type == IOMMU_DOMAIN_BLOCKED) > + return;
Out of curiosity, why do you need to check the domain type? And, in which case could the domain for the device be changed to a blocking one?
Once a driver is bound to the device, the driver "owns" the DMA of the device. No one else could change the domain except the driver itself.
> + > + iommu_detach_device_pasid(domain, dev, idxd->pasid); > + iommu_free_global_pasid(idxd->pasid); > > - iommu_sva_unbind_device(idxd->sva); > + gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET); > + gencfg.user_int_en = 0; > + iowrite32(gencfg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET); > idxd->sva = NULL; > + idxd->pasid = IOMMU_PASID_INVALID; > }
Best regards, baolu
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