From: Lu Baolu Date: Mon, 26 Sep 2022 13:15:24 +0000 (+0800) Subject: iommu/vt-d: Remove unnecessary SVA data accesses in page fault path X-Git-Tag: v6.6.17~6412^2^6~5 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=06f4b8d09dbabec631ed7b033f5d5413d86c7134;p=platform%2Fkernel%2Flinux-rpi.git iommu/vt-d: Remove unnecessary SVA data accesses in page fault path The existing I/O page fault handling code accesses the per-PASID SVA data structures. This is unnecessary and makes the fault handling code only suitable for SVA scenarios. This removes the SVA data accesses from the I/O page fault reporting and responding code, so that the fault handling code could be generic. Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20220914011821.400986-1-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h index 74b0e19..b5fb770 100644 --- a/drivers/iommu/intel/iommu.h +++ b/drivers/iommu/intel/iommu.h @@ -586,6 +586,7 @@ struct intel_iommu { #ifdef CONFIG_INTEL_IOMMU_SVM struct page_req_dsc *prq; unsigned char prq_name[16]; /* Name for PRQ interrupt */ + unsigned long prq_seq_number; struct completion prq_complete; struct ioasid_allocator_ops pasid_allocator; /* Custom allocator for PASIDs */ #endif @@ -761,7 +762,6 @@ struct intel_svm_dev { struct device *dev; struct intel_iommu *iommu; struct iommu_sva sva; - unsigned long prq_seq_number; u32 pasid; int users; u16 did; diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 8bcfb93..d1cab93 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -49,23 +49,6 @@ static void *pasid_private_find(ioasid_t pasid) } static struct intel_svm_dev * -svm_lookup_device_by_sid(struct intel_svm *svm, u16 sid) -{ - struct intel_svm_dev *sdev = NULL, *t; - - rcu_read_lock(); - list_for_each_entry_rcu(t, &svm->devs, list) { - if (t->sid == sid) { - sdev = t; - break; - } - } - rcu_read_unlock(); - - return sdev; -} - -static struct intel_svm_dev * svm_lookup_device_by_dev(struct intel_svm *svm, struct device *dev) { struct intel_svm_dev *sdev = NULL, *t; @@ -706,11 +689,10 @@ static void handle_bad_prq_event(struct intel_iommu *iommu, static irqreturn_t prq_event_thread(int irq, void *d) { - struct intel_svm_dev *sdev = NULL; struct intel_iommu *iommu = d; - struct intel_svm *svm = NULL; struct page_req_dsc *req; int head, tail, handled; + struct pci_dev *pdev; u64 address; /* @@ -730,8 +712,6 @@ static irqreturn_t prq_event_thread(int irq, void *d) pr_err("IOMMU: %s: Page request without PASID\n", iommu->name); bad_req: - svm = NULL; - sdev = NULL; handle_bad_prq_event(iommu, req, QI_RESP_INVALID); goto prq_advance; } @@ -758,34 +738,19 @@ bad_req: if (unlikely(req->lpig && !req->rd_req && !req->wr_req)) goto prq_advance; - if (!svm || svm->pasid != req->pasid) { - /* - * It can't go away, because the driver is not permitted - * to unbind the mm while any page faults are outstanding. - */ - svm = pasid_private_find(req->pasid); - if (IS_ERR_OR_NULL(svm) || (svm->flags & SVM_FLAG_SUPERVISOR_MODE)) - goto bad_req; - } - - if (!sdev || sdev->sid != req->rid) { - sdev = svm_lookup_device_by_sid(svm, req->rid); - if (!sdev) - goto bad_req; - } - - sdev->prq_seq_number++; - + pdev = pci_get_domain_bus_and_slot(iommu->segment, + PCI_BUS_NUM(req->rid), + req->rid & 0xff); /* * If prq is to be handled outside iommu driver via receiver of * the fault notifiers, we skip the page response here. */ - if (intel_svm_prq_report(iommu, sdev->dev, req)) + if (!pdev || intel_svm_prq_report(iommu, &pdev->dev, req)) handle_bad_prq_event(iommu, req, QI_RESP_INVALID); - trace_prq_report(iommu, sdev->dev, req->qw_0, req->qw_1, + trace_prq_report(iommu, &pdev->dev, req->qw_0, req->qw_1, req->priv_data[0], req->priv_data[1], - sdev->prq_seq_number); + iommu->prq_seq_number++); prq_advance: head = (head + sizeof(*req)) & PRQ_RING_MASK; } @@ -881,8 +846,6 @@ int intel_svm_page_response(struct device *dev, struct iommu_page_response *msg) { struct iommu_fault_page_request *prm; - struct intel_svm_dev *sdev = NULL; - struct intel_svm *svm = NULL; struct intel_iommu *iommu; bool private_present; bool pasid_present; @@ -901,8 +864,6 @@ int intel_svm_page_response(struct device *dev, if (!msg || !evt) return -EINVAL; - mutex_lock(&pasid_mutex); - prm = &evt->fault.prm; sid = PCI_DEVID(bus, devfn); pasid_present = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID; @@ -919,12 +880,6 @@ int intel_svm_page_response(struct device *dev, goto out; } - ret = pasid_to_svm_sdev(dev, prm->pasid, &svm, &sdev); - if (ret || !sdev) { - ret = -ENODEV; - goto out; - } - /* * Per VT-d spec. v3.0 ch7.7, system software must respond * with page group response if private data is present (PDP) @@ -954,6 +909,5 @@ int intel_svm_page_response(struct device *dev, qi_submit_sync(iommu, &desc, 1, 0); } out: - mutex_unlock(&pasid_mutex); return ret; }