Refactor prq_event_thread() by moving handling single prq event out of the main loop.
Signed-off-by: Lu Baolu <baolu...@linux.intel.com> Link: https://lore.kernel.org/r/20210520031531.712333-1-baolu...@linux.intel.com --- drivers/iommu/intel/svm.c | 239 ++++++++++++++++++++++---------------- 1 file changed, 136 insertions(+), 103 deletions(-) diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 57867ff97bc2..d51ddece4259 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -866,141 +866,174 @@ intel_svm_prq_report(struct device *dev, struct page_req_dsc *desc) return iommu_report_device_fault(dev, &event); } +static void handle_bad_prq_event(struct intel_iommu *iommu, + struct page_req_dsc *req, int result) +{ + struct qi_desc desc; + + pr_err("%s: Invalid page request: %08llx %08llx\n", + iommu->name, ((unsigned long long *)req)[0], + ((unsigned long long *)req)[1]); + + /* + * Per VT-d spec. v3.0 ch7.7, system software must + * respond with page group response if private data + * is present (PDP) or last page in group (LPIG) bit + * is set. This is an additional VT-d feature beyond + * PCI ATS spec. + */ + if (!req->lpig && !req->priv_data_present) + return; + + desc.qw0 = QI_PGRP_PASID(req->pasid) | + QI_PGRP_DID(req->rid) | + QI_PGRP_PASID_P(req->pasid_present) | + QI_PGRP_PDP(req->priv_data_present) | + QI_PGRP_RESP_CODE(result) | + QI_PGRP_RESP_TYPE; + desc.qw1 = QI_PGRP_IDX(req->prg_index) | + QI_PGRP_LPIG(req->lpig); + desc.qw2 = 0; + desc.qw3 = 0; + + if (req->priv_data_present) + memcpy(&desc.qw2, req->priv_data, sizeof(req->priv_data)); + qi_submit_sync(iommu, &desc, 1, 0); +} + +static void handle_single_prq_event(struct intel_iommu *iommu, + struct mm_struct *mm, + struct page_req_dsc *req) +{ + u64 address = (u64)req->addr << VTD_PAGE_SHIFT; + int result = QI_RESP_INVALID; + struct vm_area_struct *vma; + struct qi_desc desc; + unsigned int flags; + vm_fault_t ret; + + /* If the mm is already defunct, don't handle faults. */ + if (!mmget_not_zero(mm)) + goto response; + + mmap_read_lock(mm); + vma = find_extend_vma(mm, address); + if (!vma || address < vma->vm_start) + goto invalid; + + if (access_error(vma, req)) + goto invalid; + + flags = FAULT_FLAG_USER | FAULT_FLAG_REMOTE; + if (req->wr_req) + flags |= FAULT_FLAG_WRITE; + + ret = handle_mm_fault(vma, address, flags, NULL); + if (!(ret & VM_FAULT_ERROR)) + result = QI_RESP_SUCCESS; +invalid: + mmap_read_unlock(mm); + mmput(mm); + +response: + if (!(req->lpig || req->priv_data_present)) + return; + + desc.qw0 = QI_PGRP_PASID(req->pasid) | + QI_PGRP_DID(req->rid) | + QI_PGRP_PASID_P(req->pasid_present) | + QI_PGRP_PDP(req->priv_data_present) | + QI_PGRP_RESP_CODE(result) | + QI_PGRP_RESP_TYPE; + desc.qw1 = QI_PGRP_IDX(req->prg_index) | + QI_PGRP_LPIG(req->lpig); + desc.qw2 = 0; + desc.qw3 = 0; + + if (req->priv_data_present) + memcpy(&desc.qw2, req->priv_data, sizeof(req->priv_data)); + + qi_submit_sync(iommu, &desc, 1, 0); +} + 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; - int head, tail, handled = 0; - unsigned int flags = 0; + struct page_req_dsc *req; + int head, tail, handled; + u64 address; - /* Clear PPR bit before reading head/tail registers, to - * ensure that we get a new interrupt if needed. */ + /* + * Clear PPR bit before reading head/tail registers, to ensure that + * we get a new interrupt if needed. + */ writel(DMA_PRS_PPR, iommu->reg + DMAR_PRS_REG); tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK; head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK; + handled = (head != tail); while (head != tail) { - struct vm_area_struct *vma; - struct page_req_dsc *req; - struct qi_desc resp; - int result; - vm_fault_t ret; - u64 address; - - handled = 1; req = &iommu->prq[head / sizeof(*req)]; - result = QI_RESP_INVALID; address = (u64)req->addr << VTD_PAGE_SHIFT; - if (!req->pasid_present) { - pr_err("%s: Page request without PASID: %08llx %08llx\n", - iommu->name, ((unsigned long long *)req)[0], - ((unsigned long long *)req)[1]); - goto no_pasid; + + if (unlikely(!req->pasid_present)) { + 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; } - /* We shall not receive page request for supervisor SVM */ - if (req->pm_req && (req->rd_req | req->wr_req)) { - pr_err("Unexpected page request in Privilege Mode"); - /* No need to find the matching sdev as for bad_req */ - goto no_pasid; + + if (unlikely(!is_canonical_address(address))) { + pr_err("IOMMU: %s: Address is not canonical\n", + iommu->name); + goto bad_req; + } + + if (unlikely(req->pm_req && (req->rd_req | req->wr_req))) { + pr_err("IOMMU: %s: Page request in Privilege Mode\n", + iommu->name); + goto bad_req; } - /* DMA read with exec requeset is not supported. */ - if (req->exe_req && req->rd_req) { - pr_err("Execution request not supported\n"); - goto no_pasid; + + if (unlikely(req->exe_req && req->rd_req)) { + pr_err("IOMMU: %s: Execution request not supported\n", + iommu->name); + goto bad_req; } + if (!svm || svm->pasid != req->pasid) { - rcu_read_lock(); - svm = pasid_private_find(req->pasid); - /* It *can't* go away, because the driver is not permitted + /* + * It can't go away, because the driver is not permitted * to unbind the mm while any page faults are outstanding. - * So we only need RCU to protect the internal idr code. */ - rcu_read_unlock(); - if (IS_ERR_OR_NULL(svm)) { - pr_err("%s: Page request for invalid PASID %d: %08llx %08llx\n", - iommu->name, req->pasid, ((unsigned long long *)req)[0], - ((unsigned long long *)req)[1]); - goto no_pasid; - } + */ + 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) + if (!sdev || sdev->sid != req->rid) { sdev = svm_lookup_device_by_sid(svm, req->rid); - - /* Since we're using init_mm.pgd directly, we should never take - * any faults on kernel addresses. */ - if (!svm->mm) - goto bad_req; - - /* If address is not canonical, return invalid response */ - if (!is_canonical_address(address)) - goto bad_req; + if (!sdev) + goto bad_req; + } /* * If prq is to be handled outside iommu driver via receiver of * the fault notifiers, we skip the page response here. */ if (svm->flags & SVM_FLAG_GUEST_MODE) { - if (sdev && !intel_svm_prq_report(sdev->dev, req)) + if (!intel_svm_prq_report(sdev->dev, req)) goto prq_advance; else goto bad_req; } - /* If the mm is already defunct, don't handle faults. */ - if (!mmget_not_zero(svm->mm)) - goto bad_req; - - mmap_read_lock(svm->mm); - vma = find_extend_vma(svm->mm, address); - if (!vma || address < vma->vm_start) - goto invalid; - - if (access_error(vma, req)) - goto invalid; - - flags = FAULT_FLAG_USER | FAULT_FLAG_REMOTE; - if (req->wr_req) - flags |= FAULT_FLAG_WRITE; - - ret = handle_mm_fault(vma, address, flags, NULL); - if (ret & VM_FAULT_ERROR) - goto invalid; - - result = QI_RESP_SUCCESS; -invalid: - mmap_read_unlock(svm->mm); - mmput(svm->mm); -bad_req: - /* We get here in the error case where the PASID lookup failed, - and these can be NULL. Do not use them below this point! */ - sdev = NULL; - svm = NULL; -no_pasid: - if (req->lpig || req->priv_data_present) { - /* - * Per VT-d spec. v3.0 ch7.7, system software must - * respond with page group response if private data - * is present (PDP) or last page in group (LPIG) bit - * is set. This is an additional VT-d feature beyond - * PCI ATS spec. - */ - resp.qw0 = QI_PGRP_PASID(req->pasid) | - QI_PGRP_DID(req->rid) | - QI_PGRP_PASID_P(req->pasid_present) | - QI_PGRP_PDP(req->priv_data_present) | - QI_PGRP_RESP_CODE(result) | - QI_PGRP_RESP_TYPE; - resp.qw1 = QI_PGRP_IDX(req->prg_index) | - QI_PGRP_LPIG(req->lpig); - resp.qw2 = 0; - resp.qw3 = 0; - - if (req->priv_data_present) - memcpy(&resp.qw2, req->priv_data, - sizeof(req->priv_data)); - qi_submit_sync(iommu, &resp, 1, 0); - } + handle_single_prq_event(iommu, svm->mm, req); prq_advance: head = (head + sizeof(*req)) & PRQ_RING_MASK; } -- 2.25.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
