Move the software processing page request descriptors part from prq_event_thread() into a separated function. No any functional changes.
Signed-off-by: Lu Baolu <[email protected]> --- drivers/iommu/intel-svm.c | 256 ++++++++++++++++++++------------------ 1 file changed, 135 insertions(+), 121 deletions(-) diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c index 83dc4319f661..a1921b462783 100644 --- a/drivers/iommu/intel-svm.c +++ b/drivers/iommu/intel-svm.c @@ -722,142 +722,156 @@ static bool is_canonical_address(u64 addr) return (((saddr << shift) >> shift) == saddr); } -static irqreturn_t prq_event_thread(int irq, void *d) +static void process_single_prq(struct intel_iommu *iommu, + struct page_req_dsc *req) { - struct intel_iommu *iommu = d; - struct intel_svm *svm = NULL; - int head, tail, handled = 0; - - /* 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; - while (head != tail) { - struct intel_svm_dev *sdev; - 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)]; + int result = QI_RESP_FAILURE; + struct intel_svm_dev *sdev; + struct vm_area_struct *vma; + struct intel_svm *svm; + struct qi_desc resp; + vm_fault_t ret; + u64 address; + + 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; + } - result = QI_RESP_FAILURE; - 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; - } + rcu_read_lock(); + svm = ioasid_find(NULL, req->pasid, NULL); + /* + * 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 (!svm || svm->pasid != req->pasid) { - rcu_read_lock(); - svm = ioasid_find(NULL, req->pasid, NULL); - /* 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; - } - } + 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; + } - result = QI_RESP_INVALID; - /* Since we're using init_mm.pgd directly, we should never take - * any faults on kernel addresses. */ - if (!svm->mm) - goto bad_req; + result = QI_RESP_INVALID; + /* 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 the mm is already defunct, don't handle faults. */ + if (!mmget_not_zero(svm->mm)) + goto bad_req; + + down_read(&svm->mm->mmap_sem); + vma = find_extend_vma(svm->mm, address); + if (!vma || address < vma->vm_start) + goto invalid; + + if (access_error(vma, req)) + goto invalid; + + ret = handle_mm_fault(vma, address, + req->wr_req ? FAULT_FLAG_WRITE : 0); + if (ret & VM_FAULT_ERROR) + goto invalid; + + result = QI_RESP_SUCCESS; +invalid: + up_read(&svm->mm->mmap_sem); + mmput(svm->mm); +bad_req: + /* Accounting for major/minor faults? */ + rcu_read_lock(); + list_for_each_entry_rcu(sdev, &svm->devs, list) { + if (sdev->sid == req->rid) + break; + } - /* If address is not canonical, return invalid response */ - if (!is_canonical_address(address)) - goto bad_req; + /* Other devices can go away, but the drivers are not permitted + * to unbind while any page faults might be in flight. So it's + * OK to drop the 'lock' here now we have it. */ + rcu_read_unlock(); - /* If the mm is already defunct, don't handle faults. */ - if (!mmget_not_zero(svm->mm)) - goto bad_req; + if (WARN_ON(&sdev->list == &svm->devs)) + sdev = NULL; - down_read(&svm->mm->mmap_sem); - vma = find_extend_vma(svm->mm, address); - if (!vma || address < vma->vm_start) - goto invalid; + if (sdev && sdev->ops && sdev->ops->fault_cb) { + int rwxp = (req->rd_req << 3) | (req->wr_req << 2) | + (req->exe_req << 1) | (req->pm_req); + sdev->ops->fault_cb(sdev->dev, req->pasid, req->addr, + req->priv_data, rwxp, result); + } - if (access_error(vma, req)) - goto invalid; + /* 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->pasid_present) | + QI_PGRP_RESP_CODE(result) | + QI_PGRP_RESP_TYPE; + resp.qw1 = QI_PGRP_IDX(req->prg_index) | + QI_PGRP_LPIG(req->lpig); + + if (req->priv_data_present) + memcpy(&resp.qw2, req->priv_data, + sizeof(req->priv_data)); + resp.qw2 = 0; + resp.qw3 = 0; + qi_submit_sync(iommu, &resp, 1, 0); + } +} - ret = handle_mm_fault(vma, address, - req->wr_req ? FAULT_FLAG_WRITE : 0); - if (ret & VM_FAULT_ERROR) - goto invalid; +static void intel_svm_process_prq(struct intel_iommu *iommu, + struct page_req_dsc *prq, + int head, int tail) +{ + struct page_req_dsc *req; - result = QI_RESP_SUCCESS; - invalid: - up_read(&svm->mm->mmap_sem); - mmput(svm->mm); - bad_req: - /* Accounting for major/minor faults? */ - rcu_read_lock(); - list_for_each_entry_rcu(sdev, &svm->devs, list) { - if (sdev->sid == req->rid) - break; - } - /* Other devices can go away, but the drivers are not permitted - * to unbind while any page faults might be in flight. So it's - * OK to drop the 'lock' here now we have it. */ - rcu_read_unlock(); - - if (WARN_ON(&sdev->list == &svm->devs)) - sdev = NULL; - - if (sdev && sdev->ops && sdev->ops->fault_cb) { - int rwxp = (req->rd_req << 3) | (req->wr_req << 2) | - (req->exe_req << 1) | (req->pm_req); - sdev->ops->fault_cb(sdev->dev, req->pasid, req->addr, - req->priv_data, rwxp, result); - } - /* 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->pasid_present) | - QI_PGRP_RESP_CODE(result) | - QI_PGRP_RESP_TYPE; - resp.qw1 = QI_PGRP_IDX(req->prg_index) | - QI_PGRP_LPIG(req->lpig); - - if (req->priv_data_present) - memcpy(&resp.qw2, req->priv_data, - sizeof(req->priv_data)); - resp.qw2 = 0; - resp.qw3 = 0; - qi_submit_sync(iommu, &resp, 1, 0); - } + while (head != tail) { + req = &iommu->prq[head / sizeof(*req)]; + process_single_prq(iommu, req); head = (head + sizeof(*req)) & PRQ_RING_MASK; } +} + +static irqreturn_t prq_event_thread(int irq, void *d) +{ + struct intel_iommu *iommu = d; + int head, tail; + /* + * 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; + intel_svm_process_prq(iommu, iommu->prq, head, tail); dmar_writeq(iommu->reg + DMAR_PQH_REG, tail); - return IRQ_RETVAL(handled); + return IRQ_RETVAL(1); } #define to_intel_svm_dev(handle) container_of(handle, struct intel_svm_dev, sva) -- 2.17.1 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
