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Date: Thu, 20 May 2021 11:15:24 +0800
From: Lu Baolu <baolu.lu@...ux.intel.com>
To: Joerg Roedel <joro@...tes.org>
Cc: ashok.raj@...el.com, kevin.tian@...el.com, jacob.jun.pan@...el.com,
Jean-Philippe Brucker <jean-philippe@...aro.org>,
iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
Lu Baolu <baolu.lu@...ux.intel.com>
Subject: [PATCH 04/11] iommu/vt-d: Refactor prq_event_thread()
Refactor prq_event_thread() by moving handling single prq event out of
the main loop.
Signed-off-by: Lu Baolu <baolu.lu@...ux.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
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