iommu/vt-d: Move PRI handling to IOPF feature path

PRI is only used for IOPF. With this move, the PCI/PRI feature could be
controlled by the device driver through iommu_dev_enable/disable_feature()
interfaces.

Reviewed-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20230324120234.313643-6-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 6d77b40..cd3a3c4 100644 (file)
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1415,11 +1415,6 @@ static void iommu_enable_pci_caps(struct device_domain_info *info)
        if (info->pasid_supported && !pci_enable_pasid(pdev, info->pasid_supported & ~1))
                info->pasid_enabled = 1;
 
-       if (info->pri_supported &&
-           (info->pasid_enabled ? pci_prg_resp_pasid_required(pdev) : 1)  &&
-           !pci_reset_pri(pdev) && !pci_enable_pri(pdev, PRQ_DEPTH))
-               info->pri_enabled = 1;
-
        if (info->ats_supported && pci_ats_page_aligned(pdev) &&
            !pci_enable_ats(pdev, VTD_PAGE_SHIFT)) {
                info->ats_enabled = 1;
@@ -1442,11 +1437,6 @@ static void iommu_disable_pci_caps(struct device_domain_info *info)
                domain_update_iotlb(info->domain);
        }
 
-       if (info->pri_enabled) {
-               pci_disable_pri(pdev);
-               info->pri_enabled = 0;
-       }
-
        if (info->pasid_enabled) {
                pci_disable_pasid(pdev);
                info->pasid_enabled = 0;
@@ -4667,23 +4657,48 @@ static int intel_iommu_enable_sva(struct device *dev)
 
 static int intel_iommu_enable_iopf(struct device *dev)
 {
+       struct pci_dev *pdev = dev_is_pci(dev) ? to_pci_dev(dev) : NULL;
        struct device_domain_info *info = dev_iommu_priv_get(dev);
        struct intel_iommu *iommu;
        int ret;
 
-       if (!info || !info->ats_enabled || !info->pri_enabled)
+       if (!pdev || !info || !info->ats_enabled || !info->pri_supported)
                return -ENODEV;
+
+       if (info->pri_enabled)
+               return -EBUSY;
+
        iommu = info->iommu;
        if (!iommu)
                return -EINVAL;
 
+       /* PASID is required in PRG Response Message. */
+       if (info->pasid_enabled && !pci_prg_resp_pasid_required(pdev))
+               return -EINVAL;
+
+       ret = pci_reset_pri(pdev);
+       if (ret)
+               return ret;
+
        ret = iopf_queue_add_device(iommu->iopf_queue, dev);
        if (ret)
                return ret;
 
        ret = iommu_register_device_fault_handler(dev, iommu_queue_iopf, dev);
        if (ret)
-               iopf_queue_remove_device(iommu->iopf_queue, dev);
+               goto iopf_remove_device;
+
+       ret = pci_enable_pri(pdev, PRQ_DEPTH);
+       if (ret)
+               goto iopf_unregister_handler;
+       info->pri_enabled = 1;
+
+       return 0;
+
+iopf_unregister_handler:
+       iommu_unregister_device_fault_handler(dev);
+iopf_remove_device:
+       iopf_queue_remove_device(iommu->iopf_queue, dev);
 
        return ret;
 }
@@ -4694,6 +4709,20 @@ static int intel_iommu_disable_iopf(struct device *dev)
        struct intel_iommu *iommu = info->iommu;
        int ret;
 
+       if (!info->pri_enabled)
+               return -EINVAL;
+
+       /*
+        * PCIe spec states that by clearing PRI enable bit, the Page
+        * Request Interface will not issue new page requests, but has
+        * outstanding page requests that have been transmitted or are
+        * queued for transmission. This is supposed to be called after
+        * the device driver has stopped DMA, all PASIDs have been
+        * unbound and the outstanding PRQs have been drained.
+        */
+       pci_disable_pri(to_pci_dev(dev));
+       info->pri_enabled = 0;
+
        ret = iommu_unregister_device_fault_handler(dev);
        if (ret)
                return ret;