[RFC 7/8] iommu/vt-d: Implement add_reserved_regions callback

[Eric Auger]

Implement the add_reserved_regions callback by registering
the [FEE0_0000h - FEF0_000h] 1MB range as a reserved region
(MSI address space).

Signed-off-by: Eric Auger <eric.au...@redhat.com>
---
 drivers/iommu/intel-iommu.c | 48 +++++++++++++++++++++++++++++++++------------
 1 file changed, 35 insertions(+), 13 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index a4407ea..fb64418 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5173,6 +5173,27 @@ static void intel_iommu_remove_device(struct device *dev)
        iommu_device_unlink(iommu->iommu_dev, dev);
 }
 
+static int intel_add_reserved_regions(struct iommu_domain *domain,
+                                     struct device *device)
+{
+       struct iommu_reserved_region *region;
+       const dma_addr_t msi_base = 0xfee00000;
+       const size_t msi_length = 0x00100000;
+
+       iommu_reserved_region_for_each(region, domain) {
+               if (region->start == msi_base && region->length == msi_length)
+                       continue;
+       }
+       region = kzalloc(sizeof(*region), GFP_KERNEL);
+       if (!region)
+               return -ENOMEM;
+
+       region->start  = msi_base;
+       region->length = msi_length;
+       list_add_tail(&region->list, &domain->reserved_regions);
+       return 0;
+}
+
 #ifdef CONFIG_INTEL_IOMMU_SVM
 int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct intel_svm_dev 
*sdev)
 {
@@ -5282,19 +5303,20 @@ struct intel_iommu *intel_svm_device_to_iommu(struct 
device *dev)
 #endif /* CONFIG_INTEL_IOMMU_SVM */
 
 static const struct iommu_ops intel_iommu_ops = {
-       .capable        = intel_iommu_capable,
-       .domain_alloc   = intel_iommu_domain_alloc,
-       .domain_free    = intel_iommu_domain_free,
-       .attach_dev     = intel_iommu_attach_device,
-       .detach_dev     = intel_iommu_detach_device,
-       .map            = intel_iommu_map,
-       .unmap          = intel_iommu_unmap,
-       .map_sg         = default_iommu_map_sg,
-       .iova_to_phys   = intel_iommu_iova_to_phys,
-       .add_device     = intel_iommu_add_device,
-       .remove_device  = intel_iommu_remove_device,
-       .device_group   = pci_device_group,
-       .pgsize_bitmap  = INTEL_IOMMU_PGSIZES,
+       .capable                = intel_iommu_capable,
+       .domain_alloc           = intel_iommu_domain_alloc,
+       .domain_free            = intel_iommu_domain_free,
+       .attach_dev             = intel_iommu_attach_device,
+       .detach_dev             = intel_iommu_detach_device,
+       .map                    = intel_iommu_map,
+       .unmap                  = intel_iommu_unmap,
+       .map_sg                 = default_iommu_map_sg,
+       .iova_to_phys           = intel_iommu_iova_to_phys,
+       .add_device             = intel_iommu_add_device,
+       .remove_device          = intel_iommu_remove_device,
+       .add_reserved_regions   = intel_iommu_add_reserved_regions,
+       .device_group           = pci_device_group,
+       .pgsize_bitmap          = INTEL_IOMMU_PGSIZES,
 };
 
 static void quirk_iommu_g4x_gfx(struct pci_dev *dev)
-- 
1.9.1