iommu/vt-d: Remove unnecessary domain_context_mapped()

The device_domain_info::domain accurately records the domain attached to
the device. It is unnecessary to check whether the context is present in
the attach_dev path. Remove it to make the code neat.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20221118132451.114406-7-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 3bd79ae238f2d05f21cb9f221bd463f2bac1e992..3b37f1b3b6deb2b862a1ad363bb1f695a0ea1fc3 100644 (file)
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -780,19 +780,6 @@ static void domain_flush_cache(struct dmar_domain *domain,
                clflush_cache_range(addr, size);
 }
 
-static int device_context_mapped(struct intel_iommu *iommu, u8 bus, u8 devfn)
-{
-       struct context_entry *context;
-       int ret = 0;
-
-       spin_lock(&iommu->lock);
-       context = iommu_context_addr(iommu, bus, devfn, 0);
-       if (context)
-               ret = context_present(context);
-       spin_unlock(&iommu->lock);
-       return ret;
-}
-
 static void free_context_table(struct intel_iommu *iommu)
 {
        struct context_entry *context;
@@ -2097,30 +2084,6 @@ domain_context_mapping(struct dmar_domain *domain, struct device *dev)
                                      &domain_context_mapping_cb, &data);
 }
 
-static int domain_context_mapped_cb(struct pci_dev *pdev,
-                                   u16 alias, void *opaque)
-{
-       struct intel_iommu *iommu = opaque;
-
-       return !device_context_mapped(iommu, PCI_BUS_NUM(alias), alias & 0xff);
-}
-
-static int domain_context_mapped(struct device *dev)
-{
-       struct intel_iommu *iommu;
-       u8 bus, devfn;
-
-       iommu = device_to_iommu(dev, &bus, &devfn);
-       if (!iommu)
-               return -ENODEV;
-
-       if (!dev_is_pci(dev))
-               return device_context_mapped(iommu, bus, devfn);
-
-       return !pci_for_each_dma_alias(to_pci_dev(dev),
-                                      domain_context_mapped_cb, iommu);
-}
-
 /* Returns a number of VTD pages, but aligned to MM page size */
 static inline unsigned long aligned_nrpages(unsigned long host_addr,
                                            size_t size)
@@ -4269,6 +4232,7 @@ static int prepare_domain_attach_device(struct iommu_domain *domain,
 static int intel_iommu_attach_device(struct iommu_domain *domain,
                                     struct device *dev)
 {
+       struct device_domain_info *info = dev_iommu_priv_get(dev);
        int ret;
 
        if (domain->type == IOMMU_DOMAIN_UNMANAGED &&
@@ -4277,13 +4241,8 @@ static int intel_iommu_attach_device(struct iommu_domain *domain,
                return -EPERM;
        }
 
-       /* normally dev is not mapped */
-       if (unlikely(domain_context_mapped(dev))) {
-               struct device_domain_info *info = dev_iommu_priv_get(dev);
-
-               if (info->domain)
-                       device_block_translation(dev);
-       }
+       if (info->domain)
+               device_block_translation(dev);
 
        ret = prepare_domain_attach_device(domain, dev);
        if (ret)