iommu/vt-d: Simplify function get_domain_for_dev()

Function get_domain_for_dev() is a little complex, simplify it
by factoring out dmar_search_domain_by_dev_info() and
dmar_insert_dev_info().

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index fffe3d166662d0114c8c12fd5f7cbbd37a405113..67b114e784bc74bcbfd7928bb6f6e3ba9f9a85e9 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1957,18 +1957,71 @@ find_domain(struct pci_dev *pdev)
        return NULL;
 }
 
+static inline struct dmar_domain *
+dmar_search_domain_by_dev_info(int segment, int bus, int devfn)
+{
+       struct device_domain_info *info;
+
+       list_for_each_entry(info, &device_domain_list, global)
+               if (info->segment == segment && info->bus == bus &&
+                   info->devfn == devfn)
+                       return info->domain;
+
+       return NULL;
+}
+
+static int dmar_insert_dev_info(int segment, int bus, int devfn,
+                               struct pci_dev *dev, struct dmar_domain **domp)
+{
+       struct dmar_domain *found, *domain = *domp;
+       struct device_domain_info *info;
+       unsigned long flags;
+
+       info = alloc_devinfo_mem();
+       if (!info)
+               return -ENOMEM;
+
+       info->segment = segment;
+       info->bus = bus;
+       info->devfn = devfn;
+       info->dev = dev;
+       info->domain = domain;
+       if (!dev)
+               domain->flags |= DOMAIN_FLAG_P2P_MULTIPLE_DEVICES;
+
+       spin_lock_irqsave(&device_domain_lock, flags);
+       if (dev)
+               found = find_domain(dev);
+       else
+               found = dmar_search_domain_by_dev_info(segment, bus, devfn);
+       if (found) {
+               spin_unlock_irqrestore(&device_domain_lock, flags);
+               free_devinfo_mem(info);
+               if (found != domain) {
+                       domain_exit(domain);
+                       *domp = found;
+               }
+       } else {
+               list_add(&info->link, &domain->devices);
+               list_add(&info->global, &device_domain_list);
+               if (dev)
+                       dev->dev.archdata.iommu = info;
+               spin_unlock_irqrestore(&device_domain_lock, flags);
+       }
+
+       return 0;
+}
+
 /* domain is initialized */
 static struct dmar_domain *get_domain_for_dev(struct pci_dev *pdev, int gaw)
 {
-       struct dmar_domain *domain, *found = NULL;
+       struct dmar_domain *domain;
        struct intel_iommu *iommu;
        struct dmar_drhd_unit *drhd;
-       struct device_domain_info *info, *tmp;
        struct pci_dev *dev_tmp;
        unsigned long flags;
        int bus = 0, devfn = 0;
        int segment;
-       int ret;
 
        domain = find_domain(pdev);
        if (domain)
@@ -1986,41 +2039,29 @@ static struct dmar_domain *get_domain_for_dev(struct pci_dev *pdev, int gaw)
                        devfn = dev_tmp->devfn;
                }
                spin_lock_irqsave(&device_domain_lock, flags);
-               list_for_each_entry(info, &device_domain_list, global) {
-                       if (info->segment == segment &&
-                           info->bus == bus && info->devfn == devfn) {
-                               found = info->domain;
-                               break;
-                       }
-               }
+               domain = dmar_search_domain_by_dev_info(segment, bus, devfn);
                spin_unlock_irqrestore(&device_domain_lock, flags);
                /* pcie-pci bridge already has a domain, uses it */
-               if (found) {
-                       domain = found;
+               if (domain)
                        goto found_domain;
-               }
        }
 
-       domain = alloc_domain();
-       if (!domain)
-               goto error;
-
-       /* Allocate new domain for the device */
        drhd = dmar_find_matched_drhd_unit(pdev);
        if (!drhd) {
                printk(KERN_ERR "IOMMU: can't find DMAR for device %s\n",
                        pci_name(pdev));
-               free_domain_mem(domain);
                return NULL;
        }
        iommu = drhd->iommu;
 
-       ret = iommu_attach_domain(domain, iommu);
-       if (ret) {
+       /* Allocate and intialize new domain for the device */
+       domain = alloc_domain();
+       if (!domain)
+               goto error;
+       if (iommu_attach_domain(domain, iommu)) {
                free_domain_mem(domain);
                goto error;
        }
-
        if (domain_init(domain, gaw)) {
                domain_exit(domain);
                goto error;
@@ -2028,67 +2069,16 @@ static struct dmar_domain *get_domain_for_dev(struct pci_dev *pdev, int gaw)
 
        /* register pcie-to-pci device */
        if (dev_tmp) {
-               info = alloc_devinfo_mem();
-               if (!info) {
+               if (dmar_insert_dev_info(segment, bus, devfn, NULL, &domain)) {
                        domain_exit(domain);
                        goto error;
                }
-               info->segment = segment;
-               info->bus = bus;
-               info->devfn = devfn;
-               info->dev = NULL;
-               info->domain = domain;
-               /* This domain is shared by devices under p2p bridge */
-               domain->flags |= DOMAIN_FLAG_P2P_MULTIPLE_DEVICES;
-
-               /* pcie-to-pci bridge already has a domain, uses it */
-               found = NULL;
-               spin_lock_irqsave(&device_domain_lock, flags);
-               list_for_each_entry(tmp, &device_domain_list, global) {
-                       if (tmp->segment == segment &&
-                           tmp->bus == bus && tmp->devfn == devfn) {
-                               found = tmp->domain;
-                               break;
-                       }
-               }
-               if (found) {
-                       spin_unlock_irqrestore(&device_domain_lock, flags);
-                       free_devinfo_mem(info);
-                       domain_exit(domain);
-                       domain = found;
-               } else {
-                       list_add(&info->link, &domain->devices);
-                       list_add(&info->global, &device_domain_list);
-                       spin_unlock_irqrestore(&device_domain_lock, flags);
-               }
        }
 
 found_domain:
-       info = alloc_devinfo_mem();
-       if (!info)
-               goto error;
-       info->segment = segment;
-       info->bus = pdev->bus->number;
-       info->devfn = pdev->devfn;
-       info->dev = pdev;
-       info->domain = domain;
-       spin_lock_irqsave(&device_domain_lock, flags);
-       /* somebody is fast */
-       found = find_domain(pdev);
-       if (found != NULL) {
-               spin_unlock_irqrestore(&device_domain_lock, flags);
-               if (found != domain) {
-                       domain_exit(domain);
-                       domain = found;
-               }
-               free_devinfo_mem(info);
+       if (dmar_insert_dev_info(segment, pdev->bus->number, pdev->devfn,
+                                pdev, &domain) == 0)
                return domain;
-       }
-       list_add(&info->link, &domain->devices);
-       list_add(&info->global, &device_domain_list);
-       pdev->dev.archdata.iommu = info;
-       spin_unlock_irqrestore(&device_domain_lock, flags);
-       return domain;
 error:
        /* recheck it here, maybe others set it */
        return find_domain(pdev);