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>

1 files changed, 66 insertions, 76 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index fffe3d166662..67b114e784bc 100644
--- 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);