iommu/vt-d: Allocate dynamic domain id for virtual domains only

[cascardo/linux.git] / drivers / iommu / intel-iommu.c

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index eae9b0d..968e3d3 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1549,15 +1549,27 @@ static int iommu_attach_domain(struct dmar_domain *domain,
 
        spin_lock_irqsave(&iommu->lock, flags);
        num = __iommu_attach_domain(domain, iommu);
+       spin_unlock_irqrestore(&iommu->lock, flags);
        if (num < 0)
                pr_err("IOMMU: no free domain ids\n");
-       else
-               domain->id = num;
-       spin_unlock_irqrestore(&iommu->lock, flags);
 
        return num;
 }
 
+static int iommu_attach_vm_domain(struct dmar_domain *domain,
+                                 struct intel_iommu *iommu)
+{
+       int num;
+       unsigned long ndomains;
+
+       ndomains = cap_ndoms(iommu->cap);
+       for_each_set_bit(num, iommu->domain_ids, ndomains)
+               if (iommu->domains[num] == domain)
+                       return num;
+
+       return __iommu_attach_domain(domain, iommu);
+}
+
 static void iommu_detach_domain(struct dmar_domain *domain,
                                struct intel_iommu *iommu)
 {
@@ -1764,8 +1776,6 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
        struct context_entry *context;
        unsigned long flags;
        struct dma_pte *pgd;
-       unsigned long num;
-       unsigned long ndomains;
        int id;
        int agaw;
        struct device_domain_info *info = NULL;
@@ -1790,20 +1800,8 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
        pgd = domain->pgd;
 
        if (domain_type_is_vm_or_si(domain)) {
-               int found = 0;
-
-               /* find an available domain id for this device in iommu */
-               ndomains = cap_ndoms(iommu->cap);
-               for_each_set_bit(num, iommu->domain_ids, ndomains) {
-                       if (iommu->domains[num] == domain) {
-                               id = num;
-                               found = 1;
-                               break;
-                       }
-               }
-
-               if (found == 0) {
-                       id = __iommu_attach_domain(domain, iommu);
+               if (domain_type_is_vm(domain)) {
+                       id = iommu_attach_vm_domain(domain, iommu);
                        if (id < 0) {
                                spin_unlock_irqrestore(&iommu->lock, flags);
                                pr_err("IOMMU: no free domain ids\n");
@@ -2257,8 +2255,8 @@ static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw)
        domain = alloc_domain(0);
        if (!domain)
                return NULL;
-
-       if (iommu_attach_domain(domain, iommu) < 0) {
+       domain->id = iommu_attach_domain(domain, iommu);
+       if (domain->id < 0) {
                free_domain_mem(domain);
                return NULL;
        }
@@ -2428,6 +2426,7 @@ static int __init si_domain_init(int hw)
        struct dmar_drhd_unit *drhd;
        struct intel_iommu *iommu;
        int nid, ret = 0;
+       bool first = true;
 
        si_domain = alloc_domain(DOMAIN_FLAG_STATIC_IDENTITY);
        if (!si_domain)
@@ -2438,6 +2437,12 @@ static int __init si_domain_init(int hw)
                if (ret < 0) {
                        domain_exit(si_domain);
                        return -EFAULT;
+               } else if (first) {
+                       si_domain->id = ret;
+                       first = false;
+               } else if (si_domain->id != ret) {
+                       domain_exit(si_domain);
+                       return -EFAULT;
                }
                domain_attach_iommu(si_domain, iommu);
        }