x86/amd-iommu: Align locking between attach_device and detach_device

This patch makes the locking behavior between the functions
attach_device and __attach_device consistent with the
locking behavior between detach_device and __detach_device.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 14 insertions, 5 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 2b1e77c714ff..9aa135d4453f 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -1077,29 +1077,38 @@ static void __attach_device(struct amd_iommu *iommu,
                             struct protection_domain *domain,
                             u16 devid)
 {
-        unsigned long flags;
-        u64 pte_root = virt_to_phys(domain->pt_root);
+        u64 pte_root;
 
-        domain->dev_cnt += 1;
+        /* lock domain */
+        spin_lock(&domain->lock);
+
+        pte_root = virt_to_phys(domain->pt_root);
 
         pte_root |= (domain->mode & DEV_ENTRY_MODE_MASK)
                     << DEV_ENTRY_MODE_SHIFT;
         pte_root |= IOMMU_PTE_IR | IOMMU_PTE_IW | IOMMU_PTE_P | IOMMU_PTE_TV;
 
-        write_lock_irqsave(&amd_iommu_devtable_lock, flags);
         amd_iommu_dev_table[devid].data[2] = domain->id;
         amd_iommu_dev_table[devid].data[1] = upper_32_bits(pte_root);
         amd_iommu_dev_table[devid].data[0] = lower_32_bits(pte_root);
 
         amd_iommu_pd_table[devid] = domain;
-        write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+
+        domain->dev_cnt += 1;
+
+        /* ready */
+        spin_unlock(&domain->lock);
 }
 
 static void attach_device(struct amd_iommu *iommu,
                           struct protection_domain *domain,
                           u16 devid)
 {
+        unsigned long flags;
+
+        write_lock_irqsave(&amd_iommu_devtable_lock, flags);
         __attach_device(iommu, domain, devid);
+        write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
 
         /*
          * We might boot into a crash-kernel here. The crashed kernel