AMD IOMMU: set iommu sunc flag after command queuing

The iommu->need_sync flag must be set after the command is queued to
avoid race conditions.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 8 insertions, 2 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 69b4d060b21c..a96d8c049a88 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -140,6 +140,7 @@ static int iommu_completion_wait(struct amd_iommu *iommu)
 static int iommu_queue_inv_dev_entry(struct amd_iommu *iommu, u16 devid)
 {
         struct iommu_cmd cmd;
+        int ret;
 
         BUG_ON(iommu == NULL);
 
@@ -147,9 +148,11 @@ static int iommu_queue_inv_dev_entry(struct amd_iommu *iommu, u16 devid)
         CMD_SET_TYPE(&cmd, CMD_INV_DEV_ENTRY);
         cmd.data[0] = devid;
 
+        ret = iommu_queue_command(iommu, &cmd);
+
         iommu->need_sync = 1;
 
-        return iommu_queue_command(iommu, &cmd);
+        return ret;
 }
 
 /*
@@ -159,6 +162,7 @@ static int iommu_queue_inv_iommu_pages(struct amd_iommu *iommu,
                 u64 address, u16 domid, int pde, int s)
 {
         struct iommu_cmd cmd;
+        int ret;
 
         memset(&cmd, 0, sizeof(cmd));
         address &= PAGE_MASK;
@@ -171,9 +175,11 @@ static int iommu_queue_inv_iommu_pages(struct amd_iommu *iommu,
         if (pde) /* PDE bit - we wan't flush everything not only the PTEs */
                 cmd.data[2] |= CMD_INV_IOMMU_PAGES_PDE_MASK;
 
+        ret = iommu_queue_command(iommu, &cmd);
+
         iommu->need_sync = 1;
 
-        return iommu_queue_command(iommu, &cmd);
+        return ret;
 }
 
 /*