iommu/amd: Make sure iommu->need_sync contains correct value

commit f1ca1512e765337a7c09eb875eedef8ea4e07654 upstream.

The value is only set to true but never set back to false,
which causes to many completion-wait commands to be sent to
hardware. Fix it with this patch.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 7b4381154dae78083764db5384799310eac72101..d3d9d50d93a549e7a2fe0981c3dcaf0a03d185da 100644 (file)
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -531,7 +531,9 @@ static void build_inv_all(struct iommu_cmd *cmd)
  * Writes the command to the IOMMUs command buffer and informs the
  * hardware about the new command.
  */
-static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
+static int iommu_queue_command_sync(struct amd_iommu *iommu,
+                                   struct iommu_cmd *cmd,
+                                   bool sync)
 {
        u32 left, tail, head, next_tail;
        unsigned long flags;
@@ -565,13 +567,18 @@ again:
        copy_cmd_to_buffer(iommu, cmd, tail);
 
        /* We need to sync now to make sure all commands are processed */
-       iommu->need_sync = true;
+       iommu->need_sync = sync;
 
        spin_unlock_irqrestore(&iommu->lock, flags);
 
        return 0;
 }
 
+static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
+{
+       return iommu_queue_command_sync(iommu, cmd, true);
+}
+
 /*
  * This function queues a completion wait command into the command
  * buffer of an IOMMU
@@ -587,7 +594,7 @@ static int iommu_completion_wait(struct amd_iommu *iommu)
 
        build_completion_wait(&cmd, (u64)&sem);
 
-       ret = iommu_queue_command(iommu, &cmd);
+       ret = iommu_queue_command_sync(iommu, &cmd, false);
        if (ret)
                return ret;