Merge tag 'iommu-updates-v4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/joro...

[cascardo/linux.git] / drivers / iommu / amd_iommu.c

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index a2479d0..754595e 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1008,15 +1008,13 @@ static void build_inv_irt(struct iommu_cmd *cmd, u16 devid)
  * Writes the command to the IOMMUs command buffer and informs the
  * hardware about the new command.
  */
-static int iommu_queue_command_sync(struct amd_iommu *iommu,
-                                   struct iommu_cmd *cmd,
-                                   bool sync)
+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;
 
 again:
-       spin_lock_irqsave(&iommu->lock, flags);
 
        head      = readl(iommu->mmio_base + MMIO_CMD_HEAD_OFFSET);
        tail      = readl(iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);
@@ -1025,15 +1023,14 @@ again:
 
        if (left <= 2) {
                struct iommu_cmd sync_cmd;
-               volatile u64 sem = 0;
                int ret;
 
-               build_completion_wait(&sync_cmd, (u64)&sem);
-               copy_cmd_to_buffer(iommu, &sync_cmd, tail);
+               iommu->cmd_sem = 0;
 
-               spin_unlock_irqrestore(&iommu->lock, flags);
+               build_completion_wait(&sync_cmd, (u64)&iommu->cmd_sem);
+               copy_cmd_to_buffer(iommu, &sync_cmd, tail);
 
-               if ((ret = wait_on_sem(&sem)) != 0)
+               if ((ret = wait_on_sem(&iommu->cmd_sem)) != 0)
                        return ret;
 
                goto again;
@@ -1044,9 +1041,21 @@ again:
        /* We need to sync now to make sure all commands are processed */
        iommu->need_sync = sync;
 
+       return 0;
+}
+
+static int iommu_queue_command_sync(struct amd_iommu *iommu,
+                                   struct iommu_cmd *cmd,
+                                   bool sync)
+{
+       unsigned long flags;
+       int ret;
+
+       spin_lock_irqsave(&iommu->lock, flags);
+       ret = __iommu_queue_command_sync(iommu, cmd, sync);
        spin_unlock_irqrestore(&iommu->lock, flags);
 
-       return 0;
+       return ret;
 }
 
 static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
@@ -1061,19 +1070,29 @@ static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
 static int iommu_completion_wait(struct amd_iommu *iommu)
 {
        struct iommu_cmd cmd;
-       volatile u64 sem = 0;
+       unsigned long flags;
        int ret;
 
        if (!iommu->need_sync)
                return 0;
 
-       build_completion_wait(&cmd, (u64)&sem);
 
-       ret = iommu_queue_command_sync(iommu, &cmd, false);
+       build_completion_wait(&cmd, (u64)&iommu->cmd_sem);
+
+       spin_lock_irqsave(&iommu->lock, flags);
+
+       iommu->cmd_sem = 0;
+
+       ret = __iommu_queue_command_sync(iommu, &cmd, false);
        if (ret)
-               return ret;
+               goto out_unlock;
+
+       ret = wait_on_sem(&iommu->cmd_sem);
 
-       return wait_on_sem(&sem);
+out_unlock:
+       spin_unlock_irqrestore(&iommu->lock, flags);
+
+       return ret;
 }
 
 static int iommu_flush_dte(struct amd_iommu *iommu, u16 devid)