From: Joerg Roedel <joerg.roedel@amd.com>
Date: Fri, 2 Sep 2011 12:10:32 +0000 (+0200)
Subject: iommu/amd: Make sure iommu->need_sync contains correct value
X-Git-Tag: v3.0.5~150
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=054b93a673c2b39106b02cbef05bfdc3f5ba6150;p=karo-tx-linux.git

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 7b4381154dae..d3d9d50d93a5 100644
--- 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;