amd-iommu: implement suspend/resume

This patch puts everything together and enables suspend/resume support
in the AMD IOMMU driver.

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

1 files changed, 20 insertions, 1 deletions

diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 330896ba6a9f..4ca8fbfb68dc 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -965,12 +965,31 @@ static void disable_iommus(void)
 
 static int amd_iommu_resume(struct sys_device *dev)
 {
+        /*
+         * Disable IOMMUs before reprogramming the hardware registers.
+         * IOMMU is still enabled from the resume kernel.
+         */
+        disable_iommus();
+
+        /* re-load the hardware */
+        enable_iommus();
+
+        /*
+         * we have to flush after the IOMMUs are enabled because a
+         * disabled IOMMU will never execute the commands we send
+         */
+        amd_iommu_flush_all_domains();
+        amd_iommu_flush_all_devices();
+
         return 0;
 }
 
 static int amd_iommu_suspend(struct sys_device *dev, pm_message_t state)
 {
-        return -EINVAL;
+        /* disable IOMMUs to go out of the way for BIOS */
+        disable_iommus();
+
+        return 0;
 }
 
 static struct sysdev_class amd_iommu_sysdev_class = {