iommu/amd: Add several helper functions

Move single iommu enabling codes into a wrapper function early_enable_iommu().
This can make later kdump change easier.

And also add iommu_disable_command_buffer and iommu_disable_event_buffer
for later usage.

Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 3f72f44fa2df22eea26e0b9f860ad4a20d38a3d5..277838dbc3a628872f85a442e2ea8e2e38d6469e 100644 (file)
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -634,6 +634,14 @@ static void iommu_enable_command_buffer(struct amd_iommu *iommu)
        amd_iommu_reset_cmd_buffer(iommu);
 }
 
+/*
+ * This function disables the command buffer
+ */
+static void iommu_disable_command_buffer(struct amd_iommu *iommu)
+{
+       iommu_feature_disable(iommu, CONTROL_CMDBUF_EN);
+}
+
 static void __init free_command_buffer(struct amd_iommu *iommu)
 {
        free_pages((unsigned long)iommu->cmd_buf, get_order(CMD_BUFFER_SIZE));
@@ -666,6 +674,14 @@ static void iommu_enable_event_buffer(struct amd_iommu *iommu)
        iommu_feature_enable(iommu, CONTROL_EVT_LOG_EN);
 }
 
+/*
+ * This function disables the event log buffer
+ */
+static void iommu_disable_event_buffer(struct amd_iommu *iommu)
+{
+       iommu_feature_disable(iommu, CONTROL_EVT_LOG_EN);
+}
+
 static void __init free_event_buffer(struct amd_iommu *iommu)
 {
        free_pages((unsigned long)iommu->evt_buf, get_order(EVT_BUFFER_SIZE));
@@ -2046,6 +2062,19 @@ static void iommu_enable_ga(struct amd_iommu *iommu)
 #endif
 }
 
+static void early_enable_iommu(struct amd_iommu *iommu)
+{
+       iommu_disable(iommu);
+       iommu_init_flags(iommu);
+       iommu_set_device_table(iommu);
+       iommu_enable_command_buffer(iommu);
+       iommu_enable_event_buffer(iommu);
+       iommu_set_exclusion_range(iommu);
+       iommu_enable_ga(iommu);
+       iommu_enable(iommu);
+       iommu_flush_all_caches(iommu);
+}
+
 /*
  * This function finally enables all IOMMUs found in the system after
  * they have been initialized
@@ -2054,17 +2083,8 @@ static void early_enable_iommus(void)
 {
        struct amd_iommu *iommu;
 
-       for_each_iommu(iommu) {
-               iommu_disable(iommu);
-               iommu_init_flags(iommu);
-               iommu_set_device_table(iommu);
-               iommu_enable_command_buffer(iommu);
-               iommu_enable_event_buffer(iommu);
-               iommu_set_exclusion_range(iommu);
-               iommu_enable_ga(iommu);
-               iommu_enable(iommu);
-               iommu_flush_all_caches(iommu);
-       }
+       for_each_iommu(iommu)
+               early_enable_iommu(iommu);
 
 #ifdef CONFIG_IRQ_REMAP
        if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))