iommu/amd: Split amd_iommu_init function

The hardware-initializtion part of the AMD IOMMU driver is
split out into a seperate function. This function can now be
called either from amd_iommu_init() itself or any other
place if the hardware needs to be ready earlier. This will
be used to implement interrupt remapping for AMD.

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

1 files changed, 79 insertions, 44 deletions

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index bdea288dc185..75653daf1de1 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -1424,10 +1424,40 @@ static struct syscore_ops amd_iommu_syscore_ops = {
         .resume = amd_iommu_resume,
 };
 
+static void __init free_on_init_error(void)
+{
+        amd_iommu_uninit_devices();
+
+        free_pages((unsigned long)amd_iommu_pd_alloc_bitmap,
+                   get_order(MAX_DOMAIN_ID/8));
+
+        free_pages((unsigned long)amd_iommu_rlookup_table,
+                   get_order(rlookup_table_size));
+
+        free_pages((unsigned long)amd_iommu_alias_table,
+                   get_order(alias_table_size));
+
+        free_pages((unsigned long)amd_iommu_dev_table,
+                   get_order(dev_table_size));
+
+        free_iommu_all();
+
+        free_unity_maps();
+
+#ifdef CONFIG_GART_IOMMU
+        /*
+         * We failed to initialize the AMD IOMMU - try fallback to GART
+         * if possible.
+         */
+        gart_iommu_init();
+
+#endif
+}
+
 /*
- * This is the core init function for AMD IOMMU hardware in the system.
- * This function is called from the generic x86 DMA layer initialization
- * code.
+ * This is the hardware init function for AMD IOMMU in the system.
+ * This function is called either from amd_iommu_init or from the interrupt
+ * remapping setup code.
  *
  * This function basically parses the ACPI table for AMD IOMMU (IVRS)
  * three times:
@@ -1446,16 +1476,21 @@ static struct syscore_ops amd_iommu_syscore_ops = {
  *              remapping requirements parsed out of the ACPI table in
  *              this last pass.
  *
- * After that the hardware is initialized and ready to go. In the last
- * step we do some Linux specific things like registering the driver in
- * the dma_ops interface and initializing the suspend/resume support
- * functions. Finally it prints some information about AMD IOMMUs and
- * the driver state and enables the hardware.
+ * After everything is set up the IOMMUs are enabled and the necessary
+ * hotplug and suspend notifiers are registered.
  */
-static int __init amd_iommu_init(void)
+int __init amd_iommu_init_hardware(void)
 {
         int i, ret = 0;
 
+        if (!amd_iommu_detected)
+                return -ENODEV;
+
+        if (amd_iommu_dev_table != NULL) {
+                /* Hardware already initialized */
+                return 0;
+        }
+
         /*
          * First parse ACPI tables to find the largest Bus/Dev/Func
          * we need to handle. Upon this information the shared data
@@ -1472,9 +1507,8 @@ static int __init amd_iommu_init(void)
         alias_table_size   = tbl_size(ALIAS_TABLE_ENTRY_SIZE);
         rlookup_table_size = tbl_size(RLOOKUP_TABLE_ENTRY_SIZE);
 
-        ret = -ENOMEM;
-
         /* Device table - directly used by all IOMMUs */
+        ret = -ENOMEM;
         amd_iommu_dev_table = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
                                       get_order(dev_table_size));
         if (amd_iommu_dev_table == NULL)
@@ -1546,20 +1580,46 @@ static int __init amd_iommu_init(void)
 
         enable_iommus();
 
+        amd_iommu_init_notifier();
+
+        register_syscore_ops(&amd_iommu_syscore_ops);
+
+out:
+        return ret;
+
+free:
+        free_on_init_error();
+
+        return ret;
+}
+
+/*
+ * This is the core init function for AMD IOMMU hardware in the system.
+ * This function is called from the generic x86 DMA layer initialization
+ * code.
+ *
+ * The function calls amd_iommu_init_hardware() to setup and enable the
+ * IOMMU hardware if this has not happened yet. After that the driver
+ * registers for the DMA-API and for the IOMMU-API as necessary.
+ */
+static int __init amd_iommu_init(void)
+{
+        int ret = 0;
+
+        ret = amd_iommu_init_hardware();
+        if (ret)
+                goto out;
+
         if (iommu_pass_through)
                 ret = amd_iommu_init_passthrough();
         else
                 ret = amd_iommu_init_dma_ops();
 
         if (ret)
-                goto free_disable;
+                goto free;
 
         amd_iommu_init_api();
 
-        amd_iommu_init_notifier();
-
-        register_syscore_ops(&amd_iommu_syscore_ops);
-
         if (iommu_pass_through)
                 goto out;
 
@@ -1569,39 +1629,14 @@ static int __init amd_iommu_init(void)
                 printk(KERN_INFO "AMD-Vi: Lazy IO/TLB flushing enabled\n");
 
         x86_platform.iommu_shutdown = disable_iommus;
+
 out:
         return ret;
 
-free_disable:
-        disable_iommus();
-
 free:
-        amd_iommu_uninit_devices();
-
-        free_pages((unsigned long)amd_iommu_pd_alloc_bitmap,
-                   get_order(MAX_DOMAIN_ID/8));
-
-        free_pages((unsigned long)amd_iommu_rlookup_table,
-                   get_order(rlookup_table_size));
-
-        free_pages((unsigned long)amd_iommu_alias_table,
-                   get_order(alias_table_size));
-
-        free_pages((unsigned long)amd_iommu_dev_table,
-                   get_order(dev_table_size));
-
-        free_iommu_all();
-
-        free_unity_maps();
-
-#ifdef CONFIG_GART_IOMMU
-        /*
-         * We failed to initialize the AMD IOMMU - try fallback to GART
-         * if possible.
-         */
-        gart_iommu_init();
+        disable_iommus();
 
-#endif
+        free_on_init_error();
 
         goto out;
 }