1 files changed, 109 insertions, 64 deletions

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 53828b61e9ac..500e7f15f5c2 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -187,7 +187,23 @@ static u32 dev_table_size;	/* size of the device table */
 static u32 alias_table_size;    /* size of the alias table */
 static u32 rlookup_table_size;  /* size if the rlookup table */
 
+enum iommu_init_state {
+        IOMMU_START_STATE,
+        IOMMU_IVRS_DETECTED,
+        IOMMU_ACPI_FINISHED,
+        IOMMU_ENABLED,
+        IOMMU_PCI_INIT,
+        IOMMU_INTERRUPTS_EN,
+        IOMMU_DMA_OPS,
+        IOMMU_INITIALIZED,
+        IOMMU_NOT_FOUND,
+        IOMMU_INIT_ERROR,
+};
+
+static enum iommu_init_state init_state = IOMMU_START_STATE;
+
 static int amd_iommu_enable_interrupts(void);
+static int __init iommu_go_to_state(enum iommu_init_state state);
 
 static inline void update_last_devid(u16 devid)
 {
@@ -1104,7 +1120,7 @@ static void print_iommu_info(void)
         }
 }
 
-static int amd_iommu_init_pci(void)
+static int __init amd_iommu_init_pci(void)
 {
         struct amd_iommu *iommu;
         int ret = 0;
@@ -1516,11 +1532,6 @@ static int __init early_amd_iommu_init(void)
         if (!amd_iommu_detected)
                 return -ENODEV;
 
-        if (amd_iommu_dev_table != NULL) {
-                /* Hardware already initialized */
-                return 0;
-        }
-
         status = acpi_get_table_with_size("IVRS", 0, &ivrs_base, &ivrs_size);
         if (status == AE_NOT_FOUND)
                 return -ENODEV;
@@ -1535,7 +1546,8 @@ static int __init early_amd_iommu_init(void)
          * we need to handle. Upon this information the shared data
          * structures for the IOMMUs in the system will be allocated
          */
-        if (find_last_devid_acpi(ivrs_base))
+        ret = find_last_devid_acpi(ivrs_base);
+        if (ret)
                 goto out;
 
         dev_table_size     = tbl_size(DEV_TABLE_ENTRY_SIZE);
@@ -1556,20 +1568,20 @@ static int __init early_amd_iommu_init(void)
         amd_iommu_alias_table = (void *)__get_free_pages(GFP_KERNEL,
                         get_order(alias_table_size));
         if (amd_iommu_alias_table == NULL)
-                goto free;
+                goto out;
 
         /* IOMMU rlookup table - find the IOMMU for a specific device */
         amd_iommu_rlookup_table = (void *)__get_free_pages(
                         GFP_KERNEL | __GFP_ZERO,
                         get_order(rlookup_table_size));
         if (amd_iommu_rlookup_table == NULL)
-                goto free;
+                goto out;
 
         amd_iommu_pd_alloc_bitmap = (void *)__get_free_pages(
                                             GFP_KERNEL | __GFP_ZERO,
                                             get_order(MAX_DOMAIN_ID/8));
         if (amd_iommu_pd_alloc_bitmap == NULL)
-                goto free;
+                goto out;
 
         /* init the device table */
         init_device_table();
@@ -1594,11 +1606,11 @@ static int __init early_amd_iommu_init(void)
          */
         ret = init_iommu_all(ivrs_base);
         if (ret)
-                goto free;
+                goto out;
 
         ret = init_memory_definitions(ivrs_base);
         if (ret)
-                goto free;
+                goto out;
 
 out:
         /* Don't leak any ACPI memory */
@@ -1606,30 +1618,6 @@ out:
         ivrs_base = NULL;
 
         return ret;
-
-free:
-        free_on_init_error();
-
-        goto out;
-}
-
-int __init amd_iommu_init_hardware(void)
-{
-        int ret = 0;
-
-        ret = early_amd_iommu_init();
-        if (ret)
-                return ret;
-
-        ret = amd_iommu_init_pci();
-        if (ret)
-                return ret;
-
-        enable_iommus();
-
-        register_syscore_ops(&amd_iommu_syscore_ops);
-
-        return ret;
 }
 
 static int amd_iommu_enable_interrupts(void)
@@ -1686,44 +1674,99 @@ static int amd_iommu_init_dma(void)
         return 0;
 }
 
-/*
- * 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)
+ * AMD IOMMU Initialization State Machine
+ *
+ ****************************************************************************/
+
+static int __init state_next(void)
 {
         int ret = 0;
 
-        ret = amd_iommu_init_hardware();
-        if (ret)
-                goto out;
-
-        ret = amd_iommu_enable_interrupts();
-        if (ret)
-                goto free;
+        switch (init_state) {
+        case IOMMU_START_STATE:
+                if (!detect_ivrs()) {
+                        init_state      = IOMMU_NOT_FOUND;
+                        ret             = -ENODEV;
+                } else {
+                        init_state      = IOMMU_IVRS_DETECTED;
+                }
+                break;
+        case IOMMU_IVRS_DETECTED:
+                ret = early_amd_iommu_init();
+                init_state = ret ? IOMMU_INIT_ERROR : IOMMU_ACPI_FINISHED;
+                break;
+        case IOMMU_ACPI_FINISHED:
+                early_enable_iommus();
+                register_syscore_ops(&amd_iommu_syscore_ops);
+                x86_platform.iommu_shutdown = disable_iommus;
+                init_state = IOMMU_ENABLED;
+                break;
+        case IOMMU_ENABLED:
+                ret = amd_iommu_init_pci();
+                init_state = ret ? IOMMU_INIT_ERROR : IOMMU_PCI_INIT;
+                enable_iommus_v2();
+                break;
+        case IOMMU_PCI_INIT:
+                ret = amd_iommu_enable_interrupts();
+                init_state = ret ? IOMMU_INIT_ERROR : IOMMU_INTERRUPTS_EN;
+                break;
+        case IOMMU_INTERRUPTS_EN:
+                ret = amd_iommu_init_dma();
+                init_state = ret ? IOMMU_INIT_ERROR : IOMMU_DMA_OPS;
+                break;
+        case IOMMU_DMA_OPS:
+                init_state = IOMMU_INITIALIZED;
+                break;
+        case IOMMU_INITIALIZED:
+                /* Nothing to do */
+                break;
+        case IOMMU_NOT_FOUND:
+        case IOMMU_INIT_ERROR:
+                /* Error states => do nothing */
+                ret = -EINVAL;
+                break;
+        default:
+                /* Unknown state */
+                BUG();
+        }
 
-        ret = amd_iommu_init_dma();
-        if (ret)
-                goto free;
+        return ret;
+}
 
-        amd_iommu_init_api();
+static int __init iommu_go_to_state(enum iommu_init_state state)
+{
+        int ret = 0;
 
-        x86_platform.iommu_shutdown = disable_iommus;
+        while (init_state != state) {
+                ret = state_next();
+                if (init_state == IOMMU_NOT_FOUND ||
+                    init_state == IOMMU_INIT_ERROR)
+                        break;
+        }
 
-out:
         return ret;
+}
 
-free:
-        disable_iommus();
 
-        free_on_init_error();
 
-        goto out;
+/*
+ * 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.
+ */
+static int __init amd_iommu_init(void)
+{
+        int ret;
+
+        ret = iommu_go_to_state(IOMMU_INITIALIZED);
+        if (ret) {
+                disable_iommus();
+                free_on_init_error();
+        }
+
+        return ret;
 }
 
 /****************************************************************************
@@ -1735,6 +1778,7 @@ free:
  ****************************************************************************/
 int __init amd_iommu_detect(void)
 {
+        int ret;
 
         if (no_iommu || (iommu_detected && !gart_iommu_aperture))
                 return -ENODEV;
@@ -1742,8 +1786,9 @@ int __init amd_iommu_detect(void)
         if (amd_iommu_disabled)
                 return -ENODEV;
 
-        if (!detect_ivrs())
-                return -ENODEV;
+        ret = iommu_go_to_state(IOMMU_IVRS_DETECTED);
+        if (ret)
+                return ret;
 
         amd_iommu_detected = true;
         iommu_detected = 1;