iommu/amd: Convert iommu initialization to state machine
This step makes it very easy to keep track about the current
intialization state of the iommu driver. With this change we
can initialize the IOMMU hardware to a point where it can
remap interrupts and later resume the initializion to enable
dma remapping.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 53828b61..500e7f1 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -187,7 +187,23 @@
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 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 @@
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 @@
* 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 @@
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 @@
*/
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 @@
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 @@
return 0;
}
+/****************************************************************************
+ *
+ * AMD IOMMU Initialization State Machine
+ *
+ ****************************************************************************/
+
+static int __init state_next(void)
+{
+ int ret = 0;
+
+ 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();
+ }
+
+ return ret;
+}
+
+static int __init iommu_go_to_state(enum iommu_init_state state)
+{
+ int ret = 0;
+
+ while (init_state != state) {
+ ret = state_next();
+ if (init_state == IOMMU_NOT_FOUND ||
+ init_state == IOMMU_INIT_ERROR)
+ break;
+ }
+
+ 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;
+ int ret;
- ret = amd_iommu_init_hardware();
- if (ret)
- goto out;
+ ret = iommu_go_to_state(IOMMU_INITIALIZED);
+ if (ret) {
+ disable_iommus();
+ free_on_init_error();
+ }
- ret = amd_iommu_enable_interrupts();
- if (ret)
- goto free;
-
- ret = amd_iommu_init_dma();
- if (ret)
- goto free;
-
- amd_iommu_init_api();
-
- x86_platform.iommu_shutdown = disable_iommus;
-
-out:
return ret;
-
-free:
- disable_iommus();
-
- free_on_init_error();
-
- goto out;
}
/****************************************************************************
@@ -1735,6 +1778,7 @@
****************************************************************************/
int __init amd_iommu_detect(void)
{
+ int ret;
if (no_iommu || (iommu_detected && !gart_iommu_aperture))
return -ENODEV;
@@ -1742,8 +1786,9 @@
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;