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iommu/amd: Convert iommu initialization to state machine
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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>
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Joerg Roedel committed Jul 17, 2012
1 parent b9b1ce7 commit 2c0ae17
Showing 1 changed file with 109 additions and 64 deletions.
173 changes: 109 additions & 64 deletions drivers/iommu/amd_iommu_init.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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)
{
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand All @@ -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);
Expand All @@ -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();
Expand All @@ -1594,41 +1606,17 @@ 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 */
early_acpi_os_unmap_memory((char __iomem *)ivrs_base, ivrs_size);
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;
}

Expand Down Expand Up @@ -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;
}

/****************************************************************************
Expand All @@ -1735,15 +1778,17 @@ static int __init amd_iommu_init(void)
****************************************************************************/
int __init amd_iommu_detect(void)
{
int ret;

if (no_iommu || (iommu_detected && !gart_iommu_aperture))
return -ENODEV;

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;
Expand Down

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