A question about state machine function state_next()

From: Baoquan He
Date: Sun May 31 2015 - 23:09:56 EST


Hi Joerg,

I am reading amd iommu code because I have some knowledge about intel
iommu since review Zhenhua's fixing kdump error patches. Now there's
a question I didn't find answer.

In amd iommu state_next() is the state machine running function. However
I only found 4 function to call iommu_go_to_state() to change the state,
they are:
amd_iommu_detect()
amd_iommu_prepare()
amd_iommu_enable()
amd_iommu_init()

And they are called according to above sequence. It means only below 4
cases are checked and the code blocks are executed. Then where to call
amd_iommu_enable_interrupts() and amd_iommu_init_dma(). Could you help
to tell what I missed?

static int __init state_next(void)
{
int ret = 0;

switch (init_state) {
case IOMMU_START_STATE: //checked and execute
case IOMMU_IVRS_DETECTED: //checked and execute
case IOMMU_ACPI_FINISHED: //checked and execute
case IOMMU_ENABLED: //checked and execute
...
}

Thanks
Baoquan
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