What is __pa(x) function, it said that it translates logical address to physical address by x-PAGE_OFFSET, PAGE_OFFSET is normally something like 0xc0000000, how can this translate? What is x input?
x is a virtual address. Virtual addresses are the physical addresses plus PAGE_OFFSET. So to go *back* to a virtual address from a physical address as the __pa macro does, you simply do the reverse operation and subtract PAGE_OFFSET.
That's my understanding, anyway. I'm a newbie too and it might not be that simple.
Kirk
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