Question about flash allocation

Josh Boyer jwboyer at
Wed Feb 16 22:26:30 EST 2011

On Tue, Feb 15, 2011 at 11:28 PM, Mitsutaka Amano
<mitsutaka.amano at> wrote:
> Hi,
> Why does CFI(or other flash memory) have to alloc amount of flash
> memory size to the vmalloc area(such as PHYSMAP or PHYSMAP_OF)?
> I wondered other devices seems to not allocating(e.g, most NAND flash,
> flash on ARM, MIPS and so on). I don't know difference between my
> board and other. Doesn't other devices need to allocate to vmalloc?

You asked this on the MTD mailing list already:

The answers aren't going to change based on which list you ask.

As for the last question, the memory space for modules are in vmalloc
space, and any HW resources they ioremap are as well.  However for
true memory allocations, most device drivers use kmalloc.  Some use
vmalloc for large buffers that don't need to be physically contiguous
but there aren't that many.


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