discontig physical memory

Petko Manolov
2001-10-08T22:57:35Z

Hi guys,

I ran into this problem with a SOC weird design.
The physical memory map looks like this:

0 - 4MB DMA-able embedded RAM;
4MB - 16MB nothing here;
16MB - 32MB external RAM;

Embedded controllers (FB/USB) can see only lowest 4MB
and they need almost all of it for buffers. The kernel
is living at phy address 16Mb.

Any ideas how to make lowest 4MB allocatable throu
kmalloc(size, GFP_DMA) without breaking the kernel?

Petko

PS: I've seen CONFIG_DISCONTIGMEM but it is not yet
implemented for MIPS and i am not sure if it is what
is required in this case.