Re: [linux-fbdev] Re: request_region for MMIO?

Jes Sorensen (Jes.Sorensen@cern.ch)
01 Feb 1999 14:28:12 +0100


>>>>> "Geert" == Geert Uytterhoeven <Geert.Uytterhoeven@cs.kuleuven.ac.be> writes:

Geert> On 1 Feb 1999, Jes Sorensen wrote:
>> >>>>> "Geert" == Geert Uytterhoeven
>> <Geert.Uytterhoeven@cs.kuleuven.ac.be> writes:
Geert> Is it OK to use request_region() for claiming memory mapped I/O
Geert> registers?
>> Certainly not.
>>
Geert> Is there any good reason why

Oh did I get you wrong here, do you mean PCI I/O registers that just
happen to be mem mapped on non x86 architectures or do you actually
mean PCI shared memory type registers?

Geert> while get_ioport_list() uses `%04lx' to print the claimed
Geert> regions? This makes me think I should use request_region() for
Geert> `PC' I/O port regions only.
>> Correct

Geert> Then what should I use?

For I/O port type things you use request_region(), for real shared
memory there is currently no mechanism afaik.

Geert> BTW, on m68k we never used request_region() and friends, so we
Geert> are wasting memory for that 128-entry table in
Geert> kernel/resource.c ;-(

We will need it for supporting the ISA bus bridges for the Amiga,
Atari and other boxes.

Jes

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