Subject: Re: port-mips/31915: provide centralized wired_map logic
To: Izumi Tsutsui <firstname.lastname@example.org>
From: SODA Noriyuki <email@example.com>
Date: 11/02/2005 00:16:56
>>>>> On Tue, 1 Nov 2005 23:30:27 +0900,
Izumi Tsutsui <firstname.lastname@example.org> said:
> which could use the functions in Garrett's patch.
If I recally correctly it couldn't.
> (hmm, it assumes bus_space functions won't use uvm/pmap functions?)
Yes. That's the main reason that it uses a wired mapping.
(Another reason is to reduce number of necessary TLB entries.)
> I'm not sure whether tga uses a new wired mapping or the PCI region
> already mapped in c_nec_pci.c:c_nec_pci_init(), though.
If I recall correctly, it doesn't use already mapped entry.
Rather, it use a new wired entry which is mapped via
arc_large_bus_space_compose_handle(), because the region of the
already mapped entry is 0x100000000 ... 0x100ffffff,
but the address of framebuffer begins from 0x108200000.