Re: mapping back to 36 bit physical
From: Matt Porter <hidden>
Date: 2003-01-06 03:22:02
On Wed, Dec 18, 2002 at 02:07:45PM +0600, Claudia Salzberg wrote:
Greetings. How does one go about aquiring the 36-bit physical address on a 440XX if you have the corresponding va from an ioremap (when your driver is not the one that did the ioremap so that you don't have the pa saved)? I see that ioremap does support 36-bit I/O mapping but _va and _pa only play with unsigned long's. So does iopa. So do the virt_to_* 's I was able to find. Also, does anyone have plans for incorporating memory access hooks above 4GB address space?
Everything is in the linuxppc-2.5 and linuxppc_2_4_devel to support all normal kernel functionality with the exception of remap_page_range(). As part of a recent checkin, the commit notice gave a reference to an ftp site to get a remap_page_range() 64-bit patch. Check your changesets or linuxppc-commit list archives. You need to save the pa. virt_to_* and friends are only valid for kernel lowmem addresses as per Documentation/IO-mapping.txt. Regardless, all new drivers should be using the dma mapping api and saving the pa as required. Regards, -- Matt Porter porter@cox.net This is Linux Country. On a quiet night, you can hear Windows reboot. ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/