mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-06 19:08:57 +09:00
76ce65464f
In M4U 4GB mode, the physical address is remapped as below:
CPU Physical address:
====================
0 1G 2G 3G 4G 5G
|---A---|---B---|---C---|---D---|---E---|
+--I/O--+------------Memory-------------+
IOMMU output physical address:
=============================
4G 5G 6G 7G 8G
|---E---|---B---|---C---|---D---|
+------------Memory-------------+
The Region 'A'(I/O) can not be mapped by M4U; For Region 'B'/'C'/'D', the
bit32 of the CPU physical address always is needed to set, and for Region
'E', the CPU physical address keep as is. something looks like this:
CPU PA -> M4U OUTPUT PA
0x4000_0000 0x1_4000_0000 (Add bit32)
0x8000_0000 0x1_8000_0000 ...
0xc000_0000 0x1_c000_0000 ...
0x1_0000_0000 0x1_0000_0000 (No change)
Additionally, the iommu consumers always use the CPU phyiscal address.
The PA in the iova_to_phys that is got from v7s always is u32, But
from the CPU point of view, PA only need add BIT(32) when PA < 0x4000_0000.
Fixes: 30e2fccf95 ("iommu/mediatek: Enlarge the validate PA range
for 4GB mode")
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.