linux/include/uapi
Matt Fleming ae2ee627dc efifb: Add support for 64-bit frame buffer addresses
The EFI Graphics Output Protocol uses 64-bit frame buffer addresses
but these get truncated to 32-bit by the EFI boot stub when storing
the address in the 'lfb_base' field of 'struct screen_info'.

Add a 'ext_lfb_base' field for the upper 32-bits of the frame buffer
address and set VIDEO_TYPE_CAPABILITY_64BIT_BASE when the field is
useable.

It turns out that the reason no one has required this support so far
is that there's actually code in tianocore to "downgrade" PCI
resources that have option ROMs and 64-bit BARS from 64-bit to 32-bit
to cope with legacy option ROMs that can't handle 64-bit addresses.
The upshot is that basically all GOP devices in the wild use a 32-bit
frame buffer address.

Still, it is possible to build firmware that uses a full 64-bit GOP
frame buffer address. Chad did, which led to him reporting this issue.

Add support in anticipation of GOP devices using 64-bit addresses more
widely, and so that efifb works out of the box when that happens.

Reported-by: Chad Page <chad.page@znyx.com>
Cc: Pete Hawkins <pete.hawkins@znyx.com>
Acked-by: Peter Jones <pjones@redhat.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-10-12 14:20:06 +01:00
..
asm-generic errno.h: Improve ENOSYS's comment 2015-04-17 09:03:58 -04:00
drm drm/amdgpu: Drop drm/ prefix for including drm.h in amdgpu_drm.h 2015-07-29 15:48:05 -04:00
linux efifb: Add support for 64-bit frame buffer addresses 2015-10-12 14:20:06 +01:00
misc cxl: Implement an ioctl to fetch afu card-id, offset-id and mode 2015-06-03 13:27:15 +10:00
mtd
rdma IB/core: Add timestamp_mask and hca_core_clock to query_device 2015-06-12 14:49:10 -04:00
scsi
sound ASoC: topology: Add private data type and bump ABI version to 3 2015-08-06 12:34:46 +01:00
video
xen
Kbuild