Re: Resizable PCI BAR support V9

From: Christian KÃnig
Date: Wed Oct 25 2017 - 07:27:58 EST


Am 24.10.2017 um 21:44 schrieb Bjorn Helgaas:
On Wed, Oct 18, 2017 at 03:58:16PM +0200, Christian KÃnig wrote:
Hi everyone,

This is the ninth and hopefully last incarnation of this set of patches. It
enables device drivers to resize and most likely also relocate the PCI BAR of
devices they manage to allow the CPU to access all of the device local memory
at once.

This is very useful for GFX device drivers where the default PCI BAR is only
about 256MB in size for compatibility reasons, but the device easily have
multiple gigabyte of local memory.

Some changes since the last version:
1. Rebased on drm-next, so should be ready to be merged for 4.15.
2. The fixup of the 64bit root window on AMD Family 15h CPUs/APUs is only
enabled when we compile a kernel supporting that hw.
3. Some minor error handling improvements for the amdgpu side. We now
gracefully abort driver loading in case of a critical error instead of
calling BUG().

Bjorn any more comments or can we finally get this into 4.15? I will remove the
version tags from the patches when I send you a pull request if you want this.

I only work on this as a background task, so sorry for the ~3 month delay
between each version of the patchset.
I put these (except for the last) on pci/resource for v4.15. I'd be
happy to merge the last as well if you like. My tree does not include
drm-next, so there would be a minor conflict when merging upstream.

Thanks Bjorn, that is great to hear.

I will sync up with Alex and Dave how to merge the last patch.

Christian.


Bjorn