On 9/19/26 8:03 AM, Alexandre Courbot wrote:
On Fri Sep 18, 2026 at 12:38 PM JST, Dave Airlie wrote:
On Wed, 9 Sept 2026 at 14:25, Eliot Courtney <[email protected]> wrote:
From: Joel Fernandes <[email protected]>
Add the BAR1 user interface for CPU access to GPU virtual memory through
the BAR1 aperture.
Signed-off-by: Joel Fernandes <[email protected]>
[ecourtney: map BAR1 in NovaCore, borrow it in Gpu and BarUser, no Devres]
[ecourtney: update for the VramAddress raw API and gsp_resources chipset]
[ecourtney: drop the owned GpuMm, pass it mutably through map and release]
Signed-off-by: Eliot Courtney <[email protected]>
---
BAR 1 and 2 need to be optionally detected and used. At least on SPARK
there is only BAR0.
I've been playing with John's branch on spark and had to rework this
code to make BAR 1 optional.
Thanks Dave - indeed we also hit an issue on a device where the FB
console was enabled (?), which preventing BAR1 from being used.
That's different: another device driver was using the GPU. People
should Kconfig their system to avoid having two device drivers
trying to claim the same hardware.
Once Nova get a bit further along, it will be a non-issue too,
because Nova can drive either an fbdev, or whatever the modern
alternative to that is.
I know Eliot has a bunch of follow-ups in the pipe, Eliot can we make
sure to dynamically detect and enable BAR1?
thanks,
--
John Hubbard
