On Thu, 27 Feb 2025 09:30:30 +0100
Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx> wrote:
> > Bifrost MMUs support AArch64 4kB granule specification. However,
> > panfrost only enables MMU in legacy mode, despite the presence of the
> > HW_FEATURE_AARCH64_MMU feature flag.
> >
> > This commit adds support to use page tables according to AArch64 4kB
> > granule specification. This feature is enabled conditionally based on
> > the GPU model's HW_FEATURE_AARCH64_MMU feature flag.
> >
> > Signed-off-by: Ariel D'Alessandro <ariel.dalessandro@xxxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/panfrost/panfrost_device.h | 1 +
> > drivers/gpu/drm/panfrost/panfrost_mmu.c | 118 +++++++++++++++++----
> > drivers/gpu/drm/panfrost/panfrost_regs.h | 29 +++++
> > 3 files changed, 128 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
> > index cffcb0ac7c11..dea252f43c58 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_device.h
> > +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
> > @@ -153,6 +153,7 @@ struct panfrost_device {
> > };
> >
> > struct panfrost_mmu {
> > + void (*enable)(struct panfrost_device *pfdev, struct panfrost_mmu *mmu);
>
> The enable sequence is the same, it's just the transtab, memattr and
> transcfg values that differ depending on the format, so let's prepare
> them at panfrost_mmu init time, and cache them here.
Just to be clear, I meant replace this ->enable() function pointer by a
struct {
u64 transtab;
u64 memattr;
u64 transcfg;
} cfg;
field.
>
> > struct panfrost_device *pfdev;
> > struct kref refcount;
> > struct io_pgtable_cfg pgtbl_cfg;
