Re: [PATCH v5 4/6] drm/panfrost: Add support for AARCH64_4K page table format

[Steven Price]

On 24/03/2025 18:57, Ariel D'Alessandro wrote:
> Currently, Panfrost only supports MMU configuration in "LEGACY" (as
> Bifrost calls it) mode, a (modified) version of LPAE "Large Physical
> Address Extension", which in Linux we've called "mali_lpae".
> 
> This commit adds support for conditionally enabling AARCH64_4K page
> table format. To achieve that, a "GPU optional quirks" field was added
> to `struct panfrost_features` with the related flag.
> 
> Note that, in order to enable AARCH64_4K mode, the GPU variant must have
> the HW_FEATURE_AARCH64_MMU feature flag present.
> 
> Signed-off-by: Ariel D'Alessandro <ariel.dalessandro@xxxxxxxxxxxxx>
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
> Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> Reviewed-by: Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx>

Reviewed-by: Steven Price <steven.price@xxxxxxx>

(one very minor nit below)

> ---
>  drivers/gpu/drm/panfrost/panfrost_device.h |  16 +++
>  drivers/gpu/drm/panfrost/panfrost_mmu.c    | 140 +++++++++++++++++++--
>  drivers/gpu/drm/panfrost/panfrost_regs.h   |  34 +++++
>  3 files changed, 183 insertions(+), 7 deletions(-)
> 

[...]

> diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> index 294f86b3c25e..ccf51fd5f9c0 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
[...]
> +
> +static int panfrost_mmu_cfg_init(struct panfrost_mmu *mmu,
> +				  enum io_pgtable_fmt fmt)

NIT: It's always hard to see in the diff, but the alignment of the
second line is wrong. But I'll fix this up when merging.

Thanks,
Steve