Re: [PATCH v5 4/6] drm/panfrost: Add support for AARCH64_4K page table format
From: Ariel D'Alessandro
Date: Mon Mar 31 2025 - 09:26:58 EST
Hi Steven,
On 3/31/25 8:15 AM, Steven Price wrote:
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.
Indeed, you're right. Thanks for the nitpick!
Happy to see this hitting drm-misc-next soon :)
--
Ariel D'Alessandro
Software Engineer
Collabora Ltd.
Platinum Building, St John's Innovation Park, Cambridge CB4 0DS, UK
Registered in England & Wales, no. 5513718