Re: [PATCH v2 0/3] MediaTek mt6572 GCE support

[AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>]

On 9/7/26 20:03, Roman Vivchar via B4 Relay wrote:
> This patch series adds support for the Global Command Engine found in
> the mt6572 SoC.
> 
> Notably, the patch 2 introduces legacy ISA format, which is used on
> mt6572, 6582 and 6592 SoCs. mt6577 doesn't have the GCE at all and
> mt6595 is much more close to 6795/8173.
> Patch 3 adds mt6572 platform data and legacy_isa forwarding to the
> instruction JIT.
> 
> This format was reverse engineered from the Android HAL and uses 22-bit
> offset with 2-bit subsystem ID, unlike the newer 16-bit offset and 8-bit
> subsystem ID.
> The mt6572 HAL includes workarounds for WFE and EOC instructions, emitting
> another WFE as barrier at WFE, and JUMP +8 at EOC.
> mt6582 and 6592 HAL dropped WFE barrier, but still have JUMP +8.
> 
> This sounds very much like some kind of software mitigations for hardware
> bugs, but during testing on 6572 nothing bad happened so far. These
> additional instructions are not included in the patches.
> 
> Note that while GCE can be used for e.g. mt6592 UFOE (which is at
> 0x14013000, so outside of the u16 range), currently the driver still uses
> u16 for the offset, because I don't have any 6592 device.
> 
> Signed-off-by: Roman Vivchar <rva333@protonmail.com>

Series is

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

> ---
> Changes in v2:
> - Move dt-bindings to mailbox directory from gce (Krzysztof)
> - Clarify that only v2 and v3 GCEs support PA writes
> - Link to v1: https://patch.msgid.link/20260728-6572-gce-v1-0-750bba32689e@protonmail.com
> 
> ---
> Roman Vivchar (3):
>        dt-bindings: mailbox: mediatek,gce-mailbox: add mt6572
>        soc: mediatek: cmdq-helper: add legacy GCE ISA support
>        mailbox: mtk-cmdq: add mt6572 support
> 
>   .../bindings/mailbox/mediatek,gce-mailbox.yaml     |  1 +
>   drivers/mailbox/mtk-cmdq-mailbox.c                 | 11 +++++
>   drivers/soc/mediatek/mtk-cmdq-helper.c             | 57 +++++++++++++++-------
>   include/dt-bindings/mailbox/mediatek,mt6572-gce.h  | 52 ++++++++++++++++++++
>   include/linux/mailbox/mtk-cmdq-mailbox.h           |  1 +
>   5 files changed, 104 insertions(+), 18 deletions(-)
> ---
> base-commit: 8cd9520d35a6c38db6567e97dd93b1f11f185dc6
> change-id: 20260727-6572-gce-6a571ef4af09
> 
> Best regards,
> --
> Roman Vivchar <rva333@protonmail.com>