[PATCH] drm/msm/a2xx: support loading legacy (iMX) firmware

[Rob Clark]

On Sun, Jan 1, 2023 at 7:57 AM Dmitry Baryshkov
<dmitry.baryshkov at linaro.org> wrote:
>
> Support loading A200 firmware generated from the iMX firmware header
> files. The firmware lacks protection support, however it allows GPU to
> function properly while using the firmware files with clear license
> which allows redistribution.
>
> Cc: Jonathan Marek <jonathan at marek.ca>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> ---
>  drivers/gpu/drm/msm/adreno/a2xx_gpu.c | 27 +++++++++++++++++++++++----
>  drivers/gpu/drm/msm/adreno/a2xx_gpu.h |  1 +
>  2 files changed, 24 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/a2xx_gpu.c b/drivers/gpu/drm/msm/adreno/a2xx_gpu.c
> index 6c9a747eb4ad..c67089a7ebc1 100644
> --- a/drivers/gpu/drm/msm/adreno/a2xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a2xx_gpu.c
> @@ -53,6 +53,8 @@ static void a2xx_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
>
>  static bool a2xx_me_init(struct msm_gpu *gpu)
>  {
> +       struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
> +       struct a2xx_gpu *a2xx_gpu = to_a2xx_gpu(adreno_gpu);
>         struct msm_ringbuffer *ring = gpu->rb[0];
>
>         OUT_PKT3(ring, CP_ME_INIT, 18);
> @@ -84,15 +86,20 @@ static bool a2xx_me_init(struct msm_gpu *gpu)
>         /* NQ and External Memory Swap */
>         OUT_RING(ring, 0x00000000);
>         /* protected mode error checking (0x1f2 is REG_AXXX_CP_INT_CNTL) */
> -       OUT_RING(ring, 0x200001f2);
> +       if (a2xx_gpu->protection_disabled)
> +               OUT_RING(ring, 0x00000000);
> +       else
> +               OUT_RING(ring, 0x200001f2);
>         /* Disable header dumping and Header dump address */
>         OUT_RING(ring, 0x00000000);
>         /* Header dump size */
>         OUT_RING(ring, 0x00000000);
>
> -       /* enable protected mode */
> -       OUT_PKT3(ring, CP_SET_PROTECTED_MODE, 1);
> -       OUT_RING(ring, 1);
> +       if (!a2xx_gpu->protection_disabled) {
> +               /* enable protected mode */
> +               OUT_PKT3(ring, CP_SET_PROTECTED_MODE, 1);
> +               OUT_RING(ring, 1);
> +       }
>
>         adreno_flush(gpu, ring, REG_AXXX_CP_RB_WPTR);
>         return a2xx_idle(gpu);
> @@ -101,6 +108,7 @@ static bool a2xx_me_init(struct msm_gpu *gpu)
>  static int a2xx_hw_init(struct msm_gpu *gpu)
>  {
>         struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
> +       struct a2xx_gpu *a2xx_gpu = to_a2xx_gpu(adreno_gpu);
>         dma_addr_t pt_base, tran_error;
>         uint32_t *ptr, len;
>         int i, ret;
> @@ -221,6 +229,17 @@ static int a2xx_hw_init(struct msm_gpu *gpu)
>         len = adreno_gpu->fw[ADRENO_FW_PM4]->size / 4;
>         DBG("loading PM4 ucode version: %x", ptr[1]);
>
> +       /*
> +        * New firmware files seem to have GPU and firmware version in this
> +        * word (0x20xxxx for A200, 0x220xxx for A220, 0x225xxx for A225).
> +        * Older firmware files, which lack protection support, have 0 instead.
> +        */
> +       if (ptr[1] == 0) {

I don't really have a good enough picture about all the possible fw
versions floating around out there, esp back to the pre-qc days, to
know if this is a good enough check.  But I guess we can go with it,
and in the worst case later add an allowlist table of fw checksums (or
similar) if this doesn't turn out to be sufficient, so the overall
approach isn't painting us into a corner.

Reviewed-by: Rob Clark <robdclark at gmail.com>

> +               dev_warn(gpu->dev->dev,
> +                        "Legacy firmware detected, disabling protection support\n");
> +               a2xx_gpu->protection_disabled = true;
> +       }
> +
>         gpu_write(gpu, REG_AXXX_CP_DEBUG,
>                         AXXX_CP_DEBUG_MIU_128BIT_WRITE_ENABLE);
>         gpu_write(gpu, REG_AXXX_CP_ME_RAM_WADDR, 0);
> diff --git a/drivers/gpu/drm/msm/adreno/a2xx_gpu.h b/drivers/gpu/drm/msm/adreno/a2xx_gpu.h
> index 02fba2cb8932..161a075f94af 100644
> --- a/drivers/gpu/drm/msm/adreno/a2xx_gpu.h
> +++ b/drivers/gpu/drm/msm/adreno/a2xx_gpu.h
> @@ -15,6 +15,7 @@
>  struct a2xx_gpu {
>         struct adreno_gpu base;
>         bool pm_enabled;
> +       bool protection_disabled;
>  };
>  #define to_a2xx_gpu(x) container_of(x, struct a2xx_gpu, base)
>
> --
> 2.39.0
>