[PATCH] drm/msm/a6xx: request memory region

[Rob Clark]

On Sat, Jun 8, 2024 at 8:44 AM Kiarash Hajian
<kiarash8112hajian at gmail.com> wrote:
>
> The driver's memory regions are currently just ioremap()ed, but not
> reserved through a request. That's not a bug, but having the request is
> a little more robust.
>
> Implement the region-request through the corresponding managed
> devres-function.
>
> Signed-off-by: Kiarash Hajian <kiarash8112hajian at gmail.com>
> ---
> Changes in v6:
>     -Fix compile error
>     -Link to v5: https://lore.kernel.org/all/20240607-memory-v1-1-8664f52fc2a1@gmail.com
>
> Changes in v5:
>     - Fix error hanlding problems.
>     - Link to v4: https://lore.kernel.org/r/20240512-msm-adreno-memory-region-v4-1-3881a64088e6@gmail.com
>
> Changes in v4:
>     - Combine v3 commits into a singel commit
>     - Link to v3: https://lore.kernel.org/r/20240512-msm-adreno-memory-region-v3-0-0a728ad45010@gmail.com
>
> Changes in v3:
>     - Remove redundant devm_iounmap calls, relying on devres for automatic resource cleanup.
>
> Changes in v2:
>     - update the subject prefix to "drm/msm/a6xx:", to match the majority of other changes to this file.
> ---
>  drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 33 +++++++++++----------------------
>  1 file changed, 11 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> index 8bea8ef26f77..d26cc6254ef9 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> @@ -525,7 +525,7 @@ static void a6xx_gmu_rpmh_init(struct a6xx_gmu *gmu)
>         bool pdc_in_aop = false;
>
>         if (IS_ERR(pdcptr))
> -               goto err;
> +               return;
>
>         if (adreno_is_a650(adreno_gpu) ||
>             adreno_is_a660_family(adreno_gpu) ||
> @@ -541,7 +541,7 @@ static void a6xx_gmu_rpmh_init(struct a6xx_gmu *gmu)
>         if (!pdc_in_aop) {
>                 seqptr = a6xx_gmu_get_mmio(pdev, "gmu_pdc_seq");
>                 if (IS_ERR(seqptr))
> -                       goto err;
> +                       return;
>         }
>
>         /* Disable SDE clock gating */
> @@ -633,12 +633,6 @@ static void a6xx_gmu_rpmh_init(struct a6xx_gmu *gmu)
>         wmb();
>
>         a6xx_rpmh_stop(gmu);
> -
> -err:
> -       if (!IS_ERR_OR_NULL(pdcptr))
> -               iounmap(pdcptr);
> -       if (!IS_ERR_OR_NULL(seqptr))
> -               iounmap(seqptr);
>  }
>
>  /*
> @@ -1503,7 +1497,7 @@ static void __iomem *a6xx_gmu_get_mmio(struct platform_device *pdev,
>                 return ERR_PTR(-EINVAL);
>         }
>
> -       ret = ioremap(res->start, resource_size(res));
> +       ret = devm_ioremap_resource(&pdev->dev, res);

So, this doesn't actually work, failing in __request_region_locked(),
because the gmu region partially overlaps with the gpucc region (which
is busy).  I think this is intentional, since gmu is controlling the
gpu clocks, etc.  In particular REG_A6XX_GPU_CC_GX_GDSCR is in this
overlapping region.  Maybe Akhil knows more about GMU.

BR,
-R

>         if (!ret) {
>                 DRM_DEV_ERROR(&pdev->dev, "Unable to map the %s registers\n", name);
>                 return ERR_PTR(-EINVAL);
> @@ -1613,13 +1607,13 @@ int a6xx_gmu_wrapper_init(struct a6xx_gpu *a6xx_gpu, struct device_node *node)
>         gmu->mmio = a6xx_gmu_get_mmio(pdev, "gmu");
>         if (IS_ERR(gmu->mmio)) {
>                 ret = PTR_ERR(gmu->mmio);
> -               goto err_mmio;
> +               goto err_cleanup;
>         }
>
>         gmu->cxpd = dev_pm_domain_attach_by_name(gmu->dev, "cx");
>         if (IS_ERR(gmu->cxpd)) {
>                 ret = PTR_ERR(gmu->cxpd);
> -               goto err_mmio;
> +               goto err_cleanup;
>         }
>
>         if (!device_link_add(gmu->dev, gmu->cxpd, DL_FLAG_PM_RUNTIME)) {
> @@ -1635,7 +1629,7 @@ int a6xx_gmu_wrapper_init(struct a6xx_gpu *a6xx_gpu, struct device_node *node)
>         gmu->gxpd = dev_pm_domain_attach_by_name(gmu->dev, "gx");
>         if (IS_ERR(gmu->gxpd)) {
>                 ret = PTR_ERR(gmu->gxpd);
> -               goto err_mmio;
> +               goto err_cleanup;
>         }
>
>         gmu->initialized = true;
> @@ -1645,9 +1639,7 @@ int a6xx_gmu_wrapper_init(struct a6xx_gpu *a6xx_gpu, struct device_node *node)
>  detach_cxpd:
>         dev_pm_domain_detach(gmu->cxpd, false);
>
> -err_mmio:
> -       iounmap(gmu->mmio);
> -
> +err_cleanup:
>         /* Drop reference taken in of_find_device_by_node */
>         put_device(gmu->dev);
>
> @@ -1762,7 +1754,7 @@ int a6xx_gmu_init(struct a6xx_gpu *a6xx_gpu, struct device_node *node)
>                 gmu->rscc = a6xx_gmu_get_mmio(pdev, "rscc");
>                 if (IS_ERR(gmu->rscc)) {
>                         ret = -ENODEV;
> -                       goto err_mmio;
> +                       goto err_cleanup;
>                 }
>         } else {
>                 gmu->rscc = gmu->mmio + 0x23000;
> @@ -1774,13 +1766,13 @@ int a6xx_gmu_init(struct a6xx_gpu *a6xx_gpu, struct device_node *node)
>
>         if (gmu->hfi_irq < 0 || gmu->gmu_irq < 0) {
>                 ret = -ENODEV;
> -               goto err_mmio;
> +               goto err_cleanup;
>         }
>
>         gmu->cxpd = dev_pm_domain_attach_by_name(gmu->dev, "cx");
>         if (IS_ERR(gmu->cxpd)) {
>                 ret = PTR_ERR(gmu->cxpd);
> -               goto err_mmio;
> +               goto err_cleanup;
>         }
>
>         link = device_link_add(gmu->dev, gmu->cxpd, DL_FLAG_PM_RUNTIME);
> @@ -1824,10 +1816,7 @@ int a6xx_gmu_init(struct a6xx_gpu *a6xx_gpu, struct device_node *node)
>  detach_cxpd:
>         dev_pm_domain_detach(gmu->cxpd, false);
>
> -err_mmio:
> -       iounmap(gmu->mmio);
> -       if (platform_get_resource_byname(pdev, IORESOURCE_MEM, "rscc"))
> -               iounmap(gmu->rscc);
> +err_cleanup:
>         free_irq(gmu->gmu_irq, gmu);
>         free_irq(gmu->hfi_irq, gmu);
>
>
> ---
> base-commit: 1b294a1f35616977caddaddf3e9d28e576a1adbc
> change-id: 20240608-adreno-98c412bfdc03
>
> Best regards,
> --
> Kiarash Hajian <kiarash8112hajian at gmail.com>
>