[PATCH v3 7/9] drm/amdgpu/ttm: Initialize AMDGPU_PL_MMIO_REMAP Heap

[Alex Deucher]

On Thu, Aug 28, 2025 at 5:53 AM Srinivasan Shanmugam
<srinivasan.shanmugam at amd.com> wrote:
>
> Add a one-page TTM range manager for AMDGPU_PL_MMIO_REMAP via
> amdgpu_ttm_init_on_chip(). This only registers the placement with TTM;
> no BO is allocated in this patch.
>
> The singleton 4K remap BO is created and freed in the following patch.
>
> This split follows to separate heap bring-up from BO allocation.
>
> Cc: Christian König <christian.koenig at amd.com>
> Suggested-by: Alex Deucher <alexander.deucher at amd.com>
> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam at amd.com>

Reviewed-by: Alex Deucher <alexander.deucher at amd.com>


> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 9211d250fcfb..7822d8969c9f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -2020,6 +2020,13 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
>                 return r;
>         }
>
> +       /* Initialize MMIO-remap pool (single page 4K) */
> +       r = amdgpu_ttm_init_on_chip(adev, AMDGPU_PL_MMIO_REMAP, 1);
> +       if (r) {
> +               dev_err(adev->dev, "Failed initializing MMIO-remap heap.\n");
> +               return r;
> +       }
> +
>         /* Initialize preemptible memory pool */
>         r = amdgpu_preempt_mgr_init(adev);
>         if (r) {
> @@ -2082,6 +2089,7 @@ void amdgpu_ttm_fini(struct amdgpu_device *adev)
>         }
>         amdgpu_bo_free_kernel(&adev->mman.sdma_access_bo, NULL,
>                                         &adev->mman.sdma_access_ptr);
> +
>         amdgpu_ttm_fw_reserve_vram_fini(adev);
>         amdgpu_ttm_drv_reserve_vram_fini(adev);
>
> @@ -2103,6 +2111,7 @@ void amdgpu_ttm_fini(struct amdgpu_device *adev)
>         ttm_range_man_fini(&adev->mman.bdev, AMDGPU_PL_GWS);
>         ttm_range_man_fini(&adev->mman.bdev, AMDGPU_PL_OA);
>         ttm_range_man_fini(&adev->mman.bdev, AMDGPU_PL_DOORBELL);
> +       ttm_range_man_fini(&adev->mman.bdev, AMDGPU_PL_MMIO_REMAP);
>         ttm_device_fini(&adev->mman.bdev);
>         adev->mman.initialized = false;
>         dev_info(adev->dev, "amdgpu: ttm finalized\n");
> --
> 2.34.1
>