[PATCH] Revert "drm/amdkfd: Relocate TBA/TMA to opposite side of VM hole"

[Alex Deucher]

+ Jay, Felix

On Wed, Jan 3, 2024 at 5:16 AM Kaibo Ma <ent3rm4n at gmail.com> wrote:
>
> That commit causes NULL pointer dereferences in dmesgs when
> running applications using ROCm, including clinfo, blender,
> and PyTorch, since v6.6.1. Revert it to fix blender again.
>
> This reverts commit 96c211f1f9ef82183493f4ceed4e347b52849149.
>
> Closes: https://github.com/ROCm/ROCm/issues/2596
> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/2991
> Signed-off-by: Kaibo Ma <ent3rm4n at gmail.com>
> ---
>  drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c | 26 ++++++++++----------
>  1 file changed, 13 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c b/drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c
> index 62b205dac..6604a3f99 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c
> @@ -330,12 +330,6 @@ static void kfd_init_apertures_vi(struct kfd_process_device *pdd, uint8_t id)
>         pdd->gpuvm_limit =
>                 pdd->dev->kfd->shared_resources.gpuvm_size - 1;
>
> -       /* dGPUs: the reserved space for kernel
> -        * before SVM
> -        */
> -       pdd->qpd.cwsr_base = SVM_CWSR_BASE;
> -       pdd->qpd.ib_base = SVM_IB_BASE;
> -
>         pdd->scratch_base = MAKE_SCRATCH_APP_BASE_VI();
>         pdd->scratch_limit = MAKE_SCRATCH_APP_LIMIT(pdd->scratch_base);
>  }
> @@ -345,18 +339,18 @@ static void kfd_init_apertures_v9(struct kfd_process_device *pdd, uint8_t id)
>         pdd->lds_base = MAKE_LDS_APP_BASE_V9();
>         pdd->lds_limit = MAKE_LDS_APP_LIMIT(pdd->lds_base);
>
> -       pdd->gpuvm_base = PAGE_SIZE;
> +        /* Raven needs SVM to support graphic handle, etc. Leave the small
> +         * reserved space before SVM on Raven as well, even though we don't
> +         * have to.
> +         * Set gpuvm_base and gpuvm_limit to CANONICAL addresses so that they
> +         * are used in Thunk to reserve SVM.
> +         */
> +        pdd->gpuvm_base = SVM_USER_BASE;
>         pdd->gpuvm_limit =
>                 pdd->dev->kfd->shared_resources.gpuvm_size - 1;
>
>         pdd->scratch_base = MAKE_SCRATCH_APP_BASE_V9();
>         pdd->scratch_limit = MAKE_SCRATCH_APP_LIMIT(pdd->scratch_base);
> -
> -       /*
> -        * Place TBA/TMA on opposite side of VM hole to prevent
> -        * stray faults from triggering SVM on these pages.
> -        */
> -       pdd->qpd.cwsr_base = pdd->dev->kfd->shared_resources.gpuvm_size;
>  }
>
>  int kfd_init_apertures(struct kfd_process *process)
> @@ -413,6 +407,12 @@ int kfd_init_apertures(struct kfd_process *process)
>                                         return -EINVAL;
>                                 }
>                         }
> +
> +                        /* dGPUs: the reserved space for kernel
> +                         * before SVM
> +                         */
> +                        pdd->qpd.cwsr_base = SVM_CWSR_BASE;
> +                        pdd->qpd.ib_base = SVM_IB_BASE;
>                 }
>
>                 dev_dbg(kfd_device, "node id %u\n", id);
> --
> 2.42.0
>