Re: [PATCH v5 16/27] drm/amdgpu: Unmap all MMIO mappings

[Christian König <ckoenig.leichtzumerken@xxxxxxxxx>]

Am 28.04.21 um 17:11 schrieb Andrey Grodzovsky:
> Access to those must be prevented post pci_remove

That is certainly a no-go. We want to get rid of the kernel pointers in 
BOs, not add another one.

Christian.

> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@xxxxxxx>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h        |  5 +++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 38 ++++++++++++++++++++--
>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 28 ++++++++++++++--
>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.h |  5 +++
>   4 files changed, 71 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 30a24db5f4d1..3e4755fc10c8 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -1056,6 +1056,11 @@ struct amdgpu_device {
>   	struct pci_saved_state          *pci_state;
>   
>   	struct list_head                device_bo_list;
> +
> +	/* List of all MMIO BOs */
> +	struct list_head                mmio_list;
> +	struct mutex                    mmio_list_lock;
> +
>   };
>   
>   static inline struct amdgpu_device *drm_to_adev(struct drm_device *ddev)
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 22b09c4db255..3ddad6cba62d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -3320,6 +3320,9 @@ int amdgpu_device_init(struct amdgpu_device *adev,
>   	INIT_LIST_HEAD(&adev->shadow_list);
>   	mutex_init(&adev->shadow_list_lock);
>   
> +	INIT_LIST_HEAD(&adev->mmio_list);
> +	mutex_init(&adev->mmio_list_lock);
> +
>   	INIT_DELAYED_WORK(&adev->delayed_init_work,
>   			  amdgpu_device_delayed_init_work_handler);
>   	INIT_DELAYED_WORK(&adev->gfx.gfx_off_delay_work,
> @@ -3636,6 +3639,36 @@ static void amdgpu_clear_dma_mappings(struct amdgpu_device *adev)
>   	spin_unlock(&adev->mman.bdev.lru_lock);
>   }
>   
> +static void amdgpu_device_unmap_mmio(struct amdgpu_device *adev)
> +{
> +	struct amdgpu_bo *bo;
> +
> +	/* Clear all CPU mappings pointing to this device */
> +	unmap_mapping_range(adev->ddev.anon_inode->i_mapping, 0, 0, 1);
> +
> +	/* Unmap all MMIO mapped kernel BOs */
> +	mutex_lock(&adev->mmio_list_lock);
> +	list_for_each_entry(bo, &adev->mmio_list, mmio_list) {
> +		amdgpu_bo_kunmap(bo);
> +		if (*bo->kmap_ptr)
> +			*bo->kmap_ptr = NULL;
> +	}
> +	mutex_unlock(&adev->mmio_list_lock);
> +
> +	/* Unmap all mapped bars - Doorbell, registers and VRAM */
> +	amdgpu_device_doorbell_fini(adev);
> +
> +	iounmap(adev->rmmio);
> +	adev->rmmio = NULL;
> +	if (adev->mman.aper_base_kaddr)
> +		iounmap(adev->mman.aper_base_kaddr);
> +	adev->mman.aper_base_kaddr = NULL;
> +
> +	/* Memory manager related */
> +	arch_phys_wc_del(adev->gmc.vram_mtrr);
> +	arch_io_free_memtype_wc(adev->gmc.aper_base, adev->gmc.aper_size);
> +}
> +
>   /**
>    * amdgpu_device_fini - tear down the driver
>    *
> @@ -3683,6 +3716,8 @@ void amdgpu_device_fini_hw(struct amdgpu_device *adev)
>   	amdgpu_clear_dma_mappings(adev);
>   
>   	amdgpu_gart_dummy_page_fini(adev);
> +
> +	amdgpu_device_unmap_mmio(adev);
>   }
>   
>   void amdgpu_device_fini_sw(struct amdgpu_device *adev)
> @@ -3713,9 +3748,6 @@ void amdgpu_device_fini_sw(struct amdgpu_device *adev)
>   	if (adev->rio_mem)
>   		pci_iounmap(adev->pdev, adev->rio_mem);
>   	adev->rio_mem = NULL;
> -	iounmap(adev->rmmio);
> -	adev->rmmio = NULL;
> -	amdgpu_device_doorbell_fini(adev);
>   
>   	if (IS_ENABLED(CONFIG_PERF_EVENTS))
>   		amdgpu_pmu_fini(adev);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> index 62d829f5e62c..9b05e3b96fa0 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> @@ -531,6 +531,9 @@ static int amdgpu_bo_do_create(struct amdgpu_device *adev,
>   		return -ENOMEM;
>   	drm_gem_private_object_init(adev_to_drm(adev), &bo->tbo.base, size);
>   	INIT_LIST_HEAD(&bo->shadow_list);
> +
> +	INIT_LIST_HEAD(&bo->mmio_list);
> +
>   	bo->vm_bo = NULL;
>   	bo->preferred_domains = bp->preferred_domain ? bp->preferred_domain :
>   		bp->domain;
> @@ -774,9 +777,21 @@ int amdgpu_bo_kmap(struct amdgpu_bo *bo, void **ptr)
>   	if (r)
>   		return r;
>   
> -	if (ptr)
> +	if (bo->kmap.bo_kmap_type == ttm_bo_map_iomap) {
> +		struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> +
> +		mutex_lock(&adev->mmio_list_lock);
> +		list_add_tail(&bo->mmio_list, &adev->mmio_list);
> +		mutex_unlock(&adev->mmio_list_lock);
> +	}
> +
> +	if (ptr) {
>   		*ptr = amdgpu_bo_kptr(bo);
>   
> +		if (bo->kmap.bo_kmap_type == ttm_bo_map_iomap)
> +			bo->kmap_ptr = ptr;
> +	}
> +
>   	return 0;
>   }
>   
> @@ -804,8 +819,17 @@ void *amdgpu_bo_kptr(struct amdgpu_bo *bo)
>    */
>   void amdgpu_bo_kunmap(struct amdgpu_bo *bo)
>   {
> -	if (bo->kmap.bo)
> +	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> +
> +	if (bo->kmap.bo) {
> +		if (bo->kmap.bo_kmap_type == ttm_bo_map_iomap) {
> +			mutex_lock(&adev->mmio_list_lock);
> +			list_del_init(&bo->mmio_list);
> +			mutex_unlock(&adev->mmio_list_lock);
> +		}
> +
>   		ttm_bo_kunmap(&bo->kmap);
> +	}
>   }
>   
>   /**
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> index 5ae8555ef275..3129d9bbfa22 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> @@ -112,6 +112,11 @@ struct amdgpu_bo {
>   	struct kgd_mem                  *kfd_bo;
>   
>   	struct list_head		bo;
> +
> +	struct list_head                mmio_list;
> +	/* Address of kernel VA pointer to MMIO so they can be updated post remap */
> +	void				**kmap_ptr;
> +
>   };
>   
>   static inline struct amdgpu_bo *ttm_to_amdgpu_bo(struct ttm_buffer_object *tbo)