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

[Andrey Grodzovsky <andrey.grodzovsky@xxxxxxx>]

On 2021-04-29 3:19 a.m., Christian König wrote:
> 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.

As we discussed internally, will drop the entire explicit BOs unmapping
approach as unmapping the VRAM bar alone will give the same results.

Andrey

> > 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)