Re: [PATCH v5 06/27] drm/amdgpu: Handle IOMMU enabled case.

[Andrey Grodzovsky <andrey.grodzovsky@xxxxxxx>]

On 2021-05-04 1:05 p.m., Felix Kuehling wrote:
> Am 2021-04-28 um 11:11 a.m. schrieb Andrey Grodzovsky:
> > Handle all DMA IOMMU gropup related dependencies before the
> > group is removed.
> >
> > v5: Drop IOMMU notifier and switch to lockless call to ttm_tt_unpopulate
> >
> > Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@xxxxxxx>
> > ---
> >   drivers/gpu/drm/amd/amdgpu/amdgpu.h        |  2 ++
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 31 ++++++++++++++++++++--
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c   |  3 +--
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_gart.h   |  1 +
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c    |  9 +++++++
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 13 ++++++++-
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_object.h |  2 ++
> >   drivers/gpu/drm/amd/amdgpu/cik_ih.c        |  1 -
> >   drivers/gpu/drm/amd/amdgpu/cz_ih.c         |  1 -
> >   drivers/gpu/drm/amd/amdgpu/iceland_ih.c    |  1 -
> >   drivers/gpu/drm/amd/amdgpu/navi10_ih.c     |  3 ---
> >   drivers/gpu/drm/amd/amdgpu/si_ih.c         |  1 -
> >   drivers/gpu/drm/amd/amdgpu/tonga_ih.c      |  1 -
> >   drivers/gpu/drm/amd/amdgpu/vega10_ih.c     |  3 ---
> >   14 files changed, 56 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > index fddb82897e5d..30a24db5f4d1 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > @@ -1054,6 +1054,8 @@ struct amdgpu_device {
> >   
> >   	bool                            in_pci_err_recovery;
> >   	struct pci_saved_state          *pci_state;
> > +
> > +	struct list_head                device_bo_list;
> >   };
> >   
> >   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 46d646c40338..91594ddc2459 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > @@ -70,6 +70,7 @@
> >   #include <drm/task_barrier.h>
> >   #include <linux/pm_runtime.h>
> >   
> > +
> >   MODULE_FIRMWARE("amdgpu/vega10_gpu_info.bin");
> >   MODULE_FIRMWARE("amdgpu/vega12_gpu_info.bin");
> >   MODULE_FIRMWARE("amdgpu/raven_gpu_info.bin");
> > @@ -3211,7 +3212,6 @@ static const struct attribute *amdgpu_dev_attributes[] = {
> >   	NULL
> >   };
> >   
> > -
> >   /**
> >    * amdgpu_device_init - initialize the driver
> >    *
> > @@ -3316,6 +3316,8 @@ int amdgpu_device_init(struct amdgpu_device *adev,
> >   
> >   	INIT_WORK(&adev->xgmi_reset_work, amdgpu_device_xgmi_reset_func);
> >   
> > +	INIT_LIST_HEAD(&adev->device_bo_list);
> > +
> >   	adev->gfx.gfx_off_req_count = 1;
> >   	adev->pm.ac_power = power_supply_is_system_supplied() > 0;
> >   
> > @@ -3601,6 +3603,28 @@ int amdgpu_device_init(struct amdgpu_device *adev,
> >   	return r;
> >   }
> >   
> > +static void amdgpu_clear_dma_mappings(struct amdgpu_device *adev)
> > +{
> > +	struct amdgpu_bo *bo = NULL;
> > +
> > +	/*
> > +	 * Unmaps all DMA mappings before device will be removed from it's
> > +	 * IOMMU group otherwise in case of IOMMU enabled system a crash
> > +	 * will happen.
> > +	 */
> > +
> > +	spin_lock(&adev->mman.bdev.lru_lock);
> > +	while (!list_empty(&adev->device_bo_list)) {
> > +		bo = list_first_entry(&adev->device_bo_list, struct amdgpu_bo, bo);
> > +		list_del_init(&bo->bo);
> > +		spin_unlock(&adev->mman.bdev.lru_lock);
> > +		if (bo->tbo.ttm)
> > +			ttm_tt_unpopulate(bo->tbo.bdev, bo->tbo.ttm);
>
> I have a patch pending (reviewed by Christian) that moves the
> dma-unmapping to amdgpu_ttm_backend_unbind. With that patch,
> ttm_tt_unpopulate would no longer be the right way to remove the DMA
> mapping.
>
> Maybe I'd need to add a check in ttm_tt_unpopulate to call
> backend_unbind first, if necessary. Or is there some other mechanism
> that moves the BO to the CPU domain before unpopulating it?
>
> Regards,
>    Felix

At least in the context of this patch we don't move the BO to system
domain but rather preemptively remove DMA mappings before IOMMU grpoup
is gone post pci_remove. So yes, I would say yes, we need to check here
for backend_unbind first.

Andrey

> > +		spin_lock(&adev->mman.bdev.lru_lock);
> > +	}
> > +	spin_unlock(&adev->mman.bdev.lru_lock);
> > +}
> > +
> >   /**
> >    * amdgpu_device_fini - tear down the driver
> >    *
> > @@ -3639,12 +3663,15 @@ void amdgpu_device_fini_hw(struct amdgpu_device *adev)
> >   		amdgpu_ucode_sysfs_fini(adev);
> >   	sysfs_remove_files(&adev->dev->kobj, amdgpu_dev_attributes);
> >   
> > -
> >   	amdgpu_fbdev_fini(adev);
> >   
> >   	amdgpu_irq_fini_hw(adev);
> >   
> >   	amdgpu_device_ip_fini_early(adev);
> > +
> > +	amdgpu_clear_dma_mappings(adev);
> > +
> > +	amdgpu_gart_dummy_page_fini(adev);
> >   }
> >   
> >   void amdgpu_device_fini_sw(struct amdgpu_device *adev)
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
> > index fde2d899b2c4..49cdcaf8512d 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
> > @@ -92,7 +92,7 @@ static int amdgpu_gart_dummy_page_init(struct amdgpu_device *adev)
> >    *
> >    * Frees the dummy page used by the driver (all asics).
> >    */
> > -static void amdgpu_gart_dummy_page_fini(struct amdgpu_device *adev)
> > +void amdgpu_gart_dummy_page_fini(struct amdgpu_device *adev)
> >   {
> >   	if (!adev->dummy_page_addr)
> >   		return;
> > @@ -397,5 +397,4 @@ void amdgpu_gart_fini(struct amdgpu_device *adev)
> >   	vfree(adev->gart.pages);
> >   	adev->gart.pages = NULL;
> >   #endif
> > -	amdgpu_gart_dummy_page_fini(adev);
> >   }
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.h
> > index afa2e2877d87..5678d9c105ab 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.h
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.h
> > @@ -61,6 +61,7 @@ int amdgpu_gart_table_vram_pin(struct amdgpu_device *adev);
> >   void amdgpu_gart_table_vram_unpin(struct amdgpu_device *adev);
> >   int amdgpu_gart_init(struct amdgpu_device *adev);
> >   void amdgpu_gart_fini(struct amdgpu_device *adev);
> > +void amdgpu_gart_dummy_page_fini(struct amdgpu_device *adev);
> >   int amdgpu_gart_unbind(struct amdgpu_device *adev, uint64_t offset,
> >   		       int pages);
> >   int amdgpu_gart_map(struct amdgpu_device *adev, uint64_t offset,
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> > index 63e815c27585..a922154953a7 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> > @@ -326,6 +326,15 @@ void amdgpu_irq_fini_hw(struct amdgpu_device *adev)
> >   		if (!amdgpu_device_has_dc_support(adev))
> >   			flush_work(&adev->hotplug_work);
> >   	}
> > +
> > +	if (adev->irq.ih_soft.ring)
> > +		amdgpu_ih_ring_fini(adev, &adev->irq.ih_soft);
> > +	if (adev->irq.ih.ring)
> > +		amdgpu_ih_ring_fini(adev, &adev->irq.ih);
> > +	if (adev->irq.ih1.ring)
> > +		amdgpu_ih_ring_fini(adev, &adev->irq.ih1);
> > +	if (adev->irq.ih2.ring)
> > +		amdgpu_ih_ring_fini(adev, &adev->irq.ih2);
> >   }
> >   
> >   /**
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> > index 485f249d063a..62d829f5e62c 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> > @@ -68,8 +68,13 @@ static void amdgpu_bo_destroy(struct ttm_buffer_object *tbo)
> >   		list_del_init(&bo->shadow_list);
> >   		mutex_unlock(&adev->shadow_list_lock);
> >   	}
> > -	amdgpu_bo_unref(&bo->parent);
> >   
> > +
> > +	spin_lock(&adev->mman.bdev.lru_lock);
> > +	list_del(&bo->bo);
> > +	spin_unlock(&adev->mman.bdev.lru_lock);
> > +
> > +	amdgpu_bo_unref(&bo->parent);
> >   	kfree(bo->metadata);
> >   	kfree(bo);
> >   }
> > @@ -585,6 +590,12 @@ static int amdgpu_bo_do_create(struct amdgpu_device *adev,
> >   	if (bp->type == ttm_bo_type_device)
> >   		bo->flags &= ~AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;
> >   
> > +	INIT_LIST_HEAD(&bo->bo);
> > +
> > +	spin_lock(&adev->mman.bdev.lru_lock);
> > +	list_add_tail(&bo->bo, &adev->device_bo_list);
> > +	spin_unlock(&adev->mman.bdev.lru_lock);
> > +
> >   	return 0;
> >   
> >   fail_unreserve:
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> > index 9ac37569823f..5ae8555ef275 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> > @@ -110,6 +110,8 @@ struct amdgpu_bo {
> >   	struct list_head		shadow_list;
> >   
> >   	struct kgd_mem                  *kfd_bo;
> > +
> > +	struct list_head		bo;
> >   };
> >   
> >   static inline struct amdgpu_bo *ttm_to_amdgpu_bo(struct ttm_buffer_object *tbo)
> > diff --git a/drivers/gpu/drm/amd/amdgpu/cik_ih.c b/drivers/gpu/drm/amd/amdgpu/cik_ih.c
> > index 183d44a6583c..df385ffc9768 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/cik_ih.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/cik_ih.c
> > @@ -310,7 +310,6 @@ static int cik_ih_sw_fini(void *handle)
> >   	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
> >   
> >   	amdgpu_irq_fini_sw(adev);
> > -	amdgpu_ih_ring_fini(adev, &adev->irq.ih);
> >   	amdgpu_irq_remove_domain(adev);
> >   
> >   	return 0;
> > diff --git a/drivers/gpu/drm/amd/amdgpu/cz_ih.c b/drivers/gpu/drm/amd/amdgpu/cz_ih.c
> > index d32743949003..b8c47e0cf37a 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/cz_ih.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/cz_ih.c
> > @@ -302,7 +302,6 @@ static int cz_ih_sw_fini(void *handle)
> >   	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
> >   
> >   	amdgpu_irq_fini_sw(adev);
> > -	amdgpu_ih_ring_fini(adev, &adev->irq.ih);
> >   	amdgpu_irq_remove_domain(adev);
> >   
> >   	return 0;
> > diff --git a/drivers/gpu/drm/amd/amdgpu/iceland_ih.c b/drivers/gpu/drm/amd/amdgpu/iceland_ih.c
> > index da96c6013477..ddfe4eaeea05 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/iceland_ih.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/iceland_ih.c
> > @@ -301,7 +301,6 @@ static int iceland_ih_sw_fini(void *handle)
> >   	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
> >   
> >   	amdgpu_irq_fini_sw(adev);
> > -	amdgpu_ih_ring_fini(adev, &adev->irq.ih);
> >   	amdgpu_irq_remove_domain(adev);
> >   
> >   	return 0;
> > diff --git a/drivers/gpu/drm/amd/amdgpu/navi10_ih.c b/drivers/gpu/drm/amd/amdgpu/navi10_ih.c
> > index 5eea4550b856..e171a9e78544 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/navi10_ih.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/navi10_ih.c
> > @@ -571,9 +571,6 @@ static int navi10_ih_sw_fini(void *handle)
> >   
> >   	amdgpu_irq_fini_sw(adev);
> >   	amdgpu_ih_ring_fini(adev, &adev->irq.ih_soft);
> > -	amdgpu_ih_ring_fini(adev, &adev->irq.ih2);
> > -	amdgpu_ih_ring_fini(adev, &adev->irq.ih1);
> > -	amdgpu_ih_ring_fini(adev, &adev->irq.ih);
> >   
> >   	return 0;
> >   }
> > diff --git a/drivers/gpu/drm/amd/amdgpu/si_ih.c b/drivers/gpu/drm/amd/amdgpu/si_ih.c
> > index 751307f3252c..9a24f17a5750 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/si_ih.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/si_ih.c
> > @@ -176,7 +176,6 @@ static int si_ih_sw_fini(void *handle)
> >   	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
> >   
> >   	amdgpu_irq_fini_sw(adev);
> > -	amdgpu_ih_ring_fini(adev, &adev->irq.ih);
> >   
> >   	return 0;
> >   }
> > diff --git a/drivers/gpu/drm/amd/amdgpu/tonga_ih.c b/drivers/gpu/drm/amd/amdgpu/tonga_ih.c
> > index 973d80ec7f6c..b08905d1c00f 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/tonga_ih.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/tonga_ih.c
> > @@ -313,7 +313,6 @@ static int tonga_ih_sw_fini(void *handle)
> >   	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
> >   
> >   	amdgpu_irq_fini_sw(adev);
> > -	amdgpu_ih_ring_fini(adev, &adev->irq.ih);
> >   	amdgpu_irq_remove_domain(adev);
> >   
> >   	return 0;
> > diff --git a/drivers/gpu/drm/amd/amdgpu/vega10_ih.c b/drivers/gpu/drm/amd/amdgpu/vega10_ih.c
> > index 2d0094c276ca..8c8abc00f710 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/vega10_ih.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/vega10_ih.c
> > @@ -525,9 +525,6 @@ static int vega10_ih_sw_fini(void *handle)
> >   
> >   	amdgpu_irq_fini_sw(adev);
> >   	amdgpu_ih_ring_fini(adev, &adev->irq.ih_soft);
> > -	amdgpu_ih_ring_fini(adev, &adev->irq.ih2);
> > -	amdgpu_ih_ring_fini(adev, &adev->irq.ih1);
> > -	amdgpu_ih_ring_fini(adev, &adev->irq.ih);
> >   
> >   	return 0;
> >   }