Re: [PATCH 9/9] drm/exynos: Convert g2d_userptr_get_dma_addr() to use get_vaddr_frames()

[Inki Dae <inki.dae@samsung.com>]

On 2015e?? 07i?? 17i? 1/4  19:20, Hans Verkuil wrote:
> On 07/13/2015 04:55 PM, Jan Kara wrote:
>> From: Jan Kara <jack@suse.cz>
>>
>> Convert g2d_userptr_get_dma_addr() to pin pages using get_vaddr_frames().
>> This removes the knowledge about vmas and mmap_sem locking from exynos
>> driver. Also it fixes a problem that the function has been mapping user
>> provided address without holding mmap_sem.
> 
> I'd like to see an Ack from one of the exynos drm driver maintainers before
> I merge this.
> 
> Inki, Marek?

I already gave Ack but it seems that Jan missed it while updating.

Anyway,
Acked-by: Inki Dae <inki.dae@samsung.com>

Thanks,
Inki Dae

> 
> Regards,
> 
> 	Hans
> 
>>
>> Signed-off-by: Jan Kara <jack@suse.cz>
>> ---
>>  drivers/gpu/drm/exynos/Kconfig          |  1 +
>>  drivers/gpu/drm/exynos/exynos_drm_g2d.c | 91 ++++++++++---------------------
>>  drivers/gpu/drm/exynos/exynos_drm_gem.c | 97 ---------------------------------
>>  3 files changed, 30 insertions(+), 159 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig
>> index 43003c4ad80b..b364562dc6c1 100644
>> --- a/drivers/gpu/drm/exynos/Kconfig
>> +++ b/drivers/gpu/drm/exynos/Kconfig
>> @@ -77,6 +77,7 @@ config DRM_EXYNOS_VIDI
>>  config DRM_EXYNOS_G2D
>>  	bool "Exynos DRM G2D"
>>  	depends on DRM_EXYNOS && !VIDEO_SAMSUNG_S5P_G2D
>> +	select FRAME_VECTOR
>>  	help
>>  	  Choose this option if you want to use Exynos G2D for DRM.
>>  
>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
>> index 81a250830808..1d8d9a508373 100644
>> --- a/drivers/gpu/drm/exynos/exynos_drm_g2d.c
>> +++ b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
>> @@ -190,10 +190,8 @@ struct g2d_cmdlist_userptr {
>>  	dma_addr_t		dma_addr;
>>  	unsigned long		userptr;
>>  	unsigned long		size;
>> -	struct page		**pages;
>> -	unsigned int		npages;
>> +	struct frame_vector	*vec;
>>  	struct sg_table		*sgt;
>> -	struct vm_area_struct	*vma;
>>  	atomic_t		refcount;
>>  	bool			in_pool;
>>  	bool			out_of_list;
>> @@ -363,6 +361,7 @@ static void g2d_userptr_put_dma_addr(struct drm_device *drm_dev,
>>  {
>>  	struct g2d_cmdlist_userptr *g2d_userptr =
>>  					(struct g2d_cmdlist_userptr *)obj;
>> +	struct page **pages;
>>  
>>  	if (!obj)
>>  		return;
>> @@ -382,19 +381,21 @@ out:
>>  	exynos_gem_unmap_sgt_from_dma(drm_dev, g2d_userptr->sgt,
>>  					DMA_BIDIRECTIONAL);
>>  
>> -	exynos_gem_put_pages_to_userptr(g2d_userptr->pages,
>> -					g2d_userptr->npages,
>> -					g2d_userptr->vma);
>> +	pages = frame_vector_pages(g2d_userptr->vec);
>> +	if (!IS_ERR(pages)) {
>> +		int i;
>>  
>> -	exynos_gem_put_vma(g2d_userptr->vma);
>> +		for (i = 0; i < frame_vector_count(g2d_userptr->vec); i++)
>> +			set_page_dirty_lock(pages[i]);
>> +	}
>> +	put_vaddr_frames(g2d_userptr->vec);
>> +	frame_vector_destroy(g2d_userptr->vec);
>>  
>>  	if (!g2d_userptr->out_of_list)
>>  		list_del_init(&g2d_userptr->list);
>>  
>>  	sg_free_table(g2d_userptr->sgt);
>>  	kfree(g2d_userptr->sgt);
>> -
>> -	drm_free_large(g2d_userptr->pages);
>>  	kfree(g2d_userptr);
>>  }
>>  
>> @@ -408,9 +409,7 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev,
>>  	struct exynos_drm_g2d_private *g2d_priv = file_priv->g2d_priv;
>>  	struct g2d_cmdlist_userptr *g2d_userptr;
>>  	struct g2d_data *g2d;
>> -	struct page **pages;
>>  	struct sg_table	*sgt;
>> -	struct vm_area_struct *vma;
>>  	unsigned long start, end;
>>  	unsigned int npages, offset;
>>  	int ret;
>> @@ -456,65 +455,38 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev,
>>  		return ERR_PTR(-ENOMEM);
>>  
>>  	atomic_set(&g2d_userptr->refcount, 1);
>> +	g2d_userptr->size = size;
>>  
>>  	start = userptr & PAGE_MASK;
>>  	offset = userptr & ~PAGE_MASK;
>>  	end = PAGE_ALIGN(userptr + size);
>>  	npages = (end - start) >> PAGE_SHIFT;
>> -	g2d_userptr->npages = npages;
>> -
>> -	pages = drm_calloc_large(npages, sizeof(struct page *));
>> -	if (!pages) {
>> -		DRM_ERROR("failed to allocate pages.\n");
>> -		ret = -ENOMEM;
>> +	g2d_userptr->vec = frame_vector_create(npages);
>> +	if (!g2d_userptr->vec)
>>  		goto err_free;
>> -	}
>>  
>> -	down_read(&current->mm->mmap_sem);
>> -	vma = find_vma(current->mm, userptr);
>> -	if (!vma) {
>> -		up_read(&current->mm->mmap_sem);
>> -		DRM_ERROR("failed to get vm region.\n");
>> +	ret = get_vaddr_frames(start, npages, true, true, g2d_userptr->vec);
>> +	if (ret != npages) {
>> +		DRM_ERROR("failed to get user pages from userptr.\n");
>> +		if (ret < 0)
>> +			goto err_destroy_framevec;
>>  		ret = -EFAULT;
>> -		goto err_free_pages;
>> +		goto err_put_framevec;
>>  	}
>> -
>> -	if (vma->vm_end < userptr + size) {
>> -		up_read(&current->mm->mmap_sem);
>> -		DRM_ERROR("vma is too small.\n");
>> +	if (frame_vector_to_pages(g2d_userptr->vec) < 0) {
>>  		ret = -EFAULT;
>> -		goto err_free_pages;
>> +		goto err_put_framevec;
>>  	}
>>  
>> -	g2d_userptr->vma = exynos_gem_get_vma(vma);
>> -	if (!g2d_userptr->vma) {
>> -		up_read(&current->mm->mmap_sem);
>> -		DRM_ERROR("failed to copy vma.\n");
>> -		ret = -ENOMEM;
>> -		goto err_free_pages;
>> -	}
>> -
>> -	g2d_userptr->size = size;
>> -
>> -	ret = exynos_gem_get_pages_from_userptr(start & PAGE_MASK,
>> -						npages, pages, vma);
>> -	if (ret < 0) {
>> -		up_read(&current->mm->mmap_sem);
>> -		DRM_ERROR("failed to get user pages from userptr.\n");
>> -		goto err_put_vma;
>> -	}
>> -
>> -	up_read(&current->mm->mmap_sem);
>> -	g2d_userptr->pages = pages;
>> -
>>  	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
>>  	if (!sgt) {
>>  		ret = -ENOMEM;
>> -		goto err_free_userptr;
>> +		goto err_put_framevec;
>>  	}
>>  
>> -	ret = sg_alloc_table_from_pages(sgt, pages, npages, offset,
>> -					size, GFP_KERNEL);
>> +	ret = sg_alloc_table_from_pages(sgt,
>> +					frame_vector_pages(g2d_userptr->vec),
>> +					npages, offset, size, GFP_KERNEL);
>>  	if (ret < 0) {
>>  		DRM_ERROR("failed to get sgt from pages.\n");
>>  		goto err_free_sgt;
>> @@ -549,16 +521,11 @@ err_sg_free_table:
>>  err_free_sgt:
>>  	kfree(sgt);
>>  
>> -err_free_userptr:
>> -	exynos_gem_put_pages_to_userptr(g2d_userptr->pages,
>> -					g2d_userptr->npages,
>> -					g2d_userptr->vma);
>> -
>> -err_put_vma:
>> -	exynos_gem_put_vma(g2d_userptr->vma);
>> +err_put_framevec:
>> +	put_vaddr_frames(g2d_userptr->vec);
>>  
>> -err_free_pages:
>> -	drm_free_large(pages);
>> +err_destroy_framevec:
>> +	frame_vector_destroy(g2d_userptr->vec);
>>  
>>  err_free:
>>  	kfree(g2d_userptr);
>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
>> index 0d5b9698d384..47068ae44ced 100644
>> --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
>> +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
>> @@ -378,103 +378,6 @@ int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
>>  	return 0;
>>  }
>>  
>> -struct vm_area_struct *exynos_gem_get_vma(struct vm_area_struct *vma)
>> -{
>> -	struct vm_area_struct *vma_copy;
>> -
>> -	vma_copy = kmalloc(sizeof(*vma_copy), GFP_KERNEL);
>> -	if (!vma_copy)
>> -		return NULL;
>> -
>> -	if (vma->vm_ops && vma->vm_ops->open)
>> -		vma->vm_ops->open(vma);
>> -
>> -	if (vma->vm_file)
>> -		get_file(vma->vm_file);
>> -
>> -	memcpy(vma_copy, vma, sizeof(*vma));
>> -
>> -	vma_copy->vm_mm = NULL;
>> -	vma_copy->vm_next = NULL;
>> -	vma_copy->vm_prev = NULL;
>> -
>> -	return vma_copy;
>> -}
>> -
>> -void exynos_gem_put_vma(struct vm_area_struct *vma)
>> -{
>> -	if (!vma)
>> -		return;
>> -
>> -	if (vma->vm_ops && vma->vm_ops->close)
>> -		vma->vm_ops->close(vma);
>> -
>> -	if (vma->vm_file)
>> -		fput(vma->vm_file);
>> -
>> -	kfree(vma);
>> -}
>> -
>> -int exynos_gem_get_pages_from_userptr(unsigned long start,
>> -						unsigned int npages,
>> -						struct page **pages,
>> -						struct vm_area_struct *vma)
>> -{
>> -	int get_npages;
>> -
>> -	/* the memory region mmaped with VM_PFNMAP. */
>> -	if (vma_is_io(vma)) {
>> -		unsigned int i;
>> -
>> -		for (i = 0; i < npages; ++i, start += PAGE_SIZE) {
>> -			unsigned long pfn;
>> -			int ret = follow_pfn(vma, start, &pfn);
>> -			if (ret)
>> -				return ret;
>> -
>> -			pages[i] = pfn_to_page(pfn);
>> -		}
>> -
>> -		if (i != npages) {
>> -			DRM_ERROR("failed to get user_pages.\n");
>> -			return -EINVAL;
>> -		}
>> -
>> -		return 0;
>> -	}
>> -
>> -	get_npages = get_user_pages(current, current->mm, start,
>> -					npages, 1, 1, pages, NULL);
>> -	get_npages = max(get_npages, 0);
>> -	if (get_npages != npages) {
>> -		DRM_ERROR("failed to get user_pages.\n");
>> -		while (get_npages)
>> -			put_page(pages[--get_npages]);
>> -		return -EFAULT;
>> -	}
>> -
>> -	return 0;
>> -}
>> -
>> -void exynos_gem_put_pages_to_userptr(struct page **pages,
>> -					unsigned int npages,
>> -					struct vm_area_struct *vma)
>> -{
>> -	if (!vma_is_io(vma)) {
>> -		unsigned int i;
>> -
>> -		for (i = 0; i < npages; i++) {
>> -			set_page_dirty_lock(pages[i]);
>> -
>> -			/*
>> -			 * undo the reference we took when populating
>> -			 * the table.
>> -			 */
>> -			put_page(pages[i]);
>> -		}
>> -	}
>> -}
>> -
>>  int exynos_gem_map_sgt_with_dma(struct drm_device *drm_dev,
>>  				struct sg_table *sgt,
>>  				enum dma_data_direction dir)
>>
> 
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