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  19:31, Hans Verkuil wrote:
> On 07/17/2015 12:29 PM, Inki Dae wrote:
>> 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!

Oops, sorry. This patch would incur a build warning. Below is my comment.

> 
> BTW, I didn't see your earlier Ack either. Was it posted to the linux-media list as well?
> It didn't turn up there.

I thought posted but I couldn't find the email in my mailbox so I may
mistake.

> 
> Regards,
> 
> 	Hans
> 
>>
>> 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)

You would need ret = -EFAULT here. And below is a patch posted already,
	http://www.spinics.net/lists/dri-devel/msg85321.html

ps. please, ignore the codes related to build error in the patch.

With the change, Acked-by: Inki Dae <inki.dae@samsung.com>

Thanks,
Inki Dae

>>>>  		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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> 
> 

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