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

Inki Dae
2015-07-18T03:14:24Z

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