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

Hans Verkuil
2015-07-17T10:31:11Z

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!

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.

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)
>>> 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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