Convert g2d_userptr_get_dma_addr() to pin pages using get_vaddr_pfn().
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.

Signed-off-by: Jan Kara <jack at suse.cz>
---
 drivers/gpu/drm/exynos/exynos_drm_g2d.c | 91 ++++++++++---------------------
 drivers/gpu/drm/exynos/exynos_drm_gem.c | 97 ---------------------------------
 2 files changed, 30 insertions(+), 158 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c 
b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
index 81a250830808..8949354a85a1 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 pinned_pfns      *pfns;
        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 = pfns_vector_pages(g2d_userptr->pfns);
+       if (pages) {
+               int i;

-       exynos_gem_put_vma(g2d_userptr->vma);
+               for (i = 0; i < pfns_vector_count(g2d_userptr->pfns); i++)
+                       set_page_dirty_lock(pages[i]);
+       }
+       put_vaddr_pfns(g2d_userptr->pfns);
+       pfns_vector_destroy(g2d_userptr->pfns);

        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);
 }

@@ -413,6 +414,7 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct 
drm_device *drm_dev,
        struct vm_area_struct *vma;
        unsigned long start, end;
        unsigned int npages, offset;
+       struct pinned_pfns *pfns;
        int ret;

        if (!size) {
@@ -456,65 +458,37 @@ 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;
+       pfns = g2d_userptr->pfns = pfns_vector_create(npages);
+       if (!pfns)
+               goto out_free;

-       pages = drm_calloc_large(npages, sizeof(struct page *));
-       if (!pages) {
-               DRM_ERROR("failed to allocate pages.\n");
-               ret = -ENOMEM;
-               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_pfn(start, npages, 1, 1, pfns);
+       if (ret != npages) {
+               DRM_ERROR("failed to get user pages from userptr.\n");
+               if (ret < 0)
+                       goto err_destroy_pfns;
                ret = -EFAULT;
-               goto err_free_pages;
+               goto err_put_pfns;
        }
-
-       if (vma->vm_end < userptr + size) {
-               up_read(&current->mm->mmap_sem);
-               DRM_ERROR("vma is too small.\n");
+       if (pfns_vector_to_pages(pfns) < 0) {
                ret = -EFAULT;
-               goto err_free_pages;
+               goto err_put_pfns;
        }

-       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_pfns;
        }

-       ret = sg_alloc_table_from_pages(sgt, pages, npages, offset,
-                                       size, GFP_KERNEL);
+       ret = sg_alloc_table_from_pages(sgt, pfns_vector_pages(pfns), npages,
+                                       offset, size, GFP_KERNEL);
        if (ret < 0) {
                DRM_ERROR("failed to get sgt from pages.\n");
                goto err_free_sgt;
@@ -549,16 +523,11 @@ 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_pfns:
+       put_vaddr_pfns(pfns);

-err_free_pages:
-       drm_free_large(pages);
+err_destroy_pfns:
+       pfns_vector_destroy(pfns);

 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)
-- 
2.1.4

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