[media] drm/exynos: Convert g2d_userptr_get_dma_addr() to use get_vaddr_frames()

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.

Acked-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

3 files changed, 30 insertions, 157 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..7584834a53c9 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 +455,40 @@ 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");
+        g2d_userptr->vec = frame_vector_create(npages);
+        if (!g2d_userptr->vec) {
                 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_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;
-        }
-
-        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;
+                goto err_put_framevec;
         }
 
-        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 +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_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)