On Thu, Nov 21, 2019 at 11:38:06AM +0100, Gerd Hoffmann wrote:

The fake offset is going to stay, so change the calling convention for drm_gem_object_funcs.mmap to include the fake offset. Update all users accordingly.

Please add to the commit message:

Note that this reverts 83b8a6f242ea ("drm/gem: Fix mmap fake offset handling for drm_gem_object_funcs.mmap") and on top then adds the fake offset to drm_gem_prime_mmap to make sure all paths leading to obj->funcs->mmap are consistent.

Fixes: 83b8a6f242ea ("drm/gem: Fix mmap fake offset handling for drm_gem_object_funcs.mmap") Cc: Gerd Hoffmann kraxel@redhat.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Rob Herring robh@kernel.org

With that also Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch -Daniel

Signed-off-by: Gerd Hoffmann kraxel@redhat.com

include/drm/drm_gem.h | 4 +--- drivers/gpu/drm/drm_gem.c | 3 --- drivers/gpu/drm/drm_gem_shmem_helper.c | 3 +++ drivers/gpu/drm/drm_prime.c | 3 +++ drivers/gpu/drm/ttm/ttm_bo_vm.c | 7 ------- 5 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h index 97a48165642c..0b375069cd48 100644 --- a/include/drm/drm_gem.h +++ b/include/drm/drm_gem.h @@ -159,9 +159,7 @@ struct drm_gem_object_funcs { * * The callback is used by by both drm_gem_mmap_obj() and * drm_gem_prime_mmap(). When @mmap is present @vm_ops is not

• * used, the @mmap callback must set vma->vm_ops instead. The @mmap
  

• * callback is always called with a 0 offset. The caller will remove
  

• * the fake offset as necessary.
  

• * used, the @mmap callback must set vma->vm_ops instead.
  

  */ int (*mmap)(struct drm_gem_object *obj, struct vm_area_struct *vma);

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 2f2b889096b0..56f42e0f2584 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -1106,9 +1106,6 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, return -EINVAL;

if (obj->funcs && obj->funcs->mmap) {

• /* Remove the fake offset */
  

• vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node);
  

• ret = obj->funcs->mmap(obj, vma); if (ret) return ret;

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index 0810d3ef6961..a421a2eed48a 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -528,6 +528,9 @@ int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) struct drm_gem_shmem_object *shmem; int ret;

• /* Remove the fake offset */

• vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node);

• shmem = to_drm_gem_shmem_obj(obj);

  ret = drm_gem_shmem_get_pages(shmem);

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 0814211b0f3f..a9633bd241bb 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -714,6 +714,9 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) int ret;

if (obj->funcs && obj->funcs->mmap) {

• /* Add the fake offset */
  

• vma->vm_pgoff += drm_vma_node_start(&obj->vma_node);
  

• ret = obj->funcs->mmap(obj, vma); if (ret) return ret;

diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index e6495ca2630b..3e8c3de91ae4 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -514,13 +514,6 @@ EXPORT_SYMBOL(ttm_bo_mmap); int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo) { ttm_bo_get(bo);

• /*

• * FIXME: &drm_gem_object_funcs.mmap is called with the fake offset
  

• * removed. Add it back here until the rest of TTM works without it.
  

• */
  

• vma->vm_pgoff += drm_vma_node_start(&bo->base.vma_node);
• ttm_bo_mmap_vma_setup(bo, vma); return 0;

}

2.18.1

-----Original Message----- From: Intel-gfx intel-gfx-bounces@lists.freedesktop.org On Behalf Of Gerd Hoffmann Sent: Thursday, November 21, 2019 5:38 AM To: dri-devel@lists.freedesktop.org Cc: David Airlie airlied@linux.ie; intel-gfx@lists.freedesktop.org; open list linux-kernel@vger.kernel.org; Maxime Ripard mripard@kernel.org; Gerd Hoffmann kraxel@redhat.com Subject: [Intel-gfx] [PATCH 2/2] drm: share address space for dma bufs

Use the shared address space of the drm device (see drm_open() in drm_file.c) for dma-bufs too. That removes a difference betweem drm device mmap vmas and dma-buf mmap vmas and fixes corner cases like unmaps not working properly.

Hi Gerd,

Just want to make sure I understand this...

So unmaps will not work correctly for mappings when a driver does a drm_vma_node_unamp()?

I.e. the dmabuf mappings will not get cleaned up correctly?

This is a day one bug?

Thanks,

Mike

Signed-off-by: Gerd Hoffmann kraxel@redhat.com

drivers/gpu/drm/drm_prime.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index a9633bd241bb..c3fc341453c0 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -240,6 +240,7 @@ void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv) struct dma_buf *drm_gem_dmabuf_export(struct drm_device *dev, struct dma_buf_export_info *exp_info) {

• struct drm_gem_object *obj = exp_info->priv; struct dma_buf *dma_buf;

  dma_buf = dma_buf_export(exp_info);

@@ -247,7 +248,8 @@ struct dma_buf *drm_gem_dmabuf_export(struct drm_device *dev, return dma_buf;

drm_dev_get(dev);

• drm_gem_object_get(exp_info->priv);

• drm_gem_object_get(obj);

• dma_buf->file->f_mapping = obj->dev->anon_inode->i_mapping;

  return dma_buf;

}

2.18.1

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