On Wed, Sep 27, 2017 at 4:01 PM, Steven Price <Steven.Price@xxxxxxx> wrote: > From: Tu Vuong <tu.vuong@xxxxxxx> > > When a CMA GEM object is exported via DRM PRIME it should be possible > to mmap the object using an offset. However drm_gem_cma_mmap_obj always > zeroed vm_pgoff. No, at least no one ever had run into this. Pretty much all drivers work like this. > Fix this by moving the zeroing of vm_pgoff to drm_gem_cma_mmap (which > is only used for non-PRIME mmap) and correct the size parameter in the > call to dma_mmap_wc as the offset may not be non-zero. Since this is an uabi change we need the corresponding patch to upstream open source userspace. Reviewed and all that and ready for acceptance. See https://dri.freedesktop.org/docs/drm/gpu/drm-uapi.html#open-source-userspace-requirements > Signed-off-by: Tu Vuong <tu.vuong@xxxxxxx> > Signed-off-by: Steven Price <steven.price@xxxxxxx> > Reviewed-by: Brian Starkey <brian.starkey@xxxxxxx> > CC: Brian Starkey <brian.starkey@xxxxxxx> > CC: Liviu Dudau <Liviu.Dudau@xxxxxxx> Thanks, Daniel > --- > drivers/gpu/drm/drm_gem_cma_helper.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c > index 373e33f22be4..25828b33c5be 100644 > --- a/drivers/gpu/drm/drm_gem_cma_helper.c > +++ b/drivers/gpu/drm/drm_gem_cma_helper.c > @@ -276,15 +276,12 @@ static int drm_gem_cma_mmap_obj(struct drm_gem_cma_object *cma_obj, > int ret; > > /* > - * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the > - * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map > - * the whole buffer. > + * Clear the VM_PFNMAP flag that was set by drm_gem_mmap() > */ > vma->vm_flags &= ~VM_PFNMAP; > - vma->vm_pgoff = 0; > > ret = dma_mmap_wc(cma_obj->base.dev->dev, vma, cma_obj->vaddr, > - cma_obj->paddr, vma->vm_end - vma->vm_start); > + cma_obj->paddr, cma_obj->base.size); > if (ret) > drm_gem_vm_close(vma); > > @@ -322,6 +319,12 @@ int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma) > gem_obj = vma->vm_private_data; > cma_obj = to_drm_gem_cma_obj(gem_obj); > > + /* > + * Set the vm_pgoff (used as a fake buffer offset by DRM) to 0 as we > + * want to map the whole buffer. > + */ > + vma->vm_pgoff = 0; > + > return drm_gem_cma_mmap_obj(cma_obj, vma); > } > EXPORT_SYMBOL_GPL(drm_gem_cma_mmap); > -- > 2.11.0 > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
