[PATCH v3 5/7] drm/vmwgfx: Inline ttm_bo_mmap() into vmwgfx driver

[Daniel Vetter]

On Tue, Apr 20, 2021 at 09:51:27AM +0200, Thomas Zimmermann wrote:
> Hi
> 
> Am 16.04.21 um 15:51 schrieb Christian König:
> > Am 16.04.21 um 15:46 schrieb Christian König:
> > > Am 16.04.21 um 15:31 schrieb Thomas Zimmermann:
> > > > The vmwgfx driver is the only remaining user of ttm_bo_mmap(). Inline
> > > > the code. The internal helper ttm_bo_vm_lookup() is now also part of
> > > > vmwgfx as vmw_bo_vm_lookup().
> > > > 
> > > > v2:
> > > >     * replace pr_err() with drm_err() (Zack)
> > > > 
> > > > Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> > > > Reviewed-by: Zack Rusin <zackr at vmware.com>
> > > > ---
> > > >   drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c | 56 ++++++++++++++++++++++--
> > > >   1 file changed, 53 insertions(+), 3 deletions(-)
> > > > 
> > > > diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
> > > > b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
> > > > index cb9975889e2f..c8b6543b4e39 100644
> > > > --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
> > > > +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
> > > > @@ -27,6 +27,32 @@
> > > >     #include "vmwgfx_drv.h"
> > > >   +static struct ttm_buffer_object *vmw_bo_vm_lookup(struct
> > > > ttm_device *bdev,
> > > > +                          unsigned long offset,
> > > > +                          unsigned long pages)
> > > > +{
> > > > +    struct vmw_private *dev_priv = container_of(bdev, struct
> > > > vmw_private, bdev);
> > > > +    struct drm_device *drm = &dev_priv->drm;
> > > > +    struct drm_vma_offset_node *node;
> > > > +    struct ttm_buffer_object *bo = NULL;
> > > > +
> > > > +    drm_vma_offset_lock_lookup(bdev->vma_manager);
> > > > +
> > > > +    node = drm_vma_offset_lookup_locked(bdev->vma_manager,
> > > > offset, pages);
> > > > +    if (likely(node)) {
> > > > +        bo = container_of(node,
> struct ttm_buffer_object,
> > > > +                  base.vma_node);
> > > > +        bo = ttm_bo_get_unless_zero(bo);
> > > > +    }
> > > > +
> > > > +    drm_vma_offset_unlock_lookup(bdev->vma_manager);
> > > > +
> > > > +    if (!bo)
> > > > +        drm_err(drm, "Could not find buffer object to map\n");
> > > > +
> > > > +    return bo;
> > > > +}
> > > > +
> > > >   int vmw_mmap(struct file *filp, struct vm_area_struct *vma)
> > > >   {
> > > >       static const struct vm_operations_struct vmw_vm_ops = {
> > > > @@ -41,10 +67,28 @@ int vmw_mmap(struct file *filp, struct
> > > > vm_area_struct *vma)
> > > >       };
> > > >       struct drm_file *file_priv = filp->private_data;
> > > >       struct vmw_private *dev_priv = vmw_priv(file_priv->minor->dev);
> > > > -    int ret = ttm_bo_mmap(filp, vma, &dev_priv->bdev);
> > > > +    struct ttm_device *bdev = &dev_priv->bdev;
> > > > +    struct ttm_buffer_object *bo;
> > > > +    int ret;
> > > > +
> > > > +    if (unlikely(vma->vm_pgoff < DRM_FILE_PAGE_OFFSET_START))
> > > > +        return -EINVAL;
> > > > +
> > > > +    bo = vmw_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
> > > > +    if (unlikely(!bo))
> > > > +        return -EINVAL;
> > > >   -    if (ret)
> > > > -        return ret;
> > > > +    if (unlikely(!bo->bdev->funcs->verify_access)) {
> > > > +        ret = -EPERM;
> > > > +        goto out_unref;
> > > > +    }
> > > > +    ret = bo->bdev->funcs->verify_access(bo, filp);
> > > 
> > > Is there any reason we can't call vmw_verify_access() directly here?
> > > 
> > > Would allow us to completely nuke the verify_access callback as well
> > > as far as I can see.
> > 
> > Forget what I said, couldn't see the next patch in my mailbox at time of
> > writing.
> > 
> > Whole series is Reviewed-by: Christian König <christian.koenig at amd.com>
> 
> Thanks a lot. If I'm not mistaken, the patches at [1] need to go in first.
> So it could take a a bit until this lands.
> 
> Otherwise, this series could go through the same tree as [1] if nouveau and
> vmwgfx devs don't mind.

I would land it all through drm-misc-next. Maybe check with Alex on irc
for an ack for merging that way, but I don't think this will cause issues
against the amdgpu tree. Lots of ttm cleanup has landed this way already
past few months. Otherwise you could create a small topic branch with
these patches here and send that to Alex, and he can sort out the
interaction with Felix' series.
-Daniel


> 
> Best regards
> Thomas
> 
> [1] https://patchwork.freedesktop.org/series/88822/
> 
> > 
> > Thanks for the nice cleanup,
> > Christian.
> > 
> > > 
> > > Regards,
> > > Christian.
> > > 
> > > > +    if (unlikely(ret != 0))
> > > > +        goto out_unref;
> > > > +
> > > > +    ret = ttm_bo_mmap_obj(vma, bo);
> > > > +    if (unlikely(ret != 0))
> > > > +        goto out_unref;
> > > >         vma->vm_ops = &vmw_vm_ops;
> > > >   @@ -52,7 +96,13 @@ int vmw_mmap(struct file *filp, struct
> > > > vm_area_struct *vma)
> > > >       if (!is_cow_mapping(vma->vm_flags))
> > > >           vma->vm_flags = (vma->vm_flags & ~VM_MIXEDMAP) | VM_PFNMAP;
> > > >   +    ttm_bo_put(bo); /* release extra ref taken
> by
> > > > ttm_bo_mmap_obj() */
> > > > +
> > > >       return 0;
> > > > +
> > > > +out_unref:
> > > > +    ttm_bo_put(bo);
> > > > +    return ret;
> > > >   }
> > > >     /* struct vmw_validation_mem callback */
> > > 
> > 
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 
> -- 
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Maxfeldstr. 5, 90409 Nürnberg, Germany
> (HRB 36809, AG Nürnberg)
> Geschäftsführer: Felix Imendörffer
> 




-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch