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drm: add mmap() to drm_gem_object_funcs

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drm_gem_object_funcs->vm_ops alone can't handle everything which needs
to be done for mmap(), tweaking vm_flags for example.  So add a new
mmap() callback to drm_gem_object_funcs where this code can go to.

Note that the vm_ops field is not used in case the mmap callback is
present, it is expected that the callback sets vma->vm_ops instead.

Also setting vm_flags and vm_page_prot is the job of the new callback.
so drivers have more control over these flags.

drm_gem_mmap_obj() will use the new callback for object specific mmap
setup.  With this in place the need for driver-speific fops->mmap
callbacks goes away, drm_gem_mmap can be hooked instead.

drm_gem_prime_mmap() will use the new callback too to just mmap gem
objects directly instead of jumping though loops to make
drm_gem_object_lookup() and fops->mmap work.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20191016115203.20095-2-kraxel@redhat.com
This commit is contained in:
Gerd Hoffmann
2019-10-16 13:51:53 +02:00
parent 3c2ed9cedd
commit c40069cb7b
3 changed files with 41 additions and 9 deletions
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27
drivers/gpu/drm/drm_gem.c
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@@ -1099,22 +1099,31 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
struct vm_area_struct *vma)
{
struct drm_device *dev = obj->dev;
int ret;
/* Check for valid size. */
if (obj_size < vma->vm_end - vma->vm_start)
return -EINVAL;
if (obj->funcs && obj->funcs->vm_ops)
vma->vm_ops = obj->funcs->vm_ops;
else if (dev->driver->gem_vm_ops)
vma->vm_ops = dev->driver->gem_vm_ops;
else
return -EINVAL;
if (obj->funcs && obj->funcs->mmap) {
ret = obj->funcs->mmap(obj, vma);
if (ret)
return ret;
WARN_ON(!(vma->vm_flags & VM_DONTEXPAND));
} else {
if (obj->funcs && obj->funcs->vm_ops)
vma->vm_ops = obj->funcs->vm_ops;
else if (dev->driver->gem_vm_ops)
vma->vm_ops = dev->driver->gem_vm_ops;
else
return -EINVAL;
vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
}
vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_private_data = obj;
vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
/* Take a ref for this mapping of the object, so that the fault
* handler can dereference the mmap offset's pointer to the object.