| Message ID | 20190913122908.784-2-kraxel@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: rework mmap() workflow | expand |
On Fri, Sep 13, 2019 at 02:29:01PM +0200, Gerd Hoffmann wrote: > 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 > presnt, it is expected that the callback sets vma->vm_ops instead. > > 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> > --- > include/drm/drm_gem.h | 14 ++++++++++++++ > drivers/gpu/drm/drm_gem.c | 27 ++++++++++++++++++--------- > drivers/gpu/drm/drm_prime.c | 9 +++++++++ > 3 files changed, 41 insertions(+), 9 deletions(-) > > diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h > index 6aaba14f5972..e71f75a2ab57 100644 > --- a/include/drm/drm_gem.h > +++ b/include/drm/drm_gem.h > @@ -150,6 +150,20 @@ struct drm_gem_object_funcs { > */ > void (*vunmap)(struct drm_gem_object *obj, void *vaddr); > > + /** > + * @mmap: > + * > + * Handle mmap() of the gem object, setup vma accordingly. > + * > + * This callback is optional. > + * > + * 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. > + * > + */ > + int (*mmap)(struct drm_gem_object *obj, struct vm_area_struct *vma); > + > /** > * @vm_ops: > * > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c > index 6854f5867d51..56f42e0f2584 100644 > --- a/drivers/gpu/drm/drm_gem.c > +++ b/drivers/gpu/drm/drm_gem.c > @@ -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)); Yeah I think checking for VM_DONTEXPAND is even better than checking for just VM_SPECIAL. Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > + } 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. > diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c > index 0a2316e0e812..0814211b0f3f 100644 > --- a/drivers/gpu/drm/drm_prime.c > +++ b/drivers/gpu/drm/drm_prime.c > @@ -713,6 +713,15 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) > struct file *fil; > int ret; > > + if (obj->funcs && obj->funcs->mmap) { > + ret = obj->funcs->mmap(obj, vma); > + if (ret) > + return ret; > + vma->vm_private_data = obj; > + drm_gem_object_get(obj); > + return 0; > + } > + > priv = kzalloc(sizeof(*priv), GFP_KERNEL); > fil = kzalloc(sizeof(*fil), GFP_KERNEL); > if (!priv || !fil) { > -- > 2.18.1 >
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h index 6aaba14f5972..e71f75a2ab57 100644 --- a/include/drm/drm_gem.h +++ b/include/drm/drm_gem.h @@ -150,6 +150,20 @@ struct drm_gem_object_funcs { */ void (*vunmap)(struct drm_gem_object *obj, void *vaddr); + /** + * @mmap: + * + * Handle mmap() of the gem object, setup vma accordingly. + * + * This callback is optional. + * + * 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. + * + */ + int (*mmap)(struct drm_gem_object *obj, struct vm_area_struct *vma); + /** * @vm_ops: * diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 6854f5867d51..56f42e0f2584 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -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. diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 0a2316e0e812..0814211b0f3f 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -713,6 +713,15 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) struct file *fil; int ret; + if (obj->funcs && obj->funcs->mmap) { + ret = obj->funcs->mmap(obj, vma); + if (ret) + return ret; + vma->vm_private_data = obj; + drm_gem_object_get(obj); + return 0; + } + priv = kzalloc(sizeof(*priv), GFP_KERNEL); fil = kzalloc(sizeof(*fil), GFP_KERNEL); if (!priv || !fil) {
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 presnt, it is expected that the callback sets vma->vm_ops instead. 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> --- include/drm/drm_gem.h | 14 ++++++++++++++ drivers/gpu/drm/drm_gem.c | 27 ++++++++++++++++++--------- drivers/gpu/drm/drm_prime.c | 9 +++++++++ 3 files changed, 41 insertions(+), 9 deletions(-)