From c40069cb7bd64903e0c0a3845ea8d3298ca57ea3 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Wed, 16 Oct 2019 13:51:53 +0200 Subject: [PATCH] drm: add mmap() to drm_gem_object_funcs 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 Reviewed-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20191016115203.20095-2-kraxel@redhat.com --- drivers/gpu/drm/drm_gem.c | 27 ++++++++++++++++++--------- drivers/gpu/drm/drm_prime.c | 9 +++++++++ include/drm/drm_gem.h | 14 ++++++++++++++ 3 files changed, 41 insertions(+), 9 deletions(-) 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) { 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: *