Am 19.10.18 um 09:49 schrieb Daniel Vetter: > On Fri, Oct 19, 2018 at 9:38 AM Thomas Zimmermann <tzimmermann@xxxxxxx> wrote: >> Hi, >> >> thanks for the review. >> >> Am 19.10.18 um 05:30 schrieb Huang Rui: >>> On Fri, Oct 19, 2018 at 12:27:50AM +0800, Thomas Zimmermann wrote: >>>> +int ttm_global_init(struct ttm_global *glob) >>>> +{ >>>> + int ret; >>>> + >>> We would better add a protection here to make sure the glob is not NULL. >>> >>> if (!glob) >>> return -EINVAL; >> Passing a NULL pointer is a programming error, not a runtime error. I'd >> rather use BUG_ON() for this test. Ok? > if (WARN_ON(!glob) > return -EINVAL; > > instead of BUG_ON is much friendly for debugging. Especially in gfx > drivers, where the entire init runs while holding a few critical > kernel locks (console_lock, among others), and so will result in a > very silent death of the entire machine. Yeah, additional to that a BUG_ON a NULL pointer is rather pointless. Dereferencing the NULL pointer has pretty much the same effect as a BUG_ON :) Christian. > -Daniel > >> Best regards >> Thomas >> >>> Others, look good for me. >>> >>> Thanks, >>> Ray >>> >>>> + glob->mem_ref.global_type = DRM_GLOBAL_TTM_MEM; >>>> + glob->mem_ref.size = sizeof(struct ttm_mem_global); >>>> + glob->bo_ref.object = NULL; >>>> + glob->mem_ref.init = &ttm_global_init_mem; >>>> + glob->mem_ref.release = &ttm_global_release_mem; >>>> + ret = drm_global_item_ref(&glob->mem_ref); >>>> + if (ret) >>>> + return ret; >>>> + >>>> + glob->bo_ref.global_type = DRM_GLOBAL_TTM_BO; >>>> + glob->bo_ref.size = sizeof(struct ttm_bo_global); >>>> + glob->bo_ref.object = NULL; >>>> + glob->bo_ref.init = &ttm_global_init_bo; >>>> + glob->bo_ref.release = &ttm_global_release_bo; >>>> + ret = drm_global_item_ref(&glob->bo_ref); >>>> + if (ret) >>>> + goto err_drm_global_item_unref_mem; >>>> + >>>> + return 0; >>>> + >>>> +err_drm_global_item_unref_mem: >>>> + drm_global_item_unref(&glob->mem_ref); >>>> + return ret; >>>> +} >>>> + >>>> +EXPORT_SYMBOL(ttm_global_init); >>>> + >>>> +void ttm_global_release(struct ttm_global *glob) >>>> +{ >>>> + drm_global_item_unref(&glob->bo_ref); >>>> + drm_global_item_unref(&glob->mem_ref); >>>> +} >>>> + >>>> +EXPORT_SYMBOL(ttm_global_release); >>>> diff --git a/include/drm/drm_global.h b/include/drm/drm_global.h >>>> index 3a830602a2e4..4482a9bbd6e9 100644 >>>> --- a/include/drm/drm_global.h >>>> +++ b/include/drm/drm_global.h >>>> @@ -28,8 +28,16 @@ >>>> * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com> >>>> */ >>>> >>>> +/* >>>> + * The interfaces in this file are deprecated. Please use ttm_global >>>> + * from <drm/ttm/ttm_global.h> instead. >>>> + */ >>>> + >>>> #ifndef _DRM_GLOBAL_H_ >>>> #define _DRM_GLOBAL_H_ >>>> + >>>> +#include <linux/types.h> >>>> + >>>> enum drm_global_types { >>>> DRM_GLOBAL_TTM_MEM = 0, >>>> DRM_GLOBAL_TTM_BO, >>>> diff --git a/include/drm/ttm/ttm_global.h b/include/drm/ttm/ttm_global.h >>>> new file mode 100644 >>>> index 000000000000..06e791499f87 >>>> --- /dev/null >>>> +++ b/include/drm/ttm/ttm_global.h >>>> @@ -0,0 +1,79 @@ >>>> +/************************************************************************** >>>> + * >>>> + * Copyright 2008-2009 VMware, Inc., Palo Alto, CA., USA >>>> + * All Rights Reserved. >>>> + * >>>> + * Permission is hereby granted, free of charge, to any person obtaining a >>>> + * copy of this software and associated documentation files (the >>>> + * "Software"), to deal in the Software without restriction, including >>>> + * without limitation the rights to use, copy, modify, merge, publish, >>>> + * distribute, sub license, and/or sell copies of the Software, and to >>>> + * permit persons to whom the Software is furnished to do so, subject to >>>> + * the following conditions: >>>> + * >>>> + * The above copyright notice and this permission notice (including the >>>> + * next paragraph) shall be included in all copies or substantial portions >>>> + * of the Software. >>>> + * >>>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR >>>> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, >>>> + * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL >>>> + * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, >>>> + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR >>>> + * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE >>>> + * USE OR OTHER DEALINGS IN THE SOFTWARE. >>>> + * >>>> + **************************************************************************/ >>>> + >>>> +#ifndef _TTM_GLOBAL_H_ >>>> +#define _TTM_GLOBAL_H_ >>>> + >>>> +#include <drm/drm_global.h> >>>> + >>>> +struct ttm_bo_global; >>>> + >>>> +/** >>>> + * struct ttm_global - Stores references to global TTM state >>>> + */ >>>> +struct ttm_global { >>>> + struct drm_global_reference mem_ref; >>>> + struct drm_global_reference bo_ref; >>>> +}; >>>> + >>>> +/** >>>> + * ttm_global_init >>>> + * >>>> + * @glob: A pointer to a struct ttm_global that is about to be initialized >>>> + * @return Zero on success, or a negative error code otherwise. >>>> + * >>>> + * Initializes an instance of struct ttm_global with TTM's global state >>>> + */ >>>> +int ttm_global_init(struct ttm_global *glob); >>>> + >>>> +/** >>>> + * ttm_global_release >>>> + * >>>> + * @glob: A pointer to an instance of struct ttm_global >>>> + * >>>> + * Releases an initialized instance of struct ttm_global. If the instance >>>> + * constains the final references to the global memory and BO, the global >>>> + * structures are released as well. >>>> + */ >>>> +void ttm_global_release(struct ttm_global *glob); >>>> + >>>> +/** >>>> + * ttm_global_get_bo_global >>>> + * >>>> + * @glob A pointer to an instance of struct ttm_global >>>> + * @return A refernce to the global BO. >>>> + * >>>> + * Returns the global BO. The BO should be forwarded to the initialization >>>> + * of a driver's TTM BO device. >>>> + */ >>>> +static inline struct ttm_bo_global* >>>> +ttm_global_get_bo_global(struct ttm_global *glob) >>>> +{ >>>> + return glob->bo_ref.object; >>>> +} >>>> + >>>> +#endif /* _TTM_GLOBAL_H_ */ >>>> -- >>>> 2.19.1 >>>> >>> _______________________________________________ >>> dri-devel mailing list >>> dri-devel@xxxxxxxxxxxxxxxxxxxxx >>> https://lists.freedesktop.org/mailman/listinfo/dri-devel >>> >> -- >> Thomas Zimmermann >> Graphics Driver Developer >> SUSE Linux GmbH, Maxfeldstr. 5, D-90409 Nürnberg >> Tel: +49-911-74053-0; Fax: +49-911-7417755; https://www.suse.com/ >> SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, >> Graham Norton, HRB 21284 (AG Nürnberg) >> >> _______________________________________________ >> dri-devel mailing list >> dri-devel@xxxxxxxxxxxxxxxxxxxxx >> https://lists.freedesktop.org/mailman/listinfo/dri-devel > > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel