drm: Introduce drm_mode_object_{get,put}()

For consistency with other reference counting APIs in the kernel, add drm_mode_object_get() and drm_mode_object_put() to reference count DRM mode objects. Compatibility aliases are added to keep existing code working. To help speed up the transition, all the instances of the old functions in the DRM core are already replaced in this commit. A semantic patch is provided that can be used to convert all drivers to the new helpers.

Thierry Reding committed 9 years ago

Commit 020a2181 parent 2135ea75 files · +95 −29Browse files

Unified · Split

5 files

drivers/gpu/drm/drm_atomic.c +7 −7
drivers/gpu/drm/drm_mode_object.c +13 −13
drivers/gpu/drm/drm_property.c +3 −3
include/drm/drm_mode_object.h +30 −6
scripts/coccinelle/api/drm-get-put.cocci +42 −0

drivers/gpu/drm/drm_atomic.c+7−7

@@ -2238,13 +2238,13 @@ retry: · 2237 unmodified lines
2238	2238	}
2239	2239
2240	2240	if (!obj->properties) {
2241		− drm_mode_object_unreference(obj);
	2241	+ drm_mode_object_put(obj);
2242	2242	ret = -ENOENT;
2243	2243	goto out;
2244	2244	}
2245	2245
2246	2246	if (get_user(count_props, count_props_ptr + copied_objs)) {
2247		− drm_mode_object_unreference(obj);
	2247	+ drm_mode_object_put(obj);
2248	2248	ret = -EFAULT;
2249	2249	goto out;
2250	2250	}
@@ -2257,14 +2257,14 @@ retry: · 6 unmodified lines
2257	2257	struct drm_property *prop;
2258	2258
2259	2259	if (get_user(prop_id, props_ptr + copied_props)) {
2260		− drm_mode_object_unreference(obj);
	2260	+ drm_mode_object_put(obj);
2261	2261	ret = -EFAULT;
2262	2262	goto out;
2263	2263	}
2264	2264
2265	2265	prop = drm_mode_obj_find_prop_id(obj, prop_id);
2266	2266	if (!prop) {
2267		− drm_mode_object_unreference(obj);
	2267	+ drm_mode_object_put(obj);
2268	2268	ret = -ENOENT;
2269	2269	goto out;
2270	2270	}
@@ -2272,14 +2272,14 @@ retry: · 1 unmodified line
2272	2272	if (copy_from_user(&prop_value,
2273	2273	prop_values_ptr + copied_props,
2274	2274	sizeof(prop_value))) {
2275		− drm_mode_object_unreference(obj);
	2275	+ drm_mode_object_put(obj);
2276	2276	ret = -EFAULT;
2277	2277	goto out;
2278	2278	}
2279	2279
2280	2280	ret = atomic_set_prop(state, obj, prop, prop_value);
2281	2281	if (ret) {
2282		− drm_mode_object_unreference(obj);
	2282	+ drm_mode_object_put(obj);
2283	2283	goto out;
2284	2284	}
2285	2285
@@ -2292,7 +2292,7 @@ retry: · 6 unmodified lines
2292	2292	plane_mask \|= (1 << drm_plane_index(plane));
2293	2293	plane->old_fb = plane->fb;
2294	2294	}
2295		− drm_mode_object_unreference(obj);
	2295	+ drm_mode_object_put(obj);
2296	2296	}
2297	2297
2298	2298	ret = prepare_crtc_signaling(dev, state, arg, file_priv, &fence_state,

drivers/gpu/drm/drm_mode_object.c+13−13

@@ -133,7 +133,7 @@ struct drm_mode_object __drm_mode_object_find(struct drm_device dev, · 132 unmodified lines
133	133	*
134	134	* This function is used to look up a modeset object. It will acquire a
135	135	* reference for reference counted objects. This reference must be dropped again
136		− * by callind drm_mode_object_unreference().
	136	+ * by callind drm_mode_object_put().
137	137	*/
138	138	struct drm_mode_object drm_mode_object_find(struct drm_device dev,
139	139	uint32_t id, uint32_t type)
@@ -146,38 +146,38 @@ struct drm_mode_object drm_mode_object_find(struct drm_device dev, · 6 unmodified lines
146	146	EXPORT_SYMBOL(drm_mode_object_find);
147	147
148	148	/**
149		− * drm_mode_object_unreference - decr the object refcnt
150		− * @obj: mode_object
	149	+ * drm_mode_object_put - release a mode object reference
	150	+ * @obj: DRM mode object
151	151	*
152	152	* This function decrements the object's refcount if it is a refcounted modeset
153	153	* object. It is a no-op on any other object. This is used to drop references
154		− * acquired with drm_mode_object_reference().
	154	+ * acquired with drm_mode_object_get().
155	155	*/
156		−void drm_mode_object_unreference(struct drm_mode_object *obj)
	156	+void drm_mode_object_put(struct drm_mode_object *obj)
157	157	{
158	158	if (obj->free_cb) {
159	159	DRM_DEBUG("OBJ ID: %d (%d)\n", obj->id, atomic_read(&obj->refcount.refcount));
160	160	kref_put(&obj->refcount, obj->free_cb);
161	161	}
162	162	}
163		−EXPORT_SYMBOL(drm_mode_object_unreference);
	163	+EXPORT_SYMBOL(drm_mode_object_put);
164	164
165	165	/**
166		− * drm_mode_object_reference - incr the object refcnt
167		− * @obj: mode_object
	166	+ * drm_mode_object_get - acquire a mode object reference
	167	+ * @obj: DRM mode object
168	168	*
169	169	* This function increments the object's refcount if it is a refcounted modeset
170	170	* object. It is a no-op on any other object. References should be dropped again
171		− * by calling drm_mode_object_unreference().
	171	+ * by calling drm_mode_object_put().
172	172	*/
173		−void drm_mode_object_reference(struct drm_mode_object *obj)
	173	+void drm_mode_object_get(struct drm_mode_object *obj)
174	174	{
175	175	if (obj->free_cb) {
176	176	DRM_DEBUG("OBJ ID: %d (%d)\n", obj->id, atomic_read(&obj->refcount.refcount));
177	177	kref_get(&obj->refcount);
178	178	}
179	179	}
180		−EXPORT_SYMBOL(drm_mode_object_reference);
	180	+EXPORT_SYMBOL(drm_mode_object_get);
181	181
182	182	/**
183	183	* drm_object_attach_property - attach a property to a modeset object
@@ -363,7 +363,7 @@ int drm_mode_obj_get_properties_ioctl(struct drm_device dev, void data, · 179 unmodified lines
363	363	&arg->count_props);
364	364
365	365	out_unref:
366		− drm_mode_object_unreference(obj);
	366	+ drm_mode_object_put(obj);
367	367	out:
368	368	drm_modeset_unlock_all(dev);
369	369	return ret;
@@ -428,7 +428,7 @@ int drm_mode_obj_set_property_ioctl(struct drm_device dev, void data, · 58 unmodified lines
428	428	drm_property_change_valid_put(property, ref);
429	429
430	430	out_unref:
431		− drm_mode_object_unreference(arg_obj);
	431	+ drm_mode_object_put(arg_obj);
432	432	out:
433	433	drm_modeset_unlock_all(dev);
434	434	return ret;

drivers/gpu/drm/drm_property.c+3−3

@@ -597,7 +597,7 @@ void drm_property_unreference_blob(struct drm_property_blob *blob) · 596 unmodified lines
597	597	if (!blob)
598	598	return;
599	599
600		− drm_mode_object_unreference(&blob->base);
	600	+ drm_mode_object_put(&blob->base);
601	601	}
602	602	EXPORT_SYMBOL(drm_property_unreference_blob);
603	603
@@ -625,7 +625,7 @@ void drm_property_destroy_user_blobs(struct drm_device *dev, · 21 unmodified lines
625	625	*/
626	626	struct drm_property_blob drm_property_reference_blob(struct drm_property_blob blob)
627	627	{
628		− drm_mode_object_reference(&blob->base);
	628	+ drm_mode_object_get(&blob->base);
629	629	return blob;
630	630	}
631	631	EXPORT_SYMBOL(drm_property_reference_blob);
@@ -906,7 +906,7 @@ void drm_property_change_valid_put(struct drm_property *property, · 274 unmodified lines
906	906	return;
907	907
908	908	if (drm_property_type_is(property, DRM_MODE_PROP_OBJECT)) {
909		− drm_mode_object_unreference(ref);
	909	+ drm_mode_object_put(ref);
910	910	} else if (drm_property_type_is(property, DRM_MODE_PROP_BLOB))
911	911	drm_property_unreference_blob(obj_to_blob(ref));
912	912	}

include/drm/drm_mode_object.h+30−6

@@ -45,10 +45,10 @@ struct drm_device; · 44 unmodified lines
45	45	* drm_object_attach_property() before the object is visible to userspace.
46	46	*
47	47	* - For objects with dynamic lifetimes (as indicated by a non-NULL @free_cb) it
48		− * provides reference counting through drm_mode_object_reference() and
49		− * drm_mode_object_unreference(). This is used by &drm_framebuffer,
50		− * &drm_connector and &drm_property_blob. These objects provide specialized
51		− * reference counting wrappers.
	48	+ * provides reference counting through drm_mode_object_get() and
	49	+ * drm_mode_object_put(). This is used by &drm_framebuffer, &drm_connector
	50	+ * and &drm_property_blob. These objects provide specialized reference
	51	+ * counting wrappers.
52	52	*/
53	53	struct drm_mode_object {
54	54	uint32_t id;
@@ -114,8 +114,32 @@ struct drm_object_properties { · 59 unmodified lines
114	114
115	115	struct drm_mode_object drm_mode_object_find(struct drm_device dev,
116	116	uint32_t id, uint32_t type);
117		−void drm_mode_object_reference(struct drm_mode_object *obj);
118		−void drm_mode_object_unreference(struct drm_mode_object *obj);
	117	+void drm_mode_object_get(struct drm_mode_object *obj);
	118	+void drm_mode_object_put(struct drm_mode_object *obj);
	119	+
	120	+/**
	121	+ * drm_mode_object_reference - acquire a mode object reference
	122	+ * @obj: DRM mode object
	123	+ *
	124	+ * This is a compatibility alias for drm_mode_object_get() and should not be
	125	+ * used by new code.
	126	+ */
	127	+static inline void drm_mode_object_reference(struct drm_mode_object *obj)
	128	+{
	129	+ drm_mode_object_get(obj);
	130	+}
	131	+
	132	+/**
	133	+ * drm_mode_object_unreference - release a mode object reference
	134	+ * @obj: DRM mode object
	135	+ *
	136	+ * This is a compatibility alias for drm_mode_object_put() and should not be
	137	+ * used by new code.
	138	+ */
	139	+static inline void drm_mode_object_unreference(struct drm_mode_object *obj)
	140	+{
	141	+ drm_mode_object_put(obj);
	142	+}
119	143
120	144	int drm_object_property_set_value(struct drm_mode_object *obj,
121	145	struct drm_property *property,

scripts/coccinelle/api/drm-get-put.cocci+42−0

@@ -0,0 +1,42 @@
	1	+///
	2	+/// Use drm__get() and drm__put() helpers instead of drm_*_reference() and
	3	+/// drm_*_unreference() helpers.
	4	+///
	5	+// Confidence: High
	6	+// Copyright: (C) 2017 NVIDIA Corporation
	7	+// Options: --no-includes --include-headers
	8	+//
	9	+
	10	+virtual patch
	11	+virtual report
	12	+
	13	+@depends on patch@
	14	+expression object;
	15	+@@
	16	+
	17	+(
	18	+- drm_mode_object_reference(object)
	19	++ drm_mode_object_get(object)
	20	+\|
	21	+- drm_mode_object_unreference(object)
	22	++ drm_mode_object_put(object)
	23	+)
	24	+
	25	+@r depends on report@
	26	+expression object;
	27	+position p;
	28	+@@
	29	+
	30	+(
	31	+drm_mode_object_unreference@p(object)
	32	+\|
	33	+drm_mode_object_reference@p(object)
	34	+)
	35	+
	36	+@script:python depends on report@
	37	+object << r.object;
	38	+p << r.p;
	39	+@@
	40	+
	41	+msg="WARNING: use get/put helpers to reference and dereference %s" % (object)
	42	+coccilib.report.print_report(p[0], msg)