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drm: allow property validation for refcnted props

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We can already have object properties, which technically can be fb's.
Switch the property validation logic over to a get/put style interface
so it can take a ref to refcnt'd objects, and then drop that ref after
the driver has a chance to take it's own ref.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Rob Clark 2014-12-16 18:05:29 -05:00 committed by Daniel Vetter
parent 07cc0ef67f
commit 3843e71f98
1 changed files with 43 additions and 15 deletions
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58
drivers/gpu/drm/drm_crtc.c
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@ -4193,12 +4193,22 @@ int drm_mode_connector_update_edid_property(struct drm_connector *connector,
}
EXPORT_SYMBOL(drm_mode_connector_update_edid_property);
static bool drm_property_change_is_valid(struct drm_property *property,
uint64_t value)
/* Some properties could refer to dynamic refcnt'd objects, or things that
* need special locking to handle lifetime issues (ie. to ensure the prop
* value doesn't become invalid part way through the property update due to
* race). The value returned by reference via 'obj' should be passed back
* to drm_property_change_valid_put() after the property is set (and the
* object to which the property is attached has a chance to take it's own
* reference).
*/
static bool drm_property_change_valid_get(struct drm_property *property,
uint64_t value, struct drm_mode_object **ref)
{
if (property->flags & DRM_MODE_PROP_IMMUTABLE)
return false;
*ref = NULL;
if (drm_property_type_is(property, DRM_MODE_PROP_RANGE)) {
if (value < property->values[0] || value > property->values[1])
return false;
@ -4219,19 +4229,23 @@ static bool drm_property_change_is_valid(struct drm_property *property,
/* Only the driver knows */
return true;
} else if (drm_property_type_is(property, DRM_MODE_PROP_OBJECT)) {
struct drm_mode_object *obj;
/* a zero value for an object property translates to null: */
if (value == 0)
return true;
/*
* NOTE: use _object_find() directly to bypass restriction on
* looking up refcnt'd objects (ie. fb's). For a refcnt'd
* object this could race against object finalization, so it
* simply tells us that the object *was* valid. Which is good
* enough.
*/
obj = _object_find(property->dev, value, property->values[0]);
return obj != NULL;
/* handle refcnt'd objects specially: */
if (property->values[0] == DRM_MODE_OBJECT_FB) {
struct drm_framebuffer *fb;
fb = drm_framebuffer_lookup(property->dev, value);
if (fb) {
*ref = &fb->base;
return true;
} else {
return false;
}
} else {
return _object_find(property->dev, value, property->values[0]) != NULL;
}
} else {
int i;
for (i = 0; i < property->num_values; i++)
@ -4241,6 +4255,18 @@ static bool drm_property_change_is_valid(struct drm_property *property,
}
}
static void drm_property_change_valid_put(struct drm_property *property,
struct drm_mode_object *ref)
{
if (!ref)
return;
if (drm_property_type_is(property, DRM_MODE_PROP_OBJECT)) {
if (property->values[0] == DRM_MODE_OBJECT_FB)
drm_framebuffer_unreference(obj_to_fb(ref));
}
}
/**
* drm_mode_connector_property_set_ioctl - set the current value of a connector property
* @dev: DRM device
@ -4429,8 +4455,8 @@ int drm_mode_obj_set_property_ioctl(struct drm_device *dev, void *data,
struct drm_mode_object *arg_obj;
struct drm_mode_object *prop_obj;
struct drm_property *property;
int ret = -EINVAL;
int i;
int i, ret = -EINVAL;
struct drm_mode_object *ref;
if (!drm_core_check_feature(dev, DRIVER_MODESET))
return -EINVAL;
@ -4460,7 +4486,7 @@ int drm_mode_obj_set_property_ioctl(struct drm_device *dev, void *data,
}
property = obj_to_property(prop_obj);
if (!drm_property_change_is_valid(property, arg->value))
if (!drm_property_change_valid_get(property, arg->value, &ref))
goto out;
switch (arg_obj->type) {
@ -4477,6 +4503,8 @@ int drm_mode_obj_set_property_ioctl(struct drm_device *dev, void *data,
break;
}
drm_property_change_valid_put(property, ref);
out:
drm_modeset_unlock_all(dev);
return ret;