On Fri, Oct 19, 2018 at 03:55:03PM +0200, Boris Brezillon wrote:
> From: Rob Clark <robdclark@xxxxxxxxx>
>
> Follow the same pattern of locking as with other state objects. This
> avoids boilerplate in the driver.
>
> Signed-off-by: Rob Clark <robdclark@xxxxxxxxx>
> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
> ---
> Changes in v2:
> - Make sure all priv objs are locked from drm_modeset_lock_all_ctx().
> This implies adding all priv objs to mode_config.privobj_list, and
> in turn means we have to change the drm_atomic_private_obj_init()
> prototype and pass it a drm_device.
> ---
> drivers/gpu/drm/drm_atomic.c | 19 +++++++++++++++----
> drivers/gpu/drm/drm_dp_mst_topology.c | 2 +-
> drivers/gpu/drm/drm_mode_config.c | 1 +
> drivers/gpu/drm/drm_modeset_lock.c | 8 ++++++++
> drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c | 2 +-
> drivers/gpu/drm/tegra/hub.c | 2 +-
> drivers/gpu/drm/vc4/vc4_kms.c | 3 ++-
> include/drm/drm_atomic.h | 17 ++++++++++++++++-
> include/drm/drm_mode_config.h | 9 +++++++++
> 9 files changed, 54 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index 2870ae205237..0e27d45feba9 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -657,6 +657,7 @@ static void drm_atomic_plane_print_state(struct drm_printer *p,
>
> /**
> * drm_atomic_private_obj_init - initialize private object
> + * @dev: DRM device this object will be attached to
> * @obj: private object
> * @state: initial private object state
> * @funcs: pointer to the struct of function pointers that identify the object
> @@ -666,14 +667,18 @@ static void drm_atomic_plane_print_state(struct drm_printer *p,
> * driver private object that needs its own atomic state.
> */
> void
> -drm_atomic_private_obj_init(struct drm_private_obj *obj,
> +drm_atomic_private_obj_init(struct drm_device *dev,
> + struct drm_private_obj *obj,
> struct drm_private_state *state,
> const struct drm_private_state_funcs *funcs)
> {
> memset(obj, 0, sizeof(*obj));
>
> + drm_modeset_lock_init(&obj->lock);
> +
> obj->state = state;
> obj->funcs = funcs;
> + list_add_tail(&obj->head, &dev->mode_config.privobj_list);
> }
> EXPORT_SYMBOL(drm_atomic_private_obj_init);
>
> @@ -686,7 +691,9 @@ EXPORT_SYMBOL(drm_atomic_private_obj_init);
> void
> drm_atomic_private_obj_fini(struct drm_private_obj *obj)
> {
> + list_del(&obj->head);
> obj->funcs->atomic_destroy_state(obj, obj->state);
> + drm_modeset_lock_fini(&obj->lock);
> }
> EXPORT_SYMBOL(drm_atomic_private_obj_fini);
>
> @@ -696,8 +703,8 @@ EXPORT_SYMBOL(drm_atomic_private_obj_fini);
> * @obj: private object to get the state for
> *
> * This function returns the private object state for the given private object,
> - * allocating the state if needed. It does not grab any locks as the caller is
> - * expected to care of any required locking.
> + * allocating the state if needed. It will also grab the relevant private
> + * object lock to make sure that the state is consistent.
> *
> * RETURNS:
> *
> @@ -707,7 +714,7 @@ struct drm_private_state *
> drm_atomic_get_private_obj_state(struct drm_atomic_state *state,
> struct drm_private_obj *obj)
> {
> - int index, num_objs, i;
> + int index, num_objs, i, ret;
> size_t size;
> struct __drm_private_objs_state *arr;
> struct drm_private_state *obj_state;
> @@ -716,6 +723,10 @@ drm_atomic_get_private_obj_state(struct drm_atomic_state *state,
> if (obj == state->private_objs[i].ptr)
> return state->private_objs[i].state;
>
> + ret = drm_modeset_lock(&obj->lock, state->acquire_ctx);
> + if (ret)
> + return ERR_PTR(ret);
> +
> num_objs = state->num_private_objs + 1;
> size = sizeof(*state->private_objs) * num_objs;
> arr = krealloc(state->private_objs, size, GFP_KERNEL);
> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
> index 5ff1d79b86c4..0ab47cd44a20 100644
> --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> @@ -3210,7 +3210,7 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
> /* max. time slots - one slot for MTP header */
> mst_state->avail_slots = 63;
>
> - drm_atomic_private_obj_init(&mgr->base,
> + drm_atomic_private_obj_init(dev, &mgr->base,
> &mst_state->base,
> &mst_state_funcs);
>
> diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
> index ee80788f2c40..931523c5bc9d 100644
> --- a/drivers/gpu/drm/drm_mode_config.c
> +++ b/drivers/gpu/drm/drm_mode_config.c
> @@ -381,6 +381,7 @@ void drm_mode_config_init(struct drm_device *dev)
> INIT_LIST_HEAD(&dev->mode_config.property_list);
> INIT_LIST_HEAD(&dev->mode_config.property_blob_list);
> INIT_LIST_HEAD(&dev->mode_config.plane_list);
> + INIT_LIST_HEAD(&dev->mode_config.privobj_list);
> idr_init(&dev->mode_config.crtc_idr);
> idr_init(&dev->mode_config.tile_idr);
> ida_init(&dev->mode_config.connector_ida);
> diff --git a/drivers/gpu/drm/drm_modeset_lock.c b/drivers/gpu/drm/drm_modeset_lock.c
> index 8a5100685875..088be2e3c399 100644
> --- a/drivers/gpu/drm/drm_modeset_lock.c
> +++ b/drivers/gpu/drm/drm_modeset_lock.c
> @@ -22,6 +22,7 @@
> */
>
> #include <drm/drmP.h>
> +#include <drm/drm_atomic.h>
> #include <drm/drm_crtc.h>
> #include <drm/drm_modeset_lock.h>
>
> @@ -388,6 +389,7 @@ EXPORT_SYMBOL(drm_modeset_unlock);
> int drm_modeset_lock_all_ctx(struct drm_device *dev,
> struct drm_modeset_acquire_ctx *ctx)
> {
> + struct drm_private_obj *privobj;
> struct drm_crtc *crtc;
> struct drm_plane *plane;
> int ret;
> @@ -408,6 +410,12 @@ int drm_modeset_lock_all_ctx(struct drm_device *dev,
> return ret;
> }
>
> + drm_for_each_privobj(privobj, dev) {
> + ret = drm_modeset_lock(&privobj->lock, ctx);
> + if (ret)
> + return ret;
> + }
> +
> return 0;
> }
> EXPORT_SYMBOL(drm_modeset_lock_all_ctx);
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> index bddd625ab91b..f71d8cf2261b 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> @@ -144,7 +144,7 @@ static int mdp5_global_obj_init(struct mdp5_kms *mdp5_kms)
>
> state->mdp5_kms = mdp5_kms;
>
> - drm_atomic_private_obj_init(&mdp5_kms->glob_state,
> + drm_atomic_private_obj_init(mdp5_kms->dev, &mdp5_kms->glob_state,
> &state->base,
> &mdp5_global_state_funcs);
> return 0;
> diff --git a/drivers/gpu/drm/tegra/hub.c b/drivers/gpu/drm/tegra/hub.c
> index 8f4fcbb515fb..20c44b412148 100644
> --- a/drivers/gpu/drm/tegra/hub.c
> +++ b/drivers/gpu/drm/tegra/hub.c
> @@ -716,7 +716,7 @@ static int tegra_display_hub_init(struct host1x_client *client)
> if (!state)
> return -ENOMEM;
>
> - drm_atomic_private_obj_init(&hub->base, &state->base,
> + drm_atomic_private_obj_init(drm, &hub->base, &state->base,
> &tegra_display_hub_state_funcs);
>
> tegra->hub = hub;
> diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c
> index 127468785f74..5c9823ccb3f8 100644
> --- a/drivers/gpu/drm/vc4/vc4_kms.c
> +++ b/drivers/gpu/drm/vc4/vc4_kms.c
> @@ -426,7 +426,8 @@ int vc4_kms_load(struct drm_device *dev)
> ctm_state = kzalloc(sizeof(*ctm_state), GFP_KERNEL);
> if (!ctm_state)
> return -ENOMEM;
> - drm_atomic_private_obj_init(&vc4->ctm_manager, &ctm_state->base,
> +
> + drm_atomic_private_obj_init(dev, &vc4->ctm_manager, &ctm_state->base,
> &vc4_ctm_state_funcs);
>
> drm_mode_config_reset(dev);
> diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
> index c09ecaf43825..99b9a91090c3 100644
> --- a/include/drm/drm_atomic.h
> +++ b/include/drm/drm_atomic.h
> @@ -219,6 +219,17 @@ struct drm_private_state_funcs {
> * &drm_modeset_lock is required to duplicate and update this object's state.
I think it'd be good to add here that private objects must have static
lifetime tied to the &struct drm_device and that it's not allowed to
remove them before drm_dev_unregister() and add them after
drm_dev_register(). Because otherwise the locking story goes all
pear-shaped.
> */
> struct drm_private_obj {
> + /**
> + * @head: List entry used to attach a private object to a drm_device
&drm_device for those lovely links :-)
> + * (queued to &drm_mode_config.privobj_list).
> + */
> + struct list_head head;
> +
> + /**
> + * @lock: Modeset lock to protect the state object.
> + */
> + struct drm_modeset_lock lock;
> +
> /**
> * @state: Current atomic state for this driver private object.
> */
> @@ -233,6 +244,9 @@ struct drm_private_obj {
> const struct drm_private_state_funcs *funcs;
> };
>
Kernel-doc here would be nice for this iterator.
> +#define drm_for_each_privobj(privobj, dev) \
> + list_for_each_entry(privobj, &(dev)->mode_config.privobj_list, head)
> +
> /**
> * struct drm_private_state - base struct for driver private object state
> * @state: backpointer to global drm_atomic_state
> @@ -389,7 +403,8 @@ struct drm_connector_state * __must_check
> drm_atomic_get_connector_state(struct drm_atomic_state *state,
> struct drm_connector *connector);
>
> -void drm_atomic_private_obj_init(struct drm_private_obj *obj,
> +void drm_atomic_private_obj_init(struct drm_device *dev,
> + struct drm_private_obj *obj,
> struct drm_private_state *state,
> const struct drm_private_state_funcs *funcs);
> void drm_atomic_private_obj_fini(struct drm_private_obj *obj);
> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> index 928e4172a0bb..abda88adcafd 100644
> --- a/include/drm/drm_mode_config.h
> +++ b/include/drm/drm_mode_config.h
> @@ -506,6 +506,15 @@ struct drm_mode_config {
> */
> struct list_head property_list;
>
> + /**
> + * @privobj_list:
> + *
> + * List of private objects linked with &drm_property.head. This is
Copypasta, should be &drm_private_obj.
With the doc nits:
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
> + * invariant over the lifetime of a device and hence doesn't need any
> + * locks.
> + */
> + struct list_head privobj_list;
> +
> int min_width, min_height;
> int max_width, max_height;
> const struct drm_mode_config_funcs *funcs;
> --
> 2.14.1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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