diff mbox

[v4,4/8] drm: Add driver-private objects to atomic state

Message ID 1489648231-30700-5-git-send-email-dhinakaran.pandiyan@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dhinakaran Pandiyan March 16, 2017, 7:10 a.m. UTC
From: "Pandiyan, Dhinakaran" <dhinakaran.pandiyan@intel.com>

It is necessary to track states for objects other than connector, crtc
and plane for atomic modesets. But adding objects like DP MST link
bandwidth to drm_atomic_state would mean that a non-core object will be
modified by the core helper functions for swapping and clearing
it's state. So, lets add void * objects and helper functions that operate
on void * types to keep these objects and states private to the core.
Drivers can then implement specific functions to swap and clear states.
The other advantage having just void * for these objects in
drm_atomic_state is that objects of different types can be managed in the
same state array.

v2: Added docs and new iterator to filter private objects (Daniel)
v3: Macro alignment (Chris)

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Harry Wentland <Harry.wentland@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
---
 drivers/gpu/drm/drm_atomic.c        | 68 +++++++++++++++++++++++++++
 drivers/gpu/drm/drm_atomic_helper.c |  5 ++
 include/drm/drm_atomic.h            | 93 +++++++++++++++++++++++++++++++++++++
 3 files changed, 166 insertions(+)

Comments

Maarten Lankhorst March 22, 2017, 10 a.m. UTC | #1
Op 16-03-17 om 08:10 schreef Dhinakaran Pandiyan:
> From: "Pandiyan, Dhinakaran" <dhinakaran.pandiyan@intel.com>
>
> It is necessary to track states for objects other than connector, crtc
> and plane for atomic modesets. But adding objects like DP MST link
> bandwidth to drm_atomic_state would mean that a non-core object will be
> modified by the core helper functions for swapping and clearing
> it's state. So, lets add void * objects and helper functions that operate
> on void * types to keep these objects and states private to the core.
> Drivers can then implement specific functions to swap and clear states.
> The other advantage having just void * for these objects in
> drm_atomic_state is that objects of different types can be managed in the
> same state array.
>
> v2: Added docs and new iterator to filter private objects (Daniel)
> v3: Macro alignment (Chris)
>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Archit Taneja <architt@codeaurora.org>
> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Cc: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Harry Wentland <Harry.wentland@amd.com>
> Acked-by: Harry Wentland <harry.wentland@amd.com>
> Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

Mostly looks good, but too many null checks. I think it's best to get rid of them all
by freeing state->driver_private in default_clear() or setting num_private_objs to 0.
It would remove the need for all null checks I think..

~Maarten
Dhinakaran Pandiyan March 22, 2017, 9:05 p.m. UTC | #2
On Wed, 2017-03-22 at 11:00 +0100, Maarten Lankhorst wrote:
> Op 16-03-17 om 08:10 schreef Dhinakaran Pandiyan:

> > From: "Pandiyan, Dhinakaran" <dhinakaran.pandiyan@intel.com>

> >

> > It is necessary to track states for objects other than connector, crtc

> > and plane for atomic modesets. But adding objects like DP MST link

> > bandwidth to drm_atomic_state would mean that a non-core object will be

> > modified by the core helper functions for swapping and clearing

> > it's state. So, lets add void * objects and helper functions that operate

> > on void * types to keep these objects and states private to the core.

> > Drivers can then implement specific functions to swap and clear states.

> > The other advantage having just void * for these objects in

> > drm_atomic_state is that objects of different types can be managed in the

> > same state array.

> >

> > v2: Added docs and new iterator to filter private objects (Daniel)

> > v3: Macro alignment (Chris)

> >

> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch>

> > Cc: Archit Taneja <architt@codeaurora.org>

> > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

> > Cc: Chris Wilson <chris@chris-wilson.co.uk>

> > Cc: Harry Wentland <Harry.wentland@amd.com>

> > Acked-by: Harry Wentland <harry.wentland@amd.com>

> > Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>

> > Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

> 

> Mostly looks good, but too many null checks. I think it's best to get rid of them all

> by freeing state->driver_private in default_clear() or setting num_private_objs to 0.

> It would remove the need for all null checks I think..

> 

> ~Maarten

> 


Did you mean the NULL checks in this loop inside
drm_atomic_get_private_obj_state()

+       for (i = 0; i < state->num_private_objs; i++)
+               if (obj == state->private_objs[i].obj &&
+                   state->private_objs[i].obj_state)
+                       return state->private_objs[i].obj_state;

and the fact that I am not setting num_private_objs = 0 in
drm_atomic_state_default_clear() ?

-DK
> _______________________________________________

> Intel-gfx mailing list

> Intel-gfx@lists.freedesktop.org

> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Maarten Lankhorst March 23, 2017, 8:54 a.m. UTC | #3
Op 22-03-17 om 22:05 schreef Pandiyan, Dhinakaran:
> On Wed, 2017-03-22 at 11:00 +0100, Maarten Lankhorst wrote:
>> Op 16-03-17 om 08:10 schreef Dhinakaran Pandiyan:
>>> From: "Pandiyan, Dhinakaran" <dhinakaran.pandiyan@intel.com>
>>>
>>> It is necessary to track states for objects other than connector, crtc
>>> and plane for atomic modesets. But adding objects like DP MST link
>>> bandwidth to drm_atomic_state would mean that a non-core object will be
>>> modified by the core helper functions for swapping and clearing
>>> it's state. So, lets add void * objects and helper functions that operate
>>> on void * types to keep these objects and states private to the core.
>>> Drivers can then implement specific functions to swap and clear states.
>>> The other advantage having just void * for these objects in
>>> drm_atomic_state is that objects of different types can be managed in the
>>> same state array.
>>>
>>> v2: Added docs and new iterator to filter private objects (Daniel)
>>> v3: Macro alignment (Chris)
>>>
>>> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
>>> Cc: Archit Taneja <architt@codeaurora.org>
>>> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
>>> Cc: Chris Wilson <chris@chris-wilson.co.uk>
>>> Cc: Harry Wentland <Harry.wentland@amd.com>
>>> Acked-by: Harry Wentland <harry.wentland@amd.com>
>>> Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>>> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
>> Mostly looks good, but too many null checks. I think it's best to get rid of them all
>> by freeing state->driver_private in default_clear() or setting num_private_objs to 0.
>> It would remove the need for all null checks I think..
>>
>> ~Maarten
>>
> Did you mean the NULL checks in this loop inside
> drm_atomic_get_private_obj_state()
>
> +       for (i = 0; i < state->num_private_objs; i++)
> +               if (obj == state->private_objs[i].obj &&
> +                   state->private_objs[i].obj_state)
> +                       return state->private_objs[i].obj_state;
>
> and the fact that I am not setting num_private_objs = 0 in
> drm_atomic_state_default_clear() ?
All of them, the NULL check in default_clear goes away, same for get_private_obj_state, and __for_each_private_obj
diff mbox

Patch

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 9b892af..d89be5c 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -57,6 +57,7 @@  void drm_atomic_state_default_release(struct drm_atomic_state *state)
 	kfree(state->connectors);
 	kfree(state->crtcs);
 	kfree(state->planes);
+	kfree(state->private_objs);
 }
 EXPORT_SYMBOL(drm_atomic_state_default_release);
 
@@ -184,6 +185,20 @@  void drm_atomic_state_default_clear(struct drm_atomic_state *state)
 		state->planes[i].ptr = NULL;
 		state->planes[i].state = NULL;
 	}
+
+	for (i = 0; i < state->num_private_objs; i++) {
+		void *private_obj = state->private_objs[i].obj;
+		void *obj_state = state->private_objs[i].obj_state;
+
+		if (!private_obj)
+			continue;
+
+		state->private_objs[i].funcs->destroy_state(obj_state);
+		state->private_objs[i].obj = NULL;
+		state->private_objs[i].obj_state = NULL;
+		state->private_objs[i].funcs = NULL;
+	}
+
 }
 EXPORT_SYMBOL(drm_atomic_state_default_clear);
 
@@ -978,6 +993,59 @@  static void drm_atomic_plane_print_state(struct drm_printer *p,
 }
 
 /**
+ * drm_atomic_get_private_obj_state - get private object state
+ * @state: global atomic state
+ * @obj: private object to get the state for
+ * @funcs: pointer to the struct of function pointers that identify the object
+ * type
+ *
+ * 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.
+ *
+ * RETURNS:
+ *
+ * Either the allocated state or the error code encoded into a pointer.
+ */
+void *
+drm_atomic_get_private_obj_state(struct drm_atomic_state *state, void *obj,
+			      const struct drm_private_state_funcs *funcs)
+{
+	int index, num_objs, i;
+	size_t size;
+	struct __drm_private_objs_state *arr;
+
+	for (i = 0; i < state->num_private_objs; i++)
+		if (obj == state->private_objs[i].obj &&
+		    state->private_objs[i].obj_state)
+			return state->private_objs[i].obj_state;
+
+	num_objs = state->num_private_objs + 1;
+	size = sizeof(*state->private_objs) * num_objs;
+	arr = krealloc(state->private_objs, size, GFP_KERNEL);
+	if (!arr)
+		return ERR_PTR(-ENOMEM);
+
+	state->private_objs = arr;
+	index = state->num_private_objs;
+	memset(&state->private_objs[index], 0, sizeof(*state->private_objs));
+
+	state->private_objs[index].obj_state = funcs->duplicate_state(state, obj);
+	if (!state->private_objs[index].obj_state)
+		return ERR_PTR(-ENOMEM);
+
+	state->private_objs[index].obj = obj;
+	state->private_objs[index].funcs = funcs;
+	state->num_private_objs = num_objs;
+
+	DRM_DEBUG_ATOMIC("Added new private object state %p to %p\n",
+			 state->private_objs[index].obj_state, state);
+
+	return state->private_objs[index].obj_state;
+}
+EXPORT_SYMBOL(drm_atomic_get_private_obj_state);
+
+/**
  * drm_atomic_get_connector_state - get connector state
  * @state: global atomic state object
  * @connector: connector to get state object for
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 4e26b73..1403334 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -2001,6 +2001,8 @@  void drm_atomic_helper_swap_state(struct drm_atomic_state *state,
 	struct drm_plane *plane;
 	struct drm_plane_state *old_plane_state, *new_plane_state;
 	struct drm_crtc_commit *commit;
+	void *obj, *obj_state;
+	const struct drm_private_state_funcs *funcs;
 
 	if (stall) {
 		for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
@@ -2061,6 +2063,9 @@  void drm_atomic_helper_swap_state(struct drm_atomic_state *state,
 		state->planes[i].state = old_plane_state;
 		plane->state = new_plane_state;
 	}
+
+	__for_each_private_obj(state, obj, obj_state, i, funcs)
+		funcs->swap_state(obj, &state->private_objs[i].obj_state);
 }
 EXPORT_SYMBOL(drm_atomic_helper_swap_state);
 
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 0147a04..c17da39 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -155,6 +155,53 @@  struct __drm_connnectors_state {
 };
 
 /**
+ * struct drm_private_state_funcs - atomic state functions for private objects
+ *
+ * These hooks are used by atomic helpers to create, swap and destroy states of
+ * private objects. The structure itself is used as a vtable to identify the
+ * associated private object type. Each private object type that needs to be
+ * added to the atomic states is expected to have an implementation of these
+ * hooks and pass a pointer to it's drm_private_state_funcs struct to
+ * drm_atomic_get_private_obj_state().
+ */
+struct drm_private_state_funcs {
+	/**
+	 * @duplicate_state:
+	 *
+	 * Duplicate the current state of the private object and return it. It
+	 * is an error to call this before obj->state has been initialized.
+	 *
+	 * RETURNS:
+	 *
+	 * Duplicated atomic state or NULL when obj->state is not
+	 * initialized or allocation failed.
+	 */
+	void *(*duplicate_state)(struct drm_atomic_state *state, void *obj);
+
+	/**
+	 * @swap_state:
+	 *
+	 * This function swaps the existing state of a private object @obj with
+	 * it's newly created state, the pointer to which is passed as
+	 * @obj_state_ptr.
+	 */
+	void (*swap_state)(void *obj, void **obj_state_ptr);
+
+	/**
+	 * @destroy_state:
+	 *
+	 * Frees the private object state created with @duplicate_state.
+	 */
+	void (*destroy_state)(void *obj_state);
+};
+
+struct __drm_private_objs_state {
+	void *obj;
+	void *obj_state;
+	const struct drm_private_state_funcs *funcs;
+};
+
+/**
  * struct drm_atomic_state - the global state object for atomic updates
  * @ref: count of all references to this state (will not be freed until zero)
  * @dev: parent DRM device
@@ -165,6 +212,8 @@  struct __drm_connnectors_state {
  * @crtcs: pointer to array of CRTC pointers
  * @num_connector: size of the @connectors and @connector_states arrays
  * @connectors: pointer to array of structures with per-connector data
+ * @num_private_objs: size of the @private_objs array
+ * @private_objs: pointer to array of private object pointers
  * @acquire_ctx: acquire context for this atomic modeset state update
  */
 struct drm_atomic_state {
@@ -178,6 +227,8 @@  struct drm_atomic_state {
 	struct __drm_crtcs_state *crtcs;
 	int num_connector;
 	struct __drm_connnectors_state *connectors;
+	int num_private_objs;
+	struct __drm_private_objs_state *private_objs;
 
 	struct drm_modeset_acquire_ctx *acquire_ctx;
 
@@ -270,6 +321,11 @@  int drm_atomic_connector_set_property(struct drm_connector *connector,
 		struct drm_connector_state *state, struct drm_property *property,
 		uint64_t val);
 
+void * __must_check
+drm_atomic_get_private_obj_state(struct drm_atomic_state *state,
+			      void *obj,
+			      const struct drm_private_state_funcs *funcs);
+
 /**
  * drm_atomic_get_existing_crtc_state - get crtc state, if it exists
  * @state: global atomic state object
@@ -598,6 +654,43 @@  void drm_state_dump(struct drm_device *dev, struct drm_printer *p);
 		for_each_if (plane)
 
 /**
+ * __for_each_private_obj - iterate over all private objects
+ * @__state: the atomic state
+ *
+ * This macro iterates over the array containing private object data in atomic
+ * state
+ */
+#define __for_each_private_obj(__state, obj, obj_state, __i, __funcs)	\
+	for ((__i) = 0;							\
+	     (__i) < (__state)->num_private_objs &&			\
+	     ((obj) = (__state)->private_objs[__i].obj,			\
+	      (__funcs) = (__state)->private_objs[__i].funcs,		\
+	      (obj_state) = (__state)->private_objs[__i].obj_state,	\
+	      1);							\
+	     (__i)++)							\
+		for_each_if (__funcs)
+
+/**
+ * for_each_private_obj - iterate over a specify type of private object
+ * @__state: the atomic state
+ * @obj_funcs: function table to filter the private objects
+ *
+ * This macro iterates over the private objects state array while filtering the
+ * objects based on the vfunc table that is passed as @obj_funcs. New macros
+ * can be created by passing in the vfunc table associated with a specific
+ * private object.
+ */
+#define for_each_private_obj(__state, obj_funcs, obj, obj_state, __i, __funcs)	\
+	for ((__i) = 0;							\
+	     (__i) < (__state)->num_private_objs &&			\
+	     ((obj) = (__state)->private_objs[__i].obj,			\
+	      (__funcs) = (__state)->private_objs[__i].funcs,		\
+	      (obj_state) = (__state)->private_objs[__i].obj_state,	\
+	      1);							\
+	     (__i)++)							\
+		for_each_if (__funcs == obj_funcs)
+
+/**
  * drm_atomic_crtc_needs_modeset - compute combined modeset need
  * @state: &drm_crtc_state for the CRTC
  *