On 12/21/2017 03:26 PM, Daniel Vetter wrote:
On Thu, Dec 21, 2017 at 11:44:23AM +0530, Archit Taneja wrote:
Global shared resources (hwpipes, hwmixers and SMP) for MDP5 are
implemented as a part of atomic state by subclassing drm_atomic_state.
The preferred approach is to use the drm_private_obj infrastructure
available in the atomic core.
mdp5_global_state is introduced as a drm atomic private object. The two
funcs mdp5_get_global_state() and mdp5_get_existing_global_state() are
the two variants that will be used to access mdp5_global_state.
This will replace the existing mdp5_state struct (which subclasses
drm_atomic_state) and the funcs around it. These will be removed later
once we mdp5_global_state is put to use everywhere.
Signed-off-by: Archit Taneja <architt@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c | 86 +++++++++++++++++++++++++++++++++
drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h | 27 +++++++++++
2 files changed, 113 insertions(+)
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
index f7c0698fec40..dfc4d81124d5 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
@@ -106,6 +106,86 @@ static void mdp5_swap_state(struct msm_kms *kms, struct drm_atomic_state *state)
swap(to_kms_state(state)->state, mdp5_kms->state);
}
+/* Global/shared object state funcs */
+
+/*
+ * This is a helper that returns the private state currently in operation.
+ * Note that this would return the "old_state" if called in the atomic check
+ * path, and the "new_state" after the atomic swap has been done.
+ */
+struct mdp5_global_state *
+mdp5_get_existing_global_state(struct mdp5_kms *mdp5_kms)
+{
+ return to_mdp5_global_state(mdp5_kms->glob_base.state);
This doesn't match the existing state stuff for everything else. Here you
look at the global state, but not at the one hanging off drm_atomic_state.
Maybe we should add a drm_atomic_get_existing_private_obj_state function
to make this easier?
I'm also not 100% sure on what semantics you want precisely.
I just wanted a func that returns me the private obj's state that is currently
"in use". I.e, the old state pre-swap, and the new state post-swap. If I use
drm_atomic_get_private_obj_state() after the swap has occurred, I get the old
state back. In other words, there aren't funcs for private objs like
drm_atomic_get_new_crtc_state() and drm_atomic_get_old_crtc_state() that we
can use. I'll go through the code again carefully to see if my understanding
isn't screwed up.
+}
+
+/*
+ * This acquires the modeset lock set aside for global state, creates
+ * a new duplicated private object state.
+ */
+struct mdp5_global_state *mdp5_get_global_state(struct drm_atomic_state *s)
+{
+ struct msm_drm_private *priv = s->dev->dev_private;
+ struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
+ struct drm_private_state *priv_state;
+ int ret;
+
+ ret = drm_modeset_lock(&mdp5_kms->glob_state_lock, s->acquire_ctx);
+ if (ret)
+ return ERR_PTR(ret);
+
+ priv_state = drm_atomic_get_private_obj_state(s, &mdp5_kms->glob_base);
+ if (IS_ERR(priv_state))
+ return ERR_CAST(priv_state);
+
+ return to_mdp5_global_state(priv_state);
+}
+
+static struct drm_private_state *
+mdp5_global_duplicate_state(struct drm_private_obj *obj)
+{
+ struct mdp5_global_state *state;
+
+ state = kmemdup(obj->state, sizeof(*state), GFP_KERNEL);
+ if (!state)
+ return NULL;
+
+ __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
+
+ return &state->base;
+}
+
+static void mdp5_global_destroy_state(struct drm_private_obj *obj,
+ struct drm_private_state *state)
+{
+ struct mdp5_global_state *mdp5_state = to_mdp5_global_state(state);
+
+ kfree(mdp5_state);
+}
+
+static const struct drm_private_state_funcs mdp5_global_state_funcs = {
+ .atomic_duplicate_state = mdp5_global_duplicate_state,
+ .atomic_destroy_state = mdp5_global_destroy_state,
+};
+
+static int mdp5_global_obj_init(struct mdp5_kms *mdp5_kms)
+{
+ struct mdp5_global_state *state;
+
+ state = kzalloc(sizeof(*state), GFP_KERNEL);
+ if (!state)
+ return -ENOMEM;
+
+ drm_modeset_lock_init(&mdp5_kms->glob_state_lock);
I thought a bit the last few days about how to integrate modeset locking
into driver private state objects. I think the simplest solution would be
if we just add a drm_modeset_lock to drm_private_obj, and push the locking
(both here and in the mst helper) into the core private obj code.
I'm also a bit unclear on how many private objs one should create. In this patchset,
I just create one private obj instance, and stuff all of our shared resources into
it (see mdp5_global_state below). I didn't see the point in creating one priv object
per shared resource, since a single lock for all of them seemed okay here.
Thanks,
Archit
Per-object locking might be a bit overkill (it's definitely overkill for
mst), but it's also easier to avoid special cases.
That would reduce the boilerplate here a bit more, essentially converting
the wrappers into type casting functions.
-Daniel
+
+ state->mdp5_kms = mdp5_kms;
+
+ drm_atomic_private_obj_init(&mdp5_kms->glob_base,
+ &state->base,
+ &mdp5_global_state_funcs);
+ return 0;
+}
+
static void mdp5_prepare_commit(struct msm_kms *kms, struct drm_atomic_state *state)
{
struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
@@ -727,6 +807,8 @@ static void mdp5_destroy(struct platform_device *pdev)
if (mdp5_kms->rpm_enabled)
pm_runtime_disable(&pdev->dev);
+ drm_atomic_private_obj_fini(&mdp5_kms->glob_base);
+
kfree(mdp5_kms->state);
}
@@ -887,6 +969,10 @@ static int mdp5_init(struct platform_device *pdev, struct drm_device *dev)
goto fail;
}
+ ret = mdp5_global_obj_init(mdp5_kms);
+ if (ret)
+ goto fail;
+
mdp5_kms->mmio = msm_ioremap(pdev, "mdp_phys", "MDP5");
if (IS_ERR(mdp5_kms->mmio)) {
ret = PTR_ERR(mdp5_kms->mmio);
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
index 9b3fe01089d1..522ddb835593 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
@@ -55,6 +55,13 @@ struct mdp5_kms {
struct mdp5_state *state;
struct drm_modeset_lock state_lock;
+ /*
+ * Global private object state, Do not access directly, use
+ * mdp5_global_get_state()
+ */
+ struct drm_private_obj glob_base;
+ struct drm_modeset_lock glob_state_lock;
+
struct mdp5_smp *smp;
struct mdp5_ctl_manager *ctlm;
@@ -95,6 +102,26 @@ struct mdp5_state {
struct mdp5_state *__must_check
mdp5_get_state(struct drm_atomic_state *s);
+/* Global private object state for tracking resources that are shared across
+ * multiple kms objects (planes/crtcs/etc).
+ */
+#define to_mdp5_global_state(x) container_of(x, struct mdp5_global_state, base)
+struct mdp5_global_state {
+ struct drm_private_state base;
+
+ struct drm_atomic_state *state;
+ struct mdp5_kms *mdp5_kms;
+
+ struct mdp5_hw_pipe_state hwpipe;
+ struct mdp5_hw_mixer_state hwmixer;
+ struct mdp5_smp_state smp;
+};
+
+struct mdp5_global_state *
+mdp5_get_existing_global_state(struct mdp5_kms *mdp5_kms);
+struct mdp5_global_state *__must_check
+mdp5_get_global_state(struct drm_atomic_state *s);
+
/* Atomic plane state. Subclasses the base drm_plane_state in order to
* track assigned hwpipe and hw specific state.
*/
--
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