[RFC 0/3] drm/msm: Avoid subclassing of drm_atomic_state

[RFC 0/3] drm/msm: Avoid subclassing of drm_atomic_state

[Archit Taneja]

It's been recommended that we use drm_private_objs embedded in
drm_atomic_state to hold shared resources instead of subclassing
drm_atomic_state.

This will also help us in getting one step closer to using the
atomic commit helpers instead of the msm_atomic_commit() funcs
in msm_atomic.c

I've taken the drm_private_obj usage in drm_dp_mst_topology as
reference. I've put this as RFC because I want others to see if
the private_obj stuff is used correctly.

Archit Taneja (3):
  drm/msm/mdp5: Add global state as a private atomic object
  drm/msm/mdp5: Use the new private_obj state
  drm/msm: Don't subclass drm_atomic_state anymore

 drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c   | 104 +++++++++++++++++++++---------
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h   |  29 +++++----
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.c |  12 ++--
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_pipe.c  |  20 +++---
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c   |  17 +++--
 drivers/gpu/drm/msm/msm_atomic.c          |  31 ---------
 drivers/gpu/drm/msm/msm_drv.c             |   3 -
 drivers/gpu/drm/msm/msm_kms.h             |  14 ----
 8 files changed, 121 insertions(+), 109 deletions(-)

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

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[RFC 1/3] drm/msm/mdp5: Add global state as a private atomic object

[Archit Taneja]

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@codeaurora.org>
---
 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 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);
+
+	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.
  */
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

[RFC 2/3] drm/msm/mdp5: Use the new private_obj state

[Archit Taneja]

This replaces the usage of the subclassed atomic state (mdp5_state)
with a private_obj state embedded within drm_atomic_state. The latter
method is the preferred approach, since it's simpler to implement
and less prone to errors.

The new API replaces the older and equivalent mdp5_state usage in the
following pattern:
- References to "mdp5_kms->state" (i.e, the old/existing state) is
  replaced with mdp5_get_existing_global_state(). In the atomic_check
  path, this should be called with the glob_state_lock drm_modeset_lock
  alredy taken.
- References to "mdp5_get_state()" are replaced with
  mdp5_get_global_state(). This acquires glob_state_lock and uses
  drm_atomic_get_private_obj_state() to create a new duplicated state.

Signed-off-by: Archit Taneja <architt@codeaurora.org>
---
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c   | 10 ++++++++--
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.c | 12 ++++++------
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_pipe.c  | 20 +++++++++++---------
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c   | 17 ++++++++++++-----
 4 files changed, 37 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
index dfc4d81124d5..dabb58ad068c 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
@@ -190,20 +190,26 @@ static void mdp5_prepare_commit(struct msm_kms *kms, struct drm_atomic_state *st
 {
 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
 	struct device *dev = &mdp5_kms->pdev->dev;
+	struct mdp5_global_state *global_state;
+
+	global_state = mdp5_get_existing_global_state(mdp5_kms);
 
 	pm_runtime_get_sync(dev);
 
 	if (mdp5_kms->smp)
-		mdp5_smp_prepare_commit(mdp5_kms->smp, &mdp5_kms->state->smp);
+		mdp5_smp_prepare_commit(mdp5_kms->smp, &global_state->smp);
 }
 
 static void mdp5_complete_commit(struct msm_kms *kms, struct drm_atomic_state *state)
 {
 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
 	struct device *dev = &mdp5_kms->pdev->dev;
+	struct mdp5_global_state *global_state;
+
+	global_state = mdp5_get_existing_global_state(mdp5_kms);
 
 	if (mdp5_kms->smp)
-		mdp5_smp_complete_commit(mdp5_kms->smp, &mdp5_kms->state->smp);
+		mdp5_smp_complete_commit(mdp5_kms->smp, &global_state->smp);
 
 	pm_runtime_put_autosuspend(dev);
 }
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.c
index 8a00991f03c7..113e6b569562 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.c
@@ -52,14 +52,14 @@ int mdp5_mixer_assign(struct drm_atomic_state *s, struct drm_crtc *crtc,
 {
 	struct msm_drm_private *priv = s->dev->dev_private;
 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
-	struct mdp5_state *state = mdp5_get_state(s);
+	struct mdp5_global_state *global_state = mdp5_get_global_state(s);
 	struct mdp5_hw_mixer_state *new_state;
 	int i;
 
-	if (IS_ERR(state))
-		return PTR_ERR(state);
+	if (IS_ERR(global_state))
+		return PTR_ERR(global_state);
 
-	new_state = &state->hwmixer;
+	new_state = &global_state->hwmixer;
 
 	for (i = 0; i < mdp5_kms->num_hwmixers; i++) {
 		struct mdp5_hw_mixer *cur = mdp5_kms->hwmixers[i];
@@ -129,8 +129,8 @@ int mdp5_mixer_assign(struct drm_atomic_state *s, struct drm_crtc *crtc,
 
 void mdp5_mixer_release(struct drm_atomic_state *s, struct mdp5_hw_mixer *mixer)
 {
-	struct mdp5_state *state = mdp5_get_state(s);
-	struct mdp5_hw_mixer_state *new_state = &state->hwmixer;
+	struct mdp5_global_state *global_state = mdp5_get_global_state(s);
+	struct mdp5_hw_mixer_state *new_state = &global_state->hwmixer;
 
 	if (!mixer)
 		return;
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_pipe.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_pipe.c
index 2bfac3712685..88a8a86c95c7 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_pipe.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_pipe.c
@@ -22,18 +22,20 @@ struct mdp5_hw_pipe *mdp5_pipe_assign(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 mdp5_state *state;
+	struct mdp5_global_state *new_global_state, *old_global_state;
 	struct mdp5_hw_pipe_state *old_state, *new_state;
 	struct mdp5_hw_pipe *hwpipe = NULL;
 	int i;
 
-	state = mdp5_get_state(s);
-	if (IS_ERR(state))
-		return ERR_CAST(state);
+	new_global_state = mdp5_get_global_state(s);
+	if (IS_ERR(new_global_state))
+		return ERR_CAST(new_global_state);
 
-	/* grab old_state after mdp5_get_state(), since now we hold lock: */
-	old_state = &mdp5_kms->state->hwpipe;
-	new_state = &state->hwpipe;
+	/* grab old_state after mdp5_get_global_state(), since now we hold lock: */
+	old_global_state = mdp5_get_existing_global_state(mdp5_kms);
+
+	old_state = &old_global_state->hwpipe;
+	new_state = &new_global_state->hwpipe;
 
 	for (i = 0; i < mdp5_kms->num_hwpipes; i++) {
 		struct mdp5_hw_pipe *cur = mdp5_kms->hwpipes[i];
@@ -76,7 +78,7 @@ struct mdp5_hw_pipe *mdp5_pipe_assign(struct drm_atomic_state *s,
 		int ret;
 
 		DBG("%s: alloc SMP blocks", hwpipe->name);
-		ret = mdp5_smp_assign(mdp5_kms->smp, &state->smp,
+		ret = mdp5_smp_assign(mdp5_kms->smp, &new_global_state->smp,
 				hwpipe->pipe, blkcfg);
 		if (ret)
 			return ERR_PTR(-ENOMEM);
@@ -95,7 +97,7 @@ void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe)
 {
 	struct msm_drm_private *priv = s->dev->dev_private;
 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
-	struct mdp5_state *state = mdp5_get_state(s);
+	struct mdp5_global_state *state = mdp5_get_global_state(s);
 	struct mdp5_hw_pipe_state *new_state = &state->hwpipe;
 
 	if (!hwpipe)
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c
index ae4983d9d0a5..96c2b828dba4 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c
@@ -340,17 +340,20 @@ void mdp5_smp_dump(struct mdp5_smp *smp, struct drm_printer *p)
 	struct mdp5_kms *mdp5_kms = get_kms(smp);
 	struct mdp5_hw_pipe_state *hwpstate;
 	struct mdp5_smp_state *state;
+	struct mdp5_global_state *global_state;
 	int total = 0, i, j;
 
 	drm_printf(p, "name\tinuse\tplane\n");
 	drm_printf(p, "----\t-----\t-----\n");
 
 	if (drm_can_sleep())
-		drm_modeset_lock(&mdp5_kms->state_lock, NULL);
+		drm_modeset_lock(&mdp5_kms->glob_state_lock, NULL);
+
+	global_state = mdp5_get_existing_global_state(mdp5_kms);
 
 	/* grab these *after* we hold the state_lock */
-	hwpstate = &mdp5_kms->state->hwpipe;
-	state = &mdp5_kms->state->smp;
+	hwpstate = &global_state->hwpipe;
+	state = &global_state->smp;
 
 	for (i = 0; i < mdp5_kms->num_hwpipes; i++) {
 		struct mdp5_hw_pipe *hwpipe = mdp5_kms->hwpipes[i];
@@ -374,7 +377,7 @@ void mdp5_smp_dump(struct mdp5_smp *smp, struct drm_printer *p)
 			bitmap_weight(state->state, smp->blk_cnt));
 
 	if (drm_can_sleep())
-		drm_modeset_unlock(&mdp5_kms->state_lock);
+		drm_modeset_unlock(&mdp5_kms->glob_state_lock);
 }
 
 void mdp5_smp_destroy(struct mdp5_smp *smp)
@@ -384,7 +387,8 @@ void mdp5_smp_destroy(struct mdp5_smp *smp)
 
 struct mdp5_smp *mdp5_smp_init(struct mdp5_kms *mdp5_kms, const struct mdp5_smp_block *cfg)
 {
-	struct mdp5_smp_state *state = &mdp5_kms->state->smp;
+	struct mdp5_smp_state *state;
+	struct mdp5_global_state *global_state;
 	struct mdp5_smp *smp = NULL;
 	int ret;
 
@@ -398,6 +402,9 @@ struct mdp5_smp *mdp5_smp_init(struct mdp5_kms *mdp5_kms, const struct mdp5_smp_
 	smp->blk_cnt = cfg->mmb_count;
 	smp->blk_size = cfg->mmb_size;
 
+	global_state = mdp5_get_existing_global_state(mdp5_kms);
+	state = &global_state->smp;
+
 	/* statically tied MMBs cannot be re-allocated: */
 	bitmap_copy(state->state, cfg->reserved_state, smp->blk_cnt);
 	memcpy(smp->reserved, cfg->reserved, sizeof(smp->reserved));
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

[RFC 3/3] drm/msm: Don't subclass drm_atomic_state anymore

[Archit Taneja]

With the addition of "private_objs" in drm_atomic_state, we no longer
need to subclass drm_atomic_state to store state of share resources
that don't perfectly fit within planes/crtc/connector state information.
We can now save this state within drm_atomic_state itself using
the private objects.

Remove the infrastructure that allowed subclassing of drm_atomic_state
in the driver.

Signed-off-by: Archit Taneja <architt@codeaurora.org>
---
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c | 46 ---------------------------------
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h | 22 ----------------
 drivers/gpu/drm/msm/msm_atomic.c        | 31 ----------------------
 drivers/gpu/drm/msm/msm_drv.c           |  3 ---
 drivers/gpu/drm/msm/msm_kms.h           | 14 ----------
 5 files changed, 116 deletions(-)

diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
index dabb58ad068c..c42a77713d74 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
@@ -70,42 +70,6 @@ static int mdp5_hw_init(struct msm_kms *kms)
 	return 0;
 }
 
-struct mdp5_state *mdp5_get_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 msm_kms_state *state = to_kms_state(s);
-	struct mdp5_state *new_state;
-	int ret;
-
-	if (state->state)
-		return state->state;
-
-	ret = drm_modeset_lock(&mdp5_kms->state_lock, s->acquire_ctx);
-	if (ret)
-		return ERR_PTR(ret);
-
-	new_state = kmalloc(sizeof(*mdp5_kms->state), GFP_KERNEL);
-	if (!new_state)
-		return ERR_PTR(-ENOMEM);
-
-	/* Copy state: */
-	new_state->hwpipe = mdp5_kms->state->hwpipe;
-	new_state->hwmixer = mdp5_kms->state->hwmixer;
-	if (mdp5_kms->smp)
-		new_state->smp = mdp5_kms->state->smp;
-
-	state->state = new_state;
-
-	return new_state;
-}
-
-static void mdp5_swap_state(struct msm_kms *kms, struct drm_atomic_state *state)
-{
-	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
-	swap(to_kms_state(state)->state, mdp5_kms->state);
-}
-
 /* Global/shared object state funcs */
 
 /*
@@ -315,7 +279,6 @@ static const struct mdp_kms_funcs kms_funcs = {
 		.irq             = mdp5_irq,
 		.enable_vblank   = mdp5_enable_vblank,
 		.disable_vblank  = mdp5_disable_vblank,
-		.swap_state      = mdp5_swap_state,
 		.prepare_commit  = mdp5_prepare_commit,
 		.complete_commit = mdp5_complete_commit,
 		.wait_for_crtc_commit_done = mdp5_wait_for_crtc_commit_done,
@@ -814,8 +777,6 @@ static void mdp5_destroy(struct platform_device *pdev)
 		pm_runtime_disable(&pdev->dev);
 
 	drm_atomic_private_obj_fini(&mdp5_kms->glob_base);
-
-	kfree(mdp5_kms->state);
 }
 
 static int construct_pipes(struct mdp5_kms *mdp5_kms, int cnt,
@@ -968,13 +929,6 @@ static int mdp5_init(struct platform_device *pdev, struct drm_device *dev)
 	mdp5_kms->dev = dev;
 	mdp5_kms->pdev = pdev;
 
-	drm_modeset_lock_init(&mdp5_kms->state_lock);
-	mdp5_kms->state = kzalloc(sizeof(*mdp5_kms->state), GFP_KERNEL);
-	if (!mdp5_kms->state) {
-		ret = -ENOMEM;
-		goto fail;
-	}
-
 	ret = mdp5_global_obj_init(mdp5_kms);
 	if (ret)
 		goto fail;
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
index 522ddb835593..6b9a7d091606 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
@@ -28,8 +28,6 @@
 #include "mdp5_ctl.h"
 #include "mdp5_smp.h"
 
-struct mdp5_state;
-
 struct mdp5_kms {
 	struct mdp_kms base;
 
@@ -49,12 +47,6 @@ struct mdp5_kms {
 	struct mdp5_cfg_handler *cfg;
 	uint32_t caps;	/* MDP capabilities (MDP_CAP_XXX bits) */
 
-	/**
-	 * Global atomic state.  Do not access directly, use mdp5_get_state()
-	 */
-	struct mdp5_state *state;
-	struct drm_modeset_lock state_lock;
-
 	/*
 	 * Global private object state, Do not access directly, use
 	 * mdp5_global_get_state()
@@ -88,20 +80,6 @@ struct mdp5_kms {
 };
 #define to_mdp5_kms(x) container_of(x, struct mdp5_kms, base)
 
-/* Global atomic state for tracking resources that are shared across
- * multiple kms objects (planes/crtcs/etc).
- *
- * For atomic updates which require modifying global state,
- */
-struct mdp5_state {
-	struct mdp5_hw_pipe_state hwpipe;
-	struct mdp5_hw_mixer_state hwmixer;
-	struct mdp5_smp_state smp;
-};
-
-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).
  */
diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c
index 025d454163b0..96a8f6a4c8eb 100644
--- a/drivers/gpu/drm/msm/msm_atomic.c
+++ b/drivers/gpu/drm/msm/msm_atomic.c
@@ -241,11 +241,7 @@ int msm_atomic_commit(struct drm_device *dev,
 	 * This is the point of no return - everything below never fails except
 	 * when the hw goes bonghits. Which means we can commit the new state on
 	 * the software side now.
-	 *
-	 * swap driver private state while still holding state_lock
 	 */
-	if (to_kms_state(state)->state)
-		priv->kms->funcs->swap_state(priv->kms, state);
 
 	/*
 	 * Everything below can be run asynchronously without the need to grab
@@ -279,30 +275,3 @@ int msm_atomic_commit(struct drm_device *dev,
 	drm_atomic_helper_cleanup_planes(dev, state);
 	return ret;
 }
-
-struct drm_atomic_state *msm_atomic_state_alloc(struct drm_device *dev)
-{
-	struct msm_kms_state *state = kzalloc(sizeof(*state), GFP_KERNEL);
-
-	if (!state || drm_atomic_state_init(dev, &state->base) < 0) {
-		kfree(state);
-		return NULL;
-	}
-
-	return &state->base;
-}
-
-void msm_atomic_state_clear(struct drm_atomic_state *s)
-{
-	struct msm_kms_state *state = to_kms_state(s);
-	drm_atomic_state_default_clear(&state->base);
-	kfree(state->state);
-	state->state = NULL;
-}
-
-void msm_atomic_state_free(struct drm_atomic_state *state)
-{
-	kfree(to_kms_state(state)->state);
-	drm_atomic_state_default_release(state);
-	kfree(state);
-}
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 606df7bea97b..5c5f7dd7e64d 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -46,9 +46,6 @@ static const struct drm_mode_config_funcs mode_config_funcs = {
 	.output_poll_changed = msm_fb_output_poll_changed,
 	.atomic_check = msm_atomic_check,
 	.atomic_commit = msm_atomic_commit,
-	.atomic_state_alloc = msm_atomic_state_alloc,
-	.atomic_state_clear = msm_atomic_state_clear,
-	.atomic_state_free = msm_atomic_state_free,
 };
 
 #ifdef CONFIG_DRM_MSM_REGISTER_LOGGING
diff --git a/drivers/gpu/drm/msm/msm_kms.h b/drivers/gpu/drm/msm/msm_kms.h
index 17d5824417ad..f0842b963df1 100644
--- a/drivers/gpu/drm/msm/msm_kms.h
+++ b/drivers/gpu/drm/msm/msm_kms.h
@@ -40,8 +40,6 @@ struct msm_kms_funcs {
 	irqreturn_t (*irq)(struct msm_kms *kms);
 	int (*enable_vblank)(struct msm_kms *kms, struct drm_crtc *crtc);
 	void (*disable_vblank)(struct msm_kms *kms, struct drm_crtc *crtc);
-	/* swap global atomic state: */
-	void (*swap_state)(struct msm_kms *kms, struct drm_atomic_state *state);
 	/* modeset, bracketing atomic_commit(): */
 	void (*prepare_commit)(struct msm_kms *kms, struct drm_atomic_state *state);
 	void (*complete_commit)(struct msm_kms *kms, struct drm_atomic_state *state);
@@ -77,18 +75,6 @@ struct msm_kms {
 	struct msm_gem_address_space *aspace;
 };
 
-/**
- * Subclass of drm_atomic_state, to allow kms backend to have driver
- * private global state.  The kms backend can do whatever it wants
- * with the ->state ptr.  On ->atomic_state_clear() the ->state ptr
- * is kfree'd and set back to NULL.
- */
-struct msm_kms_state {
-	struct drm_atomic_state base;
-	void *state;
-};
-#define to_kms_state(x) container_of(x, struct msm_kms_state, base)
-
 static inline void msm_kms_init(struct msm_kms *kms,
 		const struct msm_kms_funcs *funcs)
 {
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

Re: [RFC 1/3] drm/msm/mdp5: Add global state as a private atomic object

[Daniel Vetter]

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@codeaurora.org>
> ---
>  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.


> +}
> +
> +/*
> + * 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.

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.
>   */
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> hosted by The Linux Foundation
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
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Re: [RFC 1/3] drm/msm/mdp5: Add global state as a private atomic object

[Archit Taneja]

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@codeaurora.org>
>> ---
>>   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.
>>    */
>> -- 
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>> hosted by The Linux Foundation
>>
> 

-- 
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a Linux Foundation Collaborative Project
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Re: [RFC 1/3] drm/msm/mdp5: Add global state as a private atomic object

[Rob Clark]

On Wed, Jan 3, 2018 at 6:32 AM, Archit Taneja <architt@codeaurora.org> wrote:
>
>
> 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@codeaurora.org>
>>> ---
>>>   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.
>

fwiw, with the current code, I stuck with just a single modeset lock,
since if you are re-assigning hwpipe's you are also re-assigning SMP
blocks.  Perhaps we should already split that into two now that we
added dynamic assignment of mixers.  (Ie. so a modeset on one output
wouldn't block pagefile on another.)

Maybe just separate private objects + locks for each thing would make
more sense than trying to micro-optimize the locking ;-)

BR,
-R

> 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.
>>>    */
>>> --
>>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
>>> Forum,
>>> hosted by The Linux Foundation
>>>
>>
>
> --
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
> a Linux Foundation Collaborative Project
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Re: [RFC 1/3] drm/msm/mdp5: Add global state as a private atomic object

[Rob Clark]

On Thu, Dec 21, 2017 at 4:56 AM, Daniel Vetter <daniel@ffwll.ch> 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@codeaurora.org>
>> ---
>>  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.
>

This is used for read-only access to current state, a couple places in
atomic update post-swap (where
drm_atomic_get_existing_private_obj_state() would work, but also for
things like debugfs, where it wouldn't)..

Probably should const'ify the return value to make it clear that this
is read-only.

>
>> +}
>> +
>> +/*
>> + * 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 like the idea of adding a modeset lock to private objs.. I've got a
WIP patch to do this.

BR,
-R

> 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.
>>   */
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>> hosted by The Linux Foundation
>>
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
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