drm/nouveau/core: rework event interface

This is a lot of prep-work for being able to send event notifications
back to userspace.  Events now contain data, rather than a "something
just happened" signal.

Handler data is now embedded into a containing structure, rather than
being kmalloc()'d, and can optionally have the notify routine handled
in a workqueue.

Various races between suspend/unload with display HPD/DP IRQ handlers
automagically solved as a result.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

3 files changed, 23 insertions, 25 deletions

diff --git a/drivers/gpu/drm/nouveau/core/engine/software/nv50.c b/drivers/gpu/drm/nouveau/core/engine/software/nv50.c
index c150fff..48678ed 100644
--- a/drivers/gpu/drm/nouveau/core/engine/software/nv50.c
+++ b/drivers/gpu/drm/nouveau/core/engine/software/nv50.c
@@ -29,6 +29,7 @@
 #include <core/handle.h>
 #include <core/gpuobj.h>
 #include <core/event.h>
+#include <nvif/event.h>
 
 #include <subdev/bar.h>
 
@@ -86,10 +87,10 @@ nv50_software_mthd_vblsem_release(struct nouveau_object *object, u32 mthd,
 {
 	struct nv50_software_chan *chan = (void *)nv_engctx(object->parent);
 	u32 head = *(u32 *)args;
-	if (head >= chan->vblank.nr_event)
+	if (head >= nouveau_disp(chan)->vblank.index_nr)
 		return -EINVAL;
 
-	nouveau_event_get(chan->vblank.event[head]);
+	nvkm_notify_get(&chan->vblank.notify[head]);
 	return 0;
 }
 
@@ -124,9 +125,10 @@ nv50_software_sclass[] = {
  ******************************************************************************/
 
 static int
-nv50_software_vblsem_release(void *data, u32 type, int head)
+nv50_software_vblsem_release(struct nvkm_notify *notify)
 {
-	struct nv50_software_chan *chan = data;
+	struct nv50_software_chan *chan =
+		container_of(notify, typeof(*chan), vblank.notify[notify->index]);
 	struct nv50_software_priv *priv = (void *)nv_object(chan)->engine;
 	struct nouveau_bar *bar = nouveau_bar(priv);
 
@@ -142,7 +144,7 @@ nv50_software_vblsem_release(void *data, u32 type, int head)
 		nv_wr32(priv, 0x060014, chan->vblank.value);
 	}
 
-	return NVKM_EVENT_DROP;
+	return NVKM_NOTIFY_DROP;
 }
 
 void
@@ -151,11 +153,8 @@ nv50_software_context_dtor(struct nouveau_object *object)
 	struct nv50_software_chan *chan = (void *)object;
 	int i;
 
-	if (chan->vblank.event) {
-		for (i = 0; i < chan->vblank.nr_event; i++)
-			nouveau_event_ref(NULL, &chan->vblank.event[i]);
-		kfree(chan->vblank.event);
-	}
+	for (i = 0; i < ARRAY_SIZE(chan->vblank.notify); i++)
+		nvkm_notify_fini(&chan->vblank.notify[i]);
 
 	nouveau_software_context_destroy(&chan->base);
 }
@@ -176,15 +175,14 @@ nv50_software_context_ctor(struct nouveau_object *parent,
 	if (ret)
 		return ret;
 
-	chan->vblank.nr_event = pdisp ? pdisp->vblank->index_nr : 0;
-	chan->vblank.event = kzalloc(chan->vblank.nr_event *
-				     sizeof(*chan->vblank.event), GFP_KERNEL);
-	if (!chan->vblank.event)
-		return -ENOMEM;
-
-	for (i = 0; i < chan->vblank.nr_event; i++) {
-		ret = nouveau_event_new(pdisp->vblank, 1, i, pclass->vblank,
-					chan, &chan->vblank.event[i]);
+	for (i = 0; pdisp && i < pdisp->vblank.index_nr; i++) {
+		ret = nvkm_notify_init(&pdisp->vblank, pclass->vblank, false,
+				       &(struct nvif_notify_head_req_v0) {
+					.head = i,
+				       },
+				       sizeof(struct nvif_notify_head_req_v0),
+				       sizeof(struct nvif_notify_head_rep_v0),
+				       &chan->vblank.notify[i]);
 		if (ret)
 			return ret;
 	}
diff --git a/drivers/gpu/drm/nouveau/core/engine/software/nv50.h b/drivers/gpu/drm/nouveau/core/engine/software/nv50.h
index bb49a7a..41542e7 100644
--- a/drivers/gpu/drm/nouveau/core/engine/software/nv50.h
+++ b/drivers/gpu/drm/nouveau/core/engine/software/nv50.h
@@ -19,14 +19,13 @@ int  nv50_software_ctor(struct nouveau_object *, struct nouveau_object *,
 
 struct nv50_software_cclass {
 	struct nouveau_oclass base;
-	int (*vblank)(void *, u32, int);
+	int (*vblank)(struct nvkm_notify *);
 };
 
 struct nv50_software_chan {
 	struct nouveau_software_chan base;
 	struct {
-		struct nouveau_eventh **event;
-		int nr_event;
+		struct nvkm_notify notify[4];
 		u32 channel;
 		u32 ctxdma;
 		u64 offset;
diff --git a/drivers/gpu/drm/nouveau/core/engine/software/nvc0.c b/drivers/gpu/drm/nouveau/core/engine/software/nvc0.c
index 6be97b0..df299a9 100644
--- a/drivers/gpu/drm/nouveau/core/engine/software/nvc0.c
+++ b/drivers/gpu/drm/nouveau/core/engine/software/nvc0.c
@@ -104,9 +104,10 @@ nvc0_software_sclass[] = {
  ******************************************************************************/
 
 static int
-nvc0_software_vblsem_release(void *data, u32 type, int head)
+nvc0_software_vblsem_release(struct nvkm_notify *notify)
 {
-	struct nv50_software_chan *chan = data;
+	struct nv50_software_chan *chan =
+		container_of(notify, typeof(*chan), vblank.notify[notify->index]);
 	struct nv50_software_priv *priv = (void *)nv_object(chan)->engine;
 	struct nouveau_bar *bar = nouveau_bar(priv);
 
@@ -116,7 +117,7 @@ nvc0_software_vblsem_release(void *data, u32 type, int head)
 	nv_wr32(priv, 0x060010, lower_32_bits(chan->vblank.offset));
 	nv_wr32(priv, 0x060014, chan->vblank.value);
 
-	return NVKM_EVENT_DROP;
+	return NVKM_NOTIFY_DROP;
 }
 
 static struct nv50_software_cclass