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>

drivers/gpu/drm/nouveau/Makefile

@@ -16,6 +16,7 @@ nouveau-y += core/core/gpuobj.o
 nouveau-y += core/core/handle.o
 nouveau-y += core/core/mm.o
 nouveau-y += core/core/namedb.o
+nouveau-y += core/core/notify.o
 nouveau-y += core/core/object.o
 nouveau-y += core/core/option.o
 nouveau-y += core/core/parent.o

drivers/gpu/drm/nouveau/core/core/event.c

 /*
- * Copyright 2013 Red Hat Inc.
+ * Copyright 2013-2014 Red Hat Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -24,173 +24,77 @@
 #include <core/event.h>
 
 void
-nouveau_event_put(struct nouveau_eventh *handler)
+nvkm_event_put(struct nvkm_event *event, u32 types, int index)
 {
-	struct nouveau_event *event = handler->event;
-	unsigned long flags;
-	u32 m, t;
-
-	if (!__test_and_clear_bit(NVKM_EVENT_ENABLE, &handler->flags))
-		return;
-
-	spin_lock_irqsave(&event->refs_lock, flags);
-	for (m = handler->types; t = __ffs(m), m; m &= ~(1 << t)) {
-		if (!--event->refs[handler->index * event->types_nr + t]) {
-			if (event->disable)
-				event->disable(event, 1 << t, handler->index);
+	BUG_ON(!spin_is_locked(&event->refs_lock));
+	while (types) {
+		int type = __ffs(types); types &= ~(1 << type);
+		if (--event->refs[index * event->types_nr + type] == 0) {
+			if (event->func->fini)
+				event->func->fini(event, 1 << type, index);
 		}
-
 	}
-	spin_unlock_irqrestore(&event->refs_lock, flags);
 }
 
 void
-nouveau_event_get(struct nouveau_eventh *handler)
+nvkm_event_get(struct nvkm_event *event, u32 types, int index)
 {
-	struct nouveau_event *event = handler->event;
-	unsigned long flags;
-	u32 m, t;
-
-	if (__test_and_set_bit(NVKM_EVENT_ENABLE, &handler->flags))
-		return;
-
-	spin_lock_irqsave(&event->refs_lock, flags);
-	for (m = handler->types; t = __ffs(m), m; m &= ~(1 << t)) {
-		if (!event->refs[handler->index * event->types_nr + t]++) {
-			if (event->enable)
-				event->enable(event, 1 << t, handler->index);
+	BUG_ON(!spin_is_locked(&event->refs_lock));
+	while (types) {
+		int type = __ffs(types); types &= ~(1 << type);
+		if (++event->refs[index * event->types_nr + type] == 1) {
+			if (event->func->init)
+				event->func->init(event, 1 << type, index);
 		}
-
 	}
-	spin_unlock_irqrestore(&event->refs_lock, flags);
-}
-
-static void
-nouveau_event_fini(struct nouveau_eventh *handler)
-{
-	struct nouveau_event *event = handler->event;
-	unsigned long flags;
-	nouveau_event_put(handler);
-	spin_lock_irqsave(&event->list_lock, flags);
-	list_del(&handler->head);
-	spin_unlock_irqrestore(&event->list_lock, flags);
-}
-
-static int
-nouveau_event_init(struct nouveau_event *event, u32 types, int index,
-		   int (*func)(void *, u32, int), void *priv,
-		   struct nouveau_eventh *handler)
-{
-	unsigned long flags;
-
-	if (types & ~((1 << event->types_nr) - 1))
-		return -EINVAL;
-	if (index >= event->index_nr)
-		return -EINVAL;
-
-	handler->event = event;
-	handler->flags = 0;
-	handler->types = types;
-	handler->index = index;
-	handler->func = func;
-	handler->priv = priv;
-
-	spin_lock_irqsave(&event->list_lock, flags);
-	list_add_tail(&handler->head, &event->list[index]);
-	spin_unlock_irqrestore(&event->list_lock, flags);
-	return 0;
-}
-
-int
-nouveau_event_new(struct nouveau_event *event, u32 types, int index,
-		  int (*func)(void *, u32, int), void *priv,
-		  struct nouveau_eventh **phandler)
-{
-	struct nouveau_eventh *handler;
-	int ret = -ENOMEM;
-
-	if (event->check) {
-		ret = event->check(event, types, index);
-		if (ret)
-			return ret;
-	}
-
-	handler = *phandler = kmalloc(sizeof(*handler), GFP_KERNEL);
-	if (handler) {
-		ret = nouveau_event_init(event, types, index, func, priv, handler);
-		if (ret)
-			kfree(handler);
-	}
-
-	return ret;
-}
-
-void
-nouveau_event_ref(struct nouveau_eventh *handler, struct nouveau_eventh **ref)
-{
-	BUG_ON(handler != NULL);
-	if (*ref) {
-		nouveau_event_fini(*ref);
-		kfree(*ref);
-	}
-	*ref = handler;
 }
 
 void
-nouveau_event_trigger(struct nouveau_event *event, u32 types, int index)
+nvkm_event_send(struct nvkm_event *event, u32 types, int index,
+		void *data, u32 size)
 {
-	struct nouveau_eventh *handler;
+	struct nvkm_notify *notify;
 	unsigned long flags;
 
-	if (WARN_ON(index >= event->index_nr))
+	if (!event->refs || WARN_ON(index >= event->index_nr))
 		return;
 
 	spin_lock_irqsave(&event->list_lock, flags);
-	list_for_each_entry(handler, &event->list[index], head) {
-		if (!test_bit(NVKM_EVENT_ENABLE, &handler->flags))
-			continue;
-		if (!(handler->types & types))
-			continue;
-		if (handler->func(handler->priv, handler->types & types, index)
-				!= NVKM_EVENT_DROP)
-			continue;
-		nouveau_event_put(handler);
+	list_for_each_entry(notify, &event->list, head) {
+		if (notify->index == index && (notify->types & types)) {
+			if (event->func->send) {
+				event->func->send(data, size, notify);
+				continue;
+			}
+			nvkm_notify_send(notify, data, size);
+		}
 	}
 	spin_unlock_irqrestore(&event->list_lock, flags);
 }
 
 void
-nouveau_event_destroy(struct nouveau_event **pevent)
+nvkm_event_fini(struct nvkm_event *event)
 {
-	struct nouveau_event *event = *pevent;
-	if (event) {
-		kfree(event);
-		*pevent = NULL;
+	if (event->refs) {
+		kfree(event->refs);
+		event->refs = NULL;
 	}
 }
 
 int
-nouveau_event_create(int types_nr, int index_nr, struct nouveau_event **pevent)
+nvkm_event_init(const struct nvkm_event_func *func, int types_nr, int index_nr,
+		struct nvkm_event *event)
 {
-	struct nouveau_event *event;
-	int i;
-
-	event = *pevent = kzalloc(sizeof(*event) + (index_nr * types_nr) *
-				  sizeof(event->refs[0]), GFP_KERNEL);
-	if (!event)
-		return -ENOMEM;
-
-	event->list = kmalloc(sizeof(*event->list) * index_nr, GFP_KERNEL);
-	if (!event->list) {
-		kfree(event);
+	event->refs = kzalloc(sizeof(*event->refs) * index_nr * types_nr,
+			      GFP_KERNEL);
+	if (!event->refs)
 		return -ENOMEM;
-	}
 
-	spin_lock_init(&event->list_lock);
-	spin_lock_init(&event->refs_lock);
-	for (i = 0; i < index_nr; i++)
-		INIT_LIST_HEAD(&event->list[i]);
+	event->func = func;
 	event->types_nr = types_nr;
 	event->index_nr = index_nr;
+	spin_lock_init(&event->refs_lock);
+	spin_lock_init(&event->list_lock);
+	INIT_LIST_HEAD(&event->list);
 	return 0;
 }

drivers/gpu/drm/nouveau/core/core/notify.c

+/*
+ * Copyright 2014 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Ben Skeggs <bskeggs@redhat.com>
+ */
+
+#include <core/os.h>
+#include <core/event.h>
+#include <core/notify.h>
+
+static inline void
+nvkm_notify_put_locked(struct nvkm_notify *notify)
+{
+	if (notify->block++ == 0)
+		nvkm_event_put(notify->event, notify->types, notify->index);
+}
+
+void
+nvkm_notify_put(struct nvkm_notify *notify)
+{
+	struct nvkm_event *event = notify->event;
+	unsigned long flags;
+	if (likely(event) &&
+	    test_and_clear_bit(NVKM_NOTIFY_USER, &notify->flags)) {
+		spin_lock_irqsave(&event->refs_lock, flags);
+		nvkm_notify_put_locked(notify);
+		spin_unlock_irqrestore(&event->refs_lock, flags);
+		if (test_bit(NVKM_NOTIFY_WORK, &notify->flags))
+			flush_work(&notify->work);
+	}
+}
+
+static inline void
+nvkm_notify_get_locked(struct nvkm_notify *notify)
+{
+	if (--notify->block == 0)
+		nvkm_event_get(notify->event, notify->types, notify->index);
+}
+
+void
+nvkm_notify_get(struct nvkm_notify *notify)
+{
+	struct nvkm_event *event = notify->event;
+	unsigned long flags;
+	if (likely(event) &&
+	    !test_and_set_bit(NVKM_NOTIFY_USER, &notify->flags)) {
+		spin_lock_irqsave(&event->refs_lock, flags);
+		nvkm_notify_get_locked(notify);
+		spin_unlock_irqrestore(&event->refs_lock, flags);
+	}
+}
+
+static inline void
+nvkm_notify_func(struct nvkm_notify *notify)
+{
+	struct nvkm_event *event = notify->event;
+	int ret = notify->func(notify);
+	unsigned long flags;
+	if ((ret == NVKM_NOTIFY_KEEP) ||
+	    !test_and_clear_bit(NVKM_NOTIFY_USER, &notify->flags)) {
+		spin_lock_irqsave(&event->refs_lock, flags);
+		nvkm_notify_get_locked(notify);
+		spin_unlock_irqrestore(&event->refs_lock, flags);
+	}
+}
+
+static void
+nvkm_notify_work(struct work_struct *work)
+{
+	struct nvkm_notify *notify = container_of(work, typeof(*notify), work);
+	nvkm_notify_func(notify);
+}
+
+void
+nvkm_notify_send(struct nvkm_notify *notify, void *data, u32 size)
+{
+	struct nvkm_event *event = notify->event;
+	unsigned long flags;
+
+	BUG_ON(!spin_is_locked(&event->list_lock));
+	BUG_ON(size != notify->size);
+
+	spin_lock_irqsave(&event->refs_lock, flags);
+	if (notify->block) {
+		spin_unlock_irqrestore(&event->refs_lock, flags);
+		return;
+	}
+	nvkm_notify_put_locked(notify);
+	spin_unlock_irqrestore(&event->refs_lock, flags);
+
+	if (test_bit(NVKM_NOTIFY_WORK, &notify->flags)) {
+		memcpy((void *)notify->data, data, size);
+		schedule_work(&notify->work);
+	} else {
+		notify->data = data;
+		nvkm_notify_func(notify);
+		notify->data = NULL;
+	}
+}
+
+void
+nvkm_notify_fini(struct nvkm_notify *notify)
+{
+	unsigned long flags;
+	if (notify->event) {
+		nvkm_notify_put(notify);
+		spin_lock_irqsave(&notify->event->list_lock, flags);
+		list_del(&notify->head);
+		spin_unlock_irqrestore(&notify->event->list_lock, flags);
+		kfree((void *)notify->data);
+		notify->event = NULL;
+	}
+}
+
+int
+nvkm_notify_init(struct nvkm_event *event, int (*func)(struct nvkm_notify *),
+		 bool work, void *data, u32 size, u32 reply,
+		 struct nvkm_notify *notify)
+{
+	unsigned long flags;
+	int ret = -ENODEV;
+	if ((notify->event = event), event->refs) {
+		ret = event->func->ctor(data, size, notify);
+		if (ret == 0 && (ret = -EINVAL, notify->size == reply)) {
+			notify->flags = 0;
+			notify->block = 1;
+			notify->func = func;
+			notify->data = NULL;
+			if (ret = 0, work) {
+				INIT_WORK(&notify->work, nvkm_notify_work);
+				set_bit(NVKM_NOTIFY_WORK, &notify->flags);
+				notify->data = kmalloc(reply, GFP_KERNEL);
+				if (!notify->data)
+					ret = -ENOMEM;
+			}
+		}
+		if (ret == 0) {
+			spin_lock_irqsave(&event->list_lock, flags);
+			list_add_tail(&notify->head, &event->list);
+			spin_unlock_irqrestore(&event->list_lock, flags);
+		}
+	}
+	if (ret)
+		notify->event = NULL;
+	return ret;
+}

drivers/gpu/drm/nouveau/core/engine/device/acpi.c

@@ -33,7 +33,7 @@ nvkm_acpi_ntfy(struct notifier_block *nb, unsigned long val, void *data)
 	struct acpi_bus_event *info = data;
 
 	if (!strcmp(info->device_class, "ac_adapter"))
-		nouveau_event_trigger(device->ntfy, 1, NVKM_DEVICE_NTFY_POWER);
+		nvkm_event_send(&device->event, 1, 0, NULL, 0);
 
 	return NOTIFY_DONE;
 }

drivers/gpu/drm/nouveau/core/engine/device/base.c

@@ -364,12 +364,30 @@ nouveau_devobj_ofuncs = {
 /******************************************************************************
  * nouveau_device: engine functions
  *****************************************************************************/
+
 static struct nouveau_oclass
 nouveau_device_sclass[] = {
 	{ 0x0080, &nouveau_devobj_ofuncs },
 	{}
 };
 
+static int
+nouveau_device_event_ctor(void *data, u32 size, struct nvkm_notify *notify)
+{
+	if (!WARN_ON(size != 0)) {
+		notify->size  = 0;
+		notify->types = 1;
+		notify->index = 0;
+		return 0;
+	}
+	return -EINVAL;
+}
+
+static const struct nvkm_event_func
+nouveau_device_event_func = {
+	.ctor = nouveau_device_event_ctor,
+};
+
 static int
 nouveau_device_fini(struct nouveau_object *object, bool suspend)
 {
@@ -445,7 +463,7 @@ nouveau_device_dtor(struct nouveau_object *object)
 {
 	struct nouveau_device *device = (void *)object;
 
-	nouveau_event_destroy(&device->ntfy);
+	nvkm_event_fini(&device->event);
 
 	mutex_lock(&nv_devices_mutex);
 	list_del(&device->head);
@@ -545,7 +563,8 @@ nouveau_device_create_(void *dev, enum nv_bus_type type, u64 name,
 	nv_engine(device)->sclass = nouveau_device_sclass;
 	list_add(&device->head, &nv_devices);
 
-	ret = nouveau_event_create(1, NVKM_DEVICE_NTFY, &device->ntfy);
+	ret = nvkm_event_init(&nouveau_device_event_func, 1, 1,
+			      &device->event);
 done:
 	mutex_unlock(&nv_devices_mutex);
 	return ret;

drivers/gpu/drm/nouveau/core/engine/disp/base.c

@@ -22,25 +22,76 @@
  * Authors: Ben Skeggs
  */
 
+#include <core/os.h>
+#include <nvif/unpack.h>
+#include <nvif/event.h>
+
 #include "priv.h"
 #include "outp.h"
 #include "conn.h"
 
+int
+nouveau_disp_vblank_ctor(void *data, u32 size, struct nvkm_notify *notify)
+{
+	struct nouveau_disp *disp =
+		container_of(notify->event, typeof(*disp), vblank);
+	union {
+		struct nvif_notify_head_req_v0 v0;
+	} *req = data;
+	int ret;
+
+	if (nvif_unpack(req->v0, 0, 0, false)) {
+		notify->size = sizeof(struct nvif_notify_head_rep_v0);
+		if (ret = -ENXIO, req->v0.head <= disp->vblank.index_nr) {
+			notify->types = 1;
+			notify->index = req->v0.head;
+			return 0;
+		}
+	}
+
+	return ret;
+}
+
+void
+nouveau_disp_vblank(struct nouveau_disp *disp, int head)
+{
+	struct nvif_notify_head_rep_v0 rep = {};
+	nvkm_event_send(&disp->vblank, 1, head, &rep, sizeof(rep));
+}
+
 static int
-nouveau_disp_hpd_check(struct nouveau_event *event, u32 types, int index)
+nouveau_disp_hpd_ctor(void *data, u32 size, struct nvkm_notify *notify)
 {
-	struct nouveau_disp *disp = event->priv;
+	struct nouveau_disp *disp =
+		container_of(notify->event, typeof(*disp), hpd);
+	union {
+		struct nvif_notify_conn_req_v0 v0;
+	} *req = data;
 	struct nvkm_output *outp;
-	list_for_each_entry(outp, &disp->outp, head) {
-		if (outp->conn->index == index) {
-			if (outp->conn->hpd.event)
-				return 0;
-			break;
+	int ret;
+
+	if (nvif_unpack(req->v0, 0, 0, false)) {
+		notify->size = sizeof(struct nvif_notify_conn_rep_v0);
+		list_for_each_entry(outp, &disp->outp, head) {
+			if (ret = -ENXIO, outp->conn->index == req->v0.conn) {
+				if (ret = -ENODEV, outp->conn->hpd.event) {
+					notify->types = req->v0.mask;
+					notify->index = req->v0.conn;
+					ret = 0;
+				}
+				break;
+			}
 		}
 	}
-	return -ENOSYS;
+
+	return ret;
 }
 
+static const struct nvkm_event_func
+nouveau_disp_hpd_func = {
+	.ctor = nouveau_disp_hpd_ctor
+};
+
 int
 _nouveau_disp_fini(struct nouveau_object *object, bool suspend)
 {
@@ -97,7 +148,8 @@ _nouveau_disp_dtor(struct nouveau_object *object)
 	struct nouveau_disp *disp = (void *)object;
 	struct nvkm_output *outp, *outt;
 
-	nouveau_event_destroy(&disp->vblank);
+	nvkm_event_fini(&disp->vblank);
+	nvkm_event_fini(&disp->hpd);
 
 	if (disp->outp.next) {
 		list_for_each_entry_safe(outp, outt, &disp->outp, head) {
@@ -157,14 +209,11 @@ nouveau_disp_create_(struct nouveau_object *parent,
 		hpd = max(hpd, (u8)(dcbE.connector + 1));
 	}
 
-	ret = nouveau_event_create(3, hpd, &disp->hpd);
+	ret = nvkm_event_init(&nouveau_disp_hpd_func, 3, hpd, &disp->hpd);
 	if (ret)
 		return ret;
 
-	disp->hpd->priv = disp;
-	disp->hpd->check = nouveau_disp_hpd_check;
-
-	ret = nouveau_event_create(1, heads, &disp->vblank);
+	ret = nvkm_event_init(impl->vblank, 1, heads, &disp->vblank);
 	if (ret)
 		return ret;
 

drivers/gpu/drm/nouveau/core/engine/disp/conn.c

@@ -22,39 +22,41 @@
  * Authors: Ben Skeggs
  */
 
+#include <core/os.h>
+#include <nvif/event.h>
+
 #include <subdev/gpio.h>
 
 #include "conn.h"
 #include "outp.h"
 
-static void
-nvkm_connector_hpd_work(struct work_struct *w)
+static int
+nvkm_connector_hpd(struct nvkm_notify *notify)
 {
-	struct nvkm_connector *conn = container_of(w, typeof(*conn), hpd.work);
+	struct nvkm_connector *conn = container_of(notify, typeof(*conn), hpd);
 	struct nouveau_disp *disp = nouveau_disp(conn);
 	struct nouveau_gpio *gpio = nouveau_gpio(conn);
-	u32 send = NVKM_HPD_UNPLUG;
-	if (gpio->get(gpio, 0, DCB_GPIO_UNUSED, conn->hpd.event->index))
-		send = NVKM_HPD_PLUG;
-	nouveau_event_trigger(disp->hpd, send, conn->index);
-	nouveau_event_get(conn->hpd.event);
-}
+	const struct nvkm_gpio_ntfy_rep *line = notify->data;
+	struct nvif_notify_conn_rep_v0 rep;
+	int index = conn->index;
 
-static int