drm/nouveau/perfmon: use private spinlock to control exclusive access to perfmon

nvkm_subdev.mutex is going away.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/include/nvkm/engine/pm.h b/drivers/gpu/drm/nouveau/include/nvkm/engine/pm.h
index 4d754e7..0054090 100644 (file)
--- a/drivers/gpu/drm/nouveau/include/nvkm/engine/pm.h
+++ b/drivers/gpu/drm/nouveau/include/nvkm/engine/pm.h
@@ -7,7 +7,10 @@ struct nvkm_pm {
        const struct nvkm_pm_func *func;
        struct nvkm_engine engine;
 
-       struct nvkm_object *perfmon;
+       struct {
+               spinlock_t lock;
+               struct nvkm_object *object;
+       } client;
 
        struct list_head domains;
        struct list_head sources;

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/pm/base.c b/drivers/gpu/drm/nouveau/nvkm/engine/pm/base.c
index b2785be..f875fb7 100644 (file)
--- a/drivers/gpu/drm/nouveau/nvkm/engine/pm/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/pm/base.c
@@ -628,10 +628,10 @@ nvkm_perfmon_dtor(struct nvkm_object *object)
 {
        struct nvkm_perfmon *perfmon = nvkm_perfmon(object);
        struct nvkm_pm *pm = perfmon->pm;
-       mutex_lock(&pm->engine.subdev.mutex);
-       if (pm->perfmon == &perfmon->object)
-               pm->perfmon = NULL;
-       mutex_unlock(&pm->engine.subdev.mutex);
+       spin_lock(&pm->client.lock);
+       if (pm->client.object == &perfmon->object)
+               pm->client.object = NULL;
+       spin_unlock(&pm->client.lock);
        return perfmon;
 }
 
@@ -671,11 +671,11 @@ nvkm_pm_oclass_new(struct nvkm_device *device, const struct nvkm_oclass *oclass,
        if (ret)
                return ret;
 
-       mutex_lock(&pm->engine.subdev.mutex);
-       if (pm->perfmon == NULL)
-               pm->perfmon = *pobject;
-       ret = (pm->perfmon == *pobject) ? 0 : -EBUSY;
-       mutex_unlock(&pm->engine.subdev.mutex);
+       spin_lock(&pm->client.lock);
+       if (pm->client.object == NULL)
+               pm->client.object = *pobject;
+       ret = (pm->client.object == *pobject) ? 0 : -EBUSY;
+       spin_unlock(&pm->client.lock);
        return ret;
 }
 
@@ -863,5 +863,6 @@ nvkm_pm_ctor(const struct nvkm_pm_func *func, struct nvkm_device *device,
        pm->func = func;
        INIT_LIST_HEAD(&pm->domains);
        INIT_LIST_HEAD(&pm->sources);
+       spin_lock_init(&pm->client.lock);
        return nvkm_engine_ctor(&nvkm_pm, device, index, true, &pm->engine);
 }