From 3acec63aee5d082f86218973912e682e84ec2a05 Mon Sep 17 00:00:00 2001 From: Ben Skeggs Date: Fri, 10 Aug 2012 13:47:56 +1000 Subject: drm/nouveau/core: protect engine context list with hardirq-safe spinlock IRQ handlers will need access to engine contexts. Signed-off-by: Ben Skeggs --- drivers/gpu/drm/nouveau/core/core/engctx.c | 74 ++++++++++++++++------ drivers/gpu/drm/nouveau/core/core/engine.c | 1 + drivers/gpu/drm/nouveau/core/include/core/engctx.h | 2 +- drivers/gpu/drm/nouveau/core/include/core/engine.h | 3 + 4 files changed, 60 insertions(+), 20 deletions(-) diff --git a/drivers/gpu/drm/nouveau/core/core/engctx.c b/drivers/gpu/drm/nouveau/core/core/engctx.c index 50dc16d29f20..38c0612a5122 100644 --- a/drivers/gpu/drm/nouveau/core/core/engctx.c +++ b/drivers/gpu/drm/nouveau/core/core/engctx.c @@ -30,6 +30,25 @@ #include +static inline int +nouveau_engctx_exists(struct nouveau_object *parent, + struct nouveau_engine *engine, void **pobject) +{ + struct nouveau_engctx *engctx; + struct nouveau_object *parctx; + + list_for_each_entry(engctx, &engine->contexts, head) { + parctx = nv_pclass(nv_object(engctx), NV_PARENT_CLASS); + if (parctx == parent) { + atomic_inc(&nv_object(engctx)->refcount); + *pobject = engctx; + return 1; + } + } + + return 0; +} + int nouveau_engctx_create_(struct nouveau_object *parent, struct nouveau_object *engobj, @@ -41,23 +60,22 @@ nouveau_engctx_create_(struct nouveau_object *parent, struct nouveau_client *client = nouveau_client(parent); struct nouveau_engine *engine = nv_engine(engobj); struct nouveau_subdev *subdev = nv_subdev(engine); - struct nouveau_engctx *engctx; - struct nouveau_object *ctxpar; + struct nouveau_object *engctx; + unsigned long save; int ret; - /* use existing context for the engine if one is available */ - mutex_lock(&subdev->mutex); - list_for_each_entry(engctx, &engine->contexts, head) { - ctxpar = nv_pclass(nv_object(engctx), NV_PARENT_CLASS); - if (ctxpar == parent) { - atomic_inc(&nv_object(engctx)->refcount); - *pobject = engctx; - mutex_unlock(&subdev->mutex); - return 1; - } - } - mutex_unlock(&subdev->mutex); + /* check if this engine already has a context for the parent object, + * and reference it instead of creating a new one + */ + spin_lock_irqsave(&engine->lock, save); + ret = nouveau_engctx_exists(parent, engine, pobject); + spin_unlock_irqrestore(&engine->lock, save); + if (ret) + return ret; + /* create the new context, supports creating both raw objects and + * objects backed by instance memory + */ if (size) { ret = nouveau_gpuobj_create_(parent, engobj, oclass, NV_ENGCTX_CLASS, @@ -69,25 +87,43 @@ nouveau_engctx_create_(struct nouveau_object *parent, } engctx = *pobject; - if (engctx && client->vm) - atomic_inc(&client->vm->engref[nv_engidx(engobj)]); if (ret) return ret; - list_add(&engctx->head, &engine->contexts); + /* must take the lock again and re-check a context doesn't already + * exist (in case of a race) - the lock had to be dropped before as + * it's not possible to allocate the object with it held. + */ + spin_lock_irqsave(&engine->lock, save); + ret = nouveau_engctx_exists(parent, engine, pobject); + if (ret) { + spin_unlock_irqrestore(&engine->lock, save); + nouveau_object_ref(NULL, &engctx); + return ret; + } + + if (client->vm) + atomic_inc(&client->vm->engref[nv_engidx(engobj)]); + list_add(&nv_engctx(engctx)->head, &engine->contexts); + spin_unlock_irqrestore(&engine->lock, save); return 0; } void nouveau_engctx_destroy(struct nouveau_engctx *engctx) { - struct nouveau_object *engine = nv_object(engctx)->engine; + struct nouveau_object *engobj = nv_object(engctx)->engine; + struct nouveau_engine *engine = nv_engine(engobj); struct nouveau_client *client = nouveau_client(engctx); + unsigned long save; nouveau_gpuobj_unmap(&engctx->vma); + spin_lock_irqsave(&engine->lock, save); list_del(&engctx->head); + spin_unlock_irqrestore(&engine->lock, save); + if (client->vm) - atomic_dec(&client->vm->engref[nv_engidx(engine)]); + atomic_dec(&client->vm->engref[nv_engidx(engobj)]); if (engctx->base.size) nouveau_gpuobj_destroy(&engctx->base); diff --git a/drivers/gpu/drm/nouveau/core/core/engine.c b/drivers/gpu/drm/nouveau/core/core/engine.c index ee2905b806c6..09b3bd502fd0 100644 --- a/drivers/gpu/drm/nouveau/core/core/engine.c +++ b/drivers/gpu/drm/nouveau/core/core/engine.c @@ -50,5 +50,6 @@ nouveau_engine_create_(struct nouveau_object *parent, } INIT_LIST_HEAD(&engine->contexts); + spin_lock_init(&engine->lock); return 0; } diff --git a/drivers/gpu/drm/nouveau/core/include/core/engctx.h b/drivers/gpu/drm/nouveau/core/include/core/engctx.h index cbc9eb3a0d1a..3bc6ccd6cbd8 100644 --- a/drivers/gpu/drm/nouveau/core/include/core/engctx.h +++ b/drivers/gpu/drm/nouveau/core/include/core/engctx.h @@ -15,7 +15,7 @@ struct nouveau_engctx { struct list_head head; }; -static inline void * +static inline struct nouveau_engctx * nv_engctx(void *obj) { #if CONFIG_NOUVEAU_DEBUG >= NV_DBG_PARANOIA diff --git a/drivers/gpu/drm/nouveau/core/include/core/engine.h b/drivers/gpu/drm/nouveau/core/include/core/engine.h index 1a7b0a7455ca..666d06de77ec 100644 --- a/drivers/gpu/drm/nouveau/core/include/core/engine.h +++ b/drivers/gpu/drm/nouveau/core/include/core/engine.h @@ -11,7 +11,10 @@ struct nouveau_engine { struct nouveau_subdev base; struct nouveau_oclass *cclass; struct nouveau_oclass *sclass; + struct list_head contexts; + spinlock_t lock; + void (*tile_prog)(struct nouveau_engine *, int region); int (*tlb_flush)(struct nouveau_engine *); }; -- cgit v1.2.3