drm/nouveau/instmem: protect instobj list with a spinlock

No locking is required for the traversal of this list, as it only
happens during suspend/resume where nothing else can be executing.

Fixes some of the issues noticed during parallel piglit runs.

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

diff --git a/drivers/gpu/drm/nouveau/include/nvkm/subdev/instmem.h b/drivers/gpu/drm/nouveau/include/nvkm/subdev/instmem.h
index 28bc202f9753e9fde7777461b5640a77a757a60b..40f845e312723744c52330bdc29b24666281b9f0 100644 (file)
--- a/drivers/gpu/drm/nouveau/include/nvkm/subdev/instmem.h
+++ b/drivers/gpu/drm/nouveau/include/nvkm/subdev/instmem.h
@@ -7,6 +7,7 @@ struct nvkm_instmem {
        const struct nvkm_instmem_func *func;
        struct nvkm_subdev subdev;
 
+       spinlock_t lock;
        struct list_head list;
        u32 reserved;
 

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/base.c
index 895ba74057d4aab45fb44ddfc707243b3252fbdb..1d7dd38292b375bd73ec35ff4e844cd2ae1defe7 100644 (file)
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/base.c
@@ -97,7 +97,9 @@ static void *
 nvkm_instobj_dtor(struct nvkm_memory *memory)
 {
        struct nvkm_instobj *iobj = nvkm_instobj(memory);
+       spin_lock(&iobj->imem->lock);
        list_del(&iobj->head);
+       spin_unlock(&iobj->imem->lock);
        nvkm_memory_del(&iobj->parent);
        return iobj;
 }
@@ -190,7 +192,9 @@ nvkm_instobj_new(struct nvkm_instmem *imem, u32 size, u32 align, bool zero,
                nvkm_memory_ctor(&nvkm_instobj_func_slow, &iobj->memory);
                iobj->parent = memory;
                iobj->imem = imem;
+               spin_lock(&iobj->imem->lock);
                list_add_tail(&iobj->head, &imem->list);
+               spin_unlock(&iobj->imem->lock);
                memory = &iobj->memory;
        }
 
@@ -309,5 +313,6 @@ nvkm_instmem_ctor(const struct nvkm_instmem_func *func,
 {
        nvkm_subdev_ctor(&nvkm_instmem, device, index, 0, &imem->subdev);
        imem->func = func;
+       spin_lock_init(&imem->lock);
        INIT_LIST_HEAD(&imem->list);
 }