drm/nouveau/imem: support allocations not preserved across suspend

Will initially be used to tag some large grctx allocations which don't
need to be saved, to speedup suspend/resume.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Acked-by: Danilo Krummrich <me@dakr.org>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230919220442.202488-3-lyude@redhat.com

drivers/gpu/drm/nouveau/include/nvkm/core/memory.h

@@ -12,6 +12,7 @@ struct nvkm_tags {
 };
 
 enum nvkm_memory_target {
+	NVKM_MEM_TARGET_INST_SR_LOST, /* instance memory - not preserved across suspend */
 	NVKM_MEM_TARGET_INST, /* instance memory */
 	NVKM_MEM_TARGET_VRAM, /* video memory */
 	NVKM_MEM_TARGET_HOST, /* coherent system memory */

drivers/gpu/drm/nouveau/include/nvkm/subdev/instmem.h

@@ -26,7 +26,7 @@ struct nvkm_instmem {
 
 u32 nvkm_instmem_rd32(struct nvkm_instmem *, u32 addr);
 void nvkm_instmem_wr32(struct nvkm_instmem *, u32 addr, u32 data);
-int nvkm_instobj_new(struct nvkm_instmem *, u32 size, u32 align, bool zero,
+int nvkm_instobj_new(struct nvkm_instmem *, u32 size, u32 align, bool zero, bool preserve,
 		     struct nvkm_memory **);
 int nvkm_instobj_wrap(struct nvkm_device *, struct nvkm_memory *, struct nvkm_memory **);
 

drivers/gpu/drm/nouveau/nvkm/core/memory.c

@@ -140,12 +140,23 @@ nvkm_memory_new(struct nvkm_device *device, enum nvkm_memory_target target,
 {
 	struct nvkm_instmem *imem = device->imem;
 	struct nvkm_memory *memory;
+	bool preserve = true;
 	int ret;
 
-	if (unlikely(target != NVKM_MEM_TARGET_INST || !imem))
+	if (unlikely(!imem))
 		return -ENOSYS;
 
-	ret = nvkm_instobj_new(imem, size, align, zero, &memory);
+	switch (target) {
+	case NVKM_MEM_TARGET_INST_SR_LOST:
+		preserve = false;
+		break;
+	case NVKM_MEM_TARGET_INST:
+		break;
+	default:
+		return -ENOSYS;
+	}
+
+	ret = nvkm_instobj_new(imem, size, align, zero, preserve, &memory);
 	if (ret)
 		return ret;
 

drivers/gpu/drm/nouveau/nvkm/subdev/instmem/base.c

@@ -94,15 +94,21 @@ nvkm_instobj_wrap(struct nvkm_device *device,
 		  struct nvkm_memory *memory, struct nvkm_memory **pmemory)
 {
 	struct nvkm_instmem *imem = device->imem;
+	int ret;
 
 	if (!imem->func->memory_wrap)
 		return -ENOSYS;
 
-	return imem->func->memory_wrap(imem, memory, pmemory);
+	ret = imem->func->memory_wrap(imem, memory, pmemory);
+	if (ret)
+		return ret;
+
+	container_of(*pmemory, struct nvkm_instobj, memory)->preserve = true;
+	return 0;
 }
 
 int
-nvkm_instobj_new(struct nvkm_instmem *imem, u32 size, u32 align, bool zero,
+nvkm_instobj_new(struct nvkm_instmem *imem, u32 size, u32 align, bool zero, bool preserve,
 		 struct nvkm_memory **pmemory)
 {
 	struct nvkm_subdev *subdev = &imem->subdev;
@@ -130,6 +136,7 @@ nvkm_instobj_new(struct nvkm_instmem *imem, u32 size, u32 align, bool zero,
 		nvkm_done(memory);
 	}
 
+	container_of(memory, struct nvkm_instobj, memory)->preserve = preserve;
 done:
 	if (ret)
 		nvkm_memory_unref(&memory);
@@ -176,9 +183,11 @@ nvkm_instmem_fini(struct nvkm_subdev *subdev, bool suspend)
 
 	if (suspend) {
 		list_for_each_entry(iobj, &imem->list, head) {
-			int ret = nvkm_instobj_save(iobj);
-			if (ret)
-				return ret;
+			if (iobj->preserve) {
+				int ret = nvkm_instobj_save(iobj);
+				if (ret)
+					return ret;
+			}
 		}
 
 		nvkm_bar_bar2_fini(subdev->device);

drivers/gpu/drm/nouveau/nvkm/subdev/instmem/priv.h

@@ -25,6 +25,7 @@ void nvkm_instmem_boot(struct nvkm_instmem *);
 struct nvkm_instobj {
 	struct nvkm_memory memory;
 	struct list_head head;
+	bool preserve;
 	u32 *suspend;
 };