From: Ben Skeggs <bskeggs@redhat.com>
Date: Wed, 1 Nov 2017 03:56:19 +1000
Subject: drm/nouveau/mmu: automatically handle "un-bootstrapping" of vmm
Git-commit: 5e075fdeb166098a3dc493026534c7631e845782
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Removes the need to expose internals outside of MMU, and GP100 is both
different, and a lot harder to deal with.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/nouveau/include/nvkm/subdev/mmu.h |    2 ++
 drivers/gpu/drm/nouveau/nvkm/subdev/bar/gf100.c   |    5 +----
 drivers/gpu/drm/nouveau/nvkm/subdev/bar/nv50.c    |    5 +----
 drivers/gpu/drm/nouveau/nvkm/subdev/mmu/base.c    |    3 +++
 4 files changed, 7 insertions(+), 8 deletions(-)

--- a/drivers/gpu/drm/nouveau/include/nvkm/subdev/mmu.h
+++ b/drivers/gpu/drm/nouveau/include/nvkm/subdev/mmu.h
@@ -38,6 +38,8 @@ struct nvkm_vm {
 	struct nvkm_vm_pgt *pgt;
 	u32 fpde;
 	u32 lpde;
+
+	bool bootstrapped;
 };
 
 int  nvkm_vm_new(struct nvkm_device *, u64 offset, u64 length, u64 mm_offset,
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/bar/gf100.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bar/gf100.c
@@ -168,10 +168,7 @@ gf100_bar_dtor(struct nvkm_bar *base)
 	nvkm_gpuobj_del(&bar->bar[1].pgd);
 	nvkm_memory_unref(&bar->bar[1].mem);
 
-	if (bar->bar[0].vm) {
-		nvkm_memory_unref(&bar->bar[0].vm->pgt[0].mem[0]);
-		nvkm_vm_ref(NULL, &bar->bar[0].vm, bar->bar[0].pgd);
-	}
+	nvkm_vm_ref(NULL, &bar->bar[0].vm, bar->bar[0].pgd);
 	nvkm_gpuobj_del(&bar->bar[0].pgd);
 	nvkm_memory_unref(&bar->bar[0].mem);
 	return bar;
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/bar/nv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bar/nv50.c
@@ -200,10 +200,7 @@ nv50_bar_dtor(struct nvkm_bar *base)
 	nvkm_gpuobj_del(&bar->bar1);
 	nvkm_vm_ref(NULL, &bar->bar1_vm, bar->pgd);
 	nvkm_gpuobj_del(&bar->bar2);
-	if (bar->bar2_vm) {
-		nvkm_memory_unref(&bar->bar2_vm->pgt[0].mem[0]);
-		nvkm_vm_ref(NULL, &bar->bar2_vm, bar->pgd);
-	}
+	nvkm_vm_ref(NULL, &bar->bar2_vm, bar->pgd);
 	nvkm_gpuobj_del(&bar->pgd);
 	nvkm_gpuobj_del(&bar->pad);
 	nvkm_gpuobj_del(&bar->mem);
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/base.c
@@ -357,6 +357,7 @@ nvkm_vm_boot(struct nvkm_vm *vm, u64 siz
 		vm->pgt[0].refcount[0] = 1;
 		vm->pgt[0].mem[0] = pgt;
 		nvkm_memory_boot(pgt, vm);
+		vm->bootstrapped = true;
 	}
 
 	return ret;
@@ -481,6 +482,8 @@ nvkm_vm_ref(struct nvkm_vm *ref, struct
 	}
 
 	if (*ptr) {
+		if ((*ptr)->bootstrapped && pgd)
+			nvkm_memory_unref(&(*ptr)->pgt[0].mem[0]);
 		nvkm_vm_unlink(*ptr, pgd);
 		kref_put(&(*ptr)->refcount, nvkm_vm_del);
 	}