drm/nouveau/gm20b: add dummy PMU device

Add a dummy PMU device so the PMU falcon is instanciated and can be used
by secure boot.

We could reuse gk20a's implementation here, but it would fight with
secboot over PMU falcon's ownership and secboot will reset the PMU,
preventing it from operating afterwards. Proper handout between secboot
and pmu is coming along with the actual gm20b PMU implementation, so
use this as a temporary solution.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

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

@@ -37,6 +37,7 @@ int gk110_pmu_new(struct nvkm_device *, int, struct nvkm_pmu **);
 int gk208_pmu_new(struct nvkm_device *, int, struct nvkm_pmu **);
 int gk20a_pmu_new(struct nvkm_device *, int, struct nvkm_pmu **);
 int gm107_pmu_new(struct nvkm_device *, int, struct nvkm_pmu **);
+int gm20b_pmu_new(struct nvkm_device *, int, struct nvkm_pmu **);
 int gp100_pmu_new(struct nvkm_device *, int, struct nvkm_pmu **);
 int gp102_pmu_new(struct nvkm_device *, int, struct nvkm_pmu **);
 

drivers/gpu/drm/nouveau/nvkm/engine/device/base.c

@@ -2138,6 +2138,7 @@ nv12b_chipset = {
 	.ltc = gm200_ltc_new,
 	.mc = gk20a_mc_new,
 	.mmu = gf100_mmu_new,
+	.pmu = gm20b_pmu_new,
 	.secboot = gm20b_secboot_new,
 	.timer = gk20a_timer_new,
 	.top = gk104_top_new,

drivers/gpu/drm/nouveau/nvkm/subdev/pmu/Kbuild

@@ -8,5 +8,6 @@ nvkm-y += nvkm/subdev/pmu/gk110.o
 nvkm-y += nvkm/subdev/pmu/gk208.o
 nvkm-y += nvkm/subdev/pmu/gk20a.o
 nvkm-y += nvkm/subdev/pmu/gm107.o
+nvkm-y += nvkm/subdev/pmu/gm20b.o
 nvkm-y += nvkm/subdev/pmu/gp100.o
 nvkm-y += nvkm/subdev/pmu/gp102.o

drivers/gpu/drm/nouveau/nvkm/subdev/pmu/gm20b.c

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "priv.h"
+
+static const struct nvkm_pmu_func
+gm20b_pmu = {
+	.reset = gt215_pmu_reset,
+};
+
+int
+gm20b_pmu_new(struct nvkm_device *device, int index, struct nvkm_pmu **ppmu)
+{
+	return nvkm_pmu_new_(&gm20b_pmu, device, index, ppmu);
+}