gpu: nvgpu: Move gk20a.c to os/linux

gk20a.c is used only in Linux build. It's in theory common code, but
in practice implements OS specific policies. Also implement
os/posix/gk20a.c to implement gk20a_init_gpu_characteristics(),
gk20a_get() and gk20a_put() which are called from common code.

JIRA NVGPU-596

Change-Id: I6a6079ca6d4c6a225f0dd0e1cd7c439333a704bf
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1944884
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/gpu/nvgpu/Makefile

@@ -79,6 +79,7 @@ nvgpu-y += common/bus/bus_gk20a.o \
 
 # Linux specific parts of nvgpu.
 nvgpu-y += \
+	os/linux/gk20a.o \
 	os/linux/os_ops.o \
 	os/linux/os_ops_gm20b.o \
 	os/linux/os_ops_gp10b.o \
@@ -266,7 +267,6 @@ nvgpu-y += \
 	common/ecc.o \
 	common/ce2.o \
 	common/debugger.o \
-	gk20a/gk20a.o \
 	gk20a/ce2_gk20a.o \
 	gk20a/fifo_gk20a.o \
 	gk20a/regops_gk20a.o \

drivers/gpu/nvgpu/Makefile.sources

@@ -45,6 +45,7 @@ srcs :=	os/posix/nvgpu.c \
 	os/posix/lock.c \
 	os/posix/stubs.c \
 	os/posix/posix-fault-injection.c \
+	os/posix/gk20a.c \
 	common/mm/nvgpu_allocator.c \
 	common/mm/bitmap_allocator.c \
 	common/mm/buddy_allocator.c \
@@ -174,7 +175,6 @@ srcs :=	os/posix/nvgpu.c \
 	pmgr/pwrpolicy.c \
 	lpwr/lpwr.c \
 	lpwr/rppg.c \
-	gk20a/gk20a.c \
 	common/ptimer/ptimer_gk20a.c \
 	gk20a/ce2_gk20a.c \
 	gk20a/fifo_gk20a.c \

drivers/gpu/nvgpu/os/posix/gk20a.c

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2018, 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 <nvgpu/gk20a.h>
+#include <nvgpu/enabled.h>
+
+int gk20a_init_gpu_characteristics(struct gk20a *g)
+{
+	BUG();
+
+	return 0;
+}
+
+struct gk20a * __must_check gk20a_get(struct gk20a *g)
+{
+	BUG();
+
+	return g;
+}
+
+void gk20a_put(struct gk20a *g)
+{
+	BUG();
+}