gpu: nvgpu: gv11b: Abstract IO aperture accessors

Implement T19x specific usermode aperture initialization functions.
Move usermode_regs field to nvgpu_os_linux_t19x, because it is
Linux specific.

JIRA NVGPU-259

Change-Id: I9d6ce243a692ab48209d468288ed85f89fb26770
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1569699
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/gpu/nvgpu/common/linux/io_t19x.c

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2017, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <nvgpu/io.h>
+#include <nvgpu/types.h>
+
+#include "common/linux/os_linux.h"
+#include "gk20a/gk20a.h"
+
+#include <nvgpu/hw/gv11b/hw_usermode_gv11b.h>
+
+void gv11b_usermode_writel(struct gk20a *g, u32 r, u32 v)
+{
+	struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+	void __iomem *reg = l->t19x.usermode_regs + (r - usermode_cfg0_r());
+
+	writel_relaxed(v, reg);
+	gk20a_dbg(gpu_dbg_reg, "usermode r=0x%x v=0x%x", r, v);
+}