gpu: nvgpu: Split as code to as IOCTL and common

Split as_gk20a.c into two parts:

common/linux/ioctl_as.c deals with as related devnodes and ioctls.
This file contains all the Linux specific parts of as_gk20a.c.

common/as.c deals with general as_gk20a maintenance and is Linux
independent.

JIRA NVGPU-16

Change-Id: I2d8541e0bd6ce159dc6e4de8e819dfcff0fa8f80
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/1330803
Reviewed-by: svccoveritychecker <svccoveritychecker@nvidia.com>
GVS: Gerrit_Virtual_Submit

drivers/gpu/nvgpu/common/as.c

@@ -0,0 +1,99 @@
+/*
+ * GK20A Address Spaces
+ *
+ * Copyright (c) 2011-2017, 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 <trace/events/gk20a.h>
+
+#include <nvgpu/kmem.h>
+
+#include "gk20a/gk20a.h"
+
+/* dumb allocator... */
+static int generate_as_share_id(struct gk20a_as *as)
+{
+	gk20a_dbg_fn("");
+	return ++as->last_share_id;
+}
+/* still dumb */
+static void release_as_share_id(struct gk20a_as *as, int id)
+{
+	gk20a_dbg_fn("");
+	return;
+}
+
+int gk20a_as_alloc_share(struct gk20a *g,
+			 u32 big_page_size, u32 flags,
+			 struct gk20a_as_share **out)
+{
+	struct gk20a_as_share *as_share;
+	int err = 0;
+
+	gk20a_dbg_fn("");
+	g = gk20a_get(g);
+	if (!g)
+		return -ENODEV;
+
+	*out = NULL;
+	as_share = nvgpu_kzalloc(g, sizeof(*as_share));
+	if (!as_share)
+		return -ENOMEM;
+
+	as_share->as = &g->as;
+	as_share->id = generate_as_share_id(as_share->as);
+
+	/* this will set as_share->vm. */
+	err = gk20a_busy(g);
+	if (err)
+		goto failed;
+	err = g->ops.mm.vm_alloc_share(as_share, big_page_size, flags);
+	gk20a_idle(g);
+
+	if (err)
+		goto failed;
+
+	*out = as_share;
+	return 0;
+
+failed:
+	nvgpu_kfree(g, as_share);
+	return err;
+}
+
+/*
+ * channels and the device nodes call this to release.
+ * once the ref_cnt hits zero the share is deleted.
+ */
+int gk20a_as_release_share(struct gk20a_as_share *as_share)
+{
+	struct gk20a *g = as_share->vm->mm->g;
+	int err;
+
+	gk20a_dbg_fn("");
+
+	err = gk20a_busy(g);
+
+	if (err)
+		goto release_fail;
+
+	err = gk20a_vm_release_share(as_share);
+
+	gk20a_idle(g);
+
+release_fail:
+	release_as_share_id(as_share->as, as_share->id);
+	gk20a_put(g);
+	nvgpu_kfree(g, as_share);
+
+	return err;
+}