1/*
 2 * Copyright © 2017 Intel Corporation
 3 *
 4 * Permission is hereby granted, free of charge, to any person obtaining a
 5 * copy of this software and associated documentation files (the "Software"),
 6 * to deal in the Software without restriction, including without limitation
 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 8 * and/or sell copies of the Software, and to permit persons to whom the
 9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 */
24
25#include <linux/fs.h>
26#include <linux/mount.h>
27#include <linux/pagemap.h>
28
29#include "i915_drv.h"
30#include "i915_gemfs.h"
31
32int i915_gemfs_init(struct drm_i915_private *i915)
33{
34	struct file_system_type *type;
35	struct vfsmount *gemfs;
36
37	type = get_fs_type("tmpfs");
38	if (!type)
39		return -ENODEV;
40
41	gemfs = kern_mount(type);
42	if (IS_ERR(gemfs))
43		return PTR_ERR(gemfs);
44
45	/*
46	 * Enable huge-pages for objects that are at least HPAGE_PMD_SIZE, most
47	 * likely 2M. Note that within_size may overallocate huge-pages, if say
48	 * we allocate an object of size 2M + 4K, we may get 2M + 2M, but under
49	 * memory pressure shmem should split any huge-pages which can be
50	 * shrunk.
51	 */
52
53	if (has_transparent_hugepage()) {
54		struct super_block *sb = gemfs->mnt_sb;
55		/* FIXME: Disabled until we get W/A for read BW issue. */
56		char options[] = "huge=never";
57		int flags = 0;
58		int err;
59
60		err = sb->s_op->remount_fs(sb, &flags, options);
61		if (err) {
62			kern_unmount(gemfs);
63			return err;
64		}
65	}
66
67	i915->mm.gemfs = gemfs;
68
69	return 0;
70}
71
72void i915_gemfs_fini(struct drm_i915_private *i915)
73{
74	kern_unmount(i915->mm.gemfs);
75}