xref: /openbmc/linux/drivers/gpu/drm/i915/gem/i915_gemfs.c (revision b830f94f)
1 /*
2  * SPDX-License-Identifier: MIT
3  *
4  * Copyright © 2017 Intel Corporation
5  */
6 
7 #include <linux/fs.h>
8 #include <linux/mount.h>
9 #include <linux/pagemap.h>
10 
11 #include "i915_drv.h"
12 #include "i915_gemfs.h"
13 
14 int i915_gemfs_init(struct drm_i915_private *i915)
15 {
16 	struct file_system_type *type;
17 	struct vfsmount *gemfs;
18 
19 	type = get_fs_type("tmpfs");
20 	if (!type)
21 		return -ENODEV;
22 
23 	gemfs = kern_mount(type);
24 	if (IS_ERR(gemfs))
25 		return PTR_ERR(gemfs);
26 
27 	/*
28 	 * Enable huge-pages for objects that are at least HPAGE_PMD_SIZE, most
29 	 * likely 2M. Note that within_size may overallocate huge-pages, if say
30 	 * we allocate an object of size 2M + 4K, we may get 2M + 2M, but under
31 	 * memory pressure shmem should split any huge-pages which can be
32 	 * shrunk.
33 	 */
34 
35 	if (has_transparent_hugepage()) {
36 		struct super_block *sb = gemfs->mnt_sb;
37 		/* FIXME: Disabled until we get W/A for read BW issue. */
38 		char options[] = "huge=never";
39 		int flags = 0;
40 		int err;
41 
42 		err = sb->s_op->remount_fs(sb, &flags, options);
43 		if (err) {
44 			kern_unmount(gemfs);
45 			return err;
46 		}
47 	}
48 
49 	i915->mm.gemfs = gemfs;
50 
51 	return 0;
52 }
53 
54 void i915_gemfs_fini(struct drm_i915_private *i915)
55 {
56 	kern_unmount(i915->mm.gemfs);
57 }
58