xref: /openbmc/linux/fs/proc/nommu.c (revision adb57164)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* nommu.c: mmu-less memory info files
3  *
4  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #include <linux/init.h>
9 #include <linux/module.h>
10 #include <linux/errno.h>
11 #include <linux/time.h>
12 #include <linux/kernel.h>
13 #include <linux/string.h>
14 #include <linux/mman.h>
15 #include <linux/proc_fs.h>
16 #include <linux/mm.h>
17 #include <linux/mmzone.h>
18 #include <linux/pagemap.h>
19 #include <linux/swap.h>
20 #include <linux/smp.h>
21 #include <linux/seq_file.h>
22 #include <linux/hugetlb.h>
23 #include <linux/vmalloc.h>
24 #include <linux/uaccess.h>
25 #include <asm/pgtable.h>
26 #include <asm/tlb.h>
27 #include <asm/div64.h>
28 #include "internal.h"
29 
30 /*
31  * display a single region to a sequenced file
32  */
33 static int nommu_region_show(struct seq_file *m, struct vm_region *region)
34 {
35 	unsigned long ino = 0;
36 	struct file *file;
37 	dev_t dev = 0;
38 	int flags;
39 
40 	flags = region->vm_flags;
41 	file = region->vm_file;
42 
43 	if (file) {
44 		struct inode *inode = file_inode(region->vm_file);
45 		dev = inode->i_sb->s_dev;
46 		ino = inode->i_ino;
47 	}
48 
49 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
50 	seq_printf(m,
51 		   "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
52 		   region->vm_start,
53 		   region->vm_end,
54 		   flags & VM_READ ? 'r' : '-',
55 		   flags & VM_WRITE ? 'w' : '-',
56 		   flags & VM_EXEC ? 'x' : '-',
57 		   flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
58 		   ((loff_t)region->vm_pgoff) << PAGE_SHIFT,
59 		   MAJOR(dev), MINOR(dev), ino);
60 
61 	if (file) {
62 		seq_pad(m, ' ');
63 		seq_file_path(m, file, "");
64 	}
65 
66 	seq_putc(m, '\n');
67 	return 0;
68 }
69 
70 /*
71  * display a list of all the REGIONs the kernel knows about
72  * - nommu kernels have a single flat list
73  */
74 static int nommu_region_list_show(struct seq_file *m, void *_p)
75 {
76 	struct rb_node *p = _p;
77 
78 	return nommu_region_show(m, rb_entry(p, struct vm_region, vm_rb));
79 }
80 
81 static void *nommu_region_list_start(struct seq_file *m, loff_t *_pos)
82 {
83 	struct rb_node *p;
84 	loff_t pos = *_pos;
85 
86 	down_read(&nommu_region_sem);
87 
88 	for (p = rb_first(&nommu_region_tree); p; p = rb_next(p))
89 		if (pos-- == 0)
90 			return p;
91 	return NULL;
92 }
93 
94 static void nommu_region_list_stop(struct seq_file *m, void *v)
95 {
96 	up_read(&nommu_region_sem);
97 }
98 
99 static void *nommu_region_list_next(struct seq_file *m, void *v, loff_t *pos)
100 {
101 	(*pos)++;
102 	return rb_next((struct rb_node *) v);
103 }
104 
105 static const struct seq_operations proc_nommu_region_list_seqop = {
106 	.start	= nommu_region_list_start,
107 	.next	= nommu_region_list_next,
108 	.stop	= nommu_region_list_stop,
109 	.show	= nommu_region_list_show
110 };
111 
112 static int __init proc_nommu_init(void)
113 {
114 	proc_create_seq("maps", S_IRUGO, NULL, &proc_nommu_region_list_seqop);
115 	return 0;
116 }
117 
118 fs_initcall(proc_nommu_init);
119