xref: /openbmc/linux/fs/proc/nommu.c (revision 4beec1d7)
1 /* nommu.c: mmu-less memory info files
2  *
3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/errno.h>
15 #include <linux/time.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/mman.h>
19 #include <linux/proc_fs.h>
20 #include <linux/mm.h>
21 #include <linux/mmzone.h>
22 #include <linux/pagemap.h>
23 #include <linux/swap.h>
24 #include <linux/smp.h>
25 #include <linux/seq_file.h>
26 #include <linux/hugetlb.h>
27 #include <linux/vmalloc.h>
28 #include <linux/uaccess.h>
29 #include <asm/pgtable.h>
30 #include <asm/tlb.h>
31 #include <asm/div64.h>
32 #include "internal.h"
33 
34 /*
35  * display a single region to a sequenced file
36  */
37 static int nommu_region_show(struct seq_file *m, struct vm_region *region)
38 {
39 	unsigned long ino = 0;
40 	struct file *file;
41 	dev_t dev = 0;
42 	int flags;
43 
44 	flags = region->vm_flags;
45 	file = region->vm_file;
46 
47 	if (file) {
48 		struct inode *inode = file_inode(region->vm_file);
49 		dev = inode->i_sb->s_dev;
50 		ino = inode->i_ino;
51 	}
52 
53 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
54 	seq_printf(m,
55 		   "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
56 		   region->vm_start,
57 		   region->vm_end,
58 		   flags & VM_READ ? 'r' : '-',
59 		   flags & VM_WRITE ? 'w' : '-',
60 		   flags & VM_EXEC ? 'x' : '-',
61 		   flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
62 		   ((loff_t)region->vm_pgoff) << PAGE_SHIFT,
63 		   MAJOR(dev), MINOR(dev), ino);
64 
65 	if (file) {
66 		seq_pad(m, ' ');
67 		seq_file_path(m, file, "");
68 	}
69 
70 	seq_putc(m, '\n');
71 	return 0;
72 }
73 
74 /*
75  * display a list of all the REGIONs the kernel knows about
76  * - nommu kernels have a single flat list
77  */
78 static int nommu_region_list_show(struct seq_file *m, void *_p)
79 {
80 	struct rb_node *p = _p;
81 
82 	return nommu_region_show(m, rb_entry(p, struct vm_region, vm_rb));
83 }
84 
85 static void *nommu_region_list_start(struct seq_file *m, loff_t *_pos)
86 {
87 	struct rb_node *p;
88 	loff_t pos = *_pos;
89 
90 	down_read(&nommu_region_sem);
91 
92 	for (p = rb_first(&nommu_region_tree); p; p = rb_next(p))
93 		if (pos-- == 0)
94 			return p;
95 	return NULL;
96 }
97 
98 static void nommu_region_list_stop(struct seq_file *m, void *v)
99 {
100 	up_read(&nommu_region_sem);
101 }
102 
103 static void *nommu_region_list_next(struct seq_file *m, void *v, loff_t *pos)
104 {
105 	(*pos)++;
106 	return rb_next((struct rb_node *) v);
107 }
108 
109 static const struct seq_operations proc_nommu_region_list_seqop = {
110 	.start	= nommu_region_list_start,
111 	.next	= nommu_region_list_next,
112 	.stop	= nommu_region_list_stop,
113 	.show	= nommu_region_list_show
114 };
115 
116 static int proc_nommu_region_list_open(struct inode *inode, struct file *file)
117 {
118 	return seq_open(file, &proc_nommu_region_list_seqop);
119 }
120 
121 static const struct file_operations proc_nommu_region_list_operations = {
122 	.open    = proc_nommu_region_list_open,
123 	.read    = seq_read,
124 	.llseek  = seq_lseek,
125 	.release = seq_release,
126 };
127 
128 static int __init proc_nommu_init(void)
129 {
130 	proc_create("maps", S_IRUGO, NULL, &proc_nommu_region_list_operations);
131 	return 0;
132 }
133 
134 fs_initcall(proc_nommu_init);
135