xref: /openbmc/linux/fs/proc/nommu.c (revision fd589a8f)
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/slab.h>
25 #include <linux/smp.h>
26 #include <linux/seq_file.h>
27 #include <linux/hugetlb.h>
28 #include <linux/vmalloc.h>
29 #include <asm/uaccess.h>
30 #include <asm/pgtable.h>
31 #include <asm/tlb.h>
32 #include <asm/div64.h>
33 #include "internal.h"
34 
35 /*
36  * display a single region to a sequenced file
37  */
38 static int nommu_region_show(struct seq_file *m, struct vm_region *region)
39 {
40 	unsigned long ino = 0;
41 	struct file *file;
42 	dev_t dev = 0;
43 	int flags, len;
44 
45 	flags = region->vm_flags;
46 	file = region->vm_file;
47 
48 	if (file) {
49 		struct inode *inode = region->vm_file->f_path.dentry->d_inode;
50 		dev = inode->i_sb->s_dev;
51 		ino = inode->i_ino;
52 	}
53 
54 	seq_printf(m,
55 		   "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
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, &len);
64 
65 	if (file) {
66 		len = 25 + sizeof(void *) * 6 - len;
67 		if (len < 1)
68 			len = 1;
69 		seq_printf(m, "%*c", len, ' ');
70 		seq_path(m, &file->f_path, "");
71 	}
72 
73 	seq_putc(m, '\n');
74 	return 0;
75 }
76 
77 /*
78  * display a list of all the REGIONs the kernel knows about
79  * - nommu kernels have a single flat list
80  */
81 static int nommu_region_list_show(struct seq_file *m, void *_p)
82 {
83 	struct rb_node *p = _p;
84 
85 	return nommu_region_show(m, rb_entry(p, struct vm_region, vm_rb));
86 }
87 
88 static void *nommu_region_list_start(struct seq_file *m, loff_t *_pos)
89 {
90 	struct rb_node *p;
91 	loff_t pos = *_pos;
92 
93 	down_read(&nommu_region_sem);
94 
95 	for (p = rb_first(&nommu_region_tree); p; p = rb_next(p))
96 		if (pos-- == 0)
97 			return p;
98 	return NULL;
99 }
100 
101 static void nommu_region_list_stop(struct seq_file *m, void *v)
102 {
103 	up_read(&nommu_region_sem);
104 }
105 
106 static void *nommu_region_list_next(struct seq_file *m, void *v, loff_t *pos)
107 {
108 	(*pos)++;
109 	return rb_next((struct rb_node *) v);
110 }
111 
112 static struct seq_operations proc_nommu_region_list_seqop = {
113 	.start	= nommu_region_list_start,
114 	.next	= nommu_region_list_next,
115 	.stop	= nommu_region_list_stop,
116 	.show	= nommu_region_list_show
117 };
118 
119 static int proc_nommu_region_list_open(struct inode *inode, struct file *file)
120 {
121 	return seq_open(file, &proc_nommu_region_list_seqop);
122 }
123 
124 static const struct file_operations proc_nommu_region_list_operations = {
125 	.open    = proc_nommu_region_list_open,
126 	.read    = seq_read,
127 	.llseek  = seq_lseek,
128 	.release = seq_release,
129 };
130 
131 static int __init proc_nommu_init(void)
132 {
133 	proc_create("maps", S_IRUGO, NULL, &proc_nommu_region_list_operations);
134 	return 0;
135 }
136 
137 module_init(proc_nommu_init);
138