1 /* mmu.c: mmu 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 #include <linux/spinlock.h>
12 #include <linux/vmalloc.h>
13 #include <linux/highmem.h>
14 #include <asm/pgtable.h>
15 #include "internal.h"
16 
get_vmalloc_info(struct vmalloc_info * vmi)17 void get_vmalloc_info(struct vmalloc_info *vmi)
18 {
19 	struct vm_struct *vma;
20 	unsigned long free_area_size;
21 	unsigned long prev_end;
22 
23 	vmi->used = 0;
24 
25 	if (!vmlist) {
26 		vmi->largest_chunk = VMALLOC_TOTAL;
27 	}
28 	else {
29 		vmi->largest_chunk = 0;
30 
31 		prev_end = VMALLOC_START;
32 
33 		read_lock(&vmlist_lock);
34 
35 		for (vma = vmlist; vma; vma = vma->next) {
36 			unsigned long addr = (unsigned long) vma->addr;
37 
38 			/*
39 			 * Some archs keep another range for modules in vmlist
40 			 */
41 			if (addr < VMALLOC_START)
42 				continue;
43 			if (addr >= VMALLOC_END)
44 				break;
45 
46 			vmi->used += vma->size;
47 
48 			free_area_size = addr - prev_end;
49 			if (vmi->largest_chunk < free_area_size)
50 				vmi->largest_chunk = free_area_size;
51 
52 			prev_end = vma->size + addr;
53 		}
54 
55 		if (VMALLOC_END - prev_end > vmi->largest_chunk)
56 			vmi->largest_chunk = VMALLOC_END - prev_end;
57 
58 		read_unlock(&vmlist_lock);
59 	}
60 }
61