mmu.c

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/* mmu.c: mmu memory info files
 *
 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include <linux/highmem.h>
#include <asm/pgtable.h>
#include "internal.h"

void get_vmalloc_info(struct vmalloc_info *vmi)
{
    struct vm_struct *vma;
    unsigned long free_area_size;
    unsigned long prev_end;

    vmi->used = 0;

    if (!vmlist) {
        vmi->largest_chunk = VMALLOC_TOTAL;
    }
    else {
        vmi->largest_chunk = 0;

        prev_end = VMALLOC_START;

        read_lock(&vmlist_lock);

        for (vma = vmlist; vma; vma = vma->next) {
            unsigned long addr = (unsigned long) vma->addr;

            /*
             * Some archs keep another range for modules in vmlist
             */
            if (addr < VMALLOC_START)
                continue;
            if (addr >= VMALLOC_END)
                break;

            vmi->used += vma->size;

            free_area_size = addr - prev_end;
            if (vmi->largest_chunk < free_area_size)
                vmi->largest_chunk = free_area_size;

            prev_end = vma->size + addr;
        }

        if (VMALLOC_END - prev_end > vmi->largest_chunk)
            vmi->largest_chunk = VMALLOC_END - prev_end;

        read_unlock(&vmlist_lock);
    }
}