LXR linux/arch/powerpc/kernel/proc

   1/*
   2 * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen IBM Corporation
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License as published by
   6 * the Free Software Foundation; either version 2 of the License, or
   7 * (at your option) any later version.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write to the Free Software
  16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  17 */
  18
  19#include <linux/init.h>
  20#include <linux/mm.h>
  21#include <linux/proc_fs.h>
  22#include <linux/slab.h>
  23#include <linux/kernel.h>
  24
  25#include <asm/machdep.h>
  26#include <asm/vdso_datapage.h>
  27#include <asm/rtas.h>
  28#include <asm/uaccess.h>
  29#include <asm/prom.h>
  30
  31static loff_t  page_map_seek( struct file *file, loff_t off, int whence);
  32static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
  33                              loff_t *ppos);
  34static int     page_map_mmap( struct file *file, struct vm_area_struct *vma );
  35
  36static const struct file_operations page_map_fops = {
  37        .llseek = page_map_seek,
  38        .read   = page_map_read,
  39        .mmap   = page_map_mmap
  40};
  41
  42/*
  43 * Create the ppc64 and ppc64/rtas directories early. This allows us to
  44 * assume that they have been previously created in drivers.
  45 */
  46static int __init proc_ppc64_create(void)
  47{
  48        struct proc_dir_entry *root;
  49
  50        root = proc_mkdir("ppc64", NULL);
  51        if (!root)
  52                return 1;
  53
  54        if (!of_find_node_by_path("/rtas"))
  55                return 0;
  56
  57        if (!proc_mkdir("rtas", root))
  58                return 1;
  59
  60        if (!proc_symlink("rtas", NULL, "ppc64/rtas"))
  61                return 1;
  62
  63        return 0;
  64}
  65core_initcall(proc_ppc64_create);
  66
  67static int __init proc_ppc64_init(void)
  68{
  69        struct proc_dir_entry *pde;
  70
  71        pde = proc_create_data("ppc64/systemcfg", S_IFREG|S_IRUGO, NULL,
  72                               &page_map_fops, vdso_data);
  73        if (!pde)
  74                return 1;
  75        pde->size = PAGE_SIZE;
  76
  77        return 0;
  78}
  79__initcall(proc_ppc64_init);
  80
  81static loff_t page_map_seek( struct file *file, loff_t off, int whence)
  82{
  83        loff_t new;
  84        struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
  85
  86        switch(whence) {
  87        case 0:
  88                new = off;
  89                break;
  90        case 1:
  91                new = file->f_pos + off;
  92                break;
  93        case 2:
  94                new = dp->size + off;
  95                break;
  96        default:
  97                return -EINVAL;
  98        }
  99        if ( new < 0 || new > dp->size )
 100                return -EINVAL;
 101        return (file->f_pos = new);
 102}
 103
 104static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
 105                              loff_t *ppos)
 106{
 107        struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
 108        return simple_read_from_buffer(buf, nbytes, ppos, dp->data, dp->size);
 109}
 110
 111static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
 112{
 113        struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
 114
 115        if ((vma->vm_end - vma->vm_start) > dp->size)
 116                return -EINVAL;
 117
 118        remap_pfn_range(vma, vma->vm_start, __pa(dp->data) >> PAGE_SHIFT,
 119                                                dp->size, vma->vm_page_prot);
 120        return 0;
 121}
 122
 123