arch/powerpc/kernel/proc_ppc64.c

   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
  31 static loff_t  page_map_seek( struct file *file, loff_t off, int whence);
  32 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
  33                               loff_t *ppos);
  34 static int     page_map_mmap( struct file *file, struct vm_area_struct *vma );
  35
  36 static 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  */
  46 static 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 }
  65 core_initcall(proc_ppc64_create);
  66
  67 static int __init proc_ppc64_init(void)
  68 {
  69         struct proc_dir_entry *pde;
  70
  71         pde = create_proc_entry("ppc64/systemcfg", S_IFREG|S_IRUGO, NULL);
  72         if (!pde)
  73                 return 1;
  74         pde->data = vdso_data;
  75         pde->size = PAGE_SIZE;
  76         pde->proc_fops = &page_map_fops;
  77
  78         return 0;
  79 }
  80 __initcall(proc_ppc64_init);
  81
  82 static loff_t page_map_seek( struct file *file, loff_t off, int whence)
  83 {
  84         loff_t new;
  85         struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
  86
  87         switch(whence) {
  88         case 0:
  89                 new = off;
  90                 break;
  91         case 1:
  92                 new = file->f_pos + off;
  93                 break;
  94         case 2:
  95                 new = dp->size + off;
  96                 break;
  97         default:
  98                 return -EINVAL;
  99         }
 100         if ( new < 0 || new > dp->size )
 101                 return -EINVAL;
 102         return (file->f_pos = new);
 103 }
 104
 105 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
 106                               loff_t *ppos)
 107 {
 108         struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
 109         return simple_read_from_buffer(buf, nbytes, ppos, dp->data, dp->size);
 110 }
 111
 112 static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
 113 {
 114         struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
 115
 116         if ((vma->vm_end - vma->vm_start) > dp->size)
 117                 return -EINVAL;
 118
 119         remap_pfn_range(vma, vma->vm_start, __pa(dp->data) >> PAGE_SHIFT,
 120                                                 dp->size, vma->vm_page_prot);
 121         return 0;
 122 }
 123