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/config.h>
  20 #include <linux/init.h>
  21 #include <linux/mm.h>
  22 #include <linux/proc_fs.h>
  23 #include <linux/slab.h>
  24 #include <linux/kernel.h>
  25
  26 #include <asm/machdep.h>
  27 #include <asm/vdso_datapage.h>
  28 #include <asm/rtas.h>
  29 #include <asm/uaccess.h>
  30 #include <asm/prom.h>
  31
  32 static loff_t  page_map_seek( struct file *file, loff_t off, int whence);
  33 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
  34                               loff_t *ppos);
  35 static int     page_map_mmap( struct file *file, struct vm_area_struct *vma );
  36
  37 static struct file_operations page_map_fops = {
  38         .llseek = page_map_seek,
  39         .read   = page_map_read,
  40         .mmap   = page_map_mmap
  41 };
  42
  43 /*
  44  * Create the ppc64 and ppc64/rtas directories early. This allows us to
  45  * assume that they have been previously created in drivers.
  46  */
  47 static int __init proc_ppc64_create(void)
  48 {
  49         struct proc_dir_entry *root;
  50
  51         root = proc_mkdir("ppc64", NULL);
  52         if (!root)
  53                 return 1;
  54
  55         if (!machine_is(pseries) && !machine_is(cell))
  56                 return 0;
  57
  58         if (!proc_mkdir("rtas", root))
  59                 return 1;
  60
  61         if (!proc_symlink("rtas", NULL, "ppc64/rtas"))
  62                 return 1;
  63
  64         return 0;
  65 }
  66 core_initcall(proc_ppc64_create);
  67
  68 static int __init proc_ppc64_init(void)
  69 {
  70         struct proc_dir_entry *pde;
  71
  72         pde = create_proc_entry("ppc64/systemcfg", S_IFREG|S_IRUGO, NULL);
  73         if (!pde)
  74                 return 1;
  75         pde->nlink = 1;
  76         pde->data = vdso_data;
  77         pde->size = PAGE_SIZE;
  78         pde->proc_fops = &page_map_fops;
  79
  80         return 0;
  81 }
  82 __initcall(proc_ppc64_init);
  83
  84 static loff_t page_map_seek( struct file *file, loff_t off, int whence)
  85 {
  86         loff_t new;
  87         struct proc_dir_entry *dp = PDE(file->f_dentry->d_inode);
  88
  89         switch(whence) {
  90         case 0:
  91                 new = off;
  92                 break;
  93         case 1:
  94                 new = file->f_pos + off;
  95                 break;
  96         case 2:
  97                 new = dp->size + off;
  98                 break;
  99         default:
 100                 return -EINVAL;
 101         }
 102         if ( new < 0 || new > dp->size )
 103                 return -EINVAL;
 104         return (file->f_pos = new);
 105 }
 106
 107 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
 108                               loff_t *ppos)
 109 {
 110         struct proc_dir_entry *dp = PDE(file->f_dentry->d_inode);
 111         return simple_read_from_buffer(buf, nbytes, ppos, dp->data, dp->size);
 112 }
 113
 114 static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
 115 {
 116         struct proc_dir_entry *dp = PDE(file->f_dentry->d_inode);
 117
 118         vma->vm_flags |= VM_SHM | VM_LOCKED;
 119
 120         if ((vma->vm_end - vma->vm_start) > dp->size)
 121                 return -EINVAL;
 122
 123         remap_pfn_range(vma, vma->vm_start, __pa(dp->data) >> PAGE_SHIFT,
 124                                                 dp->size, vma->vm_page_prot);
 125         return 0;
 126 }
 127