arch/powerpc/kernel/proc_powerpc.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/kernel.h>
  23
  24 #include <asm/machdep.h>
  25 #include <asm/vdso_datapage.h>
  26 #include <asm/rtas.h>
  27 #include <asm/uaccess.h>
  28 #include <asm/prom.h>
  29
  30 #ifdef CONFIG_PPC64
  31
  32 static loff_t page_map_seek( struct file *file, loff_t off, int whence)
  33 {
  34         loff_t new;
  35         switch(whence) {
  36         case 0:
  37                 new = off;
  38                 break;
  39         case 1:
  40                 new = file->f_pos + off;
  41                 break;
  42         case 2:
  43                 new = PAGE_SIZE + off;
  44                 break;
  45         default:
  46                 return -EINVAL;
  47         }
  48         if ( new < 0 || new > PAGE_SIZE )
  49                 return -EINVAL;
  50         return (file->f_pos = new);
  51 }
  52
  53 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
  54                               loff_t *ppos)
  55 {
  56         return simple_read_from_buffer(buf, nbytes, ppos,
  57                         PDE_DATA(file_inode(file)), PAGE_SIZE);
  58 }
  59
  60 static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
  61 {
  62         if ((vma->vm_end - vma->vm_start) > PAGE_SIZE)
  63                 return -EINVAL;
  64
  65         remap_pfn_range(vma, vma->vm_start,
  66                         __pa(PDE_DATA(file_inode(file))) >> PAGE_SHIFT,
  67                         PAGE_SIZE, vma->vm_page_prot);
  68         return 0;
  69 }
  70
  71 static const struct file_operations page_map_fops = {
  72         .llseek = page_map_seek,
  73         .read   = page_map_read,
  74         .mmap   = page_map_mmap
  75 };
  76
  77
  78 static int __init proc_ppc64_init(void)
  79 {
  80         struct proc_dir_entry *pde;
  81
  82         pde = proc_create_data("powerpc/systemcfg", S_IFREG|S_IRUGO, NULL,
  83                                &page_map_fops, vdso_data);
  84         if (!pde)
  85                 return 1;
  86         pde->size = PAGE_SIZE;
  87
  88         return 0;
  89 }
  90 __initcall(proc_ppc64_init);
  91
  92 #endif /* CONFIG_PPC64 */
  93
  94 /*
  95  * Create the ppc64 and ppc64/rtas directories early. This allows us to
  96  * assume that they have been previously created in drivers.
  97  */
  98 static int __init proc_ppc64_create(void)
  99 {
 100         struct proc_dir_entry *root;
 101
 102         root = proc_mkdir("powerpc", NULL);
 103         if (!root)
 104                 return 1;
 105
 106 #ifdef CONFIG_PPC64
 107         if (!proc_symlink("ppc64", NULL, "powerpc"))
 108                 pr_err("Failed to create link /proc/ppc64 -> /proc/powerpc\n");
 109 #endif
 110
 111         if (!of_find_node_by_path("/rtas"))
 112                 return 0;
 113
 114         if (!proc_mkdir("rtas", root))
 115                 return 1;
 116
 117         if (!proc_symlink("rtas", NULL, "powerpc/rtas"))
 118                 return 1;
 119
 120         return 0;
 121 }
 122 core_initcall(proc_ppc64_create);