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         struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
  36
  37         switch(whence) {
  38         case 0:
  39                 new = off;
  40                 break;
  41         case 1:
  42                 new = file->f_pos + off;
  43                 break;
  44         case 2:
  45                 new = dp->size + off;
  46                 break;
  47         default:
  48                 return -EINVAL;
  49         }
  50         if ( new < 0 || new > dp->size )
  51                 return -EINVAL;
  52         return (file->f_pos = new);
  53 }
  54
  55 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
  56                               loff_t *ppos)
  57 {
  58         struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
  59         return simple_read_from_buffer(buf, nbytes, ppos, dp->data, dp->size);
  60 }
  61
  62 static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
  63 {
  64         struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
  65
  66         if ((vma->vm_end - vma->vm_start) > dp->size)
  67                 return -EINVAL;
  68
  69         remap_pfn_range(vma, vma->vm_start, __pa(dp->data) >> PAGE_SHIFT,
  70                                                 dp->size, vma->vm_page_prot);
  71         return 0;
  72 }
  73
  74 static const struct file_operations page_map_fops = {
  75         .llseek = page_map_seek,
  76         .read   = page_map_read,
  77         .mmap   = page_map_mmap
  78 };
  79
  80
  81 static int __init proc_ppc64_init(void)
  82 {
  83         struct proc_dir_entry *pde;
  84
  85         pde = proc_create_data("powerpc/systemcfg", S_IFREG|S_IRUGO, NULL,
  86                                &page_map_fops, vdso_data);
  87         if (!pde)
  88                 return 1;
  89         pde->size = PAGE_SIZE;
  90
  91         return 0;
  92 }
  93 __initcall(proc_ppc64_init);
  94
  95 #endif /* CONFIG_PPC64 */
  96
  97 /*
  98  * Create the ppc64 and ppc64/rtas directories early. This allows us to
  99  * assume that they have been previously created in drivers.
 100  */
 101 static int __init proc_ppc64_create(void)
 102 {
 103         struct proc_dir_entry *root;
 104
 105         root = proc_mkdir("powerpc", NULL);
 106         if (!root)
 107                 return 1;
 108
 109 #ifdef CONFIG_PPC64
 110         if (!proc_symlink("ppc64", NULL, "powerpc"))
 111                 pr_err("Failed to create link /proc/ppc64 -> /proc/powerpc\n");
 112 #endif
 113
 114         if (!of_find_node_by_path("/rtas"))
 115                 return 0;
 116
 117         if (!proc_mkdir("rtas", root))
 118                 return 1;
 119
 120         if (!proc_symlink("rtas", NULL, "powerpc/rtas"))
 121                 return 1;
 122
 123         return 0;
 124 }
 125 core_initcall(proc_ppc64_create);