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         return fixed_size_llseek(file, off, whence, PAGE_SIZE);
  35 }
  36
  37 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
  38                               loff_t *ppos)
  39 {
  40         return simple_read_from_buffer(buf, nbytes, ppos,
  41                         PDE_DATA(file_inode(file)), PAGE_SIZE);
  42 }
  43
  44 static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
  45 {
  46         if ((vma->vm_end - vma->vm_start) > PAGE_SIZE)
  47                 return -EINVAL;
  48
  49         remap_pfn_range(vma, vma->vm_start,
  50                         __pa(PDE_DATA(file_inode(file))) >> PAGE_SHIFT,
  51                         PAGE_SIZE, vma->vm_page_prot);
  52         return 0;
  53 }
  54
  55 static const struct file_operations page_map_fops = {
  56         .llseek = page_map_seek,
  57         .read   = page_map_read,
  58         .mmap   = page_map_mmap
  59 };
  60
  61
  62 static int __init proc_ppc64_init(void)
  63 {
  64         struct proc_dir_entry *pde;
  65
  66         pde = proc_create_data("powerpc/systemcfg", S_IFREG|S_IRUGO, NULL,
  67                                &page_map_fops, vdso_data);
  68         if (!pde)
  69                 return 1;
  70         proc_set_size(pde, PAGE_SIZE);
  71
  72         return 0;
  73 }
  74 __initcall(proc_ppc64_init);
  75
  76 #endif /* CONFIG_PPC64 */
  77
  78 /*
  79  * Create the ppc64 and ppc64/rtas directories early. This allows us to
  80  * assume that they have been previously created in drivers.
  81  */
  82 static int __init proc_ppc64_create(void)
  83 {
  84         struct proc_dir_entry *root;
  85
  86         root = proc_mkdir("powerpc", NULL);
  87         if (!root)
  88                 return 1;
  89
  90 #ifdef CONFIG_PPC64
  91         if (!proc_symlink("ppc64", NULL, "powerpc"))
  92                 pr_err("Failed to create link /proc/ppc64 -> /proc/powerpc\n");
  93 #endif
  94
  95         if (!of_find_node_by_path("/rtas"))
  96                 return 0;
  97
  98         if (!proc_mkdir("rtas", root))
  99                 return 1;
 100
 101         if (!proc_symlink("rtas", NULL, "powerpc/rtas"))
 102                 return 1;
 103
 104         return 0;
 105 }
 106 core_initcall(proc_ppc64_create);