arch/ppc64/kernel/proc_ppc64.c

   1 /*
   2  * arch/ppc64/kernel/proc_ppc64.c
   3  *
   4  * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen IBM Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  */
  20
  21 #include <linux/config.h>
  22 #include <linux/init.h>
  23 #include <linux/mm.h>
  24 #include <linux/proc_fs.h>
  25 #include <linux/slab.h>
  26 #include <linux/kernel.h>
  27
  28 #include <asm/systemcfg.h>
  29 #include <asm/rtas.h>
  30 #include <asm/uaccess.h>
  31 #include <asm/prom.h>
  32
  33 static loff_t  page_map_seek( struct file *file, loff_t off, int whence);
  34 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
  35                               loff_t *ppos);
  36 static int     page_map_mmap( struct file *file, struct vm_area_struct *vma );
  37
  38 static struct file_operations page_map_fops = {
  39         .llseek = page_map_seek,
  40         .read   = page_map_read,
  41         .mmap   = page_map_mmap
  42 };
  43
  44 /*
  45  * Create the ppc64 and ppc64/rtas directories early. This allows us to
  46  * assume that they have been previously created in drivers.
  47  */
  48 static int __init proc_ppc64_create(void)
  49 {
  50         struct proc_dir_entry *root;
  51
  52         root = proc_mkdir("ppc64", NULL);
  53         if (!root)
  54                 return 1;
  55
  56         if (!(systemcfg->platform & (PLATFORM_PSERIES | PLATFORM_BPA)))
  57                 return 0;
  58
  59         if (!proc_mkdir("rtas", root))
  60                 return 1;
  61
  62         if (!proc_symlink("rtas", NULL, "ppc64/rtas"))
  63                 return 1;
  64
  65         return 0;
  66 }
  67 core_initcall(proc_ppc64_create);
  68
  69 static int __init proc_ppc64_init(void)
  70 {
  71         struct proc_dir_entry *pde;
  72
  73         pde = create_proc_entry("ppc64/systemcfg", S_IFREG|S_IRUGO, NULL);
  74         if (!pde)
  75                 return 1;
  76         pde->nlink = 1;
  77         pde->data = systemcfg;
  78         pde->size = PAGE_SIZE;
  79         pde->proc_fops = &page_map_fops;
  80
  81         return 0;
  82 }
  83 __initcall(proc_ppc64_init);
  84
  85 static loff_t page_map_seek( struct file *file, loff_t off, int whence)
  86 {
  87         loff_t new;
  88         struct proc_dir_entry *dp = PDE(file->f_dentry->d_inode);
  89
  90         switch(whence) {
  91         case 0:
  92                 new = off;
  93                 break;
  94         case 1:
  95                 new = file->f_pos + off;
  96                 break;
  97         case 2:
  98                 new = dp->size + off;
  99                 break;
 100         default:
 101                 return -EINVAL;
 102         }
 103         if ( new < 0 || new > dp->size )
 104                 return -EINVAL;
 105         return (file->f_pos = new);
 106 }
 107
 108 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
 109                               loff_t *ppos)
 110 {
 111         struct proc_dir_entry *dp = PDE(file->f_dentry->d_inode);
 112         return simple_read_from_buffer(buf, nbytes, ppos, dp->data, dp->size);
 113 }
 114
 115 static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
 116 {
 117         struct proc_dir_entry *dp = PDE(file->f_dentry->d_inode);
 118
 119         vma->vm_flags |= VM_SHM | VM_LOCKED;
 120
 121         if ((vma->vm_end - vma->vm_start) > dp->size)
 122                 return -EINVAL;
 123
 124         remap_pfn_range(vma, vma->vm_start, __pa(dp->data) >> PAGE_SHIFT,
 125                                                 dp->size, vma->vm_page_prot);
 126         return 0;
 127 }
 128