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 proc_set_size(pde, 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); 123