1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen IBM Corporation 4 */ 5 6 #include <linux/init.h> 7 #include <linux/mm.h> 8 #include <linux/proc_fs.h> 9 #include <linux/kernel.h> 10 11 #include <asm/machdep.h> 12 #include <asm/vdso_datapage.h> 13 #include <asm/rtas.h> 14 #include <linux/uaccess.h> 15 #include <asm/prom.h> 16 17 #ifdef CONFIG_PPC64 18 19 static loff_t page_map_seek(struct file *file, loff_t off, int whence) 20 { 21 return fixed_size_llseek(file, off, whence, PAGE_SIZE); 22 } 23 24 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes, 25 loff_t *ppos) 26 { 27 return simple_read_from_buffer(buf, nbytes, ppos, 28 pde_data(file_inode(file)), PAGE_SIZE); 29 } 30 31 static int page_map_mmap( struct file *file, struct vm_area_struct *vma ) 32 { 33 if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) 34 return -EINVAL; 35 36 remap_pfn_range(vma, vma->vm_start, 37 __pa(pde_data(file_inode(file))) >> PAGE_SHIFT, 38 PAGE_SIZE, vma->vm_page_prot); 39 return 0; 40 } 41 42 static const struct proc_ops page_map_proc_ops = { 43 .proc_lseek = page_map_seek, 44 .proc_read = page_map_read, 45 .proc_mmap = page_map_mmap, 46 }; 47 48 49 static int __init proc_ppc64_init(void) 50 { 51 struct proc_dir_entry *pde; 52 53 pde = proc_create_data("powerpc/systemcfg", S_IFREG | 0444, NULL, 54 &page_map_proc_ops, vdso_data); 55 if (!pde) 56 return 1; 57 proc_set_size(pde, PAGE_SIZE); 58 59 return 0; 60 } 61 __initcall(proc_ppc64_init); 62 63 #endif /* CONFIG_PPC64 */ 64 65 /* 66 * Create the ppc64 and ppc64/rtas directories early. This allows us to 67 * assume that they have been previously created in drivers. 68 */ 69 static int __init proc_ppc64_create(void) 70 { 71 struct proc_dir_entry *root; 72 73 root = proc_mkdir("powerpc", NULL); 74 if (!root) 75 return 1; 76 77 #ifdef CONFIG_PPC64 78 if (!proc_symlink("ppc64", NULL, "powerpc")) 79 pr_err("Failed to create link /proc/ppc64 -> /proc/powerpc\n"); 80 #endif 81 82 if (!of_find_node_by_path("/rtas")) 83 return 0; 84 85 if (!proc_mkdir("rtas", root)) 86 return 1; 87 88 if (!proc_symlink("rtas", NULL, "powerpc/rtas")) 89 return 1; 90 91 return 0; 92 } 93 core_initcall(proc_ppc64_create); 94