1 /* 2 * Architecture specific debugfs files 3 * 4 * Copyright (C) 2007, Intel Corp. 5 * Huang Ying <ying.huang@intel.com> 6 * 7 * This file is released under the GPLv2. 8 */ 9 #include <linux/debugfs.h> 10 #include <linux/uaccess.h> 11 #include <linux/module.h> 12 #include <linux/slab.h> 13 #include <linux/init.h> 14 #include <linux/stat.h> 15 #include <linux/io.h> 16 #include <linux/mm.h> 17 18 #include <asm/setup.h> 19 20 struct dentry *arch_debugfs_dir; 21 EXPORT_SYMBOL(arch_debugfs_dir); 22 23 #ifdef CONFIG_DEBUG_BOOT_PARAMS 24 struct setup_data_node { 25 u64 paddr; 26 u32 type; 27 u32 len; 28 }; 29 30 static ssize_t setup_data_read(struct file *file, char __user *user_buf, 31 size_t count, loff_t *ppos) 32 { 33 struct setup_data_node *node = file->private_data; 34 unsigned long remain; 35 loff_t pos = *ppos; 36 struct page *pg; 37 void *p; 38 u64 pa; 39 40 if (pos < 0) 41 return -EINVAL; 42 43 if (pos >= node->len) 44 return 0; 45 46 if (count > node->len - pos) 47 count = node->len - pos; 48 49 pa = node->paddr + sizeof(struct setup_data) + pos; 50 pg = pfn_to_page((pa + count - 1) >> PAGE_SHIFT); 51 if (PageHighMem(pg)) { 52 p = ioremap_cache(pa, count); 53 if (!p) 54 return -ENXIO; 55 } else 56 p = __va(pa); 57 58 remain = copy_to_user(user_buf, p, count); 59 60 if (PageHighMem(pg)) 61 iounmap(p); 62 63 if (remain) 64 return -EFAULT; 65 66 *ppos = pos + count; 67 68 return count; 69 } 70 71 static const struct file_operations fops_setup_data = { 72 .read = setup_data_read, 73 .open = simple_open, 74 .llseek = default_llseek, 75 }; 76 77 static int __init 78 create_setup_data_node(struct dentry *parent, int no, 79 struct setup_data_node *node) 80 { 81 struct dentry *d, *type, *data; 82 char buf[16]; 83 84 sprintf(buf, "%d", no); 85 d = debugfs_create_dir(buf, parent); 86 if (!d) 87 return -ENOMEM; 88 89 type = debugfs_create_x32("type", S_IRUGO, d, &node->type); 90 if (!type) 91 goto err_dir; 92 93 data = debugfs_create_file("data", S_IRUGO, d, node, &fops_setup_data); 94 if (!data) 95 goto err_type; 96 97 return 0; 98 99 err_type: 100 debugfs_remove(type); 101 err_dir: 102 debugfs_remove(d); 103 return -ENOMEM; 104 } 105 106 static int __init create_setup_data_nodes(struct dentry *parent) 107 { 108 struct setup_data_node *node; 109 struct setup_data *data; 110 int error; 111 struct dentry *d; 112 struct page *pg; 113 u64 pa_data; 114 int no = 0; 115 116 d = debugfs_create_dir("setup_data", parent); 117 if (!d) 118 return -ENOMEM; 119 120 pa_data = boot_params.hdr.setup_data; 121 122 while (pa_data) { 123 node = kmalloc(sizeof(*node), GFP_KERNEL); 124 if (!node) { 125 error = -ENOMEM; 126 goto err_dir; 127 } 128 129 pg = pfn_to_page((pa_data+sizeof(*data)-1) >> PAGE_SHIFT); 130 if (PageHighMem(pg)) { 131 data = ioremap_cache(pa_data, sizeof(*data)); 132 if (!data) { 133 kfree(node); 134 error = -ENXIO; 135 goto err_dir; 136 } 137 } else 138 data = __va(pa_data); 139 140 node->paddr = pa_data; 141 node->type = data->type; 142 node->len = data->len; 143 error = create_setup_data_node(d, no, node); 144 pa_data = data->next; 145 146 if (PageHighMem(pg)) 147 iounmap(data); 148 if (error) 149 goto err_dir; 150 no++; 151 } 152 153 return 0; 154 155 err_dir: 156 debugfs_remove(d); 157 return error; 158 } 159 160 static struct debugfs_blob_wrapper boot_params_blob = { 161 .data = &boot_params, 162 .size = sizeof(boot_params), 163 }; 164 165 static int __init boot_params_kdebugfs_init(void) 166 { 167 struct dentry *dbp, *version, *data; 168 int error = -ENOMEM; 169 170 dbp = debugfs_create_dir("boot_params", NULL); 171 if (!dbp) 172 return -ENOMEM; 173 174 version = debugfs_create_x16("version", S_IRUGO, dbp, 175 &boot_params.hdr.version); 176 if (!version) 177 goto err_dir; 178 179 data = debugfs_create_blob("data", S_IRUGO, dbp, 180 &boot_params_blob); 181 if (!data) 182 goto err_version; 183 184 error = create_setup_data_nodes(dbp); 185 if (error) 186 goto err_data; 187 188 return 0; 189 190 err_data: 191 debugfs_remove(data); 192 err_version: 193 debugfs_remove(version); 194 err_dir: 195 debugfs_remove(dbp); 196 return error; 197 } 198 #endif /* CONFIG_DEBUG_BOOT_PARAMS */ 199 200 static int __init arch_kdebugfs_init(void) 201 { 202 int error = 0; 203 204 arch_debugfs_dir = debugfs_create_dir("x86", NULL); 205 if (!arch_debugfs_dir) 206 return -ENOMEM; 207 208 #ifdef CONFIG_DEBUG_BOOT_PARAMS 209 error = boot_params_kdebugfs_init(); 210 #endif 211 212 return error; 213 } 214 arch_initcall(arch_kdebugfs_init); 215