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 = -ENOMEM; 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 goto err_dir; 126 127 pg = pfn_to_page((pa_data+sizeof(*data)-1) >> PAGE_SHIFT); 128 if (PageHighMem(pg)) { 129 data = ioremap_cache(pa_data, sizeof(*data)); 130 if (!data) { 131 kfree(node); 132 error = -ENXIO; 133 goto err_dir; 134 } 135 } else 136 data = __va(pa_data); 137 138 node->paddr = pa_data; 139 node->type = data->type; 140 node->len = data->len; 141 error = create_setup_data_node(d, no, node); 142 pa_data = data->next; 143 144 if (PageHighMem(pg)) 145 iounmap(data); 146 if (error) 147 goto err_dir; 148 no++; 149 } 150 151 return 0; 152 153 err_dir: 154 debugfs_remove(d); 155 return error; 156 } 157 158 static struct debugfs_blob_wrapper boot_params_blob = { 159 .data = &boot_params, 160 .size = sizeof(boot_params), 161 }; 162 163 static int __init boot_params_kdebugfs_init(void) 164 { 165 struct dentry *dbp, *version, *data; 166 int error = -ENOMEM; 167 168 dbp = debugfs_create_dir("boot_params", NULL); 169 if (!dbp) 170 return -ENOMEM; 171 172 version = debugfs_create_x16("version", S_IRUGO, dbp, 173 &boot_params.hdr.version); 174 if (!version) 175 goto err_dir; 176 177 data = debugfs_create_blob("data", S_IRUGO, dbp, 178 &boot_params_blob); 179 if (!data) 180 goto err_version; 181 182 error = create_setup_data_nodes(dbp); 183 if (error) 184 goto err_data; 185 186 return 0; 187 188 err_data: 189 debugfs_remove(data); 190 err_version: 191 debugfs_remove(version); 192 err_dir: 193 debugfs_remove(dbp); 194 return error; 195 } 196 #endif /* CONFIG_DEBUG_BOOT_PARAMS */ 197 198 static int __init arch_kdebugfs_init(void) 199 { 200 int error = 0; 201 202 arch_debugfs_dir = debugfs_create_dir("x86", NULL); 203 if (!arch_debugfs_dir) 204 return -ENOMEM; 205 206 #ifdef CONFIG_DEBUG_BOOT_PARAMS 207 error = boot_params_kdebugfs_init(); 208 #endif 209 210 return error; 211 } 212 arch_initcall(arch_kdebugfs_init); 213