1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Architecture specific debugfs files 4 * 5 * Copyright (C) 2007, Intel Corp. 6 * Huang Ying <ying.huang@intel.com> 7 */ 8 #include <linux/debugfs.h> 9 #include <linux/uaccess.h> 10 #include <linux/export.h> 11 #include <linux/slab.h> 12 #include <linux/init.h> 13 #include <linux/stat.h> 14 #include <linux/io.h> 15 #include <linux/mm.h> 16 17 #include <asm/setup.h> 18 19 struct dentry *arch_debugfs_dir; 20 EXPORT_SYMBOL(arch_debugfs_dir); 21 22 #ifdef CONFIG_DEBUG_BOOT_PARAMS 23 struct setup_data_node { 24 u64 paddr; 25 u32 type; 26 u32 len; 27 }; 28 29 static ssize_t setup_data_read(struct file *file, char __user *user_buf, 30 size_t count, loff_t *ppos) 31 { 32 struct setup_data_node *node = file->private_data; 33 unsigned long remain; 34 loff_t pos = *ppos; 35 void *p; 36 u64 pa; 37 38 if (pos < 0) 39 return -EINVAL; 40 41 if (pos >= node->len) 42 return 0; 43 44 if (count > node->len - pos) 45 count = node->len - pos; 46 47 pa = node->paddr + sizeof(struct setup_data) + pos; 48 p = memremap(pa, count, MEMREMAP_WB); 49 if (!p) 50 return -ENOMEM; 51 52 remain = copy_to_user(user_buf, p, count); 53 54 memunmap(p); 55 56 if (remain) 57 return -EFAULT; 58 59 *ppos = pos + count; 60 61 return count; 62 } 63 64 static const struct file_operations fops_setup_data = { 65 .read = setup_data_read, 66 .open = simple_open, 67 .llseek = default_llseek, 68 }; 69 70 static int __init 71 create_setup_data_node(struct dentry *parent, int no, 72 struct setup_data_node *node) 73 { 74 struct dentry *d, *type, *data; 75 char buf[16]; 76 77 sprintf(buf, "%d", no); 78 d = debugfs_create_dir(buf, parent); 79 if (!d) 80 return -ENOMEM; 81 82 type = debugfs_create_x32("type", S_IRUGO, d, &node->type); 83 if (!type) 84 goto err_dir; 85 86 data = debugfs_create_file("data", S_IRUGO, d, node, &fops_setup_data); 87 if (!data) 88 goto err_type; 89 90 return 0; 91 92 err_type: 93 debugfs_remove(type); 94 err_dir: 95 debugfs_remove(d); 96 return -ENOMEM; 97 } 98 99 static int __init create_setup_data_nodes(struct dentry *parent) 100 { 101 struct setup_data_node *node; 102 struct setup_data *data; 103 int error; 104 struct dentry *d; 105 u64 pa_data; 106 int no = 0; 107 108 d = debugfs_create_dir("setup_data", parent); 109 if (!d) 110 return -ENOMEM; 111 112 pa_data = boot_params.hdr.setup_data; 113 114 while (pa_data) { 115 node = kmalloc(sizeof(*node), GFP_KERNEL); 116 if (!node) { 117 error = -ENOMEM; 118 goto err_dir; 119 } 120 121 data = memremap(pa_data, sizeof(*data), MEMREMAP_WB); 122 if (!data) { 123 kfree(node); 124 error = -ENOMEM; 125 goto err_dir; 126 } 127 128 node->paddr = pa_data; 129 node->type = data->type; 130 node->len = data->len; 131 error = create_setup_data_node(d, no, node); 132 pa_data = data->next; 133 134 memunmap(data); 135 if (error) 136 goto err_dir; 137 no++; 138 } 139 140 return 0; 141 142 err_dir: 143 debugfs_remove(d); 144 return error; 145 } 146 147 static struct debugfs_blob_wrapper boot_params_blob = { 148 .data = &boot_params, 149 .size = sizeof(boot_params), 150 }; 151 152 static int __init boot_params_kdebugfs_init(void) 153 { 154 struct dentry *dbp, *version, *data; 155 int error = -ENOMEM; 156 157 dbp = debugfs_create_dir("boot_params", arch_debugfs_dir); 158 if (!dbp) 159 return -ENOMEM; 160 161 version = debugfs_create_x16("version", S_IRUGO, dbp, 162 &boot_params.hdr.version); 163 if (!version) 164 goto err_dir; 165 166 data = debugfs_create_blob("data", S_IRUGO, dbp, 167 &boot_params_blob); 168 if (!data) 169 goto err_version; 170 171 error = create_setup_data_nodes(dbp); 172 if (error) 173 goto err_data; 174 175 return 0; 176 177 err_data: 178 debugfs_remove(data); 179 err_version: 180 debugfs_remove(version); 181 err_dir: 182 debugfs_remove(dbp); 183 return error; 184 } 185 #endif /* CONFIG_DEBUG_BOOT_PARAMS */ 186 187 static int __init arch_kdebugfs_init(void) 188 { 189 int error = 0; 190 191 arch_debugfs_dir = debugfs_create_dir("x86", NULL); 192 if (!arch_debugfs_dir) 193 return -ENOMEM; 194 195 #ifdef CONFIG_DEBUG_BOOT_PARAMS 196 error = boot_params_kdebugfs_init(); 197 #endif 198 199 return error; 200 } 201 arch_initcall(arch_kdebugfs_init); 202