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 + pos; 48 49 /* Is it direct data or invalid indirect one? */ 50 if (!(node->type & SETUP_INDIRECT) || node->type == SETUP_INDIRECT) 51 pa += sizeof(struct setup_data); 52 53 p = memremap(pa, count, MEMREMAP_WB); 54 if (!p) 55 return -ENOMEM; 56 57 remain = copy_to_user(user_buf, p, count); 58 59 memunmap(p); 60 61 if (remain) 62 return -EFAULT; 63 64 *ppos = pos + count; 65 66 return count; 67 } 68 69 static const struct file_operations fops_setup_data = { 70 .read = setup_data_read, 71 .open = simple_open, 72 .llseek = default_llseek, 73 }; 74 75 static void __init 76 create_setup_data_node(struct dentry *parent, int no, 77 struct setup_data_node *node) 78 { 79 struct dentry *d; 80 char buf[16]; 81 82 sprintf(buf, "%d", no); 83 d = debugfs_create_dir(buf, parent); 84 85 debugfs_create_x32("type", S_IRUGO, d, &node->type); 86 debugfs_create_file("data", S_IRUGO, d, node, &fops_setup_data); 87 } 88 89 static int __init create_setup_data_nodes(struct dentry *parent) 90 { 91 struct setup_indirect *indirect; 92 struct setup_data_node *node; 93 struct setup_data *data; 94 u64 pa_data, pa_next; 95 struct dentry *d; 96 int error; 97 u32 len; 98 int no = 0; 99 100 d = debugfs_create_dir("setup_data", parent); 101 102 pa_data = boot_params.hdr.setup_data; 103 104 while (pa_data) { 105 node = kmalloc(sizeof(*node), GFP_KERNEL); 106 if (!node) { 107 error = -ENOMEM; 108 goto err_dir; 109 } 110 111 data = memremap(pa_data, sizeof(*data), MEMREMAP_WB); 112 if (!data) { 113 kfree(node); 114 error = -ENOMEM; 115 goto err_dir; 116 } 117 pa_next = data->next; 118 119 if (data->type == SETUP_INDIRECT) { 120 len = sizeof(*data) + data->len; 121 memunmap(data); 122 data = memremap(pa_data, len, MEMREMAP_WB); 123 if (!data) { 124 kfree(node); 125 error = -ENOMEM; 126 goto err_dir; 127 } 128 129 indirect = (struct setup_indirect *)data->data; 130 131 if (indirect->type != SETUP_INDIRECT) { 132 node->paddr = indirect->addr; 133 node->type = indirect->type; 134 node->len = indirect->len; 135 } else { 136 node->paddr = pa_data; 137 node->type = data->type; 138 node->len = data->len; 139 } 140 } else { 141 node->paddr = pa_data; 142 node->type = data->type; 143 node->len = data->len; 144 } 145 146 create_setup_data_node(d, no, node); 147 pa_data = pa_next; 148 149 memunmap(data); 150 no++; 151 } 152 153 return 0; 154 155 err_dir: 156 debugfs_remove_recursive(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; 168 int error; 169 170 dbp = debugfs_create_dir("boot_params", arch_debugfs_dir); 171 172 debugfs_create_x16("version", S_IRUGO, dbp, &boot_params.hdr.version); 173 debugfs_create_blob("data", S_IRUGO, dbp, &boot_params_blob); 174 175 error = create_setup_data_nodes(dbp); 176 if (error) 177 debugfs_remove_recursive(dbp); 178 179 return error; 180 } 181 #endif /* CONFIG_DEBUG_BOOT_PARAMS */ 182 183 static int __init arch_kdebugfs_init(void) 184 { 185 int error = 0; 186 187 arch_debugfs_dir = debugfs_create_dir("x86", NULL); 188 189 #ifdef CONFIG_DEBUG_BOOT_PARAMS 190 error = boot_params_kdebugfs_init(); 191 #endif 192 193 return error; 194 } 195 arch_initcall(arch_kdebugfs_init); 196