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 void __init 71 create_setup_data_node(struct dentry *parent, int no, 72 struct setup_data_node *node) 73 { 74 struct dentry *d; 75 char buf[16]; 76 77 sprintf(buf, "%d", no); 78 d = debugfs_create_dir(buf, parent); 79 80 debugfs_create_x32("type", S_IRUGO, d, &node->type); 81 debugfs_create_file("data", S_IRUGO, d, node, &fops_setup_data); 82 } 83 84 static int __init create_setup_data_nodes(struct dentry *parent) 85 { 86 struct setup_data_node *node; 87 struct setup_data *data; 88 int error; 89 struct dentry *d; 90 u64 pa_data; 91 int no = 0; 92 93 d = debugfs_create_dir("setup_data", parent); 94 95 pa_data = boot_params.hdr.setup_data; 96 97 while (pa_data) { 98 node = kmalloc(sizeof(*node), GFP_KERNEL); 99 if (!node) { 100 error = -ENOMEM; 101 goto err_dir; 102 } 103 104 data = memremap(pa_data, sizeof(*data), MEMREMAP_WB); 105 if (!data) { 106 kfree(node); 107 error = -ENOMEM; 108 goto err_dir; 109 } 110 111 node->paddr = pa_data; 112 node->type = data->type; 113 node->len = data->len; 114 create_setup_data_node(d, no, node); 115 pa_data = data->next; 116 117 memunmap(data); 118 no++; 119 } 120 121 return 0; 122 123 err_dir: 124 debugfs_remove_recursive(d); 125 return error; 126 } 127 128 static struct debugfs_blob_wrapper boot_params_blob = { 129 .data = &boot_params, 130 .size = sizeof(boot_params), 131 }; 132 133 static int __init boot_params_kdebugfs_init(void) 134 { 135 struct dentry *dbp; 136 int error; 137 138 dbp = debugfs_create_dir("boot_params", arch_debugfs_dir); 139 140 debugfs_create_x16("version", S_IRUGO, dbp, &boot_params.hdr.version); 141 debugfs_create_blob("data", S_IRUGO, dbp, &boot_params_blob); 142 143 error = create_setup_data_nodes(dbp); 144 if (error) 145 debugfs_remove_recursive(dbp); 146 147 return error; 148 } 149 #endif /* CONFIG_DEBUG_BOOT_PARAMS */ 150 151 static int __init arch_kdebugfs_init(void) 152 { 153 int error = 0; 154 155 arch_debugfs_dir = debugfs_create_dir("x86", NULL); 156 157 #ifdef CONFIG_DEBUG_BOOT_PARAMS 158 error = boot_params_kdebugfs_init(); 159 #endif 160 161 return error; 162 } 163 arch_initcall(arch_kdebugfs_init); 164