1 // SPDX-License-Identifier: GPL-2.0-only
3 * Architecture specific sysfs attributes in /sys/kernel
5 * Copyright (C) 2007, Intel Corp.
6 * Huang Ying <ying.huang@intel.com>
7 * Copyright (C) 2013, 2013 Red Hat, Inc.
8 * Dave Young <dyoung@redhat.com>
11 #include <linux/kobject.h>
12 #include <linux/string.h>
13 #include <linux/sysfs.h>
14 #include <linux/init.h>
15 #include <linux/stat.h>
16 #include <linux/slab.h>
20 #include <asm/setup.h>
22 static ssize_t version_show(struct kobject *kobj,
23 struct kobj_attribute *attr, char *buf)
25 return sprintf(buf, "0x%04x\n", boot_params.hdr.version);
28 static struct kobj_attribute boot_params_version_attr = __ATTR_RO(version);
30 static ssize_t boot_params_data_read(struct file *fp, struct kobject *kobj,
31 struct bin_attribute *bin_attr,
32 char *buf, loff_t off, size_t count)
34 memcpy(buf, (void *)&boot_params + off, count);
38 static struct bin_attribute boot_params_data_attr = {
43 .read = boot_params_data_read,
44 .size = sizeof(boot_params),
47 static struct attribute *boot_params_version_attrs[] = {
48 &boot_params_version_attr.attr,
52 static struct bin_attribute *boot_params_data_attrs[] = {
53 &boot_params_data_attr,
57 static const struct attribute_group boot_params_attr_group = {
58 .attrs = boot_params_version_attrs,
59 .bin_attrs = boot_params_data_attrs,
62 static int kobj_to_setup_data_nr(struct kobject *kobj, int *nr)
66 name = kobject_name(kobj);
67 return kstrtoint(name, 10, nr);
70 static int get_setup_data_paddr(int nr, u64 *paddr)
73 struct setup_data *data;
74 u64 pa_data = boot_params.hdr.setup_data;
81 data = memremap(pa_data, sizeof(*data), MEMREMAP_WB);
92 static int __init get_setup_data_size(int nr, size_t *size)
94 u64 pa_data = boot_params.hdr.setup_data, pa_next;
95 struct setup_indirect *indirect;
96 struct setup_data *data;
101 data = memremap(pa_data, sizeof(*data), MEMREMAP_WB);
104 pa_next = data->next;
107 if (data->type == SETUP_INDIRECT) {
108 len = sizeof(*data) + data->len;
110 data = memremap(pa_data, len, MEMREMAP_WB);
114 indirect = (struct setup_indirect *)data->data;
116 if (indirect->type != SETUP_INDIRECT)
117 *size = indirect->len;
135 static ssize_t type_show(struct kobject *kobj,
136 struct kobj_attribute *attr, char *buf)
138 struct setup_indirect *indirect;
139 struct setup_data *data;
144 ret = kobj_to_setup_data_nr(kobj, &nr);
148 ret = get_setup_data_paddr(nr, &paddr);
151 data = memremap(paddr, sizeof(*data), MEMREMAP_WB);
155 if (data->type == SETUP_INDIRECT) {
156 len = sizeof(*data) + data->len;
158 data = memremap(paddr, len, MEMREMAP_WB);
162 indirect = (struct setup_indirect *)data->data;
164 ret = sprintf(buf, "0x%x\n", indirect->type);
166 ret = sprintf(buf, "0x%x\n", data->type);
173 static ssize_t setup_data_data_read(struct file *fp,
174 struct kobject *kobj,
175 struct bin_attribute *bin_attr,
177 loff_t off, size_t count)
179 struct setup_indirect *indirect;
180 struct setup_data *data;
185 ret = kobj_to_setup_data_nr(kobj, &nr);
189 ret = get_setup_data_paddr(nr, &paddr);
192 data = memremap(paddr, sizeof(*data), MEMREMAP_WB);
196 if (data->type == SETUP_INDIRECT) {
197 len = sizeof(*data) + data->len;
199 data = memremap(paddr, len, MEMREMAP_WB);
203 indirect = (struct setup_indirect *)data->data;
205 if (indirect->type != SETUP_INDIRECT) {
206 paddr = indirect->addr;
210 * Even though this is technically undefined, return
211 * the data as though it is a normal setup_data struct.
212 * This will at least allow it to be inspected.
214 paddr += sizeof(*data);
218 paddr += sizeof(*data);
227 if (count > len - off)
234 p = memremap(paddr, len, MEMREMAP_WB);
239 memcpy(buf, p + off, count);
246 static struct kobj_attribute type_attr = __ATTR_RO(type);
248 static struct bin_attribute data_attr __ro_after_init = {
253 .read = setup_data_data_read,
256 static struct attribute *setup_data_type_attrs[] = {
261 static struct bin_attribute *setup_data_data_attrs[] = {
266 static const struct attribute_group setup_data_attr_group = {
267 .attrs = setup_data_type_attrs,
268 .bin_attrs = setup_data_data_attrs,
271 static int __init create_setup_data_node(struct kobject *parent,
272 struct kobject **kobjp, int nr)
276 struct kobject *kobj;
277 char name[16]; /* should be enough for setup_data nodes numbers */
278 snprintf(name, 16, "%d", nr);
280 kobj = kobject_create_and_add(name, parent);
284 ret = get_setup_data_size(nr, &size);
288 data_attr.size = size;
289 ret = sysfs_create_group(kobj, &setup_data_attr_group);
300 static void __init cleanup_setup_data_node(struct kobject *kobj)
302 sysfs_remove_group(kobj, &setup_data_attr_group);
306 static int __init get_setup_data_total_num(u64 pa_data, int *nr)
309 struct setup_data *data;
314 data = memremap(pa_data, sizeof(*data), MEMREMAP_WB);
319 pa_data = data->next;
327 static int __init create_setup_data_nodes(struct kobject *parent)
329 struct kobject *setup_data_kobj, **kobjp;
331 int i, j, nr, ret = 0;
333 pa_data = boot_params.hdr.setup_data;
337 setup_data_kobj = kobject_create_and_add("setup_data", parent);
338 if (!setup_data_kobj) {
343 ret = get_setup_data_total_num(pa_data, &nr);
345 goto out_setup_data_kobj;
347 kobjp = kmalloc_array(nr, sizeof(*kobjp), GFP_KERNEL);
350 goto out_setup_data_kobj;
353 for (i = 0; i < nr; i++) {
354 ret = create_setup_data_node(setup_data_kobj, kobjp + i, i);
356 goto out_clean_nodes;
363 for (j = i - 1; j >= 0; j--)
364 cleanup_setup_data_node(*(kobjp + j));
367 kobject_put(setup_data_kobj);
372 static int __init boot_params_ksysfs_init(void)
375 struct kobject *boot_params_kobj;
377 boot_params_kobj = kobject_create_and_add("boot_params",
379 if (!boot_params_kobj) {
384 ret = sysfs_create_group(boot_params_kobj, &boot_params_attr_group);
386 goto out_boot_params_kobj;
388 ret = create_setup_data_nodes(boot_params_kobj);
390 goto out_create_group;
394 sysfs_remove_group(boot_params_kobj, &boot_params_attr_group);
395 out_boot_params_kobj:
396 kobject_put(boot_params_kobj);
401 arch_initcall(boot_params_ksysfs_init);