1/*
  2 * Architecture specific sysfs attributes in /sys/kernel
  3 *
  4 * Copyright (C) 2007, Intel Corp.
  5 *      Huang Ying <ying.huang@intel.com>
  6 * Copyright (C) 2013, 2013 Red Hat, Inc.
  7 *      Dave Young <dyoung@redhat.com>
  8 *
  9 * This file is released under the GPLv2
 10 */
 11
 12#include <linux/kobject.h>
 13#include <linux/string.h>
 14#include <linux/sysfs.h>
 15#include <linux/init.h>
 16#include <linux/stat.h>
 17#include <linux/slab.h>
 18#include <linux/mm.h>
 19
 20#include <asm/io.h>
 21#include <asm/setup.h>
 22
 23static ssize_t version_show(struct kobject *kobj,
 24			    struct kobj_attribute *attr, char *buf)
 25{
 26	return sprintf(buf, "0x%04x\n", boot_params.hdr.version);
 27}
 28
 29static struct kobj_attribute boot_params_version_attr = __ATTR_RO(version);
 30
 31static ssize_t boot_params_data_read(struct file *fp, struct kobject *kobj,
 32				     struct bin_attribute *bin_attr,
 33				     char *buf, loff_t off, size_t count)
 34{
 35	memcpy(buf, (void *)&boot_params + off, count);
 36	return count;
 37}
 38
 39static struct bin_attribute boot_params_data_attr = {
 40	.attr = {
 41		.name = "data",
 42		.mode = S_IRUGO,
 43	},
 44	.read = boot_params_data_read,
 45	.size = sizeof(boot_params),
 46};
 47
 48static struct attribute *boot_params_version_attrs[] = {
 49	&boot_params_version_attr.attr,
 50	NULL,
 51};
 52
 53static struct bin_attribute *boot_params_data_attrs[] = {
 54	&boot_params_data_attr,
 55	NULL,
 56};
 57
 58static struct attribute_group boot_params_attr_group = {
 59	.attrs = boot_params_version_attrs,
 60	.bin_attrs = boot_params_data_attrs,
 61};
 62
 63static int kobj_to_setup_data_nr(struct kobject *kobj, int *nr)
 64{
 65	const char *name;
 66
 67	name = kobject_name(kobj);
 68	return kstrtoint(name, 10, nr);
 69}
 70
 71static int get_setup_data_paddr(int nr, u64 *paddr)
 72{
 73	int i = 0;
 74	struct setup_data *data;
 75	u64 pa_data = boot_params.hdr.setup_data;
 76
 77	while (pa_data) {
 78		if (nr == i) {
 79			*paddr = pa_data;
 80			return 0;
 81		}
 82		data = ioremap_cache(pa_data, sizeof(*data));
 83		if (!data)
 84			return -ENOMEM;
 85
 86		pa_data = data->next;
 87		iounmap(data);
 88		i++;
 89	}
 90	return -EINVAL;
 91}
 92
 93static int __init get_setup_data_size(int nr, size_t *size)
 94{
 95	int i = 0;
 96	struct setup_data *data;
 97	u64 pa_data = boot_params.hdr.setup_data;
 98
 99	while (pa_data) {
100		data = ioremap_cache(pa_data, sizeof(*data));
101		if (!data)
102			return -ENOMEM;
103		if (nr == i) {
104			*size = data->len;
105			iounmap(data);
106			return 0;
107		}
108
109		pa_data = data->next;
110		iounmap(data);
111		i++;
112	}
113	return -EINVAL;
114}
115
116static ssize_t type_show(struct kobject *kobj,
117			 struct kobj_attribute *attr, char *buf)
118{
119	int nr, ret;
120	u64 paddr;
121	struct setup_data *data;
122
123	ret = kobj_to_setup_data_nr(kobj, &nr);
124	if (ret)
125		return ret;
126
127	ret = get_setup_data_paddr(nr, &paddr);
128	if (ret)
129		return ret;
130	data = ioremap_cache(paddr, sizeof(*data));
131	if (!data)
132		return -ENOMEM;
133
134	ret = sprintf(buf, "0x%x\n", data->type);
135	iounmap(data);
136	return ret;
137}
138
139static ssize_t setup_data_data_read(struct file *fp,
140				    struct kobject *kobj,
141				    struct bin_attribute *bin_attr,
142				    char *buf,
143				    loff_t off, size_t count)
144{
145	int nr, ret = 0;
146	u64 paddr;
147	struct setup_data *data;
148	void *p;
149
150	ret = kobj_to_setup_data_nr(kobj, &nr);
151	if (ret)
152		return ret;
153
154	ret = get_setup_data_paddr(nr, &paddr);
155	if (ret)
156		return ret;
157	data = ioremap_cache(paddr, sizeof(*data));
158	if (!data)
159		return -ENOMEM;
160
161	if (off > data->len) {
162		ret = -EINVAL;
163		goto out;
164	}
165
166	if (count > data->len - off)
167		count = data->len - off;
168
169	if (!count)
170		goto out;
171
172	ret = count;
173	p = ioremap_cache(paddr + sizeof(*data), data->len);
174	if (!p) {
175		ret = -ENOMEM;
176		goto out;
177	}
178	memcpy(buf, p + off, count);
179	iounmap(p);
180out:
181	iounmap(data);
182	return ret;
183}
184
185static struct kobj_attribute type_attr = __ATTR_RO(type);
186
187static struct bin_attribute data_attr = {
188	.attr = {
189		.name = "data",
190		.mode = S_IRUGO,
191	},
192	.read = setup_data_data_read,
193};
194
195static struct attribute *setup_data_type_attrs[] = {
196	&type_attr.attr,
197	NULL,
198};
199
200static struct bin_attribute *setup_data_data_attrs[] = {
201	&data_attr,
202	NULL,
203};
204
205static struct attribute_group setup_data_attr_group = {
206	.attrs = setup_data_type_attrs,
207	.bin_attrs = setup_data_data_attrs,
208};
209
210static int __init create_setup_data_node(struct kobject *parent,
211					 struct kobject **kobjp, int nr)
212{
213	int ret = 0;
214	size_t size;
215	struct kobject *kobj;
216	char name[16]; /* should be enough for setup_data nodes numbers */
217	snprintf(name, 16, "%d", nr);
218
219	kobj = kobject_create_and_add(name, parent);
220	if (!kobj)
221		return -ENOMEM;
222
223	ret = get_setup_data_size(nr, &size);
224	if (ret)
225		goto out_kobj;
226
227	data_attr.size = size;
228	ret = sysfs_create_group(kobj, &setup_data_attr_group);
229	if (ret)
230		goto out_kobj;
231	*kobjp = kobj;
232
233	return 0;
234out_kobj:
235	kobject_put(kobj);
236	return ret;
237}
238
239static void __init cleanup_setup_data_node(struct kobject *kobj)
240{
241	sysfs_remove_group(kobj, &setup_data_attr_group);
242	kobject_put(kobj);
243}
244
245static int __init get_setup_data_total_num(u64 pa_data, int *nr)
246{
247	int ret = 0;
248	struct setup_data *data;
249
250	*nr = 0;
251	while (pa_data) {
252		*nr += 1;
253		data = ioremap_cache(pa_data, sizeof(*data));
254		if (!data) {
255			ret = -ENOMEM;
256			goto out;
257		}
258		pa_data = data->next;
259		iounmap(data);
260	}
261
262out:
263	return ret;
264}
265
266static int __init create_setup_data_nodes(struct kobject *parent)
267{
268	struct kobject *setup_data_kobj, **kobjp;
269	u64 pa_data;
270	int i, j, nr, ret = 0;
271
272	pa_data = boot_params.hdr.setup_data;
273	if (!pa_data)
274		return 0;
275
276	setup_data_kobj = kobject_create_and_add("setup_data", parent);
277	if (!setup_data_kobj) {
278		ret = -ENOMEM;
279		goto out;
280	}
281
282	ret = get_setup_data_total_num(pa_data, &nr);
283	if (ret)
284		goto out_setup_data_kobj;
285
286	kobjp = kmalloc(sizeof(*kobjp) * nr, GFP_KERNEL);
287	if (!kobjp) {
288		ret = -ENOMEM;
289		goto out_setup_data_kobj;
290	}
291
292	for (i = 0; i < nr; i++) {
293		ret = create_setup_data_node(setup_data_kobj, kobjp + i, i);
294		if (ret)
295			goto out_clean_nodes;
296	}
297
298	kfree(kobjp);
299	return 0;
300
301out_clean_nodes:
302	for (j = i - 1; j > 0; j--)
303		cleanup_setup_data_node(*(kobjp + j));
304	kfree(kobjp);
305out_setup_data_kobj:
306	kobject_put(setup_data_kobj);
307out:
308	return ret;
309}
310
311static int __init boot_params_ksysfs_init(void)
312{
313	int ret;
314	struct kobject *boot_params_kobj;
315
316	boot_params_kobj = kobject_create_and_add("boot_params",
317						  kernel_kobj);
318	if (!boot_params_kobj) {
319		ret = -ENOMEM;
320		goto out;
321	}
322
323	ret = sysfs_create_group(boot_params_kobj, &boot_params_attr_group);
324	if (ret)
325		goto out_boot_params_kobj;
326
327	ret = create_setup_data_nodes(boot_params_kobj);
328	if (ret)
329		goto out_create_group;
330
331	return 0;
332out_create_group:
333	sysfs_remove_group(boot_params_kobj, &boot_params_attr_group);
334out_boot_params_kobj:
335	kobject_put(boot_params_kobj);
336out:
337	return ret;
338}
339
340arch_initcall(boot_params_ksysfs_init);