1/*
  2 * ACPI configfs support
  3 *
  4 * Copyright (c) 2016 Intel Corporation
  5 *
  6 * This program is free software; you can redistribute it and/or modify it
  7 * under the terms of the GNU General Public License version 2 as published by
  8 * the Free Software Foundation.
  9 */
 10
 11#define pr_fmt(fmt) "ACPI configfs: " fmt
 12
 13#include <linux/init.h>
 14#include <linux/module.h>
 15#include <linux/configfs.h>
 16#include <linux/acpi.h>
 17
 18#include "acpica/accommon.h"
 19#include "acpica/actables.h"
 20
 21static struct config_group *acpi_table_group;
 22
 23struct acpi_table {
 24	struct config_item cfg;
 25	struct acpi_table_header *header;
 26	u32 index;
 27};
 28
 29static ssize_t acpi_table_aml_write(struct config_item *cfg,
 30				    const void *data, size_t size)
 31{
 32	const struct acpi_table_header *header = data;
 33	struct acpi_table *table;
 34	int ret;
 35
 36	table = container_of(cfg, struct acpi_table, cfg);
 37
 38	if (table->header) {
 39		pr_err("table already loaded\n");
 40		return -EBUSY;
 41	}
 42
 43	if (header->length != size) {
 44		pr_err("invalid table length\n");
 45		return -EINVAL;
 46	}
 47
 48	if (memcmp(header->signature, ACPI_SIG_SSDT, 4)) {
 49		pr_err("invalid table signature\n");
 50		return -EINVAL;
 51	}
 52
 53	table = container_of(cfg, struct acpi_table, cfg);
 54
 55	table->header = kmemdup(header, header->length, GFP_KERNEL);
 56	if (!table->header)
 57		return -ENOMEM;
 58
 59	ACPI_INFO(("Host-directed Dynamic ACPI Table Load:"));
 60	ret = acpi_tb_install_and_load_table(
 61			ACPI_PTR_TO_PHYSADDR(table->header),
 62			ACPI_TABLE_ORIGIN_EXTERNAL_VIRTUAL, FALSE,
 63			&table->index);
 64	if (ret) {
 65		kfree(table->header);
 66		table->header = NULL;
 67	}
 68
 69	return ret;
 70}
 71
 72static inline struct acpi_table_header *get_header(struct config_item *cfg)
 73{
 74	struct acpi_table *table = container_of(cfg, struct acpi_table, cfg);
 75
 76	if (!table->header)
 77		pr_err("table not loaded\n");
 78
 79	return table->header;
 80}
 81
 82static ssize_t acpi_table_aml_read(struct config_item *cfg,
 83				   void *data, size_t size)
 84{
 85	struct acpi_table_header *h = get_header(cfg);
 86
 87	if (!h)
 88		return -EINVAL;
 89
 90	if (data)
 91		memcpy(data, h, h->length);
 92
 93	return h->length;
 94}
 95
 96#define MAX_ACPI_TABLE_SIZE (128 * 1024)
 97
 98CONFIGFS_BIN_ATTR(acpi_table_, aml, NULL, MAX_ACPI_TABLE_SIZE);
 99
100struct configfs_bin_attribute *acpi_table_bin_attrs[] = {
101	&acpi_table_attr_aml,
102	NULL,
103};
104
105ssize_t acpi_table_signature_show(struct config_item *cfg, char *str)
106{
107	struct acpi_table_header *h = get_header(cfg);
108
109	if (!h)
110		return -EINVAL;
111
112	return sprintf(str, "%.*s\n", ACPI_NAME_SIZE, h->signature);
113}
114
115ssize_t acpi_table_length_show(struct config_item *cfg, char *str)
116{
117	struct acpi_table_header *h = get_header(cfg);
118
119	if (!h)
120		return -EINVAL;
121
122	return sprintf(str, "%d\n", h->length);
123}
124
125ssize_t acpi_table_revision_show(struct config_item *cfg, char *str)
126{
127	struct acpi_table_header *h = get_header(cfg);
128
129	if (!h)
130		return -EINVAL;
131
132	return sprintf(str, "%d\n", h->revision);
133}
134
135ssize_t acpi_table_oem_id_show(struct config_item *cfg, char *str)
136{
137	struct acpi_table_header *h = get_header(cfg);
138
139	if (!h)
140		return -EINVAL;
141
142	return sprintf(str, "%.*s\n", ACPI_OEM_ID_SIZE, h->oem_id);
143}
144
145ssize_t acpi_table_oem_table_id_show(struct config_item *cfg, char *str)
146{
147	struct acpi_table_header *h = get_header(cfg);
148
149	if (!h)
150		return -EINVAL;
151
152	return sprintf(str, "%.*s\n", ACPI_OEM_TABLE_ID_SIZE, h->oem_table_id);
153}
154
155ssize_t acpi_table_oem_revision_show(struct config_item *cfg, char *str)
156{
157	struct acpi_table_header *h = get_header(cfg);
158
159	if (!h)
160		return -EINVAL;
161
162	return sprintf(str, "%d\n", h->oem_revision);
163}
164
165ssize_t acpi_table_asl_compiler_id_show(struct config_item *cfg, char *str)
166{
167	struct acpi_table_header *h = get_header(cfg);
168
169	if (!h)
170		return -EINVAL;
171
172	return sprintf(str, "%.*s\n", ACPI_NAME_SIZE, h->asl_compiler_id);
173}
174
175ssize_t acpi_table_asl_compiler_revision_show(struct config_item *cfg,
176					      char *str)
177{
178	struct acpi_table_header *h = get_header(cfg);
179
180	if (!h)
181		return -EINVAL;
182
183	return sprintf(str, "%d\n", h->asl_compiler_revision);
184}
185
186CONFIGFS_ATTR_RO(acpi_table_, signature);
187CONFIGFS_ATTR_RO(acpi_table_, length);
188CONFIGFS_ATTR_RO(acpi_table_, revision);
189CONFIGFS_ATTR_RO(acpi_table_, oem_id);
190CONFIGFS_ATTR_RO(acpi_table_, oem_table_id);
191CONFIGFS_ATTR_RO(acpi_table_, oem_revision);
192CONFIGFS_ATTR_RO(acpi_table_, asl_compiler_id);
193CONFIGFS_ATTR_RO(acpi_table_, asl_compiler_revision);
194
195struct configfs_attribute *acpi_table_attrs[] = {
196	&acpi_table_attr_signature,
197	&acpi_table_attr_length,
198	&acpi_table_attr_revision,
199	&acpi_table_attr_oem_id,
200	&acpi_table_attr_oem_table_id,
201	&acpi_table_attr_oem_revision,
202	&acpi_table_attr_asl_compiler_id,
203	&acpi_table_attr_asl_compiler_revision,
204	NULL,
205};
206
207static const struct config_item_type acpi_table_type = {
208	.ct_owner = THIS_MODULE,
209	.ct_bin_attrs = acpi_table_bin_attrs,
210	.ct_attrs = acpi_table_attrs,
211};
212
213static struct config_item *acpi_table_make_item(struct config_group *group,
214						const char *name)
215{
216	struct acpi_table *table;
217
218	table = kzalloc(sizeof(*table), GFP_KERNEL);
219	if (!table)
220		return ERR_PTR(-ENOMEM);
221
222	config_item_init_type_name(&table->cfg, name, &acpi_table_type);
223	return &table->cfg;
224}
225
226static void acpi_table_drop_item(struct config_group *group,
227				 struct config_item *cfg)
228{
229	struct acpi_table *table = container_of(cfg, struct acpi_table, cfg);
230
231	ACPI_INFO(("Host-directed Dynamic ACPI Table Unload"));
232	acpi_tb_unload_table(table->index);
233}
234
235struct configfs_group_operations acpi_table_group_ops = {
236	.make_item = acpi_table_make_item,
237	.drop_item = acpi_table_drop_item,
238};
239
240static const struct config_item_type acpi_tables_type = {
241	.ct_owner = THIS_MODULE,
242	.ct_group_ops = &acpi_table_group_ops,
243};
244
245static const struct config_item_type acpi_root_group_type = {
246	.ct_owner = THIS_MODULE,
247};
248
249static struct configfs_subsystem acpi_configfs = {
250	.su_group = {
251		.cg_item = {
252			.ci_namebuf = "acpi",
253			.ci_type = &acpi_root_group_type,
254		},
255	},
256	.su_mutex = __MUTEX_INITIALIZER(acpi_configfs.su_mutex),
257};
258
259static int __init acpi_configfs_init(void)
260{
261	int ret;
262	struct config_group *root = &acpi_configfs.su_group;
263
264	config_group_init(root);
265
266	ret = configfs_register_subsystem(&acpi_configfs);
267	if (ret)
268		return ret;
269
270	acpi_table_group = configfs_register_default_group(root, "table",
271							   &acpi_tables_type);
272	return PTR_ERR_OR_ZERO(acpi_table_group);
273}
274module_init(acpi_configfs_init);
275
276static void __exit acpi_configfs_exit(void)
277{
278	configfs_unregister_default_group(acpi_table_group);
279	configfs_unregister_subsystem(&acpi_configfs);
280}
281module_exit(acpi_configfs_exit);
282
283MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>");
284MODULE_DESCRIPTION("ACPI configfs support");
285MODULE_LICENSE("GPL v2");