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path: root/drivers/acpi/acpi_configfs.c
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Diffstat (limited to 'drivers/acpi/acpi_configfs.c')
-rw-r--r--drivers/acpi/acpi_configfs.c286
1 files changed, 286 insertions, 0 deletions
diff --git a/drivers/acpi/acpi_configfs.c b/drivers/acpi/acpi_configfs.c
new file mode 100644
index 000000000..c970792b1
--- /dev/null
+++ b/drivers/acpi/acpi_configfs.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ACPI configfs support
+ *
+ * Copyright (c) 2016 Intel Corporation
+ */
+
+#define pr_fmt(fmt) "ACPI configfs: " fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/configfs.h>
+#include <linux/acpi.h>
+#include <linux/security.h>
+
+static struct config_group *acpi_table_group;
+
+struct acpi_table {
+ struct config_item cfg;
+ struct acpi_table_header *header;
+ u32 index;
+};
+
+static ssize_t acpi_table_aml_write(struct config_item *cfg,
+ const void *data, size_t size)
+{
+ const struct acpi_table_header *header = data;
+ struct acpi_table *table;
+ int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
+
+ if (ret)
+ return ret;
+
+ table = container_of(cfg, struct acpi_table, cfg);
+
+ if (table->header) {
+ pr_err("table already loaded\n");
+ return -EBUSY;
+ }
+
+ if (header->length != size) {
+ pr_err("invalid table length\n");
+ return -EINVAL;
+ }
+
+ if (memcmp(header->signature, ACPI_SIG_SSDT, 4)) {
+ pr_err("invalid table signature\n");
+ return -EINVAL;
+ }
+
+ table = container_of(cfg, struct acpi_table, cfg);
+
+ table->header = kmemdup(header, header->length, GFP_KERNEL);
+ if (!table->header)
+ return -ENOMEM;
+
+ ret = acpi_load_table(table->header, &table->index);
+ if (ret) {
+ kfree(table->header);
+ table->header = NULL;
+ }
+
+ return ret;
+}
+
+static inline struct acpi_table_header *get_header(struct config_item *cfg)
+{
+ struct acpi_table *table = container_of(cfg, struct acpi_table, cfg);
+
+ if (!table->header)
+ pr_err("table not loaded\n");
+
+ return table->header ?: ERR_PTR(-EINVAL);
+}
+
+static ssize_t acpi_table_aml_read(struct config_item *cfg,
+ void *data, size_t size)
+{
+ struct acpi_table_header *h = get_header(cfg);
+
+ if (IS_ERR(h))
+ return PTR_ERR(h);
+
+ if (data)
+ memcpy(data, h, h->length);
+
+ return h->length;
+}
+
+#define MAX_ACPI_TABLE_SIZE (128 * 1024)
+
+CONFIGFS_BIN_ATTR(acpi_table_, aml, NULL, MAX_ACPI_TABLE_SIZE);
+
+static struct configfs_bin_attribute *acpi_table_bin_attrs[] = {
+ &acpi_table_attr_aml,
+ NULL,
+};
+
+static ssize_t acpi_table_signature_show(struct config_item *cfg, char *str)
+{
+ struct acpi_table_header *h = get_header(cfg);
+
+ if (IS_ERR(h))
+ return PTR_ERR(h);
+
+ return sysfs_emit(str, "%.*s\n", ACPI_NAMESEG_SIZE, h->signature);
+}
+
+static ssize_t acpi_table_length_show(struct config_item *cfg, char *str)
+{
+ struct acpi_table_header *h = get_header(cfg);
+
+ if (IS_ERR(h))
+ return PTR_ERR(h);
+
+ return sysfs_emit(str, "%d\n", h->length);
+}
+
+static ssize_t acpi_table_revision_show(struct config_item *cfg, char *str)
+{
+ struct acpi_table_header *h = get_header(cfg);
+
+ if (IS_ERR(h))
+ return PTR_ERR(h);
+
+ return sysfs_emit(str, "%d\n", h->revision);
+}
+
+static ssize_t acpi_table_oem_id_show(struct config_item *cfg, char *str)
+{
+ struct acpi_table_header *h = get_header(cfg);
+
+ if (IS_ERR(h))
+ return PTR_ERR(h);
+
+ return sysfs_emit(str, "%.*s\n", ACPI_OEM_ID_SIZE, h->oem_id);
+}
+
+static ssize_t acpi_table_oem_table_id_show(struct config_item *cfg, char *str)
+{
+ struct acpi_table_header *h = get_header(cfg);
+
+ if (IS_ERR(h))
+ return PTR_ERR(h);
+
+ return sysfs_emit(str, "%.*s\n", ACPI_OEM_TABLE_ID_SIZE, h->oem_table_id);
+}
+
+static ssize_t acpi_table_oem_revision_show(struct config_item *cfg, char *str)
+{
+ struct acpi_table_header *h = get_header(cfg);
+
+ if (IS_ERR(h))
+ return PTR_ERR(h);
+
+ return sysfs_emit(str, "%d\n", h->oem_revision);
+}
+
+static ssize_t acpi_table_asl_compiler_id_show(struct config_item *cfg,
+ char *str)
+{
+ struct acpi_table_header *h = get_header(cfg);
+
+ if (IS_ERR(h))
+ return PTR_ERR(h);
+
+ return sysfs_emit(str, "%.*s\n", ACPI_NAMESEG_SIZE, h->asl_compiler_id);
+}
+
+static ssize_t acpi_table_asl_compiler_revision_show(struct config_item *cfg,
+ char *str)
+{
+ struct acpi_table_header *h = get_header(cfg);
+
+ if (IS_ERR(h))
+ return PTR_ERR(h);
+
+ return sysfs_emit(str, "%d\n", h->asl_compiler_revision);
+}
+
+CONFIGFS_ATTR_RO(acpi_table_, signature);
+CONFIGFS_ATTR_RO(acpi_table_, length);
+CONFIGFS_ATTR_RO(acpi_table_, revision);
+CONFIGFS_ATTR_RO(acpi_table_, oem_id);
+CONFIGFS_ATTR_RO(acpi_table_, oem_table_id);
+CONFIGFS_ATTR_RO(acpi_table_, oem_revision);
+CONFIGFS_ATTR_RO(acpi_table_, asl_compiler_id);
+CONFIGFS_ATTR_RO(acpi_table_, asl_compiler_revision);
+
+static struct configfs_attribute *acpi_table_attrs[] = {
+ &acpi_table_attr_signature,
+ &acpi_table_attr_length,
+ &acpi_table_attr_revision,
+ &acpi_table_attr_oem_id,
+ &acpi_table_attr_oem_table_id,
+ &acpi_table_attr_oem_revision,
+ &acpi_table_attr_asl_compiler_id,
+ &acpi_table_attr_asl_compiler_revision,
+ NULL,
+};
+
+static const struct config_item_type acpi_table_type = {
+ .ct_owner = THIS_MODULE,
+ .ct_bin_attrs = acpi_table_bin_attrs,
+ .ct_attrs = acpi_table_attrs,
+};
+
+static struct config_item *acpi_table_make_item(struct config_group *group,
+ const char *name)
+{
+ struct acpi_table *table;
+
+ table = kzalloc(sizeof(*table), GFP_KERNEL);
+ if (!table)
+ return ERR_PTR(-ENOMEM);
+
+ config_item_init_type_name(&table->cfg, name, &acpi_table_type);
+ return &table->cfg;
+}
+
+static void acpi_table_drop_item(struct config_group *group,
+ struct config_item *cfg)
+{
+ struct acpi_table *table = container_of(cfg, struct acpi_table, cfg);
+
+ pr_debug("Host-directed Dynamic ACPI Table Unload\n");
+ acpi_unload_table(table->index);
+ config_item_put(cfg);
+}
+
+static struct configfs_group_operations acpi_table_group_ops = {
+ .make_item = acpi_table_make_item,
+ .drop_item = acpi_table_drop_item,
+};
+
+static const struct config_item_type acpi_tables_type = {
+ .ct_owner = THIS_MODULE,
+ .ct_group_ops = &acpi_table_group_ops,
+};
+
+static const struct config_item_type acpi_root_group_type = {
+ .ct_owner = THIS_MODULE,
+};
+
+static struct configfs_subsystem acpi_configfs = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "acpi",
+ .ci_type = &acpi_root_group_type,
+ },
+ },
+ .su_mutex = __MUTEX_INITIALIZER(acpi_configfs.su_mutex),
+};
+
+static int __init acpi_configfs_init(void)
+{
+ int ret;
+ struct config_group *root = &acpi_configfs.su_group;
+
+ config_group_init(root);
+
+ ret = configfs_register_subsystem(&acpi_configfs);
+ if (ret)
+ return ret;
+
+ acpi_table_group = configfs_register_default_group(root, "table",
+ &acpi_tables_type);
+ if (IS_ERR(acpi_table_group)) {
+ configfs_unregister_subsystem(&acpi_configfs);
+ return PTR_ERR(acpi_table_group);
+ }
+
+ return 0;
+}
+module_init(acpi_configfs_init);
+
+static void __exit acpi_configfs_exit(void)
+{
+ configfs_unregister_default_group(acpi_table_group);
+ configfs_unregister_subsystem(&acpi_configfs);
+}
+module_exit(acpi_configfs_exit);
+
+MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>");
+MODULE_DESCRIPTION("ACPI configfs support");
+MODULE_LICENSE("GPL v2");