From: Zhang Rui <rui.zhang@xxxxxxxxx>
This is the basic functionality of exposing ACPI tables in sysfs.
Only static tables are exposed to user space in this patch.
Every static table has a file under /sys/firmware/acpi/tables/.
The file name is constituted of the table signature and instance number.
With this patch, we can get all the static ACPI tables except for RSDP and RSDT.
For example, "#cat /sys/firmware/acpi/tables/dsdt > /tmp/dsdt.bin"
can help you get the content of dsdt table.
But iasl is still needed to disassemble the acpi tables.
Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
---
drivers/acpi/system.c | 165 +++++++++++++++++++++++++++++++++++++++++++-------
1 files changed, 144 insertions(+), 21 deletions(-)
Index: linux-2.6.22-rc4/drivers/acpi/system.c
===================================================================
--- linux-2.6.22-rc4.orig/drivers/acpi/system.c 2007-06-13 16:00:45.000000000 +0800
+++ linux-2.6.22-rc4/drivers/acpi/system.c 2007-06-14 19:06:03.000000000 +0800
@@ -39,15 +39,12 @@ ACPI_MODULE_NAME("system");
#define ACPI_SYSTEM_CLASS "system"
#define ACPI_SYSTEM_DEVICE_NAME "System"
-#define ACPI_SYSTEM_FILE_INFO "info"
-#define ACPI_SYSTEM_FILE_EVENT "event"
-#define ACPI_SYSTEM_FILE_DSDT "dsdt"
-#define ACPI_SYSTEM_FILE_FADT "fadt"
/*
* Make ACPICA version work as module param
*/
-static int param_get_acpica_version(char *buffer, struct kernel_param *kp) {
+static int param_get_acpica_version(char *buffer, struct kernel_param *kp)
+{
int result;
result = sprintf(buffer, "%x", ACPI_CA_VERSION);
@@ -58,9 +55,126 @@ static int param_get_acpica_version(char
module_param_call(acpica_version, NULL, param_get_acpica_version, NULL, 0444);
/* --------------------------------------------------------------------------
+ FS Interface (/sys)
+ -------------------------------------------------------------------------- */
+static LIST_HEAD(acpi_table_attr_list);
+static struct kobject tables_kobj;
+
+struct acpi_table_attr {
+ struct bin_attribute attr;
+ char name[8];
+ int instance;
+ struct list_head node;
+};
+
+static ssize_t acpi_table_show(struct kobject *kobj,
+ struct bin_attribute *bin_attr, char *buf,
+ loff_t offset, size_t count)
+{
+ struct acpi_table_attr *table_attr =
+ container_of(bin_attr, struct acpi_table_attr, attr);
+ struct acpi_table_header *table_header = NULL;
+ acpi_status status;
+ ssize_t ret_count = count;
+
+ status =
+ acpi_get_table(table_attr->name, table_attr->instance,
+ &table_header);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ if (offset >= table_header->length) {
+ ret_count = 0;
+ goto end;
+ }
+
+ if (offset + ret_count > table_header->length)
+ ret_count = table_header->length - offset;
+
+ memcpy(buf, ((char *)table_header) + offset, ret_count);
+
+ end:
+ return ret_count;
+}
+
+static void acpi_table_attr_init(struct acpi_table_attr *table_attr,
+ struct acpi_table_header *table_header)
+{
+ struct acpi_table_header *header = NULL;
+ struct acpi_table_attr *attr = NULL;
+
+ memcpy(table_attr->name, table_header->signature, ACPI_NAME_SIZE);
+
+ list_for_each_entry(attr, &acpi_table_attr_list, node) {
+ if (!memcmp(table_header->signature, attr->name,
+ ACPI_NAME_SIZE))
+ if (table_attr->instance < attr->instance)
+ table_attr->instance = attr->instance;
+ }
+ table_attr->instance++;
+
+ if (table_attr->instance > 1 || (table_attr->instance == 1 &&
+ !acpi_get_table(table_header->
+ signature, 2,
+ &header)))
+ sprintf(table_attr->name + 4, "%d", table_attr->instance);
+
+ table_attr->attr.size = 0;
+ table_attr->attr.read = acpi_table_show;
+ table_attr->attr.attr.name = table_attr->name;
+ table_attr->attr.attr.mode = 0444;
+ table_attr->attr.attr.owner = THIS_MODULE;
+
+ return;
+}
+
+static int acpi_system_sysfs_init(void)
+{
+ struct acpi_table_attr *table_attr;
+ struct acpi_table_header *table_header = NULL;
+ int table_index = 0;
+ int result;
+
+ tables_kobj.parent = &acpi_subsys.kobj;
+ kobject_set_name(&tables_kobj, "tables");
+ result = kobject_register(&tables_kobj);
+ if (result)
+ return result;
+
+ do {
+ result = acpi_get_table_by_index(table_index, &table_header);
+ if (!result) {
+ table_index++;
+ table_attr = NULL;
+ table_attr =
+ kzalloc(sizeof(struct acpi_table_attr), GFP_KERNEL);
+ if (!table_attr)
+ return -ENOMEM;
+
+ acpi_table_attr_init(table_attr, table_header);
+ result =
+ sysfs_create_bin_file(&tables_kobj,
+ &table_attr->attr);
+ if (result) {
+ kfree(table_attr);
+ return result;
+ } else
+ list_add_tail(&table_attr->node,
+ &acpi_table_attr_list);
+ }
+ } while (!result);
+
+ return 0;
+}
+
+/* --------------------------------------------------------------------------
FS Interface (/proc)
-------------------------------------------------------------------------- */
#ifdef CONFIG_ACPI_PROCFS
+#define ACPI_SYSTEM_FILE_INFO "info"
+#define ACPI_SYSTEM_FILE_EVENT "event"
+#define ACPI_SYSTEM_FILE_DSDT "dsdt"
+#define ACPI_SYSTEM_FILE_FADT "fadt"
static int acpi_system_read_info(struct seq_file *seq, void *offset)
{
@@ -80,7 +194,6 @@ static const struct file_operations acpi
.llseek = seq_lseek,
.release = single_release,
};
-#endif
static ssize_t acpi_system_read_dsdt(struct file *, char __user *, size_t,
loff_t *);
@@ -97,13 +210,11 @@ acpi_system_read_dsdt(struct file *file,
struct acpi_table_header *dsdt = NULL;
ssize_t res;
-
status = acpi_get_table(ACPI_SIG_DSDT, 1, &dsdt);
if (ACPI_FAILURE(status))
return -ENODEV;
- res = simple_read_from_buffer(buffer, count, ppos,
- dsdt, dsdt->length);
+ res = simple_read_from_buffer(buffer, count, ppos, dsdt, dsdt->length);
return res;
}
@@ -123,28 +234,21 @@ acpi_system_read_fadt(struct file *file,
struct acpi_table_header *fadt = NULL;
ssize_t res;
-
status = acpi_get_table(ACPI_SIG_FADT, 1, &fadt);
if (ACPI_FAILURE(status))
return -ENODEV;
- res = simple_read_from_buffer(buffer, count, ppos,
- fadt, fadt->length);
+ res = simple_read_from_buffer(buffer, count, ppos, fadt, fadt->length);
return res;
}
-static int __init acpi_system_init(void)
+static int acpi_system_procfs_init(void)
{
struct proc_dir_entry *entry;
int error = 0;
char *name;
-
- if (acpi_disabled)
- return 0;
-
-#ifdef CONFIG_ACPI_PROCFS
/* 'info' [R] */
name = ACPI_SYSTEM_FILE_INFO;
entry = create_proc_entry(name, S_IRUGO, acpi_root_dir);
@@ -153,7 +257,6 @@ static int __init acpi_system_init(void)
else {
entry->proc_fops = &acpi_system_info_ops;
}
-#endif
/* 'dsdt' [R] */
name = ACPI_SYSTEM_FILE_DSDT;
@@ -177,12 +280,32 @@ static int __init acpi_system_init(void)
Error:
remove_proc_entry(ACPI_SYSTEM_FILE_FADT, acpi_root_dir);
remove_proc_entry(ACPI_SYSTEM_FILE_DSDT, acpi_root_dir);
-#ifdef CONFIG_ACPI_PROCFS
remove_proc_entry(ACPI_SYSTEM_FILE_INFO, acpi_root_dir);
-#endif
error = -EFAULT;
goto Done;
}
+#else
+static int acpi_system_procfs_init(void)
+{
+ return 0;
+}
+#endif
+
+static int __init acpi_system_init(void)
+{
+ int result = 0;
+
+ if (acpi_disabled)
+ return 0;
+
+ result = acpi_system_procfs_init();
+ if (result)
+ return result;
+
+ result = acpi_system_sysfs_init();
+
+ return result;
+}
subsys_initcall(acpi_system_init);
-
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