ACPI / debugger: Add module support for ACPI debugger
This patch converts AML debugger into a loadable module.
Note that, it implements driver unloading at the level dependent on the
module reference count. Which means if ACPI debugger is being used by a
userspace program, "rmmod acpi_dbg" should result in failure.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/acpi_dbg.c b/drivers/acpi/acpi_dbg.c
index abc23b2..381beb2 100644
--- a/drivers/acpi/acpi_dbg.c
+++ b/drivers/acpi/acpi_dbg.c
@@ -21,7 +21,7 @@
#include <linux/proc_fs.h>
#include <linux/debugfs.h>
#include <linux/circ_buf.h>
-#include <linux/acpi_dbg.h>
+#include <linux/acpi.h>
#include "internal.h"
#define ACPI_AML_BUF_ALIGN (sizeof (acpi_size))
@@ -307,7 +307,7 @@
* the debugger output and store the output into the debugger interface
* buffer. Return the size of stored logs or errno.
*/
-ssize_t acpi_aml_write_log(const char *msg)
+static ssize_t acpi_aml_write_log(const char *msg)
{
int ret = 0;
int count = 0, size = 0;
@@ -337,7 +337,6 @@
}
return size > 0 ? size : ret;
}
-EXPORT_SYMBOL(acpi_aml_write_log);
/*
* acpi_aml_read_cmd() - Capture debugger input
@@ -348,7 +347,7 @@
* the debugger input commands and store the input commands into the
* debugger interface buffer. Return the size of stored commands or errno.
*/
-ssize_t acpi_aml_read_cmd(char *msg, size_t count)
+static ssize_t acpi_aml_read_cmd(char *msg, size_t count)
{
int ret = 0;
int size = 0;
@@ -390,7 +389,6 @@
}
return size > 0 ? size : ret;
}
-EXPORT_SYMBOL(acpi_aml_read_cmd);
static int acpi_aml_thread(void *unsed)
{
@@ -427,7 +425,7 @@
* This function should be used to implement acpi_os_execute() which is
* used by the ACPICA debugger to create the debugger thread.
*/
-int acpi_aml_create_thread(acpi_osd_exec_callback function, void *context)
+static int acpi_aml_create_thread(acpi_osd_exec_callback function, void *context)
{
struct task_struct *t;
@@ -449,30 +447,27 @@
mutex_unlock(&acpi_aml_io.lock);
return 0;
}
-EXPORT_SYMBOL(acpi_aml_create_thread);
-int acpi_aml_wait_command_ready(void)
+static int acpi_aml_wait_command_ready(bool single_step,
+ char *buffer, size_t length)
{
acpi_status status;
- if (!acpi_gbl_method_executing)
- acpi_os_printf("\n%1c ", ACPI_DEBUGGER_COMMAND_PROMPT);
- else
+ if (single_step)
acpi_os_printf("\n%1c ", ACPI_DEBUGGER_EXECUTE_PROMPT);
+ else
+ acpi_os_printf("\n%1c ", ACPI_DEBUGGER_COMMAND_PROMPT);
- status = acpi_os_get_line(acpi_gbl_db_line_buf,
- ACPI_DB_LINE_BUFFER_SIZE, NULL);
+ status = acpi_os_get_line(buffer, length, NULL);
if (ACPI_FAILURE(status))
return -EINVAL;
return 0;
}
-EXPORT_SYMBOL(acpi_aml_wait_command_ready);
-int acpi_aml_notify_command_complete(void)
+static int acpi_aml_notify_command_complete(void)
{
return 0;
}
-EXPORT_SYMBOL(acpi_aml_notify_command_complete);
static int acpi_aml_open(struct inode *inode, struct file *file)
{
@@ -746,10 +741,23 @@
.llseek = generic_file_llseek,
};
+static const struct acpi_debugger_ops acpi_aml_debugger = {
+ .create_thread = acpi_aml_create_thread,
+ .read_cmd = acpi_aml_read_cmd,
+ .write_log = acpi_aml_write_log,
+ .wait_command_ready = acpi_aml_wait_command_ready,
+ .notify_command_complete = acpi_aml_notify_command_complete,
+};
+
int __init acpi_aml_init(void)
{
- if (!acpi_debugfs_dir)
- return -ENOENT;
+ int ret = 0;
+
+ if (!acpi_debugfs_dir) {
+ ret = -ENOENT;
+ goto err_exit;
+ }
+
/* Initialize AML IO interface */
mutex_init(&acpi_aml_io.lock);
init_waitqueue_head(&acpi_aml_io.wait);
@@ -759,21 +767,39 @@
S_IFREG | S_IRUGO | S_IWUSR,
acpi_debugfs_dir, NULL,
&acpi_aml_operations);
- if (acpi_aml_dentry == NULL)
- return -ENODEV;
+ if (acpi_aml_dentry == NULL) {
+ ret = -ENODEV;
+ goto err_exit;
+ }
+ ret = acpi_register_debugger(THIS_MODULE, &acpi_aml_debugger);
+ if (ret)
+ goto err_fs;
acpi_aml_initialized = true;
- return 0;
+
+err_fs:
+ if (ret) {
+ debugfs_remove(acpi_aml_dentry);
+ acpi_aml_dentry = NULL;
+ }
+err_exit:
+ return ret;
}
-#if 0
void __exit acpi_aml_exit(void)
{
- /* TODO: Stop the in kernel debugger */
- if (acpi_aml_dentry)
- debugfs_remove(acpi_aml_dentry);
- acpi_aml_initialized = false;
+ if (acpi_aml_initialized) {
+ acpi_unregister_debugger(&acpi_aml_debugger);
+ if (acpi_aml_dentry) {
+ debugfs_remove(acpi_aml_dentry);
+ acpi_aml_dentry = NULL;
+ }
+ acpi_aml_initialized = false;
+ }
}
module_init(acpi_aml_init);
module_exit(acpi_aml_exit);
-#endif
+
+MODULE_AUTHOR("Lv Zheng");
+MODULE_DESCRIPTION("ACPI debugger userspace IO driver");
+MODULE_LICENSE("GPL");