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/Kconfig b/drivers/acpi/Kconfig
index 2a7e6d4..82b96ee 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -60,13 +60,23 @@
config ACPI_DEBUGGER
bool "AML debugger interface"
select ACPI_DEBUG
- depends on DEBUG_FS
help
- Enable in-kernel debugging of AML facilities: statistics, internal
- object dump, single step control method execution.
+ Enable in-kernel debugging of AML facilities: statistics,
+ internal object dump, single step control method execution.
This is still under development, currently enabling this only
results in the compilation of the ACPICA debugger files.
+if ACPI_DEBUGGER
+
+config ACPI_DEBUGGER_USER
+ tristate "Userspace debugger accessiblity"
+ depends on DEBUG_FS
+ help
+ Export /sys/kernel/debug/acpi/acpidbg for userspace utilities
+ to access the debugger functionalities.
+
+endif
+
config ACPI_SLEEP
bool
depends on SUSPEND || HIBERNATION
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 102b5e6..c6f236f 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -50,7 +50,6 @@
acpi-y += property.o
acpi-$(CONFIG_X86) += acpi_cmos_rtc.o
acpi-$(CONFIG_DEBUG_FS) += debugfs.o
-acpi-$(CONFIG_ACPI_DEBUGGER) += acpi_dbg.o
acpi-$(CONFIG_ACPI_NUMA) += numa.o
acpi-$(CONFIG_ACPI_PROCFS_POWER) += cm_sbs.o
acpi-y += acpi_lpat.o
@@ -80,6 +79,7 @@
obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o
obj-$(CONFIG_ACPI_BGRT) += bgrt.o
obj-$(CONFIG_ACPI_CPPC_LIB) += cppc_acpi.o
+obj-$(CONFIG_ACPI_DEBUGGER_USER) += acpi_dbg.o
# processor has its own "processor." module_param namespace
processor-y := processor_driver.o
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");
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 06fbba9..1a40111 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -37,7 +37,6 @@
#include <acpi/apei.h>
#include <linux/dmi.h>
#include <linux/suspend.h>
-#include <linux/acpi_dbg.h>
#include "internal.h"
@@ -1095,7 +1094,7 @@
acpi_debugfs_init();
acpi_sleep_proc_init();
acpi_wakeup_device_init();
- acpi_aml_init();
+ acpi_debugger_init();
return 0;
}
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 4c13398..bb66093 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -40,7 +40,6 @@
#include <linux/list.h>
#include <linux/jiffies.h>
#include <linux/semaphore.h>
-#include <linux/acpi_dbg.h>
#include <asm/io.h>
#include <asm/uaccess.h>
@@ -221,6 +220,7 @@
acpi_os_vprintf(fmt, args);
va_end(args);
}
+EXPORT_SYMBOL(acpi_os_printf);
void acpi_os_vprintf(const char *fmt, va_list args)
{
@@ -235,7 +235,7 @@
printk(KERN_CONT "%s", buffer);
}
#else
- if (acpi_aml_write_log(buffer) < 0)
+ if (acpi_debugger_write_log(buffer) < 0)
printk(KERN_CONT "%s", buffer);
#endif
}
@@ -1103,6 +1103,200 @@
kfree(dpc);
}
+#ifdef CONFIG_ACPI_DEBUGGER
+static struct acpi_debugger acpi_debugger;
+static bool acpi_debugger_initialized;
+
+int acpi_register_debugger(struct module *owner,
+ const struct acpi_debugger_ops *ops)
+{
+ int ret = 0;
+
+ mutex_lock(&acpi_debugger.lock);
+ if (acpi_debugger.ops) {
+ ret = -EBUSY;
+ goto err_lock;
+ }
+
+ acpi_debugger.owner = owner;
+ acpi_debugger.ops = ops;
+
+err_lock:
+ mutex_unlock(&acpi_debugger.lock);
+ return ret;
+}
+EXPORT_SYMBOL(acpi_register_debugger);
+
+void acpi_unregister_debugger(const struct acpi_debugger_ops *ops)
+{
+ mutex_lock(&acpi_debugger.lock);
+ if (ops == acpi_debugger.ops) {
+ acpi_debugger.ops = NULL;
+ acpi_debugger.owner = NULL;
+ }
+ mutex_unlock(&acpi_debugger.lock);
+}
+EXPORT_SYMBOL(acpi_unregister_debugger);
+
+int acpi_debugger_create_thread(acpi_osd_exec_callback function, void *context)
+{
+ int ret;
+ int (*func)(acpi_osd_exec_callback, void *);
+ struct module *owner;
+
+ if (!acpi_debugger_initialized)
+ return -ENODEV;
+ mutex_lock(&acpi_debugger.lock);
+ if (!acpi_debugger.ops) {
+ ret = -ENODEV;
+ goto err_lock;
+ }
+ if (!try_module_get(acpi_debugger.owner)) {
+ ret = -ENODEV;
+ goto err_lock;
+ }
+ func = acpi_debugger.ops->create_thread;
+ owner = acpi_debugger.owner;
+ mutex_unlock(&acpi_debugger.lock);
+
+ ret = func(function, context);
+
+ mutex_lock(&acpi_debugger.lock);
+ module_put(owner);
+err_lock:
+ mutex_unlock(&acpi_debugger.lock);
+ return ret;
+}
+
+ssize_t acpi_debugger_write_log(const char *msg)
+{
+ ssize_t ret;
+ ssize_t (*func)(const char *);
+ struct module *owner;
+
+ if (!acpi_debugger_initialized)
+ return -ENODEV;
+ mutex_lock(&acpi_debugger.lock);
+ if (!acpi_debugger.ops) {
+ ret = -ENODEV;
+ goto err_lock;
+ }
+ if (!try_module_get(acpi_debugger.owner)) {
+ ret = -ENODEV;
+ goto err_lock;
+ }
+ func = acpi_debugger.ops->write_log;
+ owner = acpi_debugger.owner;
+ mutex_unlock(&acpi_debugger.lock);
+
+ ret = func(msg);
+
+ mutex_lock(&acpi_debugger.lock);
+ module_put(owner);
+err_lock:
+ mutex_unlock(&acpi_debugger.lock);
+ return ret;
+}
+
+ssize_t acpi_debugger_read_cmd(char *buffer, size_t buffer_length)
+{
+ ssize_t ret;
+ ssize_t (*func)(char *, size_t);
+ struct module *owner;
+
+ if (!acpi_debugger_initialized)
+ return -ENODEV;
+ mutex_lock(&acpi_debugger.lock);
+ if (!acpi_debugger.ops) {
+ ret = -ENODEV;
+ goto err_lock;
+ }
+ if (!try_module_get(acpi_debugger.owner)) {
+ ret = -ENODEV;
+ goto err_lock;
+ }
+ func = acpi_debugger.ops->read_cmd;
+ owner = acpi_debugger.owner;
+ mutex_unlock(&acpi_debugger.lock);
+
+ ret = func(buffer, buffer_length);
+
+ mutex_lock(&acpi_debugger.lock);
+ module_put(owner);
+err_lock:
+ mutex_unlock(&acpi_debugger.lock);
+ return ret;
+}
+
+int acpi_debugger_wait_command_ready(void)
+{
+ int ret;
+ int (*func)(bool, char *, size_t);
+ struct module *owner;
+
+ if (!acpi_debugger_initialized)
+ return -ENODEV;
+ mutex_lock(&acpi_debugger.lock);
+ if (!acpi_debugger.ops) {
+ ret = -ENODEV;
+ goto err_lock;
+ }
+ if (!try_module_get(acpi_debugger.owner)) {
+ ret = -ENODEV;
+ goto err_lock;
+ }
+ func = acpi_debugger.ops->wait_command_ready;
+ owner = acpi_debugger.owner;
+ mutex_unlock(&acpi_debugger.lock);
+
+ ret = func(acpi_gbl_method_executing,
+ acpi_gbl_db_line_buf, ACPI_DB_LINE_BUFFER_SIZE);
+
+ mutex_lock(&acpi_debugger.lock);
+ module_put(owner);
+err_lock:
+ mutex_unlock(&acpi_debugger.lock);
+ return ret;
+}
+
+int acpi_debugger_notify_command_complete(void)
+{
+ int ret;
+ int (*func)(void);
+ struct module *owner;
+
+ if (!acpi_debugger_initialized)
+ return -ENODEV;
+ mutex_lock(&acpi_debugger.lock);
+ if (!acpi_debugger.ops) {
+ ret = -ENODEV;
+ goto err_lock;
+ }
+ if (!try_module_get(acpi_debugger.owner)) {
+ ret = -ENODEV;
+ goto err_lock;
+ }
+ func = acpi_debugger.ops->notify_command_complete;
+ owner = acpi_debugger.owner;
+ mutex_unlock(&acpi_debugger.lock);
+
+ ret = func();
+
+ mutex_lock(&acpi_debugger.lock);
+ module_put(owner);
+err_lock:
+ mutex_unlock(&acpi_debugger.lock);
+ return ret;
+}
+
+int __init acpi_debugger_init(void)
+{
+ mutex_init(&acpi_debugger.lock);
+ acpi_debugger_initialized = true;
+ return 0;
+}
+#endif
+
/*******************************************************************************
*
* FUNCTION: acpi_os_execute
@@ -1130,7 +1324,7 @@
function, context));
if (type == OSL_DEBUGGER_MAIN_THREAD) {
- ret = acpi_aml_create_thread(function, context);
+ ret = acpi_debugger_create_thread(function, context);
if (ret) {
pr_err("Call to kthread_create() failed.\n");
status = AE_ERROR;
@@ -1380,7 +1574,7 @@
#else
int ret;
- ret = acpi_aml_read_cmd(buffer, buffer_length);
+ ret = acpi_debugger_read_cmd(buffer, buffer_length);
if (ret < 0)
return AE_ERROR;
if (bytes_read)
@@ -1389,12 +1583,13 @@
return AE_OK;
}
+EXPORT_SYMBOL(acpi_os_get_line);
acpi_status acpi_os_wait_command_ready(void)
{
int ret;
- ret = acpi_aml_wait_command_ready();
+ ret = acpi_debugger_wait_command_ready();
if (ret < 0)
return AE_ERROR;
return AE_OK;
@@ -1404,7 +1599,7 @@
{
int ret;
- ret = acpi_aml_notify_command_complete();
+ ret = acpi_debugger_notify_command_complete();
if (ret < 0)
return AE_ERROR;
return AE_OK;