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Commit 836d0830 authored by Lv Zheng's avatar Lv Zheng Committed by Rafael J. Wysocki
Browse files

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: default avatarLv Zheng <lv.zheng@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 37645d65

drivers/acpi/Kconfig

+13 −3
Original line number Diff line number Diff line
@@ -60,13 +60,23 @@ config ACPI_CCA_REQUIRED 
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

drivers/acpi/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -50,7 +50,6 @@ acpi-y += sysfs.o 
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-$(CONFIG_ACPI_EC_DEBUGFS) += ec_sys.o 
obj-$(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

drivers/acpi/acpi_dbg.c

+53 −27
Original line number Diff line number Diff line
@@ -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 @@ static int acpi_aml_readb_kern(void) 
 * 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 @@ ssize_t acpi_aml_write_log(const char *msg) 
	}

	return size > 0 ? size : ret;

}

EXPORT_SYMBOL(acpi_aml_write_log);



/*

 * acpi_aml_read_cmd() - Capture debugger input
@@ -348,7 +347,7 @@ EXPORT_SYMBOL(acpi_aml_write_log); 
 * 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 @@ ssize_t acpi_aml_read_cmd(char *msg, size_t count) 
	}

	return size > 0 ? size : ret;

}

EXPORT_SYMBOL(acpi_aml_read_cmd);



static int acpi_aml_thread(void *unsed)

{
@@ -427,7 +425,7 @@ static int acpi_aml_thread(void *unsed) 
 * 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 @@ int acpi_aml_create_thread(acpi_osd_exec_callback function, void *context) 
	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 @@ static const struct file_operations acpi_aml_operations = { 
	.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 @@ int __init acpi_aml_init(void) 
					      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)

	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");

drivers/acpi/bus.c

+1 −2
Original line number Diff line number Diff line
@@ -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 @@ static int __init acpi_init(void) 
	acpi_debugfs_init();

	acpi_sleep_proc_init();

	acpi_wakeup_device_init();

	acpi_aml_init();

	acpi_debugger_init();

	return 0;

}

drivers/acpi/osl.c

+201 −6
Original line number Diff line number Diff line
@@ -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 @@ void acpi_os_printf(const char *fmt, ...) 
	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 @@ void acpi_os_vprintf(const char *fmt, va_list args) 
		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 @@ static void acpi_os_execute_deferred(struct work_struct *work) 
	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 @@ acpi_status acpi_os_execute(acpi_execute_type type, 
			  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 @@ acpi_status acpi_os_get_line(char *buffer, u32 buffer_length, u32 *bytes_read) 
#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 @@ acpi_status acpi_os_get_line(char *buffer, u32 buffer_length, u32 *bytes_read) 


	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 @@ acpi_status acpi_os_notify_command_complete(void) 
{

	int ret;



	ret = acpi_aml_notify_command_complete();

	ret = acpi_debugger_notify_command_complete();

	if (ret < 0)

		return AE_ERROR;

	return AE_OK;