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

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
......@@ -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
......
......@@ -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
......
......@@ -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)
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");
......@@ -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;
}
......
......@@ -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;
......
......@@ -37,6 +37,8 @@
#include <linux/list.h>
#include <linux/mod_devicetable.h>
#include <linux/dynamic_debug.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
......@@ -119,6 +121,75 @@ typedef int (*acpi_tbl_table_handler)(struct acpi_table_header *table);
typedef int (*acpi_tbl_entry_handler)(struct acpi_subtable_header *header,
const unsigned long end);
/* Debugger support */
struct acpi_debugger_ops {
int (*create_thread)(acpi_osd_exec_callback function, void *context);
ssize_t (*write_log)(const char *msg);
ssize_t (*read_cmd)(char *buffer, size_t length);
int (*wait_command_ready)(bool single_step, char *buffer, size_t length);
int (*notify_command_complete)(void);
};
struct acpi_debugger {
const struct acpi_debugger_ops *ops;
struct module *owner;
struct mutex lock;
};
#ifdef CONFIG_ACPI_DEBUGGER
int __init acpi_debugger_init(void);
int acpi_register_debugger(struct module *owner,
const struct acpi_debugger_ops *ops);
void acpi_unregister_debugger(const struct acpi_debugger_ops *ops);
int acpi_debugger_create_thread(acpi_osd_exec_callback function, void *context);
ssize_t acpi_debugger_write_log(const char *msg);
ssize_t acpi_debugger_read_cmd(char *buffer, size_t buffer_length);
int acpi_debugger_wait_command_ready(void);
int acpi_debugger_notify_command_complete(void);
#else
static inline int acpi_debugger_init(void)
{
return -ENODEV;
}
static inline int acpi_register_debugger(struct module *owner,
const struct acpi_debugger_ops *ops)
{
return -ENODEV;
}
static inline void acpi_unregister_debugger(const struct acpi_debugger_ops *ops)
{
}
static inline int acpi_debugger_create_thread(acpi_osd_exec_callback function,
void *context)
{
return -ENODEV;
}
static inline int acpi_debugger_write_log(const char *msg)
{
return -ENODEV;
}
static inline int acpi_debugger_read_cmd(char *buffer, u32 buffer_length)
{
return -ENODEV;
}
static inline int acpi_debugger_wait_command_ready(void)
{
return -ENODEV;
}
static inline int acpi_debugger_notify_command_complete(void)
{
return -ENODEV;
}
#endif
#ifdef CONFIG_ACPI_INITRD_TABLE_OVERRIDE
void acpi_initrd_override(void *data, size_t size);
#else
......
/*
* ACPI AML interfacing support
*
* Copyright (C) 2015, Intel Corporation
* Authors: Lv Zheng <lv.zheng@intel.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef _LINUX_ACPI_DBG_H
#define _LINUX_ACPI_DBG_H
#include <linux/acpi.h>
#ifdef CONFIG_ACPI_DEBUGGER
int __init acpi_aml_init(void);
int acpi_aml_create_thread(acpi_osd_exec_callback function, void *context);
ssize_t acpi_aml_write_log(const char *msg);
ssize_t acpi_aml_read_cmd(char *buffer, size_t buffer_length);
int acpi_aml_wait_command_ready(void);
int acpi_aml_notify_command_complete(void);
#else
static int inline acpi_aml_init(void)
{
return 0;
}
static inline int acpi_aml_create_thread(acpi_osd_exec_callback function,
void *context)
{
return -ENODEV;
}
static inline int acpi_aml_write_log(const char *msg)
{
return -ENODEV;
}
static inline int acpi_aml_read_cmd(char *buffer, u32 buffer_length)
{
return -ENODEV;
}
static inline int acpi_aml_wait_command_ready(void)
{
return -ENODEV;
}
static inline int acpi_aml_notify_command_complete(void)
{
return -ENODEV;
}
#endif
#endif /* _LINUX_ACPI_DBG_H */
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