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/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;