c637e4861c
Introduce module parameter acpi.aml_debug_output. With acpi.aml_debug_output set, we can get AML debug object output (Store (AAA, Debug)), even with CONFIG_ACPI_DEBUG cleared. Together with the runtime custom method mechanism, we can debug AML code problems without rebuilding the kernel. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
93 lines
1.9 KiB
C
93 lines
1.9 KiB
C
/*
|
|
* debugfs.c - ACPI debugfs interface to userspace.
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/debugfs.h>
|
|
#include <acpi/acpi_drivers.h>
|
|
|
|
#define _COMPONENT ACPI_SYSTEM_COMPONENT
|
|
ACPI_MODULE_NAME("debugfs");
|
|
|
|
|
|
/* /sys/modules/acpi/parameters/aml_debug_output */
|
|
|
|
module_param_named(aml_debug_output, acpi_gbl_enable_aml_debug_object,
|
|
bool, 0644);
|
|
MODULE_PARM_DESC(aml_debug_output,
|
|
"To enable/disable the ACPI Debug Object output.");
|
|
|
|
/* /sys/kernel/debug/acpi/custom_method */
|
|
|
|
static ssize_t cm_write(struct file *file, const char __user * user_buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
static char *buf;
|
|
static int uncopied_bytes;
|
|
struct acpi_table_header table;
|
|
acpi_status status;
|
|
|
|
if (!(*ppos)) {
|
|
/* parse the table header to get the table length */
|
|
if (count <= sizeof(struct acpi_table_header))
|
|
return -EINVAL;
|
|
if (copy_from_user(&table, user_buf,
|
|
sizeof(struct acpi_table_header)))
|
|
return -EFAULT;
|
|
uncopied_bytes = table.length;
|
|
buf = kzalloc(uncopied_bytes, GFP_KERNEL);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
if (uncopied_bytes < count) {
|
|
kfree(buf);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (copy_from_user(buf + (*ppos), user_buf, count)) {
|
|
kfree(buf);
|
|
return -EFAULT;
|
|
}
|
|
|
|
uncopied_bytes -= count;
|
|
*ppos += count;
|
|
|
|
if (!uncopied_bytes) {
|
|
status = acpi_install_method(buf);
|
|
kfree(buf);
|
|
if (ACPI_FAILURE(status))
|
|
return -EINVAL;
|
|
add_taint(TAINT_OVERRIDDEN_ACPI_TABLE);
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|
|
static const struct file_operations cm_fops = {
|
|
.write = cm_write,
|
|
};
|
|
|
|
int __init acpi_debugfs_init(void)
|
|
{
|
|
struct dentry *acpi_dir, *cm_dentry;
|
|
|
|
acpi_dir = debugfs_create_dir("acpi", NULL);
|
|
if (!acpi_dir)
|
|
goto err;
|
|
|
|
cm_dentry = debugfs_create_file("custom_method", S_IWUGO,
|
|
acpi_dir, NULL, &cm_fops);
|
|
if (!cm_dentry)
|
|
goto err;
|
|
|
|
return 0;
|
|
|
|
err:
|
|
if (acpi_dir)
|
|
debugfs_remove(acpi_dir);
|
|
return -EINVAL;
|
|
}
|