ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/drivers/acpi/custom_method.c b/marvell/linux/drivers/acpi/custom_method.c
new file mode 100644
index 0000000..e7716c7
--- /dev/null
+++ b/marvell/linux/drivers/acpi/custom_method.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * custom_method.c - debugfs interface for customizing ACPI control method
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/uaccess.h>
+#include <linux/debugfs.h>
+#include <linux/acpi.h>
+#include <linux/security.h>
+
+#include "internal.h"
+
+#define _COMPONENT ACPI_SYSTEM_COMPONENT
+ACPI_MODULE_NAME("custom_method");
+MODULE_LICENSE("GPL");
+
+static struct dentry *cm_dentry;
+
+/* /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 u32 max_size;
+ static u32 uncopied_bytes;
+
+ struct acpi_table_header table;
+ acpi_status status;
+ int ret;
+
+ ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
+ if (ret)
+ return ret;
+
+ 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 = max_size = table.length;
+ /* make sure the buf is not allocated */
+ kfree(buf);
+ buf = kzalloc(max_size, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+ }
+
+ if (buf == NULL)
+ return -EINVAL;
+
+ if ((*ppos > max_size) ||
+ (*ppos + count > max_size) ||
+ (*ppos + count < count) ||
+ (count > uncopied_bytes)) {
+ kfree(buf);
+ buf = NULL;
+ return -EINVAL;
+ }
+
+ if (copy_from_user(buf + (*ppos), user_buf, count)) {
+ kfree(buf);
+ buf = NULL;
+ return -EFAULT;
+ }
+
+ uncopied_bytes -= count;
+ *ppos += count;
+
+ if (!uncopied_bytes) {
+ status = acpi_install_method(buf);
+ kfree(buf);
+ buf = NULL;
+ if (ACPI_FAILURE(status))
+ return -EINVAL;
+ add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
+ }
+
+ return count;
+}
+
+static const struct file_operations cm_fops = {
+ .write = cm_write,
+ .llseek = default_llseek,
+};
+
+static int __init acpi_custom_method_init(void)
+{
+ cm_dentry = debugfs_create_file("custom_method", S_IWUSR,
+ acpi_debugfs_dir, NULL, &cm_fops);
+ return 0;
+}
+
+static void __exit acpi_custom_method_exit(void)
+{
+ debugfs_remove(cm_dentry);
+}
+
+module_init(acpi_custom_method_init);
+module_exit(acpi_custom_method_exit);