dept: Add lock dependency tracker APIs

Wrapped the base APIs for easier annotation on typical lock.

Signed-off-by: Byungchul Park <max.byungchul.park@gmail.com>

include/linux/dept_ldt.h

@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Lock Dependency Tracker
+ *
+ * Started by Byungchul Park <max.byungchul.park@gmail.com>:
+ *
+ *  Copyright (c) 2020 LG Electronics, Inc., Byungchul Park
+ */
+
+#ifndef __LINUX_DEPT_LDT_H
+#define __LINUX_DEPT_LDT_H
+
+#include <linux/dept.h>
+
+#ifdef CONFIG_DEPT
+#define LDT_EVT_L			1UL
+#define LDT_EVT_R			2UL
+#define LDT_EVT_W			1UL
+#define LDT_EVT_RW			(LDT_EVT_R | LDT_EVT_W)
+#define LDT_EVT_ALL			(LDT_EVT_L | LDT_EVT_RW)
+
+#define ldt_init(m, k, su, n)		dept_map_init(m, k, su, n)
+#define ldt_lock(m, sl, t, n, i)					\
+	do {								\
+		if (n)							\
+			dept_ecxt_enter_nokeep(m);			\
+		else if (t)						\
+			dept_ecxt_enter(m, LDT_EVT_L, i, "trylock", "unlock", sl);\
+		else {							\
+			dept_wait(m, LDT_EVT_L, i, "lock", sl);		\
+			dept_ecxt_enter(m, LDT_EVT_L, i, "lock", "unlock", sl);\
+		}							\
+	} while (0)
+
+#define ldt_rlock(m, sl, t, n, i, q)					\
+	do {								\
+		if (n)							\
+			dept_ecxt_enter_nokeep(m);			\
+		else if (t)						\
+			dept_ecxt_enter(m, LDT_EVT_R, i, "read_trylock", "read_unlock", sl);\
+		else {							\
+			dept_wait(m, q ? LDT_EVT_RW : LDT_EVT_W, i, "read_lock", sl);\
+			dept_ecxt_enter(m, LDT_EVT_R, i, "read_lock", "read_unlock", sl);\
+		}							\
+	} while (0)
+
+#define ldt_wlock(m, sl, t, n, i)					\
+	do {								\
+		if (n)							\
+			dept_ecxt_enter_nokeep(m);			\
+		else if (t)						\
+			dept_ecxt_enter(m, LDT_EVT_W, i, "write_trylock", "write_unlock", sl);\
+		else {							\
+			dept_wait(m, LDT_EVT_RW, i, "write_lock", sl);	\
+			dept_ecxt_enter(m, LDT_EVT_W, i, "write_lock", "write_unlock", sl);\
+		}							\
+	} while (0)
+
+#define ldt_unlock(m, i)		dept_ecxt_exit(m, LDT_EVT_ALL, i)
+
+#define ldt_downgrade(m, i)						\
+	do {								\
+		if (dept_ecxt_holding(m, LDT_EVT_W))			\
+			dept_map_ecxt_modify(m, LDT_EVT_W, NULL, LDT_EVT_R, i, "downgrade", "read_unlock", -1);\
+	} while (0)
+
+#define ldt_set_class(m, n, k, sl, i)	dept_map_ecxt_modify(m, LDT_EVT_ALL, k, 0UL, i, "lock_set_class", "(any)unlock", sl)
+#else /* !CONFIG_DEPT */
+#define ldt_init(m, k, su, n)		do { (void)(k); } while (0)
+#define ldt_lock(m, sl, t, n, i)	do { } while (0)
+#define ldt_rlock(m, sl, t, n, i, q)	do { } while (0)
+#define ldt_wlock(m, sl, t, n, i)	do { } while (0)
+#define ldt_unlock(m, i)		do { } while (0)
+#define ldt_downgrade(m, i)		do { } while (0)
+#define ldt_set_class(m, n, k, sl, i)	do { } while (0)
+#endif
+#endif /* __LINUX_DEPT_LDT_H */