api: spinlock_recursive: added recursive spinlock

Applications can use recursive spinlocks to avoid deadlock from
single thread acquiring the same lock multiple times. Recursive
locks are used in legacy applications. ODP version of recursive
spinlock enable porting of those applications.

Signed-off-by: Petri Savolainen <petri.savolainen@nokia.com>
Reviewed-by: Bill Fischofer <bill.fischofer@linaro.org>
Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>

Conflicts:
	platform/linux-generic/Makefile.am

7 files changed, 232 insertions, 0 deletions

diff --git a/include/odp.h b/include/odp.h
index fe1dc7459..b47ab8231 100644
--- a/include/odp.h
+++ b/include/odp.h
@@ -54,6 +54,7 @@ extern "C" {
 #include <odp/random.h>
 #include <odp/errno.h>
 #include <odp/thrmask.h>
+#include <odp/spinlock_recursive.h>
 
 #ifdef __cplusplus
 }
diff --git a/include/odp/api/spinlock_recursive.h b/include/odp/api/spinlock_recursive.h
new file mode 100644
index 000000000..46b6be762
--- /dev/null
+++ b/include/odp/api/spinlock_recursive.h
@@ -0,0 +1,82 @@
+/* Copyright (c) 2015, Linaro Limited
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier:     BSD-3-Clause
+ */
+
+/**
+ * @file
+ *
+ * ODP recursive spinlock
+ */
+
+#ifndef ODP_API_SPINLOCK_RECURSIVE_H_
+#define ODP_API_SPINLOCK_RECURSIVE_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** @addtogroup odp_synchronizers
+ *  Operations on recursive spinlocks.
+ *  @{
+ */
+
+/**
+ * @typedef odp_spinlock_recursive_t
+ * Recursive spinlock
+ *
+ * A thread can acquire the lock multiple times without a deadlock. To release
+ * the lock, the thread must unlock it the same number of times.
+ */
+
+/**
+ * Initialize recursive spinlock.
+ *
+ * @param lock    Pointer to a lock
+ */
+void odp_spinlock_recursive_init(odp_spinlock_recursive_t *lock);
+
+/**
+ * Acquire recursive spinlock.
+ *
+ * @param lock    Pointer to a lock
+ */
+void odp_spinlock_recursive_lock(odp_spinlock_recursive_t *lock);
+
+/**
+ * Try to acquire recursive spinlock.
+ *
+ * @param lock    Pointer to a lock
+ *
+ * @retval 1 lock acquired
+ * @retval 0 lock not acquired
+ */
+int odp_spinlock_recursive_trylock(odp_spinlock_recursive_t *lock);
+
+/**
+ * Release recursive spinlock.
+ *
+ * @param lock    Pointer to a lock
+ */
+void odp_spinlock_recursive_unlock(odp_spinlock_recursive_t *lock);
+
+/**
+ * Check if recursive spinlock is locked.
+ *
+ * @param lock    Pointer to a lock
+ *
+ * @retval 1 lock is locked
+ * @retval 0 lock is not locked
+ */
+int odp_spinlock_recursive_is_locked(odp_spinlock_recursive_t *lock);
+
+/**
+ * @}
+ */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/platform/Makefile.inc b/platform/Makefile.inc
index 5d589b1b0..cc86b993a 100644
--- a/platform/Makefile.inc
+++ b/platform/Makefile.inc
@@ -45,6 +45,7 @@ odpapiinclude_HEADERS = \
 		  $(top_srcdir)/include/odp/api/schedule_types.h \
 		  $(top_srcdir)/include/odp/api/shared_memory.h \
 		  $(top_srcdir)/include/odp/api/spinlock.h \
+		  $(top_srcdir)/include/odp/api/spinlock_recursive.h \
 		  $(top_srcdir)/include/odp/api/std_types.h \
 		  $(top_srcdir)/include/odp/api/sync.h \
 		  $(top_srcdir)/include/odp/api/system_info.h \
diff --git a/platform/linux-generic/Makefile.am b/platform/linux-generic/Makefile.am
index a0de35b03..8bcd6a943 100644
--- a/platform/linux-generic/Makefile.am
+++ b/platform/linux-generic/Makefile.am
@@ -39,6 +39,7 @@ odpinclude_HEADERS = \
 		  $(srcdir)/include/odp/schedule_types.h \
 		  $(srcdir)/include/odp/shared_memory.h \
 		  $(srcdir)/include/odp/spinlock.h \
+		  $(srcdir)/include/odp/spinlock_recursive.h \
 		  $(srcdir)/include/odp/std_types.h \
 		  $(srcdir)/include/odp/sync.h \
 		  $(srcdir)/include/odp/system_info.h \
@@ -67,6 +68,7 @@ odpplatinclude_HEADERS = \
 		  $(srcdir)/include/odp/plat/schedule_types.h \
 		  $(srcdir)/include/odp/plat/shared_memory_types.h \
 		  $(srcdir)/include/odp/plat/spinlock_types.h \
+		  $(srcdir)/include/odp/plat/spinlock_recursive_types.h \
 		  $(srcdir)/include/odp/plat/strong_types.h \
 		  $(srcdir)/include/odp/plat/thread_types.h \
 		  $(srcdir)/include/odp/plat/thrmask_types.h \
@@ -129,6 +131,7 @@ __LIB__libodp_la_SOURCES = \
 			   odp_schedule.c \
 			   odp_shared_memory.c \
 			   odp_spinlock.c \
+			   odp_spinlock_recursive.c \
 			   odp_system_info.c \
 			   odp_thread.c \
 			   odp_thrmask.c \
diff --git a/platform/linux-generic/include/odp/plat/spinlock_recursive_types.h b/platform/linux-generic/include/odp/plat/spinlock_recursive_types.h
new file mode 100644
index 000000000..cae47a4b1
--- /dev/null
+++ b/platform/linux-generic/include/odp/plat/spinlock_recursive_types.h
@@ -0,0 +1,47 @@
+/* Copyright (c) 2015, Linaro Limited
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier:     BSD-3-Clause
+ */
+
+/**
+ * @file
+ *
+ * ODP recursive spinlock
+ */
+
+#ifndef ODP_SPINLOCK_RECURSIVE_TYPES_H_
+#define ODP_SPINLOCK_RECURSIVE_TYPES_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <odp/spinlock.h>
+#include <odp/std_types.h>
+
+/**
+ * @internal
+ * ODP recursive spinlock
+ */
+struct odp_spinlock_recursive_s {
+	odp_spinlock_t lock; /**< the lock */
+	int owner;           /**< thread owning the lock */
+	uint32_t cnt;        /**< recursion count */
+};
+
+/** @addtogroup odp_synchronizers
+ *  @{
+ */
+
+typedef struct odp_spinlock_recursive_s odp_spinlock_recursive_t;
+
+/**
+ * @}
+ */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/platform/linux-generic/include/odp/spinlock_recursive.h b/platform/linux-generic/include/odp/spinlock_recursive.h
new file mode 100644
index 000000000..e8a996837
--- /dev/null
+++ b/platform/linux-generic/include/odp/spinlock_recursive.h
@@ -0,0 +1,28 @@
+/* Copyright (c) 2015, Linaro Limited
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier:     BSD-3-Clause
+ */
+
+/**
+ * @file
+ *
+ * ODP resursive spinlock
+ */
+
+#ifndef ODP_PLAT_SPINLOCK_RECURSIVE_H_
+#define ODP_PLAT_SPINLOCK_RECURSIVE_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <odp/plat/spinlock_recursive_types.h>
+
+#include <odp/api/spinlock_recursive.h>
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/platform/linux-generic/odp_spinlock_recursive.c b/platform/linux-generic/odp_spinlock_recursive.c
new file mode 100644
index 000000000..8ffe6b3dd
--- /dev/null
+++ b/platform/linux-generic/odp_spinlock_recursive.c
@@ -0,0 +1,70 @@
+/* Copyright (c) 2013, Linaro Limited
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier:     BSD-3-Clause
+ */
+
+#include <odp/spinlock_recursive.h>
+#include <odp/thread.h>
+
+#define NO_OWNER (-1)
+
+void odp_spinlock_recursive_init(odp_spinlock_recursive_t *rlock)
+{
+	odp_spinlock_init(&rlock->lock);
+	rlock->owner = NO_OWNER;
+	rlock->cnt   = 0;
+}
+
+void odp_spinlock_recursive_lock(odp_spinlock_recursive_t *rlock)
+{
+	int thr = odp_thread_id();
+
+	if (rlock->owner == thr) {
+		rlock->cnt++;
+		return;
+	}
+
+	odp_spinlock_lock(&rlock->lock);
+	rlock->owner = thr;
+	rlock->cnt   = 1;
+}
+
+int odp_spinlock_recursive_trylock(odp_spinlock_recursive_t *rlock)
+{
+	int thr = odp_thread_id();
+
+	if (rlock->owner == thr) {
+		rlock->cnt++;
+		return 1;
+	}
+
+	if (odp_spinlock_trylock(&rlock->lock)) {
+		rlock->owner = thr;
+		rlock->cnt   = 1;
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
+void odp_spinlock_recursive_unlock(odp_spinlock_recursive_t *rlock)
+{
+	rlock->cnt--;
+
+	if (rlock->cnt > 0)
+		return;
+
+	rlock->owner = NO_OWNER;
+	odp_spinlock_unlock(&rlock->lock);
+}
+
+int odp_spinlock_recursive_is_locked(odp_spinlock_recursive_t *rlock)
+{
+	int thr = odp_thread_id();
+
+	if (rlock->owner == thr)
+		return 1;
+
+	return odp_spinlock_is_locked(&rlock->lock);
+}