5 files changed, 101 insertions, 4 deletions

diff --git a/include/litmus/locking.h b/include/litmus/locking.h
index e0c13f4c31e5..972cbdb7fdd5 100644
--- a/include/litmus/locking.h
+++ b/include/litmus/locking.h
@@ -36,6 +36,29 @@ struct litmus_lock {
 #endif
 };
 
+#ifdef CONFIG_LITMUS_DGL_SUPPORT
+
+#define MAX_DGL_SIZE CONFIG_LITMUS_MAX_DGL_SIZE
+
+typedef struct dgl_wait_state {
+        struct task_struct *task;
+        struct litmus_lock *locks[MAX_DGL_SIZE];
+        int size;
+        int nr_remaining;
+        
+        int last_primary;
+        
+        wait_queue_t wq_nodes[MAX_DGL_SIZE];
+} dgl_wait_state_t;
+
+void wake_or_wait_on_next_lock(dgl_wait_state_t *dgl_wait);
+void select_next_lock(dgl_wait_state_t* dgl_wait, struct litmus_lock* prev_lock);
+
+void init_dgl_waitqueue_entry(wait_queue_t *wq_node, dgl_wait_state_t* dgl_wait);
+int dgl_wake_up(wait_queue_t *wq_node, unsigned mode, int sync, void *key);
+void __waitqueue_dgl_remove_first(wait_queue_head_t *wq, dgl_wait_state_t** dgl_wait, struct task_struct **task);
+#endif
+
 struct litmus_lock_ops {
         /* Current task tries to obtain / drop a reference to a lock.
          * Optional methods, allowed by default. */
@@ -45,7 +68,7 @@ struct litmus_lock_ops {
         /* Current tries to lock/unlock this lock (mandatory methods). */
         int (*lock)(struct litmus_lock*);
         int (*unlock)(struct litmus_lock*);
-
+        
         /* The lock is no longer being referenced (mandatory method). */
         void (*deallocate)(struct litmus_lock*);
         
@@ -53,6 +76,57 @@ struct litmus_lock_ops {
         void (*propagate_increase_inheritance)(struct litmus_lock* l, struct task_struct* t, raw_spinlock_t* to_unlock, unsigned long irqflags);
         void (*propagate_decrease_inheritance)(struct litmus_lock* l, struct task_struct* t, raw_spinlock_t* to_unlock, unsigned long irqflags);
 #endif
+        
+#ifdef CONFIG_LITMUS_DGL_SUPPORT
+        raw_spinlock_t* (*get_dgl_spin_lock)(struct litmus_lock *l);
+        int (*dgl_lock)(struct litmus_lock *l, dgl_wait_state_t* dgl_wait, wait_queue_t* wq_node);
+        int (*is_owner)(struct litmus_lock *l, struct task_struct *t);
+        void (*enable_priority)(struct litmus_lock *l, dgl_wait_state_t* dgl_wait);
+#endif
 };
 
+
+#ifdef CONFIG_LITMUS_DGL_SUPPORT
+#define lock_global_irqsave(lock, flags)                raw_spin_lock_irqsave((lock), (flags))
+#define lock_global(lock)                                               raw_spin_lock((lock))
+#define unlock_global_irqrestore(lock, flags)   raw_spin_unlock_irqrestore((lock), (flags))
+#define unlock_global(lock)                                             raw_spin_unlock((lock))
+
+/* fine-grain locking are no-ops with DGL support */
+#define lock_fine_irqsave(lock, flags)
+#define lock_fine(lock)
+#define unlock_fine_irqrestore(lock, flags)
+#define unlock_fine(lock)
+
+#elif CONFIG_LITMUS_NESTED_LOCKING
+
+/* global locking are no-ops without DGL support */
+#define lock_global_irqsave(lock, flags)
+#define lock_global(lock)
+#define unlock_global_irqrestore(lock, flags)
+#define unlock_global(lock)
+
+#define lock_fine_irqsave(lock, flags)                  raw_spin_lock_irqsave((lock), (flags))
+#define lock_fine(lock)                                                 raw_spin_lock((lock))
+#define unlock_fine_irqrestore(lock, flags)             raw_spin_unlock_irqrestore((lock), (flags))
+#define unlock_fine(lock)                                               raw_spin_unlock((lock))
+
 #endif
+
+
+#endif
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/include/litmus/sched_plugin.h b/include/litmus/sched_plugin.h
index 6e7cabdddae8..ae11e3ac9266 100644
--- a/include/litmus/sched_plugin.h
+++ b/include/litmus/sched_plugin.h
@@ -58,6 +58,7 @@ typedef void (*task_exit_t)    (struct task_struct *);
 typedef long (*allocate_lock_t) (struct litmus_lock **lock, int type,
                                  void* __user config);
 
+typedef raw_spinlock_t* (*get_dgl_spinlock_t) (struct task_struct *t);
 
 /********************* sys call backends  ********************/
 /* This function causes the caller to sleep until the next release */
@@ -97,6 +98,10 @@ struct sched_plugin {
         /*      locking protocols       */
         allocate_lock_t         allocate_lock;
 #endif
+        
+#ifdef CONFIG_LITMUS_DGL_SUPPORT
+        get_dgl_spinlock_t      get_dgl_spinlock;
+#endif
 } __attribute__ ((__aligned__(SMP_CACHE_BYTES)));
 
 
diff --git a/include/litmus/trace.h b/include/litmus/trace.h
index e809376d6487..1a1b0d479f61 100644
--- a/include/litmus/trace.h
+++ b/include/litmus/trace.h
@@ -103,11 +103,23 @@ feather_callback void save_task_latency(unsigned long event, unsigned long when_
 #define TS_LOCK_START                   TIMESTAMP(170)
 #define TS_LOCK_SUSPEND                 TIMESTAMP(171)
 #define TS_LOCK_RESUME                  TIMESTAMP(172)
-#define TS_LOCK_END                     TIMESTAMP(173)
+#define TS_LOCK_END                             TIMESTAMP(173)
+
+#ifdef CONFIG_LITMUS_DGL_SUPPORT
+#define TS_DGL_LOCK_START                       TIMESTAMP(175)
+#define TS_DGL_LOCK_SUSPEND                     TIMESTAMP(176)
+#define TS_DGL_LOCK_RESUME                      TIMESTAMP(177)
+#define TS_DGL_LOCK_END                         TIMESTAMP(178)
+#endif
 
 #define TS_UNLOCK_START                 TIMESTAMP(180)
 #define TS_UNLOCK_END                   TIMESTAMP(181)
 
+#ifdef CONFIG_LITMUS_DGL_SUPPORT
+#define TS_DGL_UNLOCK_START                     TIMESTAMP(185)
+#define TS_DGL_UNLOCK_END                       TIMESTAMP(186)
+#endif
+
 #define TS_SEND_RESCHED_START(c)        CTIMESTAMP(190, c)
 #define TS_SEND_RESCHED_END             DTIMESTAMP(191, TSK_UNKNOWN)
 
diff --git a/include/litmus/unistd_32.h b/include/litmus/unistd_32.h
index 94264c27d9ac..941231c8184b 100644
--- a/include/litmus/unistd_32.h
+++ b/include/litmus/unistd_32.h
@@ -17,5 +17,7 @@
 #define __NR_wait_for_ts_release __LSC(9)
 #define __NR_release_ts         __LSC(10)
 #define __NR_null_call          __LSC(11)
+#define __NR_litmus_dgl_lock    __LSC(12)
+#define __NR_litmus_dgl_unlock  __LSC(13)
 
-#define NR_litmus_syscalls 12
+#define NR_litmus_syscalls 14
diff --git a/include/litmus/unistd_64.h b/include/litmus/unistd_64.h
index d5ced0d2642c..bf2ffeac2dbb 100644
--- a/include/litmus/unistd_64.h
+++ b/include/litmus/unistd_64.h
@@ -29,5 +29,9 @@ __SYSCALL(__NR_wait_for_ts_release, sys_wait_for_ts_release)
 __SYSCALL(__NR_release_ts, sys_release_ts)
 #define __NR_null_call                          __LSC(11)
 __SYSCALL(__NR_null_call, sys_null_call)
+#define __NR_litmus_dgl_lock            __LSC(12)
+__SYSCALL(__NR_litmus_dgl_lock, sys_litmus_dgl_lock)
+#define __NR_litmus_dgl_unlock          __LSC(13)
+__SYSCALL(__NR_litmus_dgl_unlock, sys_litmus_dgl_unlock)
 
-#define NR_litmus_syscalls 12
+#define NR_litmus_syscalls 14