Changeset 189 for soft/giet_vm/libs/spin_lock.c

Timestamp:

Aug 7, 2012, 6:37:49 PM (12 years ago)

Author:

alain

Message:

Introducing a new release where all initialisation
is done in the boot code.

File:

• soft/giet_vm/libs/spin_lock.c (modified) (2 diffs)

soft/giet_vm/libs/spin_lock.c

@@ -10 +10 @@
 // It is a simple binary lock, without waiting queue.
 // 
-// The lock_acquire(), lock_try_acquire() and lock_release() functions do 
-// not require a system call.
+// The lock_acquire() and lock_release() functions do not require a system call.
+// The barrier itself must have been allocated in a non cacheable segment,
+// if the platform does not provide hardwate cache coherence.
 //
 // ALL locks must be defined in the mapping_info data structure, 
 // to be initialised by the GIET in the boot phase.
 // The vobj_get_vbase() system call (defined in stdio.c and stdio.h files)
-// can be used to get the virtual base address of the lock from it's name.
+// can be used to get the virtual base address of the lock fro it's name.
 ///////////////////////////////////////////////////////////////////////////////////
 
@@ -64 +65 @@
 }
 
-//////////////////////////////////////////////////////////////////////////////
-// lock_try_acquire()
-//////////////////////////////////////////////////////////////////////////////
-int lock_try_acquire( giet_lock_t* lock )
-{
-        register int ret = 0;   
-    register unsigned int*      plock = &lock->value;
-
-        asm volatile ("ll   $2,    0(%1)                    \n" // $2 <= _locks_lock
-                  "bnez $2,    _lock_done           \n" // exitif busy
-                  "li   $3,    1                            \n" // prepare argument for sc  
-                  "sc   $3,    0(%1)                \n" // try to set _locks_busy
-                  "xori %0, $3, 1                   \n" // ret = !$3
-                  "_lock_done:                          \n"
-                  :"=r"(ret)
-                  :"r"(plock)
-                  :"$2","$3");
-    return ret;
-}