Changeset 313 for soft/giet_vm/giet_drivers/tty_driver.c

Timestamp:

Apr 21, 2014, 5:46:38 AM (10 years ago)

Author:

alain

Message:

The main modif is in TTY driver: The hard lock implemented in the
vci_multi_tty component is not used anymore, because this (non cacheable)
lock was not scalable... It has been replaced by a software (cacheable) lock
that has a better scalability in case of hardware cache coherence.
(see the _tty_get_lock() and _tty_release_lock() functions)

File:

• soft/giet_vm/giet_drivers/tty_driver.c (modified) (4 diffs)

soft/giet_vm/giet_drivers/tty_driver.c

@@ -40 +40 @@
 
 #define in_unckdata __attribute__((section (".unckdata")))
+#define in_kdata    __attribute__((section (".kdata")))
 
 //////////////////////////////////////////////////////////////////////////////
@@ -46 +47 @@
 
 in_unckdata volatile unsigned int _tty_rx_buf[NB_TTY_CHANNELS];
+
 in_unckdata volatile unsigned int _tty_rx_full[NB_TTY_CHANNELS] 
                                      = { [0 ... NB_TTY_CHANNELS - 1] = 0 };
+
+in_kdata unsigned int _tty_lock[NB_TTY_CHANNELS] 
+                        = { [0 ... NB_TTY_CHANNELS - 1] = 0 };
 
 //////////////////////////////////////////////////////////////////////////////
@@ -150 +155 @@
 {
     if( channel >= NB_TTY_CHANNELS ) _exit();
+
     _it_disable( save_sr_ptr );
-    while ( _tty_get_register( channel, TTY_CONFIG ) ); // busy waiting
+
+//    while ( _tty_get_register( channel, TTY_CONFIG ) ); // busy waiting
+
+    _get_lock( &_tty_lock[channel] );
 }
 
@@ -165 +174 @@
     if( channel >= NB_TTY_CHANNELS ) _exit();
 
-    _tty_set_register( channel, TTY_CONFIG, 0 );
+//    _tty_set_register( channel, TTY_CONFIG, 0 );
+
+    _release_lock( &_tty_lock[channel] );
+    
     _it_restore( save_sr_ptr );
 }