score: Add and use _Giant_Drop()

New test smptests/smpfatal03.

cpukit/score/include/rtems/score/threaddispatch.h

@@ -108,6 +108,18 @@ RTEMS_INLINE_ROUTINE void _Thread_Dispatch_initialization( void )
    */
   void _Giant_Release( void );
 
+  /**
+   * @brief Releases the giant lock completely if held by the executing processor.
+   *
+   * The thread dispatch disable level is not altered by this function.
+   *
+   * The only use case for this operation is in
+   * _SMP_Request_shutdown().
+   *
+   * @param[in] self_cpu The current processor index.
+   */
+  void _Giant_Drop( uint32_t self_cpu );
+
   /**
    *  @brief Sets thread dispatch level to the value passed in.
    *

cpukit/score/src/smp.c

@@ -73,6 +73,14 @@ void _SMP_Request_shutdown( void )
   Per_CPU_Control *self_cpu = _Per_CPU_Get_by_index( self );
 
   _Per_CPU_State_change( self_cpu, PER_CPU_STATE_SHUTDOWN );
+
+  /*
+   * We have to drop the Giant lock here in order to give other processors the
+   * opportunity to receive the inter-processor interrupts issued previously.
+   * In case the executing thread still holds SMP locks, then other processors
+   * already waiting for this SMP lock will spin forever.
+   */
+  _Giant_Drop( self );
 }
 
 void _SMP_Send_message( uint32_t cpu, uint32_t message )

cpukit/score/src/threaddispatchdisablelevel.c

@@ -57,6 +57,19 @@ static void _Giant_Do_release( void )
   }
 }
 
+void _Giant_Drop( uint32_t self_cpu )
+{
+  Giant_Control *giant = &_Giant;
+
+  _Assert( _ISR_Get_level() != 0 );
+
+  if ( giant->owner_cpu == self_cpu ) {
+    giant->nest_level = 0;
+    giant->owner_cpu = NO_OWNER_CPU;
+    _SMP_lock_Release( &giant->lock );
+  }
+}
+
 uint32_t _Thread_Dispatch_increment_disable_level( void )
 {
   ISR_Level isr_level;

testsuites/smptests/Makefile.am

@@ -13,6 +13,7 @@ SUBDIRS += smp09
 SUBDIRS += smpatomic01
 SUBDIRS += smpfatal01
 SUBDIRS += smpfatal02
+SUBDIRS += smpfatal03
 SUBDIRS += smplock01
 SUBDIRS += smpmigration01
 SUBDIRS += smpschedule01

testsuites/smptests/configure.ac

@@ -67,6 +67,7 @@ smp09/Makefile
 smpatomic01/Makefile
 smpfatal01/Makefile
 smpfatal02/Makefile
+smpfatal03/Makefile
 smplock01/Makefile
 smpmigration01/Makefile
 smppsxsignal01/Makefile

testsuites/smptests/smpfatal03/Makefile.am

@@ -0,0 +1,19 @@
+rtems_tests_PROGRAMS = smpfatal03
+smpfatal03_SOURCES = init.c
+
+dist_rtems_tests_DATA = smpfatal03.scn smpfatal03.doc
+
+include $(RTEMS_ROOT)/make/custom/@RTEMS_BSP@.cfg
+include $(top_srcdir)/../automake/compile.am
+include $(top_srcdir)/../automake/leaf.am
+
+AM_CPPFLAGS += -I$(top_srcdir)/../support/include
+
+LINK_OBJS = $(smpfatal03_OBJECTS)
+LINK_LIBS = $(smpfatal03_LDLIBS)
+
+smpfatal03$(EXEEXT): $(smpfatal03_OBJECTS) $(smpfatal03_DEPENDENCIES)
+	@rm -f smpfatal03$(EXEEXT)
+	$(make-exe)
+
+include $(top_srcdir)/../automake/local.am

testsuites/smptests/smpfatal03/init.c

@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2014 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#ifdef HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems.h>
+#include <rtems/counter.h>
+#include <rtems/score/smpbarrier.h>
+#include <rtems/score/smpimpl.h>
+#include <rtems/score/threaddispatch.h>
+
+#include <assert.h>
+#include <stdlib.h>
+
+#define CPU_COUNT 2
+
+static uint32_t main_cpu;
+
+static SMP_barrier_Control barrier = SMP_BARRIER_CONTROL_INITIALIZER;
+
+static void end_of_test(void)
+{
+  printk( "*** END OF TEST SMPFATAL 3 ***\n" );
+}
+
+static void acquire_giant_and_fatal_task(rtems_task_argument arg)
+{
+  SMP_barrier_State state = SMP_BARRIER_STATE_INITIALIZER;
+  int i;
+
+  for (i = 0; i < 13; ++i) {
+    _Giant_Acquire();
+  }
+
+  _SMP_barrier_Wait(&barrier, &state, CPU_COUNT);
+
+  /*
+   * Now we have to wait some time so that the other thread can actually start
+   * with the _Giant_Acquire() procedure.
+   */
+  rtems_counter_delay_nanoseconds(1000000);
+
+  rtems_fatal(RTEMS_FATAL_SOURCE_APPLICATION, 0xdeadbeef);
+}
+
+static void wait_for_giant(void)
+{
+  SMP_barrier_State state = SMP_BARRIER_STATE_INITIALIZER;
+
+  _SMP_barrier_Wait(&barrier, &state, CPU_COUNT);
+
+  _Giant_Acquire();
+}
+
+static void Init(rtems_task_argument arg)
+{
+  uint32_t self = rtems_smp_get_current_processor();
+  uint32_t cpu_count = rtems_smp_get_processor_count();
+
+  printk("\n\n*** TEST SMPFATAL 3 ***\n");
+
+  main_cpu = self;
+
+  if (cpu_count >= CPU_COUNT) {
+    rtems_status_code sc;
+    rtems_id id;
+
+    sc = rtems_task_create(
+      rtems_build_name( 'W', 'A', 'I', 'T' ),
+      1,
+      RTEMS_MINIMUM_STACK_SIZE,
+      RTEMS_DEFAULT_MODES,
+      RTEMS_DEFAULT_ATTRIBUTES,
+      &id
+    );
+    assert(sc == RTEMS_SUCCESSFUL);
+
+    sc = rtems_task_start(id, acquire_giant_and_fatal_task, 0);
+    assert(sc == RTEMS_SUCCESSFUL);
+
+    wait_for_giant();
+  } else {
+    end_of_test();
+    exit(0);
+  }
+}
+
+static void fatal_extension(
+  rtems_fatal_source source,
+  bool is_internal,
+  rtems_fatal_code code
+)
+{
+  if (
+    source == RTEMS_FATAL_SOURCE_APPLICATION
+      || source == RTEMS_FATAL_SOURCE_SMP
+  ) {
+    uint32_t self = rtems_smp_get_current_processor();
+
+    assert(!is_internal);
+
+    if (self == main_cpu) {
+      assert(source == RTEMS_FATAL_SOURCE_SMP);
+      assert(code == SMP_FATAL_SHUTDOWN);
+
+      end_of_test();
+    } else {
+      assert(source == RTEMS_FATAL_SOURCE_APPLICATION);
+      assert(code == 0xdeadbeef);
+    }
+  }
+}
+
+#define CONFIGURE_APPLICATION_DOES_NOT_NEED_CLOCK_DRIVER
+#define CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER
+
+#define CONFIGURE_INITIAL_EXTENSIONS { .fatal = fatal_extension }
+
+#define CONFIGURE_SMP_APPLICATION
+
+#define CONFIGURE_SMP_MAXIMUM_PROCESSORS CPU_COUNT
+
+#define CONFIGURE_MAXIMUM_TASKS 2
+
+#define CONFIGURE_RTEMS_INIT_TASKS_TABLE
+
+#define CONFIGURE_INIT
+
+#include <rtems/confdefs.h>

testsuites/smptests/smpfatal03/smpfatal03.doc

@@ -0,0 +1,12 @@
+This file describes the directives and concepts tested by this test set.
+
+test set name: smpfatal03
+
+directives:
+
+  - _Terminate()
+
+concepts:
+
+  - Ensure that _Terminate() drops the Giant lock so that other processors
+    waiting on the Giant lock can receive shutdown requests.

testsuites/smptests/smpfatal03/smpfatal03.scn

@@ -0,0 +1,2 @@
+*** TEST SMPFATAL 3 ***
+*** END OF TEST SMPFATAL 3 ***