smp: Simplify SMP initialization sequence

Delete bsp_smp_wait_for().  Other parts of the system work without
timeout, e.g. the spinlocks.  Using a timeout here does not make the
system more robust.

Delete bsp_smp_cpu_state and replace it with Per_CPU_State.  The
Per_CPU_State follows the Score naming conventions.  Add
_Per_CPU_Change_state() and _Per_CPU_Wait_for_state() functions to
change and observe states.

Use Per_CPU_State in Per_CPU_Control instead of the anonymous integer.

Add _CPU_Processor_event_broadcast() and _CPU_Processor_event_receive()
functions provided by the CPU port.  Use these functions in
_Per_CPU_Change_state() and _Per_CPU_Wait_for_state().

Add prototype for _SMP_Send_message().

Delete RTEMS_BSP_SMP_FIRST_TASK message.  The first context switch is
now performed in rtems_smp_secondary_cpu_initialize().  Issuing the
first context switch in the context of the inter-processor interrupt is
not possible on systems with a modern interrupt controller.  Such an
interrupt controler usually requires a handshake protocol with interrupt
acknowledge and end of interrupt signals.  A direct context switch in an
interrupt handler circumvents the interrupt processing epilogue and may
leave the system in an inconsistent state.

Release lock in rtems_smp_process_interrupt() even if no message was
delivered.  This prevents deadlock of the system.

Simplify and format _SMP_Send_message(),
_SMP_Request_other_cores_to_perform_first_context_switch(),
_SMP_Request_other_cores_to_dispatch() and
_SMP_Request_other_cores_to_shutdown().

1 files changed, 0 insertions, 28 deletions

diff --git a/c/src/lib/libbsp/shared/smp/bspsmp_wait_for.c b/c/src/lib/libbsp/shared/smp/bspsmp_wait_for.c
deleted file mode 100644
index 8c4dcf75c1..0000000000
--- a/c/src/lib/libbsp/shared/smp/bspsmp_wait_for.c
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
- *
- *  COPYRIGHT (c) 1989-2011.
- *  On-Line Applications Research Corporation (OAR).
- *
- *  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.
- */
-
-void rtems_bsp_delay( int usec );
-
-void bsp_smp_wait_for(
-  volatile unsigned int *address,
-  unsigned int           desired,
-  int                    maximum_usecs
-)
-{
-  int iterations;
-  volatile unsigned int *p = address;
-
-  for (iterations=0 ;  iterations < maximum_usecs ; iterations++ ) {
-    if ( *p == desired )
-      break;
-
-    rtems_bsp_delay( 1 );
-  }
-}