cpukit: Add AArch64 SMP Support

This adds SMP support for AArch64 in cpukit and for the ZynqMP BSPs.

2 files changed, 91 insertions, 6 deletions

diff --git a/bsps/aarch64/shared/start/aarch64-smp.c b/bsps/aarch64/shared/start/aarch64-smp.c
new file mode 100644
index 0000000000..5ec7babce7
--- /dev/null
+++ b/bsps/aarch64/shared/start/aarch64-smp.c
@@ -0,0 +1,85 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup RTEMSBSPsAArch64Shared
+ *
+ * @brief SMP startup and interop code.
+ */
+
+/*
+ * Copyright (C) 2021 On-Line Applications Research Corporation (OAR)
+ * Written by Kinsey Moore <kinsey.moore@oarcorp.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <rtems/score/smpimpl.h>
+
+#include <bsp/irq.h>
+
+static void bsp_inter_processor_interrupt( void *arg )
+{
+  _SMP_Inter_processor_interrupt_handler( _Per_CPU_Get() );
+}
+
+uint32_t _CPU_SMP_Initialize( void )
+{
+  return arm_gic_irq_processor_count();
+}
+
+void _CPU_SMP_Finalize_initialization( uint32_t cpu_count )
+{
+  if ( cpu_count > 0 ) {
+    rtems_status_code sc;
+
+    sc = rtems_interrupt_handler_install(
+      ARM_GIC_IRQ_SGI_0,
+      "IPI",
+      RTEMS_INTERRUPT_UNIQUE,
+      bsp_inter_processor_interrupt,
+      NULL
+    );
+    _Assert( sc == RTEMS_SUCCESSFUL );
+    (void) sc;
+
+#if defined( BSP_DATA_CACHE_ENABLED ) || \
+    defined( BSP_INSTRUCTION_CACHE_ENABLED )
+    /* Enable unified L2 cache */
+    rtems_cache_enable_data();
+#endif
+  }
+}
+
+void _CPU_SMP_Prepare_start_multitasking( void )
+{
+  /* Do nothing */
+}
+
+void _CPU_SMP_Send_interrupt( uint32_t target_processor_index )
+{
+  arm_gic_irq_generate_software_irq(
+    ARM_GIC_IRQ_SGI_0,
+    1U << target_processor_index
+  );
+}
diff --git a/bsps/aarch64/shared/start/start.S b/bsps/aarch64/shared/start/start.S
index f4c39dacdf..bc6a855217 100644
--- a/bsps/aarch64/shared/start/start.S
+++ b/bsps/aarch64/shared/start/start.S
@@ -166,21 +166,21 @@ _el1_start:
 #ifdef RTEMS_SMP
   /* Read MPIDR and get current processor index */
   mrs x7, mpidr_el1
-  and x7, #0xff
+  and x7, x7, #0xff
 #endif
 
 #ifdef RTEMS_SMP
   /*
    * Get current per-CPU control and store it in PL1 only Thread ID
-   * Register (TPIDRPRW).
+   * Register (TPIDR_EL1).
    */
 #ifdef AARCH64_MULTILIB_ARCH_V8_ILP32
   ldr w1, =_Per_CPU_Information
 #else
   ldr x1, =_Per_CPU_Information
 #endif
-  add x1, x1, x7, asl #PER_CPU_CONTROL_SIZE_LOG2
-  mcr p15, 0, x1, c13, c0, 4
+  add x1, x1, x7, lsl #PER_CPU_CONTROL_SIZE_LOG2
+  msr TPIDR_EL1, x1
 
 #endif
 
@@ -201,8 +201,8 @@ _el1_start:
 #endif
   add x3, x1, x2
 
-  /* Save original DAIF value */
-  mrs  x4, DAIF
+  /* Disable interrupts */
+  msr DAIFSet, #0x2
 
 #ifdef BSP_START_NEEDS_REGISTER_INITIALIZATION
   mov x8, XZR