cpukit/confdefs: Add CAN stack resource calculation

The CAN/CAN FD stack requires a worker task per configured queue.
Empirical profiling confirms the CAN worker task utilizes ~404 bytes
of stack space on 32-bit architectures.

This patch introduces CONFIGURE_MAXIMUM_CAN_QUEUES to dynamically
inject the required CAN worker tasks into the master _CONFIGURE_TASKS
pool. Because the 404-byte usage falls below RTEMS_MINIMUM_STACK_SIZE,
provisioning them as standard system tasks automatically guarantees
sufficient stack space overhead.

Additionally, this patch removes the hardcoded +0x1000 stack padding
in rtems_task_create to prevent workspace exhaustion, and adds the
spcan01 test to verify the CONFIGURE_MAXIMUM_CAN_QUEUES macro behavior.

Closes #5193

cpukit/dev/can/can-quekern.c

@@ -465,7 +465,7 @@ int rtems_can_queue_kern_initialize( void )
   sc = rtems_task_create(
     rtems_build_name( 'C', 'A', 'N', 'D' ),
     CAN_DEAD_FUNC_PRIORITY,
-    RTEMS_MINIMUM_STACK_SIZE + 0x1000,
+    RTEMS_MINIMUM_STACK_SIZE,
     RTEMS_DEFAULT_MODES,
     RTEMS_DEFAULT_ATTRIBUTES,
     &dead_func_id

cpukit/include/rtems/confdefs/threads.h

@@ -59,8 +59,15 @@
   #define CONFIGURE_MAXIMUM_TASKS 0
 #endif
 
-#define _CONFIGURE_TASKS \
-  ( CONFIGURE_MAXIMUM_TASKS + _CONFIGURE_LIBBLOCK_TASKS )
+#ifdef CONFIGURE_MAXIMUM_CAN_CHIPS
+  #define _CONFIGURE_CAN_TASKS ( CONFIGURE_MAXIMUM_CAN_CHIPS + 1 )
+#else
+  #define _CONFIGURE_CAN_TASKS 0
+#endif
+
+#define _CONFIGURE_TASKS                                  \
+  ( CONFIGURE_MAXIMUM_TASKS + _CONFIGURE_LIBBLOCK_TASKS + \
+    _CONFIGURE_CAN_TASKS )
 
 #ifndef CONFIGURE_MINIMUM_TASKS_WITH_USER_PROVIDED_STORAGE
   #define CONFIGURE_MINIMUM_TASKS_WITH_USER_PROVIDED_STORAGE 0

spec/build/testsuites/sptests/grp.yml

@@ -168,6 +168,8 @@ links:
     uid: spatomic01
   - role: build-dependency
     uid: spcache01
+  - role: build-dependency
+    uid: spcan01
   - role: build-dependency
     uid: spcbssched01
   - role: build-dependency

spec/build/testsuites/sptests/spcan01.yml

@@ -0,0 +1,19 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2026 Mithilesh Mattapalli
+cppflags: []
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes: []
+ldflags: []
+links: []
+source:
+- testsuites/sptests/spcan01/init.c
+stlib: []
+target: testsuites/sptests/spcan01.exe
+type: build
+use-after: []
+use-before: []

testsuites/sptests/spcan01/init.c

@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/*
+ * Copyright (C) 2026 Mithilesh Mattapalli
+ *
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems.h>
+#include <tmacros.h>
+#include <dev/can/can.h>
+#include <dev/can/can-virtual.h>
+
+const char rtems_test_name[] = "SPCAN 1";
+
+static rtems_task Init( rtems_task_argument ignored )
+{
+  struct rtems_can_chip *chip;
+
+  (void) ignored;
+  rtems_print_printer_fprintf_putc( &rtems_test_printer );
+  TEST_BEGIN();
+
+  chip = rtems_can_virtual_initialize();
+  rtems_test_assert( chip != NULL );
+
+  TEST_END();
+  rtems_test_exit( 0 );
+}
+
+#define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER
+#define CONFIGURE_APPLICATION_NEEDS_SIMPLE_CONSOLE_DRIVER
+
+#define CONFIGURE_MAXIMUM_TASKS          1
+#define CONFIGURE_MAXIMUM_SEMAPHORES     10
+#define CONFIGURE_MAXIMUM_MESSAGE_QUEUES 10
+#define CONFIGURE_MAXIMUM_CAN_CHIPS      1
+
+#define CONFIGURE_RTEMS_INIT_TASKS_TABLE
+#define CONFIGURE_INIT_TASK_ATTRIBUTES RTEMS_FLOATING_POINT
+#define CONFIGURE_INITIAL_EXTENSIONS   RTEMS_TEST_INITIAL_EXTENSION
+
+#define CONFIGURE_INIT
+#include <rtems/confdefs.h>