tests: arc_vpx_lock

Add tests to verify arc_vpx_lock/unlock API.

Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>

tests/arch/arc/arc_vpx_lock/CMakeLists.txt

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+# Copyright (c) 2024 Intel Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(arc_vpx_lock)
+
+target_sources(app PRIVATE
+    src/main.c
+    )
+
+if(COMPILER STREQUAL arcmwdt)
+zephyr_include_directories(${ARCMWDT_TOOLCHAIN_PATH}/MetaWare/arc/lib/src/fx/include/)
+endif()

tests/arch/arc/arc_vpx_lock/README.txt

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+Title: ARC VPX Lock
+
+Description:
+
+This test verifies that the ARC VPX lock/unlock mechanism used to bookend
+code that uses the ARC VPX vector registers works correctly. As this VPX
+lock/unlock mechanism does not technically require those registers to be
+used to control access to them (they bookend the relevant code sections),
+the test does not actually access those VPX registers.
+
+However, it does check that the system behaves as expected when the ARC VPX
+lock/unlock mechanism is used.

tests/arch/arc/arc_vpx_lock/prj.conf

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+CONFIG_ZTEST=y
+CONFIG_MAIN_STACK_SIZE=1024
+CONFIG_ARC_VPX_COOPERATIVE_SHARING=y

tests/arch/arc/arc_vpx_lock/src/main.c

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+/*
+ * Copyright (c) 2024 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/ztest.h>
+
+#include <zephyr/arch/arc/v2/vpx/arc_vpx.h>
+
+#ifndef CONFIG_ARC_VPX_COOPERATIVE_SHARING
+#error "Rebuild with the ARC_VPX_COOPERATIVE_SHARING config option enabled"
+#endif
+
+#define STACK_SIZE (1024 + CONFIG_TEST_EXTRA_STACK_SIZE)
+
+static void timer_func(struct k_timer *timer);
+
+K_THREAD_STACK_DEFINE(payload_stack, STACK_SIZE);
+
+static K_TIMER_DEFINE(my_timer, timer_func, NULL);
+
+static struct k_thread payload_thread;
+
+static volatile int isr_result;
+static volatile unsigned int isr_vpx_lock_id;
+
+/**
+ * Obtain the current CPU id.
+ */
+static int current_cpu_id_get(void)
+{
+	int key;
+	int id;
+
+	key = arch_irq_lock();
+	id = _current_cpu->id;
+	arch_irq_unlock(key);
+
+	return id;
+}
+
+static void timer_func(struct k_timer *timer)
+{
+	arc_vpx_unlock_force(isr_vpx_lock_id);
+}
+
+static void arc_vpx_lock_unlock_timed_payload(void *p1, void *p2, void *p3)
+{
+	int status;
+	unsigned int cpu_id;
+	unsigned int lock_id;
+
+	cpu_id = (unsigned int)(uintptr_t)(p1);
+	ARG_UNUSED(p2);
+	ARG_UNUSED(p3);
+
+	status = arc_vpx_lock(K_NO_WAIT);
+	zassert_equal(0, status, "Expected return value %d, not %d\n", 0, status);
+
+	/*
+	 * In 1 second, forcibly release the VPX lock. However, wait up to
+	 * 5 seconds before considering this a failure.
+	 */
+
+	isr_vpx_lock_id = cpu_id;
+	k_timer_start(&my_timer, K_MSEC(1000), K_FOREVER);
+
+	status = arc_vpx_lock(K_MSEC(5000));
+	zassert_equal(0, status, "Expected return value %d, not %d\n", 0, status);
+
+	arc_vpx_unlock();
+}
+
+ZTEST(vpx_lock, test_arc_vpx_lock_unlock_timed)
+{
+	int priority;
+	int cpu_id;
+
+	priority = k_thread_priority_get(k_current_get());
+	cpu_id = current_cpu_id_get();
+
+	k_thread_create(&payload_thread, payload_stack, STACK_SIZE,
+			arc_vpx_lock_unlock_timed_payload,
+			(void *)(uintptr_t)cpu_id, NULL, NULL,
+			priority - 2, 0, K_FOREVER);
+
+#if defined(CONFIG_SCHED_CPU_MASK) && (CONFIG_MP_MAX_NUM_CPUS > 1)
+	k_thread_cpu_pin(&payload_thread, cpu_id);
+#endif
+	k_thread_start(&payload_thread);
+
+	k_thread_join(&payload_thread, K_FOREVER);
+}
+
+static void arc_vpx_lock_unlock_payload(void *p1, void *p2, void *p3)
+{
+	int status;
+
+	ARG_UNUSED(p1);
+	ARG_UNUSED(p2);
+	ARG_UNUSED(p3);
+
+	/* The VPX lock is available; take it. */
+
+	status = arc_vpx_lock(K_NO_WAIT);
+	zassert_equal(0, status, "Expected return value %d, not %d\n", 0, status);
+
+	/* The VPX lock has already been taken; expect errors */
+
+	status = arc_vpx_lock(K_NO_WAIT);
+	zassert_equal(-EBUSY, status, "Expected return value %d (-EBUSY), not %d\n",
+		      -EBUSY, status);
+
+	status = arc_vpx_lock(K_MSEC(10));
+	zassert_equal(-EAGAIN, status, "Expected return value %d (-EAGAIN), not %d\n",
+		      -EAGAIN, status);
+
+	/* Verify that unlocking makes it available */
+
+	arc_vpx_unlock();
+
+	status = arc_vpx_lock(K_NO_WAIT);
+	zassert_equal(0, status, "Expected return value %d, not %d\n", 0, status);
+	arc_vpx_unlock();
+}
+
+ZTEST(vpx_lock, test_arc_vpx_lock_unlock)
+{
+	int priority;
+	int cpu_id;
+
+	priority = k_thread_priority_get(k_current_get());
+	cpu_id = current_cpu_id_get();
+
+	k_thread_create(&payload_thread, payload_stack, STACK_SIZE,
+			arc_vpx_lock_unlock_payload, NULL, NULL, NULL,
+			priority - 2, 0, K_FOREVER);
+
+#if defined(CONFIG_SCHED_CPU_MASK) && (CONFIG_MP_MAX_NUM_CPUS > 1)
+	k_thread_cpu_pin(&payload_thread, cpu_id);
+#endif
+	k_thread_start(&payload_thread);
+
+	k_thread_join(&payload_thread, K_FOREVER);
+}
+
+ZTEST_SUITE(vpx_lock, NULL, NULL, NULL, NULL, NULL);

tests/arch/arc/arc_vpx_lock/testcase.yaml

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+tests:
+  arch.arc.vpx_lock:
+    filter: CONFIG_ISA_ARCV2
+    toolchain_allow: arcmwdt
+    platform_allow: nsim/nsim_vpx5
+  arch.arc.vpx_lock.cpu_mask:
+    filter: CONFIG_ISA_ARCV2 and (CONFIG_MP_MAX_NUM_CPUS > 1)
+    toolchain_allow: arcmwdt
+    platform_allow: nsim/nsim_vpx5
+    extra_configs:
+      - CONFIG_SCHED_CPU_MASK=y