tests/kernel/interrupt: Add a simple dynamic interrupt test

Platforms which use the GEN_SW_ISR mechanism for interrupt handling
can make use of a really simple whitebox trick for verifying that it
worked (i.e. that the pointer and argument get placed in the table
correctly).

Easy and simple way to get some coverage for dynamic IRQs, which is
currently entirely missing.  Long term we'll want to replace this with
a test that uses the API directly and chooses an arch-specific vector
to set, and triggers it using arch-specific code, but that's quite a
bit more effort and for now we need to land patches to
z_irq_connect_dynamic() which show test coverage.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>

tests/kernel/interrupt/prj.conf

@@ -1,2 +1,3 @@
 CONFIG_ZTEST=y
 CONFIG_IRQ_OFFLOAD=y
+CONFIG_DYNAMIC_INTERRUPTS=y

tests/kernel/interrupt/src/main.c

@@ -9,9 +9,60 @@
 extern void test_nested_isr(void);
 extern void test_prevent_interruption(void);
 
+extern void z_irq_spurious(void *unused);
+
+/* Simple whitebox test of dynamic interrupt handlers as implemented
+ * by the GEN_SW_ISR feature.
+ */
+#if (defined(CONFIG_DYNAMIC_INTERRUPTS)		\
+     && defined(CONFIG_GEN_SW_ISR_TABLE))
+#define DYNTEST 1
+#endif
+
+#ifdef DYNTEST
+static void dyn_isr(void *arg)
+{
+	ARG_UNUSED(arg);
+}
+
+extern struct _isr_table_entry __sw_isr_table _sw_isr_table[];
+
+static void do_isr_dynamic(void)
+{
+	int i;
+	void *argval;
+
+	for (i = CONFIG_GEN_IRQ_START_VECTOR; i < CONFIG_NUM_IRQS; i++) {
+		if (_sw_isr_table[i].isr == z_irq_spurious) {
+			break;
+		}
+	}
+
+	zassert_true(_sw_isr_table[i].isr == z_irq_spurious,
+		     "could not find slot for dynamic isr");
+
+	argval = &i;
+	z_arch_irq_connect_dynamic(i, 0, dyn_isr, argval, 0);
+
+	zassert_true(_sw_isr_table[i].isr == dyn_isr &&
+		     _sw_isr_table[i].arg == argval,
+		     "dynamic isr did not install successfully");
+}
+#endif /* DYNTEST */
+
+void test_isr_dynamic(void)
+{
+#ifdef DYNTEST
+	do_isr_dynamic();
+#else
+	ztest_test_skip();
+#endif
+}
+
 void test_main(void)
 {
 	ztest_test_suite(interrupt_feature,
+			ztest_unit_test(test_isr_dynamic),
 			ztest_unit_test(test_nested_isr),
 			ztest_unit_test(test_prevent_interruption)
 			);

tests/kernel/interrupt/testcase.yaml

@@ -1,7 +1,14 @@
 tests:
   arch.interrupt:
-    arch_exclude: nios2 riscv32
+    arch_exclude: nios2 riscv32 arc qemu_x86 qemu_x86_coverage qemu_x86_64
     platform_exclude: hexiwear_kw40z frdm_kw41z frdm_kl25z nucleo_f103rb
         nucleo_f091rc olimexino_stm32 usb_kw24d512 stm32_min_dev_blue
         stm32_min_dev_black v2m_beetle
     tags: interrupt
+
+  # Platforms without relevant (gen isr) dynamic interrupt support:
+  arch.interrupt.nodyn:
+    arch_whitelist: arc qemu_x86 qemu_x86_coverage qemu_x86_64
+    tags: interrupt
+    extra_configs:
+      - CONFIG_DYNAMIC_INTERRUPTS=n