kernel/poll: Mark incompatibility with KERNEL_COHERENCE

The k_poll implementation places a struct _poller on the stack and
shares it with other threads, which is incompatible with the
KERNEL_COHERENCE model of cached stacks.

Make this a hard build failure instead of a kconfig dependency for
clarity.  The failures if a user actually enables both are subtle and
difficult to debug.

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

kernel/poll.c

@@ -243,11 +243,19 @@ static int k_poll_poller_cb(struct k_poll_event *event, uint32_t state)
 	return 0;
 }
 
+#ifdef CONFIG_KERNEL_COHERENCE
+#error CONFIG_POLL and CONFIG_KERNEL_COHERENCE are not compatible
+#endif
+
 int z_impl_k_poll(struct k_poll_event *events, int num_events,
 		  k_timeout_t timeout)
 {
 	int events_registered;
 	k_spinlock_key_t key;
+
+	/* FIXME: this shared data is stack-allocated and needs
+	 * proper treatment to be compatible with KERNEL_COHERENCE.
+	 */
 	struct _poller poller = { .is_polling = true,
 				  .thread     = _current,
 				  .cb         = k_poll_poller_cb };

tests/kernel/common/testcase.yaml

@@ -3,10 +3,11 @@ tests:
     tags: kernel userspace
     build_on_all: true
     min_flash: 33
+    filter: not CONFIG_KERNEL_COHERENCE
   kernel.common.misra:
     tags: kernel userspace
     min_flash: 33
     # Some configurations are known-incompliant and won't build
-    filter: not ((CONFIG_I2C or CONFIG_SPI) and CONFIG_USERSPACE)
+    filter: not ((CONFIG_I2C or CONFIG_SPI) and CONFIG_USERSPACE or CONFIG_KERNEL_COHERENCE)
     extra_configs:
       - CONFIG_MISRA_SANE=y

tests/kernel/fifo/fifo_api/testcase.yaml

@@ -4,3 +4,4 @@ tests:
   kernel.fifo.poll:
     extra_args: CONF_FILE="prj_poll.conf"
     tags: kernel
+    filter: not CONFIG_KERNEL_COHERENCE

tests/kernel/fifo/fifo_timeout/testcase.yaml

@@ -4,3 +4,4 @@ tests:
   kernel.fifo.timeout.poll:
     extra_args: CONF_FILE="prj_poll.conf"
     tags: kernel
+    filter: not CONFIG_KERNEL_COHERENCE

tests/kernel/fifo/fifo_usage/testcase.yaml

@@ -4,3 +4,4 @@ tests:
   kernel.fifo.usage.poll:
     extra_args: CONF_FILE="prj_poll.conf"
     tags: kernel
+    filter: not CONFIG_KERNEL_COHERENCE

tests/kernel/poll/testcase.yaml

@@ -2,3 +2,4 @@ tests:
   kernel.poll:
     tags: kernel userspace
     platform_exclude: nrf52dk_nrf52810
+    filter: not CONFIG_KERNEL_COHERENCE

tests/kernel/queue/testcase.yaml

@@ -4,3 +4,4 @@ tests:
   kernel.queue.poll:
     extra_args: CONF_FILE="prj_poll.conf"
     tags: kernel userspace
+    filter: not CONFIG_KERNEL_COHERENCE

tests/kernel/workq/work_queue/testcase.yaml

@@ -2,3 +2,4 @@ tests:
   kernel.workqueue:
     min_flash: 34
     tags: kernel
+    filter: not CONFIG_KERNEL_COHERENCE

tests/kernel/workq/work_queue_api/testcase.yaml

@@ -2,3 +2,4 @@ tests:
   kernel.workqueue.api:
     min_flash: 34
     tags: kernel userspace
+    filter: not CONFIG_KERNEL_COHERENCE