irq: add note about irq_lock/unlock access
On ARM irq_lock() simply fails silently instead of generating
an exception.
Fixes: #21735
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
diff --git a/include/irq.h b/include/irq.h
index c53a33c..3dcec83 100644
--- a/include/irq.h
+++ b/include/irq.h
@@ -197,6 +197,10 @@
* acquired. (That is, each call to irq_lock() must be balanced by
* a corresponding call to irq_unlock().)
*
+ * This routine can only be invoked from supervisor mode. Some architectures
+ * (for example, ARM) will fail silently if invoked from user mode instead
+ * of generating an exception.
+ *
* @note
* This routine can be called by ISRs or by threads. If it is called by a
* thread, the interrupt lock is thread-specific; this means that interrupts
@@ -231,6 +235,10 @@
* each time it called irq_lock(), supplying the keys in the reverse order
* they were acquired, before interrupts are enabled.
*
+ * This routine can only be invoked from supervisor mode. Some architectures
+ * (for example, ARM) will fail silently if invoked from user mode instead
+ * of generating an exception.
+ *
* @note Can be called by ISRs.
*
* @param key Lock-out key generated by irq_lock().
