nrf52_bsim: irq handling: Add function z_arm_irq_can_preempt

Added a simulation replacement for NVIC_GetPriority()
+
Added a function (like for ARM) to check if current context
can be preempted by given interrupt.

Signed-off-by: Alberto Escolar Piedras <[email protected]>

Author: aescolar

boards/posix/nrf52_bsim/board_irq.h

@@ -10,6 +10,7 @@
 
 #include "sw_isr_table.h"
 #include "zephyr/types.h"
+#include "NRF_regs.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -18,6 +19,8 @@ extern "C" {
 void z_isr_declare(unsigned int irq_p, int flags, void isr_p(void *),
 		void *isr_param_p);
 void z_irq_priority_set(unsigned int irq, unsigned int prio, u32_t flags);
+bool z_arm_irq_can_preempt(u32_t irq_line);
+unsigned int NVIC_GetPriority(IRQn_Type IRQn);
 
 /**
  * Configure a static interrupt.

boards/posix/nrf52_bsim/irq_handler.c

@@ -327,6 +327,25 @@ void z_irq_priority_set(unsigned int irq, unsigned int prio, uint32_t flags)
 	hw_irq_ctrl_prio_set(irq, prio);
 }
 
+/**
+ * @brief Return current context priority.
+ *
+ * @return Interrupt priority or INT_MAX if in thread mode.
+ */
+static int z_arm_irq_current_prio(void)
+{
+	if (_kernel.nested == 0) {
+		return INT_MAX;
+	} else {
+		return hw_irq_ctrl_get_cur_prio();
+	}
+}
+
+bool z_arm_irq_can_preempt(u32_t irq_line)
+{
+	return z_arm_irq_current_prio() > NVIC_GetPriority((IRQn_Type)irq_line);
+}
+
 /**
  * Similar to ARM's NVIC_SetPendingIRQ
  * set a pending IRQ from SW
@@ -402,6 +421,15 @@ void NVIC_ClearPendingIRQ(IRQn_Type IRQn)
 	hw_irq_ctrl_clear_irq(IRQn);
 }
 
+/*
+ * Replacement for ARMs NVIC_GetPriority()
+ * Return the programmed priority of IRQn
+ */
+unsigned int NVIC_GetPriority(IRQn_Type IRQn)
+{
+	return hw_irq_ctrl_get_prio(IRQn);
+}
+
 /*
  * Very simple model of the WFE and SEV ARM instructions
  * which seems good enough for the Nordic controller