From 27523579226b7dbff68d12ca28abce63d52e77d2 Mon Sep 17 00:00:00 2001
From: Andrew Boie <andrew.p.boie@intel.com>
Date: Thu, 9 Feb 2017 12:40:08 -0800
Subject: [PATCH] arm: enable direct interrupts feature

Issue: ZEP-1038
Change-Id: I5417e516cc994e2bbe6bb987d9ed95e912941aa0
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
---
 arch/arm/core/irq_manage.c      | 57 +++++++++++++++++++++++++++++++++
 include/arch/arm/cortex_m/irq.h | 53 ++++++++++++++++++++++++++++++
 2 files changed, 110 insertions(+)

diff --git a/arch/arm/core/irq_manage.c b/arch/arm/core/irq_manage.c
index d2cc2dbbfd4..b36b007800d 100644
--- a/arch/arm/core/irq_manage.c
+++ b/arch/arm/core/irq_manage.c
@@ -22,6 +22,8 @@
 #include <sections.h>
 #include <sw_isr_table.h>
 #include <irq.h>
+#include <kernel_structs.h>
+#include <logging/kernel_event_logger.h>
 
 extern void __reserved(void);
 
@@ -131,3 +133,58 @@ void _irq_spurious(void *unused)
 	__reserved();
 }
 
+/* FIXME: IRQ direct inline functions have to be placed here and not in
+ * arch/cpu.h as inline functions due to nasty circular dependency between
+ * arch/cpu.h and kernel_structs.h; the inline functions typically need to
+ * perform operations on _kernel.  For now, leave as regular functions, a
+ * future iteration will resolve this.
+ * We have a similar issue with the k_event_logger functions.
+ *
+ * See https://jira.zephyrproject.org/browse/ZEP-1595
+ */
+
+#ifdef CONFIG_SYS_POWER_MANAGEMENT
+void _arch_isr_direct_pm(void)
+{
+#if defined(CONFIG_ARMV6_M)
+	int key;
+
+	/* irq_lock() does what we wan for this CPU */
+	key = irq_lock();
+#elif defined(CONFIG_ARMV7_M)
+	/* Lock all interrupts. irq_lock() will on this CPU only disable those
+	 * lower than BASEPRI, which is not what we want. See comments in
+	 * arch/arm/core/isr_wrapper.S
+	 */
+	__asm__ volatile("cpsid i" : : : "memory");
+#else
+#error Unknown ARM architecture
+#endif /* CONFIG_ARMV6_M */
+
+	if (_kernel.idle) {
+		int32_t idle_val = _kernel.idle;
+
+		_kernel.idle = 0;
+		_sys_power_save_idle_exit(idle_val);
+	}
+
+#if defined(CONFIG_ARMV6_M)
+	irq_unlock(key);
+#elif defined(CONFIG_ARMV7_M)
+	__asm__ volatile("cpsie i" : : : "memory");
+#else
+#error Unknown ARM architecture
+#endif /* CONFIG_ARMV6_M */
+
+}
+#endif
+
+#if defined(CONFIG_KERNEL_EVENT_LOGGER_SLEEP) || \
+	defined(CONFIG_KERNEL_EVENT_LOGGER_INTERRUPT)
+void _arch_isr_direct_header(void)
+{
+	_sys_k_event_logger_interrupt();
+	_sys_k_event_logger_exit_sleep();
+}
+#endif
+
diff --git a/include/arch/arm/cortex_m/irq.h b/include/arch/arm/cortex_m/irq.h
index 971aca71a2c..da8a6b4b7b4 100644
--- a/include/arch/arm/cortex_m/irq.h
+++ b/include/arch/arm/cortex_m/irq.h
@@ -85,6 +85,59 @@ extern void _irq_priority_set(unsigned int irq, unsigned int prio,
 	irq_p; \
 })
 
+
+/**
+ * Configure a 'direct' static interrupt.
+ *
+ * See include/irq.h for details.
+ * All arguments must be computable at build time.
+ */
+#define _ARCH_IRQ_DIRECT_CONNECT(irq_p, priority_p, isr_p, flags_p) \
+({ \
+	_ISR_DECLARE(irq_p, ISR_FLAG_DIRECT, isr_p, NULL); \
+	_irq_priority_set(irq_p, priority_p, flags_p); \
+	irq_p; \
+})
+
+/* FIXME prefer these inline, but see ZEP-1595 */
+#ifdef CONFIG_SYS_POWER_MANAGEMENT
+extern void _arch_isr_direct_pm(void);
+#define _ARCH_ISR_DIRECT_PM() _arch_isr_direct_pm()
+#else
+#define _ARCH_ISR_DIRECT_PM() do { } while (0)
+#endif
+
+#if defined(CONFIG_KERNEL_EVENT_LOGGER_SLEEP) || \
+	defined(CONFIG_KERNEL_EVENT_LOGGER_INTERRUPT)
+#define _ARCH_ISR_DIRECT_HEADER() _arch_isr_direct_header()
+extern void _arch_isr_direct_header(void);
+#else
+#define _ARCH_ISR_DIRECT_HEADER() do { } while (0)
+#endif
+
+#define _ARCH_ISR_DIRECT_FOOTER(swap) _arch_isr_direct_footer(swap)
+
+/* arch/arm/core/exc_exit.S */
+extern void _IntExit(void);
+
+static inline void _arch_isr_direct_footer(int maybe_swap)
+{
+	if (maybe_swap) {
+		_IntExit();
+	}
+}
+
+#define _ARCH_ISR_DIRECT_DECLARE(name) \
+	static inline int name##_body(void); \
+	__attribute__ ((interrupt ("IRQ"))) void name(void) \
+	{ \
+		int check_reschedule; \
+		ISR_DIRECT_HEADER(); \
+		check_reschedule = name##_body(); \
+		ISR_DIRECT_FOOTER(check_reschedule); \
+	} \
+	static inline int name##_body(void)
+
 /* Spurious interrupt handler. Throws an error if called */
 extern void _irq_spurious(void *unused);