From eba2131f34db2f28a2d3228db739fc87e78a4f48 Mon Sep 17 00:00:00 2001
From: "Shiratori, Takehiro" <fj0300es@aa.jp.fujitsu.com>
Date: Fri, 8 Mar 2019 20:55:58 +0900
Subject: [PATCH] clv: Change no_preempt from int to ihk_atomic_t.

Fix the issue where the value of no_preempt gets unexpected value
(-1, 1, 2 etc.) after process ends when running the UTI tests.

Change-Id: I7d9c08b754a171ea3fdec20ab2e635df3b607cbd
---
 kernel/cls.c             | 10 +++++-----
 kernel/include/cls.h     |  2 +-
 kernel/include/kmalloc.h |  6 ++++--
 kernel/process.c         |  4 ++--
 kernel/syscall.c         |  3 ++-
 5 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/kernel/cls.c b/kernel/cls.c
index bfa669c3..7e8981b5 100644
--- a/kernel/cls.c
+++ b/kernel/cls.c
@@ -66,15 +66,15 @@ void preempt_enable(void)
 {
 #ifndef ENABLE_FUGAKU_HACKS
 	if (cpu_local_var_initialized)
-		--cpu_local_var(no_preempt);
+		ihk_atomic_dec(&cpu_local_var(no_preempt));
 #else
 	if (cpu_local_var_initialized) {
-		--cpu_local_var(no_preempt);
+		ihk_atomic_dec(&cpu_local_var(no_preempt));
 
-		if (cpu_local_var(no_preempt) < 0) {
+		if (ihk_atomic_read(&cpu_local_var(no_preempt)) < 0) {
 			//cpu_disable_interrupt();
 
-	__kprintf("%s: %d\n", __func__, cpu_local_var(no_preempt));
+		__kprintf("%s: %d\n", __func__, ihk_atomic_read(&cpu_local_var(no_preempt)));
     __kprintf("TID: %d, call stack from builtin frame (most recent first):\n",
         cpu_local_var(current)->tid);
 	__show_context_stack(cpu_local_var(current), (uintptr_t)&preempt_enable,
@@ -93,7 +93,7 @@ void preempt_enable(void)
 void preempt_disable(void)
 {
 	if (cpu_local_var_initialized) {
-		++cpu_local_var(no_preempt);
+		ihk_atomic_inc(&cpu_local_var(no_preempt));
 	}
 }
 
diff --git a/kernel/include/cls.h b/kernel/include/cls.h
index 0cd2ad11..6516718f 100644
--- a/kernel/include/cls.h
+++ b/kernel/include/cls.h
@@ -107,7 +107,7 @@ struct cpu_local_var {
 	struct list_head migq;
 	int in_interrupt;
 	int in_page_fault;
-	int no_preempt;
+	ihk_atomic_t no_preempt;
 	int timer_enabled;
 	unsigned long nr_ctx_switches;
 	int kmalloc_initialized;
diff --git a/kernel/include/kmalloc.h b/kernel/include/kmalloc.h
index a389ee7c..e7fb8526 100644
--- a/kernel/include/kmalloc.h
+++ b/kernel/include/kmalloc.h
@@ -19,8 +19,10 @@
 
 #define kmalloc(size, flag) ({\
 void *r = _kmalloc(size, flag, __FILE__, __LINE__);\
-if(r == NULL){\
-kprintf("kmalloc: out of memory %s:%d no_preempt=%d\n", __FILE__, __LINE__, cpu_local_var(no_preempt)); \
+if (r == NULL) {\
+	kprintf("kmalloc: out of memory %s:%d no_preempt=%d\n", \
+		__FILE__, __LINE__, \
+		ihk_atomic_read(&cpu_local_var(no_preempt))); \
 }\
 r;\
 })
diff --git a/kernel/process.c b/kernel/process.c
index 6d3c1d27..6edf61e0 100644
--- a/kernel/process.c
+++ b/kernel/process.c
@@ -3726,9 +3726,9 @@ void schedule(void)
 	int prevpid;
 	unsigned long irqstate = 0;
 
-	if (cpu_local_var(no_preempt)) {
+	if (ihk_atomic_read(&cpu_local_var(no_preempt))) {
 		kprintf("%s: WARNING can't schedule() while no preemption, cnt: %d\n",
-			__func__, cpu_local_var(no_preempt));
+			__func__, ihk_atomic_read(&cpu_local_var(no_preempt)));
 
 		irqstate = cpu_disable_interrupt_save();
 		ihk_mc_spinlock_lock_noirq(
diff --git a/kernel/syscall.c b/kernel/syscall.c
index b5ecdb05..d6509b6d 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -260,7 +260,8 @@ long do_syscall(struct syscall_request *req, int cpu)
 			cpu_pause();
 
 			/* Spin if not preemptable */
-			if (cpu_local_var(no_preempt) || !thread->tid) {
+			if (ihk_atomic_read(&cpu_local_var(no_preempt))
+				|| !thread->tid) {
 				continue;
 			}