From d886375ee4e457bd30759130e8af3775532ee516 Mon Sep 17 00:00:00 2001
From: Shiqing Gao <shiqing.gao@intel.com>
Date: Thu, 13 Sep 2018 10:50:46 +0800
Subject: [PATCH] hv: clean up spinlock

- move spinlock_init and spinlock_obtain to spinlock.h as inline APIs
- remove spinlock.c

Tracked-On: #861
Signed-off-by: Shiqing Gao <shiqing.gao@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>
---
 hypervisor/Makefile               |  1 -
 hypervisor/include/lib/spinlock.h | 30 +++++++++++++++++++++++++--
 hypervisor/lib/spinlock.c         | 34 -------------------------------
 3 files changed, 28 insertions(+), 37 deletions(-)
 delete mode 100644 hypervisor/lib/spinlock.c

diff --git a/hypervisor/Makefile b/hypervisor/Makefile
index f5e4713ff..cc18804a9 100644
--- a/hypervisor/Makefile
+++ b/hypervisor/Makefile
@@ -151,7 +151,6 @@ C_SRCS += arch/x86/guest/vmsr.c
 C_SRCS += arch/x86/guest/instr_emul.c
 C_SRCS += arch/x86/guest/ucode.c
 C_SRCS += arch/x86/guest/pm.c
-C_SRCS += lib/spinlock.c
 C_SRCS += lib/misc.c
 C_SRCS += lib/string.c
 C_SRCS += lib/memory.c
diff --git a/hypervisor/include/lib/spinlock.h b/hypervisor/include/lib/spinlock.h
index d6383bc8b..53190001c 100644
--- a/hypervisor/include/lib/spinlock.h
+++ b/hypervisor/include/lib/spinlock.h
@@ -10,6 +10,7 @@
 #ifndef ASSEMBLER
 
 #include <types.h>
+#include <rtl.h>
 
 /** The architecture dependent spinlock type. */
 typedef struct _spinlock {
@@ -19,8 +20,33 @@ typedef struct _spinlock {
 } spinlock_t;
 
 /* Function prototypes */
-void spinlock_init(spinlock_t *lock);
-void spinlock_obtain(spinlock_t *lock);
+static inline void spinlock_init(spinlock_t *lock)
+{
+	(void)memset(lock, 0U, sizeof(spinlock_t));
+}
+
+static inline void spinlock_obtain(spinlock_t *lock)
+{
+
+	/* The lock function atomically increments and exchanges the head
+	 * counter of the queue. If the old head of the queue is equal to the
+	 * tail, we have locked the spinlock. Otherwise we have to wait.
+	 */
+
+	asm volatile ("   movl $0x1,%%eax\n"
+		      "   lock xaddl %%eax,%[head]\n"
+		      "   cmpl %%eax,%[tail]\n"
+		      "   jz 1f\n"
+		      "2: pause\n"
+		      "   cmpl %%eax,%[tail]\n"
+		      "   jnz 2b\n"
+		      "1:\n"
+		      :
+		      :
+		      [head] "m"(lock->head),
+		      [tail] "m"(lock->tail)
+		      : "cc", "memory", "eax");
+}
 
 static inline void spinlock_release(spinlock_t *lock)
 {
diff --git a/hypervisor/lib/spinlock.c b/hypervisor/lib/spinlock.c
deleted file mode 100644
index 1611d13f4..000000000
--- a/hypervisor/lib/spinlock.c
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * Copyright (C) 2018 Intel Corporation. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#include <hv_lib.h>
-
-void spinlock_init(spinlock_t *lock)
-{
-	(void)memset(lock, 0U, sizeof(spinlock_t));
-}
-
-void spinlock_obtain(spinlock_t *lock)
-{
-
-	/* The lock function atomically increments and exchanges the head
-	 * counter of the queue. If the old head of the queue is equal to the
-	 * tail, we have locked the spinlock. Otherwise we have to wait.
-	 */
-
-	asm volatile ("   lock xaddl %%eax,%[head]\n"
-		      "   cmpl %%eax,%[tail]\n"
-		      "   jz 1f\n"
-		      "2: pause\n"
-		      "   cmpl %%eax,%[tail]\n"
-		      "   jnz 2b\n"
-		      "1:\n"
-		      :
-		      : "a" (1),
-		      [head] "m"(lock->head),
-		      [tail] "m"(lock->tail)
-		      : "cc", "memory");
-}