[PATCH AUTOSEL 6.3 28/30] tools/virtio: Fix arm64 ringtest compilation error

From: Sasha Levin
Date: Fri Jun 16 2023 - 06:30:34 EST


From: Rong Tao <rongtao@xxxxxxxx>

[ Upstream commit 57380fd1249b20ef772549af2c58ef57b21faba7 ]

Add cpu_relax() for arm64 instead of directly assert(), and add assert.h
header file. Also, add smp_wmb and smp_mb for arm64.

Compilation error as follows, avoid __always_inline undefined.

$ make
cc -Wall -pthread -O2 -ggdb -flto -fwhole-program -c -o ring.o ring.c
In file included from ring.c:10:
main.h: In function ‘busy_wait’:
main.h:99:21: warning: implicit declaration of function ‘assert’
[-Wimplicit-function-declaration]
99 | #define cpu_relax() assert(0)
| ^~~~~~
main.h:107:17: note: in expansion of macro ‘cpu_relax’
107 | cpu_relax();
| ^~~~~~~~~
main.h:12:1: note: ‘assert’ is defined in header ‘<assert.h>’; did you
forget to ‘#include <assert.h>’?
11 | #include <stdbool.h>
+++ |+#include <assert.h>
12 |
main.h: At top level:
main.h:143:23: error: expected ‘;’ before ‘void’
143 | static __always_inline
| ^
| ;
144 | void __read_once_size(const volatile void *p, void *res, int
size)
| ~~~~
main.h:158:23: error: expected ‘;’ before ‘void’
158 | static __always_inline void __write_once_size(volatile void *p,
void *res, int size)
| ^~~~~
| ;
make: *** [<builtin>: ring.o] Error 1

Signed-off-by: Rong Tao <rongtao@xxxxxxxx>
Message-Id: <tencent_F53E159DD7925174445D830DA19FACF44B07@xxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/virtio/ringtest/main.h | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h
index b68920d527503..d18dd317e27f9 100644
--- a/tools/virtio/ringtest/main.h
+++ b/tools/virtio/ringtest/main.h
@@ -8,6 +8,7 @@
#ifndef MAIN_H
#define MAIN_H

+#include <assert.h>
#include <stdbool.h>

extern int param;
@@ -95,6 +96,8 @@ extern unsigned ring_size;
#define cpu_relax() asm ("rep; nop" ::: "memory")
#elif defined(__s390x__)
#define cpu_relax() barrier()
+#elif defined(__aarch64__)
+#define cpu_relax() asm ("yield" ::: "memory")
#else
#define cpu_relax() assert(0)
#endif
@@ -112,6 +115,8 @@ static inline void busy_wait(void)

#if defined(__x86_64__) || defined(__i386__)
#define smp_mb() asm volatile("lock; addl $0,-132(%%rsp)" ::: "memory", "cc")
+#elif defined(__aarch64__)
+#define smp_mb() asm volatile("dmb ish" ::: "memory")
#else
/*
* Not using __ATOMIC_SEQ_CST since gcc docs say they are only synchronized
@@ -136,10 +141,16 @@ static inline void busy_wait(void)

#if defined(__i386__) || defined(__x86_64__) || defined(__s390x__)
#define smp_wmb() barrier()
+#elif defined(__aarch64__)
+#define smp_wmb() asm volatile("dmb ishst" ::: "memory")
#else
#define smp_wmb() smp_release()
#endif

+#ifndef __always_inline
+#define __always_inline inline __attribute__((always_inline))
+#endif
+
static __always_inline
void __read_once_size(const volatile void *p, void *res, int size)
{
--
2.39.2