[PATCH v2] KVM: selftests: hyperv_tlb_flush: use swap() to swap PTEs

[Piotr Zarycki]

Replace the open-coded swap with the swap() macro.

Signed-off-by: Piotr Zarycki <piotr.zary...@gmail.com>
---
tools/include/linux/kernel.h breaks perf — swap is used there as a
function pointer call. Using tools/testing/selftests/kselftest.h instead.

 tools/testing/selftests/kselftest.h                | 4 ++++
 tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c | 6 +-----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/kselftest.h 
b/tools/testing/selftests/kselftest.h
index 60838b61a2da..7f53751523d8 100644
--- a/tools/testing/selftests/kselftest.h
+++ b/tools/testing/selftests/kselftest.h
@@ -64,6 +64,10 @@
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
 #endif
 
+#ifndef swap
+#define swap(a, b)  do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } 
while (0)
+#endif
+
 #if defined(__i386__) || defined(__x86_64__) /* arch */
 /*
  * gcc cpuid.h provides __cpuid_count() since v4.4.
diff --git a/tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c 
b/tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c
index 15ee8b7bfc11..514d41f00714 100644
--- a/tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c
+++ b/tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c
@@ -131,14 +131,10 @@ static void set_expected_val(void *addr, u64 val, int 
vcpu_id)
 
 /*
  * Update PTEs swapping two test pages.
- * TODO: use swap()/xchg() when these are provided.
  */
 static void swap_two_test_pages(gpa_t pte_gva1, gpa_t pte_gva2)
 {
-       u64 tmp = *(u64 *)pte_gva1;
-
-       *(u64 *)pte_gva1 = *(u64 *)pte_gva2;
-       *(u64 *)pte_gva2 = tmp;
+       swap(*(u64 *)pte_gva1, *(u64 *)pte_gva2);
 }
 
 /*
-- 
2.54.0