selftests/bpf: Use CAN_USE_LOAD_ACQ_STORE_REL when appropriate

Instead of open-coding the conditions, use
'#ifdef CAN_USE_LOAD_ACQ_STORE_REL' to guard the following tests:

  verifier_precision/bpf_load_acquire
  verifier_precision/bpf_store_release
  verifier_store_release/*

Note that, for the first two tests in verifier_precision.c, switching to
'#ifdef CAN_USE_LOAD_ACQ_STORE_REL' means also checking if
'__clang_major__ >= 18', which has already been guaranteed by the outer
'#if' check.

Acked-by: Björn Töpel <[email protected]>
Reviewed-by: Pu Lehui <[email protected]>
Tested-by: Björn Töpel <[email protected]> # QEMU/RVA23
Signed-off-by: Peilin Ye <[email protected]>
Link: https://lore.kernel.org/r/45d7e025f6e390a8ff36f08fc51e31705ac896bd.1746588351.git.yepeilin@google.com
Signed-off-by: Alexei Starovoitov <[email protected]>

Author: peilin-ye

tools/testing/selftests/bpf/progs/verifier_precision.c

@@ -91,8 +91,7 @@ __naked int bpf_end_bswap(void)
 		::: __clobber_all);
 }
 
-#if defined(ENABLE_ATOMICS_TESTS) && \
-	(defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86))
+#ifdef CAN_USE_LOAD_ACQ_STORE_REL
 
 SEC("?raw_tp")
 __success __log_level(2)
@@ -138,7 +137,7 @@ __naked int bpf_store_release(void)
 	: __clobber_all);
 }
 
-#endif /* load-acquire, store-release */
+#endif /* CAN_USE_LOAD_ACQ_STORE_REL */
 #endif /* v4 instruction */
 
 SEC("?raw_tp")

tools/testing/selftests/bpf/progs/verifier_store_release.c

@@ -6,8 +6,7 @@
 #include "../../../include/linux/filter.h"
 #include "bpf_misc.h"
 
-#if __clang_major__ >= 18 && defined(ENABLE_ATOMICS_TESTS) && \
-	(defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86))
+#ifdef CAN_USE_LOAD_ACQ_STORE_REL
 
 SEC("socket")
 __description("store-release, 8-bit")
@@ -271,7 +270,7 @@ __naked void store_release_with_invalid_reg(void)
 	: __clobber_all);
 }
 
-#else
+#else /* CAN_USE_LOAD_ACQ_STORE_REL */
 
 SEC("socket")
 __description("Clang version < 18, ENABLE_ATOMICS_TESTS not defined, and/or JIT doesn't support store-release, use a dummy test")
@@ -281,6 +280,6 @@ int dummy_test(void)
 	return 0;
 }
 
-#endif
+#endif /* CAN_USE_LOAD_ACQ_STORE_REL */
 
 char _license[] SEC("license") = "GPL";