s390: introduce nospec_uses_trampoline()

and replace all of the "__is_defined(CC_USING_EXPOLINE) && !nospec_disable"
occurrences.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

arch/s390/include/asm/nospec-branch.h

@@ -12,6 +12,11 @@ void nospec_init_branches(void);
 void nospec_auto_detect(void);
 void nospec_revert(s32 *start, s32 *end);
 
+static inline bool nospec_uses_trampoline(void)
+{
+	return __is_defined(CC_USING_EXPOLINE) && !nospec_disable;
+}
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_S390_EXPOLINE_H */

arch/s390/kernel/nospec-branch.c

@@ -38,7 +38,7 @@ static int __init nospec_report(void)
 {
 	if (test_facility(156))
 		pr_info("Spectre V2 mitigation: etokens\n");
-	if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable)
+	if (nospec_uses_trampoline())
 		pr_info("Spectre V2 mitigation: execute trampolines\n");
 	if (__test_facility(82, alt_stfle_fac_list))
 		pr_info("Spectre V2 mitigation: limited branch prediction\n");

arch/s390/kernel/nospec-sysfs.c

@@ -15,7 +15,7 @@ ssize_t cpu_show_spectre_v2(struct device *dev,
 {
 	if (test_facility(156))
 		return sprintf(buf, "Mitigation: etokens\n");
-	if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable)
+	if (nospec_uses_trampoline())
 		return sprintf(buf, "Mitigation: execute trampolines\n");
 	if (__test_facility(82, alt_stfle_fac_list))
 		return sprintf(buf, "Mitigation: limited branch prediction\n");

arch/s390/net/bpf_jit_comp.c

@@ -567,7 +567,7 @@ static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
 	EMIT4(0xb9040000, REG_2, BPF_REG_0);
 	/* Restore registers */
 	save_restore_regs(jit, REGS_RESTORE, stack_depth);
-	if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable) {
+	if (nospec_uses_trampoline()) {
 		jit->r14_thunk_ip = jit->prg;
 		/* Generate __s390_indirect_jump_r14 thunk */
 		if (test_facility(35)) {
@@ -585,7 +585,7 @@ static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
 	/* br %r14 */
 	_EMIT2(0x07fe);
 
-	if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable &&
+	if ((nospec_uses_trampoline()) &&
 	    (is_first_pass(jit) || (jit->seen & SEEN_FUNC))) {
 		jit->r1_thunk_ip = jit->prg;
 		/* Generate __s390_indirect_jump_r1 thunk */
@@ -1332,7 +1332,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 		jit->seen |= SEEN_FUNC;
 		/* lgrl %w1,func */
 		EMIT6_PCREL_RILB(0xc4080000, REG_W1, _EMIT_CONST_U64(func));
-		if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable) {
+		if (nospec_uses_trampoline()) {
 			/* brasl %r14,__s390_indirect_jump_r1 */
 			EMIT6_PCREL_RILB(0xc0050000, REG_14, jit->r1_thunk_ip);
 		} else {