[S390] use inline assembly contraints available with gcc 3.3.3

Drop support to compile the kernel with gcc versions older than 3.3.3.
This allows us to use the "Q" inline assembly contraint on some more
inline assemblies without duplicating a lot of complex code (e.g. __xchg
and __cmpxchg). The distinction for older gcc versions can be removed
which saves a few lines and simplifies the code.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index 63e46433e81d..a5850a0cfe80 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -9,6 +9,14 @@
 #include <asm/vdso.h>
 #include <asm/sigp.h>
 
+/*
+ * Make sure that the compiler is new enough. We want a compiler that
+ * is known to work with the "Q" assembler constraint.
+ */
+#if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 3)
+#error Your compiler is too old; please use version 3.3.3 or newer
+#endif
+
 int main(void)
 {
         DEFINE(__THREAD_info, offsetof(struct task_struct, stack));