buildsys: Stop checking for ESA/390 host

We still build QEMU tools on 32-bit hosts (see commit
cf634dfcd8), however no OS supported by QEMU still runs
on ESA/390 (Linux dropped support in release 4.1 in 2015).

Remove the configure check, directly checking for the 64-bit
z/Architecture.

Also per commit 3704993f54 from 2020:

  "we don't support s390, only 64-bit s390x hosts".

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20260519171240.97420-4-philmd@linaro.org>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

block/file-posix.c

@@ -79,7 +79,7 @@
 #include <linux/hdreg.h>
 #include <linux/magic.h>
 #include <scsi/sg.h>
-#ifdef __s390__
+#ifdef __s390x__
 #include <asm/dasd.h>
 #endif
 #ifndef FS_NOCOW_FL

configure

@@ -399,12 +399,8 @@ elif check_define _ARCH_PPC64 ; then
   else
     cpu="ppc64"
   fi
-elif check_define __s390__ ; then
-  if check_define __s390x__ ; then
-    cpu="s390x"
-  else
-    cpu="s390"
-  fi
+elif check_define __s390x__ ; then
+  cpu="s390x"
 elif check_define __riscv && check_define _LP64 ; then
   cpu="riscv64"
 elif check_define __aarch64__ ; then
@@ -461,10 +457,6 @@ case "$cpu" in
     linux_arch=riscv
     ;;
 
-  s390)
-    linux_arch=s390
-    CPU_CFLAGS="-m31"
-    ;;
   s390x)
     host_arch=s390x
     linux_arch=s390

disas/disas-host.c

@@ -74,7 +74,7 @@ static void initialize_debug_host(CPUDebug *s)
     s->info.print_insn = print_insn_little_mips;
 #elif defined(__m68k__)
     s->info.print_insn = print_insn_m68k;
-#elif defined(__s390__)
+#elif defined(__s390x__)
     s->info.cap_arch = CS_ARCH_SYSZ;
     s->info.cap_insn_unit = 2;
     s->info.cap_insn_split = 6;

include/qemu/cacheflush.h

@@ -19,7 +19,7 @@
  * mappings of the same physical page(s).
  */
 
-#if defined(__x86_64__) || defined(__s390__)
+#if defined(__x86_64__) || defined(__s390x__)
 
 static inline void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
 {

include/qemu/timer.h

@@ -889,7 +889,7 @@ static inline int64_t cpu_get_host_ticks(void)
     return val;
 }
 
-#elif defined(__s390__)
+#elif defined(__s390x__)
 
 static inline int64_t cpu_get_host_ticks(void)
 {

util/cacheflush.c

@@ -223,7 +223,7 @@ static void __attribute__((constructor)) init_cache_info(void)
  * Architecture (+ OS) specific cache flushing mechanisms.
  */
 
-#if defined(__x86_64__) || defined(__s390__)
+#if defined(__x86_64__) || defined(__s390x__)
 
 /* Caches are coherent and do not require flushing; symbol inline. */