tests/tcg/s390x: Test CKSM

Add a small test to prevent regressions.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230724082032.66864-9-iii@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

tests/tcg/s390x/Makefile.softmmu-target

@@ -16,6 +16,7 @@ LDFLAGS=-nostdlib -static
 
 ASM_TESTS =                                                                    \
     bal                                                                        \
+    cksm                                                                       \
     exrl-ssm-early                                                             \
     sam                                                                        \
     lpsw                                                                       \

tests/tcg/s390x/cksm.S

@@ -0,0 +1,29 @@
+    .org 0x8e
+program_interruption_code:
+    .org 0x1d0                         /* program new PSW */
+    .quad 0,pgm
+    .org 0x200                         /* lowcore padding */
+    .globl _start
+_start:
+    lmg %r0,%r1,cksm_args
+    cksm %r2,%r0
+    c %r2,cksm_exp
+    jne failure
+    .insn rre,0xb2410000,%r2,%r15      /* cksm %r2,%r15 */
+failure:
+    lpswe failure_psw
+pgm:
+    chhsi program_interruption_code,6  /* specification exception? */
+    jne failure
+    lpswe success_psw
+cksm_args:
+    .quad cksm_buf, 16
+cksm_buf:
+    .quad 0xaaaabbbbcccc0000, 0x12345678
+cksm_exp:
+    .long 0x89ab1234
+    .align 8
+success_psw:
+    .quad 0x2000000000000,0xfff        /* see is_special_wait_psw() */
+failure_psw:
+    .quad 0x2000000000000,0            /* disabled wait */