selftests/powerpc: Check FP/VEC on exception in TM

Add a self test to check if FP/VEC/VSX registers are sane (restored
correctly) after a FP/VEC/VSX unavailable exception is caught during a
transaction.

This test checks all possibilities in a thread regarding the combination
of MSR.[FP|VEC] states in a thread and for each scenario raises a
FP/VEC/VSX unavailable exception in transactional state, verifying if
vs0 and vs32 registers, which are representatives of FP/VEC/VSX reg
sets, are not corrupted.

Signed-off-by: Gustavo Romero <gromero@linux.vnet.ibm.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

tools/testing/selftests/powerpc/tm/tm.h

@@ -47,6 +47,11 @@ static inline bool failure_is_syscall(void)
 	return (failure_code() & TM_CAUSE_SYSCALL) == TM_CAUSE_SYSCALL;
 }
 
+static inline bool failure_is_unavailable(void)
+{
+	return (failure_code() & TM_CAUSE_FAC_UNAV) == TM_CAUSE_FAC_UNAV;
+}
+
 static inline bool failure_is_nesting(void)
 {
 	return (__builtin_get_texasru() & 0x400000);