MDEV-27956 hardware lock ellision on s390x/ppc64{,le}

Per https://gcc.gnu.org/onlinedocs/gcc/PowerPC-Hardware-Transactional-Memory-Built-in-Functions.html

The .. high level HTM interface .. is common between PowerPC and S/390

Reimplemented the transactional_lock_enabled() detection mechanism for
s390x and POWER based on SIGILL. This also gives non-Linux based unixes
the ability to use HTM. The implementation is based off openssl.
(ref:
1c0eede982/crypto/s390xcap.c (L104))

The other ppc64{,le} problems with getauxvec based detection:
* Checking PPC_FEATURE2_HTM_NOSC not needed as we do not do syscalls while
  in a transactional state.
* As we don't use, and never should use PPC_FEATURE2_HTM_NO_SUSPEND,
  or do syscalls while in transactional state, don't test it.
From: https://www.kernel.org/doc/html/v5.4/powerpc/syscall64-abi.html#transactional-memory

S390x high level __builtin_tbegin functions in the htmxlintrin.h are not
inline. This header file can be included once in the entire set of sources for
a linked target, otherwise duplicate symbols occur. While we could use inline
xabort/xend functions using the low level interface, we keep this the same as
ppc64 for simplicity.

SLES-15, gcc-7, appeared to want everything that included the htmlxlintrin to
be compiled with -mhtm otherwise the __builtin_t{func} where not defined
(in addition to a #ifdef __HTM__ #error). Debian sid gcc-11.2 wanted the same
on ppc64le/ppc64. In general we want to avoid a wide spread use of architecture
cflags as it makes justifications for selective optimizations easier.
(ref: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1006702)

storage/innobase/CMakeLists.txt

@@ -384,7 +384,10 @@ ENDIF()
 # Older gcc version insist on -mhtm flag for including the
 # htmxlintrin.h header. This is also true for new gcc versions
 # like 11.2.0 in Debian Sid
-IF(CMAKE_SYSTEM_PROCESSOR MATCHES "ppc64|powerpc64")
+# s390x because of the way it defines the high level intrinsics
+# as not-inline in the header file can only be included by one
+# source file that has -mhtm enabled.
+IF(CMAKE_SYSTEM_PROCESSOR MATCHES "ppc64|powerpc64|s390x")
   ADD_COMPILE_FLAGS(
       sync/srw_lock.cc
       COMPILE_FLAGS "-mhtm"

storage/innobase/include/transactional_lock_guard.h

@@ -18,8 +18,8 @@ this program; if not, write to the Free Software Foundation, Inc.,
 
 #pragma once
 
-#if defined __powerpc64__ && defined __clang__ && defined __linux__
-#elif defined __powerpc64__&&defined __GNUC__&&defined __linux__&&__GNUC__ > 4
+#if defined __powerpc64__
+#elif defined __s390__
 #elif defined _MSC_VER && (defined _M_IX86 || defined _M_X64) && !defined(__clang__)
 #elif defined __GNUC__ && (defined __i386__ || defined __x86_64__)
 # if __GNUC__ >= 8
@@ -69,7 +69,7 @@ static inline bool xtest() { return have_transactional_memory && _xtest(); }
 TRANSACTIONAL_INLINE static inline void xabort() { _xabort(0); }
 
 TRANSACTIONAL_INLINE static inline void xend() { _xend(); }
-# elif defined __powerpc64__
+# elif defined __powerpc64__ || defined __s390__
 extern bool have_transactional_memory;
 bool transactional_lock_enabled();
 #   define TRANSACTIONAL_TARGET __attribute__((hot))
@@ -77,10 +77,17 @@ bool transactional_lock_enabled();
 
 /**
   Newer gcc compilers only provide __builtin_{htm}
-  function when the -mhtm is actually provided. So
+  functions when the -mhtm CFLAG is actually provided. So
   we've got the option of including it globally, or
-  pushing down to one file with that enabled and removing
-  the inline optimization.
+  pushing down the inclusion of htmxlintrin.h to one
+  file with -mhtm enabled and removing the inline
+  optimization.
+
+  Per FIXME in s390x's htmxlintrin.h, the __TM_simple_begin
+  isn't always_inline resulting in duplicate definitions if
+  it where included more than once.  While xabort and xend
+  could be implemented here, we keep the implementation the
+  same as ppc64.
  */
 TRANSACTIONAL_TARGET bool xbegin();
 TRANSACTIONAL_TARGET void xabort();

storage/innobase/sync/srw_lock.cc

@@ -54,8 +54,10 @@ bool transactional_lock_enabled()
 TRANSACTIONAL_TARGET
 bool xtest() { return have_transactional_memory && _xtest(); }
 # endif
-#elif defined __powerpc64__
+#elif defined __powerpc64__ || defined __s390__
 # include <htmxlintrin.h>
+# include <setjmp.h>
+# include <signal.h>
 
 __attribute__((target("htm"),hot))
 bool xbegin()
@@ -69,27 +71,46 @@ void xabort() { __TM_abort(); }
 
 __attribute__((target("htm"),hot))
 void xend() { __TM_end(); }
-# ifdef __linux__
-#  include <sys/auxv.h>
 
-#  ifndef PPC_FEATURE2_HTM_NOSC
-#   define PPC_FEATURE2_HTM_NOSC 0x01000000
-#  endif
-#  ifndef PPC_FEATURE2_HTM_NO_SUSPEND
-#   define PPC_FEATURE2_HTM_NO_SUSPEND 0x00080000
-#  endif
-
-#  ifndef AT_HWCAP2
-#   define AT_HWCAP2 26
-#  endif
-# endif
 bool have_transactional_memory;
+static sigjmp_buf ill_jmp;
+static void ill_handler(int sig)
+{
+  siglongjmp(ill_jmp, sig);
+}
+/**
+  Here we are testing we can do a transaction without SIGILL
+  and a 1 instruction store can succeed.
+*/
+__attribute__((noinline))
+static void test_tm(bool *r)
+{
+  if (__TM_simple_begin() == _HTM_TBEGIN_STARTED)
+  {
+    *r= true;
+    __TM_end();
+  }
+}
 bool transactional_lock_enabled()
 {
-# ifdef __linux__
-  return getauxval(AT_HWCAP2) &
-    (PPC_FEATURE2_HTM_NOSC | PPC_FEATURE2_HTM_NO_SUSPEND);
-# endif
+  bool r= false;
+  sigset_t oset;
+  struct sigaction ill_act, oact_ill;
+
+  memset(&ill_act, 0, sizeof(ill_act));
+  ill_act.sa_handler = ill_handler;
+  sigfillset(&ill_act.sa_mask);
+  sigdelset(&ill_act.sa_mask, SIGILL);
+
+  sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
+  sigaction(SIGILL, &ill_act, &oact_ill);
+  if (sigsetjmp(ill_jmp, 1) == 0)
+  {
+    test_tm(&r);
+  }
+  sigaction(SIGILL, &oact_ill, NULL);
+  sigprocmask(SIG_SETMASK, &oset, NULL);
+  return r;
 }
 
 # ifdef UNIV_DEBUG

storage/innobase/unittest/CMakeLists.txt

@@ -21,7 +21,8 @@ ADD_EXECUTABLE(innodb_fts-t innodb_fts-t.cc)
 TARGET_LINK_LIBRARIES(innodb_fts-t mysys mytap)
 ADD_DEPENDENCIES(innodb_fts-t GenError)
 MY_ADD_TEST(innodb_fts)
-IF(CMAKE_SYSTEM_PROCESSOR MATCHES "ppc64|powerpc64")
+# See explanation in innobase/CmakeLists.txt
+IF(CMAKE_SYSTEM_PROCESSOR MATCHES "ppc64|powerpc64|s390x")
   ADD_COMPILE_FLAGS(
       ../sync/srw_lock.cc
       COMPILE_FLAGS "-mhtm"