[v3] s390x: Add glibc-hwcaps support

  Subdirectories z13, z14, z15 can be selected, mostly based on the
level of support for vector instructions.

Co-Authored-By: Stefan Liebler <stli@linux.ibm.com>

---
v3: Incorporated suggestions from Stefan.  Tested on z14 and z15.

 elf/Makefile                             |  2 +-
 elf/tst-glibc-hwcaps-cache.script        | 10 ++++
 sysdeps/s390/s390-64/Makefile            | 39 +++++++++++++++
 sysdeps/s390/s390-64/dl-hwcaps-subdirs.c | 54 +++++++++++++++++++++
 sysdeps/s390/s390-64/tst-glibc-hwcaps.c  | 82 ++++++++++++++++++++++++++++++++
 5 files changed, 186 insertions(+), 1 deletion(-)
  

Hi Florian,

this patch is okay.

Thanks,
Stefan

On 12/9/20 9:12 PM, Florian Weimer wrote:
> Subdirectories z13, z14, z15 can be selected, mostly based on the
> level of support for vector instructions.
> 
> Co-Authored-By: Stefan Liebler <stli@linux.ibm.com>
> 
> ---
> v3: Incorporated suggestions from Stefan.  Tested on z14 and z15.
> 
>  elf/Makefile                             |  2 +-
>  elf/tst-glibc-hwcaps-cache.script        | 10 ++++
>  sysdeps/s390/s390-64/Makefile            | 39 +++++++++++++++
>  sysdeps/s390/s390-64/dl-hwcaps-subdirs.c | 54 +++++++++++++++++++++
>  sysdeps/s390/s390-64/tst-glibc-hwcaps.c  | 82 ++++++++++++++++++++++++++++++++
>  5 files changed, 186 insertions(+), 1 deletion(-)
> 
> diff --git a/elf/Makefile b/elf/Makefile
> index 395381ca42..59bce97a3b 100644
> --- a/elf/Makefile
> +++ b/elf/Makefile
> @@ -1832,7 +1832,7 @@ $(objpfx)argv0test.out: tst-rtld-argv0.sh $(objpfx)ld.so \
>  # glibc-hwcaps mechanism for this architecture).  Used to obtain test
>  # coverage for some glibc-hwcaps tests for the widest possible range
>  # of systems.
> -glibc-hwcaps-first-subdirs-for-tests = power9 x86-64-v2
> +glibc-hwcaps-first-subdirs-for-tests = power9 x86-64-v2 z13
>  
>  # The test modules are parameterized by preprocessor macros.
>  LDFLAGS-libmarkermod1-1.so += -Wl,-soname,libmarkermod1.so
> diff --git a/elf/tst-glibc-hwcaps-cache.script b/elf/tst-glibc-hwcaps-cache.script
> index 6a4675f9bd..c3271f61f9 100644
> --- a/elf/tst-glibc-hwcaps-cache.script
> +++ b/elf/tst-glibc-hwcaps-cache.script
> @@ -11,6 +11,16 @@ mkdirp 0770 $L/glibc-hwcaps/power10
>  cp $B/elf/libmarkermod3-2.so $L/glibc-hwcaps/power9/libmarkermod3.so
>  cp $B/elf/libmarkermod3-3.so $L/glibc-hwcaps/power10/libmarkermod3.so
>  
> +mkdirp 0770 $L/glibc-hwcaps/z13
> +cp $B/elf/libmarkermod2-2.so $L/glibc-hwcaps/z13/libmarkermod2.so
> +mkdirp 0770 $L/glibc-hwcaps/z14
> +cp $B/elf/libmarkermod3-2.so $L/glibc-hwcaps/z13/libmarkermod3.so
> +cp $B/elf/libmarkermod3-3.so $L/glibc-hwcaps/z14/libmarkermod3.so
> +mkdirp 0770 $L/glibc-hwcaps/z15
> +cp $B/elf/libmarkermod4-2.so $L/glibc-hwcaps/z13/libmarkermod4.so
> +cp $B/elf/libmarkermod4-3.so $L/glibc-hwcaps/z14/libmarkermod4.so
> +cp $B/elf/libmarkermod4-4.so $L/glibc-hwcaps/z15/libmarkermod4.so
> +
>  mkdirp 0770 $L/glibc-hwcaps/x86-64-v2
>  cp $B/elf/libmarkermod2-2.so $L/glibc-hwcaps/x86-64-v2/libmarkermod2.so
>  mkdirp 0770 $L/glibc-hwcaps/x86-64-v3
> diff --git a/sysdeps/s390/s390-64/Makefile b/sysdeps/s390/s390-64/Makefile
> index b4d793bb3d..e5da26871c 100644
> --- a/sysdeps/s390/s390-64/Makefile
> +++ b/sysdeps/s390/s390-64/Makefile
> @@ -6,4 +6,43 @@ ifeq ($(subdir),elf)
>  CFLAGS-rtld.c += -Wno-uninitialized -Wno-unused
>  CFLAGS-dl-load.c += -Wno-unused
>  CFLAGS-dl-reloc.c += -Wno-unused
> +
> +$(objpfx)tst-glibc-hwcaps: $(objpfx)libmarkermod2-1.so \
> +  $(objpfx)libmarkermod3-1.so $(objpfx)libmarkermod4-1.so
> +$(objpfx)tst-glibc-hwcaps.out: \
> +  $(objpfx)libmarkermod2.so \
> +    $(objpfx)glibc-hwcaps/z13/libmarkermod2.so \
> +  $(objpfx)libmarkermod3.so \
> +    $(objpfx)glibc-hwcaps/z13/libmarkermod3.so \
> +    $(objpfx)glibc-hwcaps/z14/libmarkermod3.so \
> +  $(objpfx)libmarkermod4.so \
> +    $(objpfx)glibc-hwcaps/z13/libmarkermod4.so \
> +    $(objpfx)glibc-hwcaps/z14/libmarkermod4.so \
> +    $(objpfx)glibc-hwcaps/z15/libmarkermod4.so \
> +
> +$(objpfx)glibc-hwcaps/z13/libmarkermod2.so: $(objpfx)libmarkermod2-2.so
> +	$(make-target-directory)
> +	cp $< $@
> +$(objpfx)glibc-hwcaps/z13/libmarkermod3.so: $(objpfx)libmarkermod3-2.so
> +	$(make-target-directory)
> +	cp $< $@
> +$(objpfx)glibc-hwcaps/z14/libmarkermod3.so: $(objpfx)libmarkermod3-3.so
> +	$(make-target-directory)
> +	cp $< $@
> +$(objpfx)glibc-hwcaps/z13/libmarkermod4.so: $(objpfx)libmarkermod4-2.so
> +	$(make-target-directory)
> +	cp $< $@
> +$(objpfx)glibc-hwcaps/z14/libmarkermod4.so: $(objpfx)libmarkermod4-3.so
> +	$(make-target-directory)
> +	cp $< $@
> +$(objpfx)glibc-hwcaps/z15/libmarkermod4.so: $(objpfx)libmarkermod4-4.so
> +	$(make-target-directory)
> +	cp $< $@
> +
> +ifeq (no,$(build-hardcoded-path-in-tests))
> +# This is an ld.so.cache test, and RPATH/RUNPATH in the executable
> +# interferes with its test objectives.
> +tests-container += tst-glibc-hwcaps-cache
>  endif
> +
> +endif # $(subdir) == elf
> diff --git a/sysdeps/s390/s390-64/dl-hwcaps-subdirs.c b/sysdeps/s390/s390-64/dl-hwcaps-subdirs.c
> new file mode 100644
> index 0000000000..3673808a45
> --- /dev/null
> +++ b/sysdeps/s390/s390-64/dl-hwcaps-subdirs.c
> @@ -0,0 +1,54 @@
> +/* Architecture-specific glibc-hwcaps subdirectories.  s390x version.
> +   Copyright (C) 2020 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#include <dl-hwcaps.h>
> +#include <ldsodefs.h>
> +
> +const char _dl_hwcaps_subdirs[] = "z15:z14:z13";
> +enum { subdirs_count = 3 }; /* Number of components in _dl_hwcaps_subdirs.  */
> +
> +uint32_t
> +_dl_hwcaps_subdirs_active (void)
> +{
> +  int active = 0;
> +
> +  /* Test in reverse preference order.  */
> +
> +  /* z13.  */
> +  if (!(GLRO (dl_hwcap) & HWCAP_S390_VX))
> +    return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
> +  ++active;
> +
> +  /* z14.  */
> +  if (!((GLRO (dl_hwcap) & HWCAP_S390_VXD)
> +        && (GLRO (dl_hwcap) & HWCAP_S390_VXE)
> +        && (GLRO (dl_hwcap) & HWCAP_S390_GS)))
> +    return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
> +  ++active;
> +
> +  /* z15.
> +     Note: We do not list HWCAP_S390_SORT and HWCAP_S390_DFLT here as,
> +     according to the Principles of Operation, those may be replaced or removed
> +     in future.  */
> +  if (!((GLRO (dl_hwcap) & HWCAP_S390_VXRS_EXT2)
> +        && (GLRO (dl_hwcap) & HWCAP_S390_VXRS_PDE)))
> +    return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
> +  ++active;
> +
> +  return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
> +}
> diff --git a/sysdeps/s390/s390-64/tst-glibc-hwcaps.c b/sysdeps/s390/s390-64/tst-glibc-hwcaps.c
> new file mode 100644
> index 0000000000..690f0d5fab
> --- /dev/null
> +++ b/sysdeps/s390/s390-64/tst-glibc-hwcaps.c
> @@ -0,0 +1,82 @@
> +/* glibc-hwcaps subdirectory test.  s390x version.
> +   Copyright (C) 2020 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#include <stdio.h>
> +#include <string.h>
> +#include <support/check.h>
> +#include <sys/auxv.h>
> +#include <sys/param.h>
> +
> +extern int marker2 (void);
> +extern int marker3 (void);
> +extern int marker4 (void);
> +
> +/* Return the arch level, 10 for the baseline libmarkermod*.so's.  */
> +static int
> +compute_level (void)
> +{
> +  const char *platform = (const char *) getauxval (AT_PLATFORM);
> +
> +  /* The arch* versions refer to the edition of the Principles of
> +     Operation, and they are off by two when compared with the recent
> +     product names.  (The code below should not be considered an
> +     accurate mapping to Principles of Operation editions for earlier
> +     AT_PLATFORM strings).  */
> +  if (strcmp (platform, "z900") == 0)
> +    return 10;
> +  if (strcmp (platform, "z990") == 0)
> +    return 10;
> +  if (strcmp (platform, "z9-109") == 0)
> +    return 10;
> +  if (strcmp (platform, "z10") == 0)
> +    return 10;
> +  if (strcmp (platform, "z196") == 0)
> +    return 10;
> +  if (strcmp (platform, "zEC12") == 0)
> +    return 10;
> +
> +  /* If we are running on z13 or newer and the kernel was booted with novx,
> +     then AT_PLATFORM is z13 or newer, but _dl_hwcaps_subdirs_active will
> +     return zero and the _dl_hwcaps_subdirs are not searched.  */
> +  const unsigned long int hwcap = getauxval (AT_HWCAP);
> +  if ((hwcap & HWCAP_S390_VX) == 0)
> +    return 10;
> +
> +  if (strcmp (platform, "z13") == 0)
> +    return 11;
> +  if (strcmp (platform, "z14") == 0)
> +    return 12;
> +  if (strcmp (platform, "z15") == 0)
> +    return 13;
> +  printf ("warning: unrecognized AT_PLATFORM value: %s\n", platform);
> +  /* Assume that the new platform supports z15.  */
> +  return 13;
> +}
> +
> +static int
> +do_test (void)
> +{
> +  int level = compute_level ();
> +  printf ("info: detected architecture level: arch%d\n", level);
> +  TEST_COMPARE (marker2 (), MIN (level - 9, 2));
> +  TEST_COMPARE (marker3 (), MIN (level - 9, 3));
> +  TEST_COMPARE (marker4 (), MIN (level - 9, 4));
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>
>