PowerPC: Influence cpu/arch hwcap features via GLIBC_TUNABLES

This patch enables the option to influence hwcaps used by PowerPC.
The environment variable, GLIBC_TUNABLES=glibc.cpu.hwcaps=-xxx,yyy,-zzz....,
can be used to enable CPU/ARCH feature yyy, disable CPU/ARCH feature xxx
and zzz, where the feature name is case-sensitive and has to match the ones
mentioned in the file{sysdeps/powerpc/dl-procinfo.c}.

Note that the hwcap tunables only used in the IFUNC selection.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
index ebe9434052..fc26dd0e17 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -17,6 +17,7 @@
    <https://www.gnu.org/licenses/>.  */
 
 #include <assert.h>
+#include <cpu-features.h>
 #include <string.h>
 #include <wchar.h>
 #include <ldsodefs.h>
@@ -27,9 +28,9 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 			size_t max)
 {
   size_t i = max;
-
-  unsigned long int hwcap = GLRO(dl_hwcap);
-  unsigned long int hwcap2 = GLRO(dl_hwcap2);
+  const struct cpu_features *features = &GLRO(dl_powerpc_cpu_features);
+  unsigned long int hwcap = features->hwcap;
+  unsigned long int hwcap2 = features->hwcap2;
 #ifdef SHARED
   int cacheline_size = GLRO(dl_cache_line_size);
 #endif