powerpc: Move cache line size to rtld_global_ro

GCC 10.0 enabled -fno-common by default and this started to point that
__cache_line_size had been implemented in 2 different places: loader and
libc.

In order to avoid this duplication, the libc variable has been removed
and the loader variable is moved to rtld_global_ro.

File sysdeps/unix/sysv/linux/powerpc/dl-auxv.h has been added in order
to reuse code for both static and dynamic linking scenarios.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

3 files changed, 14 insertions, 18 deletions

diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c b/sysdeps/unix/sysv/linux/powerpc/dl-auxv.h
index 5d65bc6303..be2189732a 100644
--- a/sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c
+++ b/sysdeps/unix/sysv/linux/powerpc/dl-auxv.h
@@ -1,5 +1,5 @@
-/* Operating system support for run-time dynamic linker.  Linux/PPC version.
-   Copyright (C) 1997-2020 Free Software Foundation, Inc.
+/* Auxiliary vector processing.  Linux/PPC 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
@@ -16,18 +16,15 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <config.h>
 #include <ldsodefs.h>
 
-int __cache_line_size attribute_hidden;
+#if IS_IN (libc) && !defined SHARED
+int GLRO(dl_cache_line_size);
+#endif
 
-/* Scan the Aux Vector for the "Data Cache Block Size" entry.  If found
-   verify that the static extern __cache_line_size is defined by checking
-   for not NULL.  If it is defined then assign the cache block size
-   value to __cache_line_size.  */
+/* Scan the Aux Vector for the "Data Cache Block Size" entry and assign it
+   to dl_cache_line_size.  */
 #define DL_PLATFORM_AUXV						      \
       case AT_DCACHEBSIZE:						      \
-	__cache_line_size = av->a_un.a_val;				      \
+	GLRO(dl_cache_line_size) = av->a_un.a_val;			      \
 	break;
-
-#include <sysdeps/unix/sysv/linux/dl-sysdep.c>
diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-static.c b/sysdeps/unix/sysv/linux/powerpc/dl-static.c
index 59ce4e8972..a77e07b503 100644
--- a/sysdeps/unix/sysv/linux/powerpc/dl-static.c
+++ b/sysdeps/unix/sysv/linux/powerpc/dl-static.c
@@ -30,12 +30,14 @@ _dl_var_init (void *array[])
       DL_AUXV = 1,
       DL_HWCAP = 2,
       DL_HWCAP2 = 3,
+      DL_CACHE_LINE_SIZE = 4
     };
 
   GLRO(dl_pagesize) = *((size_t *) array[DL_PAGESIZE]);
   GLRO(dl_auxv) = (ElfW(auxv_t) *) *((size_t *) array[DL_AUXV]);
   GLRO(dl_hwcap)  = *((unsigned long int *) array[DL_HWCAP]);
   GLRO(dl_hwcap2) = *((unsigned long int *) array[DL_HWCAP2]);
+  GLRO(dl_cache_line_size) = (int) *((int *) array[DL_CACHE_LINE_SIZE]);
 }
 
 #else
@@ -46,6 +48,7 @@ static void *variables[] =
   &GLRO(dl_auxv),
   &GLRO(dl_hwcap),
   &GLRO(dl_hwcap2),
+  &GLRO(dl_cache_line_size)
 };
 
 static void
diff --git a/sysdeps/unix/sysv/linux/powerpc/libc-start.c b/sysdeps/unix/sysv/linux/powerpc/libc-start.c
index 93f8659fa6..fc86d6e234 100644
--- a/sysdeps/unix/sysv/linux/powerpc/libc-start.c
+++ b/sysdeps/unix/sysv/linux/powerpc/libc-start.c
@@ -24,7 +24,6 @@
 #include <hwcapinfo.h>
 #endif
 
-int __cache_line_size attribute_hidden;
 /* The main work is done in the generic function.  */
 #define LIBC_START_MAIN generic_start_main
 #define LIBC_START_DISABLE_INLINE
@@ -71,15 +70,12 @@ __libc_start_main (int argc, char **argv,
       rtld_fini = NULL;
     }
 
-  /* Initialize the __cache_line_size variable from the aux vector.  For the
-     static case, we also need _dl_hwcap, _dl_hwcap2 and _dl_platform, so we
-     can call __tcb_parse_hwcap_and_convert_at_platform ().  */
   for (ElfW (auxv_t) * av = auxvec; av->a_type != AT_NULL; ++av)
     switch (av->a_type)
       {
-      case AT_DCACHEBSIZE:
-	__cache_line_size = av->a_un.a_val;
-	break;
+      /* For the static case, we also need _dl_hwcap, _dl_hwcap2 and
+         _dl_platform, so we can call
+         __tcb_parse_hwcap_and_convert_at_platform ().  */
 #ifndef SHARED
       case AT_HWCAP:
 	_dl_hwcap = (unsigned long int) av->a_un.a_val;