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[PATCH] powerpc: Move cache line size to rtld_global_ro
- From: Tulio Magno Quites Machado Filho <tuliom at linux dot ibm dot com>
- To: libc-alpha at sourceware dot org
- Cc: Andreas Schwab <schwab at suse dot de>, Joseph Myers <joseph at codesourcery dot com>, fw at deneb dot enyo dot de
- Date: Mon, 23 Dec 2019 15:45:23 -0300
- Subject: [PATCH] powerpc: Move cache line size to rtld_global_ro
- References: <mvmh82xeg6n.fsf@suse.de>
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.
Signed-off-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
---
sysdeps/powerpc/dl-procinfo.c | 17 ++++++++++++
sysdeps/powerpc/powerpc32/a2/memcpy.S | 23 ++++++++--------
sysdeps/powerpc/powerpc32/dl-machine.c | 11 ++------
sysdeps/powerpc/powerpc32/memset.S | 29 +++++++++-----------
sysdeps/powerpc/powerpc32/sysdep.h | 26 ++++++++++++++++++
sysdeps/powerpc/powerpc64/a2/memcpy.S | 21 +++++++++++---
sysdeps/powerpc/powerpc64/memset.S | 24 ++++++++++++++--
sysdeps/powerpc/rtld-global-offsets.sym | 1 +
sysdeps/unix/sysv/linux/powerpc/dl-auxv.h | 24 ++++++++++++++++
sysdeps/unix/sysv/linux/powerpc/dl-support.c | 23 ++++++++++++++++
sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c | 12 +-------
sysdeps/unix/sysv/linux/powerpc/libc-start.c | 10 ++-----
12 files changed, 160 insertions(+), 61 deletions(-)
create mode 100644 sysdeps/unix/sysv/linux/powerpc/dl-auxv.h
create mode 100644 sysdeps/unix/sysv/linux/powerpc/dl-support.c
diff --git a/sysdeps/powerpc/dl-procinfo.c b/sysdeps/powerpc/dl-procinfo.c
index 20706a648a..94b33d0c16 100644
--- a/sysdeps/powerpc/dl-procinfo.c
+++ b/sysdeps/powerpc/dl-procinfo.c
@@ -89,5 +89,22 @@ PROCINFO_CLASS const char _dl_powerpc_cap_flags[64][15]
,
#endif
+#if !IS_IN (ldconfig)
+# if !defined PROCINFO_DECL && defined SHARED
+ ._dl_cache_line_size
+# else
+PROCINFO_CLASS int _dl_cache_line_size
+# endif
+# ifndef PROCINFO_DECL
+ = 0
+# endif
+# if !defined SHARED || defined PROCINFO_DECL
+;
+# else
+,
+# endif
+#endif
+
+
#undef PROCINFO_DECL
#undef PROCINFO_CLASS
diff --git a/sysdeps/powerpc/powerpc32/a2/memcpy.S b/sysdeps/powerpc/powerpc32/a2/memcpy.S
index 9bc91a8df1..ecfea5c832 100644
--- a/sysdeps/powerpc/powerpc32/a2/memcpy.S
+++ b/sysdeps/powerpc/powerpc32/a2/memcpy.S
@@ -18,6 +18,7 @@
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
+#include <rtld-global-offsets.h>
#define PREFETCH_AHEAD 4 /* no cache lines SRC prefetching ahead */
#define ZERO_AHEAD 2 /* no cache lines DST zeroing ahead */
@@ -106,25 +107,23 @@ EALIGN (memcpy, 5, 0)
L(dst_aligned):
-#ifdef SHARED
+#ifdef PIC
mflr r0
-/* Establishes GOT addressability so we can load __cache_line_size
- from static. This value was set from the aux vector during startup. */
+/* Establishes GOT addressability so we can load the cache line size
+ from rtld_global_ro. This value was set from the aux vector during
+ startup. */
SETUP_GOT_ACCESS(r9,got_label)
- addis r9,r9,__cache_line_size-got_label@ha
- lwz r9,__cache_line_size-got_label@l(r9)
- mtlr r0
-#else
-/* Load __cache_line_size from static. This value was set from the
- aux vector during startup. */
- lis r9,__cache_line_size@ha
- lwz r9,__cache_line_size@l(r9)
+ addis r9,r9,_GLOBAL_OFFSET_TABLE_-got_label@ha
+ addi r9,r9,_GLOBAL_OFFSET_TABLE_-got_label@l
+ mtlr r0
#endif
+ __GLRO(r9, r9, _dl_cache_line_size,
+ RTLD_GLOBAL_RO_DL_CACHE_LINE_SIZE_OFFSET)
cmplwi cr5, r9, 0
bne+ cr5,L(cachelineset)
-/* __cache_line_size not set: generic byte copy without much optimization */
+/* Cache line size not set: generic byte copy without much optimization */
andi. r0,r5,1 /* If length is odd copy one byte. */
beq L(cachelinenotset_align)
lbz r7,0(r4) /* Read one byte from source. */
diff --git a/sysdeps/powerpc/powerpc32/dl-machine.c b/sysdeps/powerpc/powerpc32/dl-machine.c
index a90cbc1ae3..740ff8f2ec 100644
--- a/sysdeps/powerpc/powerpc32/dl-machine.c
+++ b/sysdeps/powerpc/powerpc32/dl-machine.c
@@ -25,11 +25,6 @@
#include <dl-machine.h>
#include <_itoa.h>
-/* The value __cache_line_size is defined in dl-sysdep.c and is initialised
- by _dl_sysdep_start via DL_PLATFORM_INIT. */
-extern int __cache_line_size attribute_hidden;
-
-
/* Stuff for the PLT. */
#define PLT_INITIAL_ENTRY_WORDS 18
#define PLT_LONGBRANCH_ENTRY_WORDS 0
@@ -309,14 +304,14 @@ __elf_machine_runtime_setup (struct link_map *map, int lazy, int profile)
Assumes that dcbst and icbi apply to lines of 16 bytes or
more. Current known line sizes are 16, 32, and 128 bytes.
- The following gets the __cache_line_size, when available. */
+ The following gets the cache line size, when available. */
/* Default minimum 4 words per cache line. */
int line_size_words = 4;
- if (lazy && __cache_line_size != 0)
+ if (lazy && GLRO(dl_cache_line_size) != 0)
/* Convert bytes to words. */
- line_size_words = __cache_line_size / 4;
+ line_size_words = GLRO(dl_cache_line_size) / 4;
size_modified = lazy ? rel_offset_words : 6;
for (i = 0; i < size_modified; i += line_size_words)
diff --git a/sysdeps/powerpc/powerpc32/memset.S b/sysdeps/powerpc/powerpc32/memset.S
index fc8b1a2547..ea96913e4e 100644
--- a/sysdeps/powerpc/powerpc32/memset.S
+++ b/sysdeps/powerpc/powerpc32/memset.S
@@ -17,12 +17,13 @@
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
+#include <rtld-global-offsets.h>
/* void * [r3] memset (void *s [r3], int c [r4], size_t n [r5]));
Returns 's'.
The memset is done in four sizes: byte (8 bits), word (32 bits),
- 32-byte blocks (256 bits) and __cache_line_size (128, 256, 1024 bits).
+ 32-byte blocks (256 bits) and cache line size (128, 256, 1024 bits).
There is a special case for setting whole cache lines to 0, which
takes advantage of the dcbz instruction. */
@@ -95,7 +96,7 @@ L(caligned):
/* Check if we can use the special case for clearing memory using dcbz.
This requires that we know the correct cache line size for this
- processor. Getting the __cache_line_size may require establishing GOT
+ processor. Getting the cache line size may require establishing GOT
addressability, so branch out of line to set this up. */
beq cr1, L(checklinesize)
@@ -230,26 +231,22 @@ L(medium_28t):
blr
L(checklinesize):
-#ifdef SHARED
- mflr rTMP
/* If the remaining length is less the 32 bytes then don't bother getting
the cache line size. */
beq L(medium)
-/* Establishes GOT addressability so we can load __cache_line_size
- from static. This value was set from the aux vector during startup. */
+#ifdef PIC
+ mflr rTMP
+/* Establishes GOT addressability so we can load the cache line size
+ from rtld_global_ro. This value was set from the aux vector during
+ startup. */
SETUP_GOT_ACCESS(rGOT,got_label)
- addis rGOT,rGOT,__cache_line_size-got_label@ha
- lwz rCLS,__cache_line_size-got_label@l(rGOT)
+ addis rGOT,rGOT,_GLOBAL_OFFSET_TABLE_-got_label@ha
+ addi rGOT,rGOT,_GLOBAL_OFFSET_TABLE_-got_label@l
mtlr rTMP
-#else
-/* Load __cache_line_size from static. This value was set from the
- aux vector during startup. */
- lis rCLS,__cache_line_size@ha
-/* If the remaining length is less the 32 bytes then don't bother getting
- the cache line size. */
- beq L(medium)
- lwz rCLS,__cache_line_size@l(rCLS)
#endif
+/* Load rtld_global_ro._dl_cache_line_size. */
+ __GLRO(rCLS, rGOT, _dl_cache_line_size,
+ RTLD_GLOBAL_RO_DL_CACHE_LINE_SIZE_OFFSET)
/* If the cache line size was not set then goto to L(nondcbz), which is
safe for any cache line size. */
diff --git a/sysdeps/powerpc/powerpc32/sysdep.h b/sysdeps/powerpc/powerpc32/sysdep.h
index c21ea87f5a..4605276ebf 100644
--- a/sysdeps/powerpc/powerpc32/sysdep.h
+++ b/sysdeps/powerpc/powerpc32/sysdep.h
@@ -157,4 +157,30 @@ GOT_LABEL: ; \
/* Label in text section. */
#define C_TEXT(name) name
+/* Read the value of member from rtld_global_ro. */
+#ifdef PIC
+# ifdef SHARED
+# if IS_IN (rtld)
+/* Inside ld.so we use the local alias to avoid runtime GOT
+ relocations. */
+# define __GLRO(rOUT, rGOT, member, offset) \
+ lwz rOUT,_rtld_local_ro@got(rGOT); \
+ lwz rOUT,offset(rOUT)
+# else
+# define __GLRO(rOUT, rGOT, member, offset) \
+ lwz rOUT,_rtld_global_ro@got(rGOT); \
+ lwz rOUT,offset(rOUT)
+# endif
+# else
+# define __GLRO(rOUT, rGOT, member, offset) \
+ lwz rOUT,member@got(rGOT); \
+ lwz rOUT,0(rOUT)
+# endif
+#else
+/* Position-dependent code does not require access to the GOT. */
+# define __GLRO(rOUT, rGOT, member, offset) \
+ lis rOUT,(member+LOWORD)@ha \
+ lwz rOUT,(member+LOWORD)@l(rOUT)
+#endif /* PIC */
+
#endif /* __ASSEMBLER__ */
diff --git a/sysdeps/powerpc/powerpc64/a2/memcpy.S b/sysdeps/powerpc/powerpc64/a2/memcpy.S
index 6d5c5afddb..e515255126 100644
--- a/sysdeps/powerpc/powerpc64/a2/memcpy.S
+++ b/sysdeps/powerpc/powerpc64/a2/memcpy.S
@@ -18,6 +18,7 @@
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
+#include <rtld-global-offsets.h>
#ifndef MEMCPY
# define MEMCPY memcpy
@@ -27,8 +28,19 @@
#define ZERO_AHEAD 2 /* no cache lines DST zeroing ahead */
.section ".toc","aw"
-.LC0:
- .tc __cache_line_size[TC],__cache_line_size
+.LC__dl_cache_line_size:
+#ifdef SHARED
+# if IS_IN (rtld)
+ /* Inside ld.so we use the local alias to avoid runtime GOT
+ relocations. */
+ .tc _rtld_local_ro[TC],_rtld_local_ro
+# else
+ .tc _rtld_global_ro[TC],_rtld_global_ro
+# endif
+#else
+ .tc _dl_cache_line_size[TC],_dl_cache_line_size
+#endif
+
.section ".text"
.align 2
@@ -55,7 +67,8 @@ ENTRY (MEMCPY, 5)
*/
neg r8,r3 /* LS 4 bits = # bytes to 8-byte dest bdry */
- ld r9,.LC0@toc(r2) /* Get cache line size (part 1) */
+ /* Get cache line size (part 1) */
+ ld r9,.LC__dl_cache_line_size@toc(r2)
clrldi r8,r8,64-4 /* align to 16byte boundary */
sub r7,r4,r3 /* compute offset to src from dest */
lwz r9,0(r9) /* Get cache line size (part 2) */
@@ -121,7 +134,7 @@ L(dst_aligned):
cmpdi cr0,r9,0 /* Cache line size set? */
bne+ cr0,L(cachelineset)
-/* __cache_line_size not set: generic byte copy without much optimization */
+/* Cache line size not set: generic byte copy without much optimization */
clrldi. r0,r5,63 /* If length is odd copy one byte */
beq L(cachelinenotset_align)
lbz r7,0(r4) /* Read one byte from source */
diff --git a/sysdeps/powerpc/powerpc64/memset.S b/sysdeps/powerpc/powerpc64/memset.S
index 5d96696e87..d49ef102d4 100644
--- a/sysdeps/powerpc/powerpc64/memset.S
+++ b/sysdeps/powerpc/powerpc64/memset.S
@@ -17,10 +17,22 @@
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
+#include <rtld-global-offsets.h>
.section ".toc","aw"
-.LC0:
- .tc __cache_line_size[TC],__cache_line_size
+.LC__dl_cache_line_size:
+#ifdef SHARED
+# if IS_IN (rtld)
+ /* Inside ld.so we use the local alias to avoid runtime GOT
+ relocations. */
+ .tc _rtld_local_ro[TC],_rtld_local_ro
+# else
+ .tc _rtld_global_ro[TC],_rtld_global_ro
+# endif
+#else
+ .tc _dl_cache_line_size[TC],_dl_cache_line_size
+#endif
+
.section ".text"
.align 2
@@ -146,8 +158,14 @@ L(zloopstart):
/* If the remaining length is less the 32 bytes, don't bother getting
the cache line size. */
beq L(medium)
- ld rCLS,.LC0@toc(r2)
+ ld rCLS,.LC__dl_cache_line_size@toc(r2)
+# ifdef SHARED
+ /* Load _rtld_global_ro._dl_cache_line_size. */
+ lwz rCLS,RTLD_GLOBAL_RO_DL_CACHE_LINE_SIZE_OFFSET(rCLS)
+# else
+ /* Load _dl_cache_line_size. */
lwz rCLS,0(rCLS)
+# endif
/* If the cache line size was not set just goto to L(nondcbz) which is
safe for any cache line size. */
cmpldi cr1,rCLS,0
diff --git a/sysdeps/powerpc/rtld-global-offsets.sym b/sysdeps/powerpc/rtld-global-offsets.sym
index f5ea5a1466..6b348fd522 100644
--- a/sysdeps/powerpc/rtld-global-offsets.sym
+++ b/sysdeps/powerpc/rtld-global-offsets.sym
@@ -6,3 +6,4 @@
RTLD_GLOBAL_RO_DL_HWCAP_OFFSET rtld_global_ro_offsetof (_dl_hwcap)
RTLD_GLOBAL_RO_DL_HWCAP2_OFFSET rtld_global_ro_offsetof (_dl_hwcap2)
+RTLD_GLOBAL_RO_DL_CACHE_LINE_SIZE_OFFSET rtld_global_ro_offsetof (_dl_cache_line_size)
diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-auxv.h b/sysdeps/unix/sysv/linux/powerpc/dl-auxv.h
new file mode 100644
index 0000000000..44bea09974
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/dl-auxv.h
@@ -0,0 +1,24 @@
+/* Auxiliary vector processing. Linux/PPC version.
+ Copyright (C) 2019 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/>. */
+
+/* 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: \
+ GLRO(dl_cache_line_size) = av->a_un.a_val; \
+ break;
diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-support.c b/sysdeps/unix/sysv/linux/powerpc/dl-support.c
new file mode 100644
index 0000000000..2a792d7092
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/dl-support.c
@@ -0,0 +1,23 @@
+/* Support for dynamic linking code in static libc. Linux/PPC version.
+ Copyright (C) 2019 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-auxv.h"
+#include <ldsodefs.h>
+int GLRO(dl_cache_line_size);
+
+#include <elf/dl-support.c>
diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c b/sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c
index fa19cc66c0..6d51d6061e 100644
--- a/sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c
+++ b/sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c
@@ -18,16 +18,6 @@
#include <config.h>
#include <ldsodefs.h>
-
-int __cache_line_size attribute_hidden;
-
-/* 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. */
-#define DL_PLATFORM_AUXV \
- case AT_DCACHEBSIZE: \
- __cache_line_size = av->a_un.a_val; \
- break;
+#include <dl-auxv.h>
#include <sysdeps/unix/sysv/linux/dl-sysdep.c>
diff --git a/sysdeps/unix/sysv/linux/powerpc/libc-start.c b/sysdeps/unix/sysv/linux/powerpc/libc-start.c
index a659a9144f..3a5eb0e952 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;
--
2.24.1