glibc/sysdeps/powerpc/hwcapinfo.c
Carlos Eduardo Seo 67385a01d2 powerpc: Add hwcap/hwcap2/platform data to TCB.
This patch adds a new feature for powerpc.  In order to get faster access to
the HWCAP/HWCAP2 bits and platform number (i.e. for implementing
__builtin_cpu_is () / __builtin_cpu_supports () in GCC) without the overhead of
reading from the auxiliary vector, we now reserve space for them in the TCB.
This is an ABI change for GLIBC 2.23.

A new versioned symbol '__parse_hwcap_and_convert_at_platform' is available to
get the data from the auxiliary vector and parse it, and store it for later use
in the TLS initialization code.  This function is called very early
(in _dl_sysdep_start () via DL_PLATFORM_INFO for the dynamic linking case, and
in __libc_start_main () for the static linking case) to make sure the data is
available at the time of TLS initialization.

	* sysdeps/powerpc/Makefile (sysdep-dl-routines): Add hwcapinfo.
	(sysdep_routines): Likewise.
	(sysdep-rtld-routines): Likewise.
	[$(subdir) = nptl](tests): Add test-get_hwcap and test-get_hwcap-static
	[$(subdir) = nptl](tests-static): test-get_hwcap-static
	* sysdeps/powerpc/Versions: Added new
	__parse_hwcap_and_convert_at_platform symbol to GLIBC-2.23.
	* sysdeps/powerpc/hwcapinfo.c: New file.
	(__tcb_parse_hwcap_and_convert_at_platform): New function to initialize
	and parse hwcap, hwcap2 and platform number information.
	* sysdeps/powerpc/hwcapinfo.h: New file.  Creates global variables
	to store HWCAP+HWCAP2 and platform number.
	* sysdeps/powerpc/nptl/tcb-offsets.sym: Added new offsets
	for HWCAP+HWCAP2 and platform number in the TCB.
	* sysdeps/powerpc/nptl/tls.h: New functionality.  Stores
	the HWCAP, HWCAP2 and platform number in the TCB.
	(dtv): Added new fields for HWCAP+HWCAP2 and platform number.
	(TLS_INIT_TP): Included calls to add the hwcap and
	at_platform values in the TCB in TP initialization.
	(TLS_DEFINE_INIT_TP): Likewise.
	(THREAD_GET_HWCAP): New macro.
	(THREAD_SET_HWCAP): Likewise.
	(THREAD_GET_AT_PLATFORM): Likewise.
	(THREAD_SET_AT_PLATFORM): Likewise.
	* sysdeps/powerpc/powerpc32/dl-machine.h:
	(dl_platform_init): New function that calls
	__parse_hwcap_and_convert_at_platform for the dymanic linking case for
	powerpc32.
	* sysdeps/powerpc/powerpc64/dl-machine.h: Likewise, for powerpc64.
	* sysdeps/powerpc/test-get_hwcap-static.c: New file.  Testcase for
	this functionality, static linking case.
	* sysdeps/powerpc/test-get_hwcap.c: New file.  Likewise, dynamic
	linking case.
	* sysdeps/unix/sysv/linux/powerpc/libc-start.c: Added call to
	__parse_hwcap_and_convert_at_platform for the static linking case.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist:
	Included the new __parse_hwcap_and_convert_at_platform symbol in the
	ABI list for GLIBC 2.23.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/ld-le.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/ld.abilist:
	Likewise.
2015-12-03 13:56:13 -02:00

77 lines
2.7 KiB
C

/* powerpc HWCAP/HWCAP2 and AT_PLATFORM data pre-processing.
Copyright (C) 2015 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
<http://www.gnu.org/licenses/>. */
#include <unistd.h>
#include <shlib-compat.h>
#include <dl-procinfo.h>
uint64_t __tcb_hwcap __attribute__ ((visibility ("hidden")));
uint32_t __tcb_platform __attribute__ ((visibility ("hidden")));
/* This function parses the HWCAP/HWCAP2 fields, adding the previous supported
ISA bits, as well as converting the AT_PLATFORM string to a number. This
data is stored in two global variables that can be used later by the
powerpc-specific code to store it into the TCB. */
void
__tcb_parse_hwcap_and_convert_at_platform (void)
{
uint64_t h1, h2;
/* Read AT_PLATFORM string from auxv and convert it to a number. */
__tcb_platform = _dl_string_platform (GLRO (dl_platform));
/* Read HWCAP and HWCAP2 from auxv. */
h1 = GLRO (dl_hwcap);
h2 = GLRO (dl_hwcap2);
/* hwcap contains only the latest supported ISA, the code checks which is
and fills the previous supported ones. */
if (h2 & PPC_FEATURE2_ARCH_2_07)
h1 |= PPC_FEATURE_ARCH_2_06
| PPC_FEATURE_ARCH_2_05
| PPC_FEATURE_POWER5_PLUS
| PPC_FEATURE_POWER5
| PPC_FEATURE_POWER4;
else if (h1 & PPC_FEATURE_ARCH_2_06)
h1 |= PPC_FEATURE_ARCH_2_05
| PPC_FEATURE_POWER5_PLUS
| PPC_FEATURE_POWER5
| PPC_FEATURE_POWER4;
else if (h1 & PPC_FEATURE_ARCH_2_05)
h1 |= PPC_FEATURE_POWER5_PLUS
| PPC_FEATURE_POWER5
| PPC_FEATURE_POWER4;
else if (h1 & PPC_FEATURE_POWER5_PLUS)
h1 |= PPC_FEATURE_POWER5
| PPC_FEATURE_POWER4;
else if (h1 & PPC_FEATURE_POWER5)
h1 |= PPC_FEATURE_POWER4;
/* Consolidate both HWCAP and HWCAP2 into a single doubleword so that
we can read both in a single load later. */
__tcb_hwcap = h2;
__tcb_hwcap = (h1 << 32) | __tcb_hwcap;
}
#if IS_IN (rtld)
versioned_symbol (ld, __tcb_parse_hwcap_and_convert_at_platform, \
__parse_hwcap_and_convert_at_platform, GLIBC_2_23);
#endif