glibc/sysdeps/unix/sysv/linux/powerpc/htm.h
Paul Murphy 86b4939846 powerpc: More elision improvements
__lll_trylock_elision sets the adapt_count variable too
aggressively, and incorrectly on persistent aborts.  Taking
a cue from s390, adapt_count is only updated if the lock
is locked, or a persistent failure occurs.

In addition, the abort codes have been renumbered and
refactored for clarity.  As it stands, glibc only cares
if the abort is persistent or not.

All aborts are now persistent, excepting a busy lock.  This
includes changing _ABORT_NESTED_TRYLOCK into a persistent
abort.

	* sysdeps/unix/sysv/linux/powerpc/elision-trylock.c
	(__lll_trylock_elision): Fix setting of adapt_count.
	* sysdeps/unix/sysv/linux/powerpc/htm.h
	(_ABORT_PERSISTENT): Define to clarify persistent aborts.
	(_ABORT_NESTED_TRYLOCK): Renumber, and make persistent.
	(_ABORT_SYSCALL): Renumber, and clarify definition.
	(_ABORT_LOCK_BUSY): Renumber, make non-persistent.
2015-11-19 16:15:42 -02:00

141 lines
3.7 KiB
C

/* Shared HTM header. Emulate transactional execution facility intrinsics for
compilers and assemblers that do not support the intrinsics and instructions
yet.
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/>. */
#ifndef _HTM_H
#define _HTM_H 1
#ifdef __ASSEMBLER__
/* tbegin. */
.macro TBEGIN
.long 0x7c00051d
.endm
/* tend. 0 */
.macro TEND
.long 0x7c00055d
.endm
/* tabort. code */
.macro TABORT code
.byte 0x7c
.byte \code
.byte 0x07
.byte 0x1d
.endm
/*"TEXASR - Transaction EXception And Summary Register"
mfspr %dst,130 */
.macro TEXASR dst
mfspr \dst,130
.endm
#else
#include <endian.h>
/* Official HTM intrinsics interface matching GCC, but works
on older GCC compatible compilers and binutils.
We should somehow detect if the compiler supports it, because
it may be able to generate slightly better code. */
#define TBEGIN ".long 0x7c00051d"
#define TEND ".long 0x7c00055d"
#if __BYTE_ORDER == __LITTLE_ENDIAN
# define TABORT ".byte 0x1d,0x07,%1,0x7c"
#else
# define TABORT ".byte 0x7c,%1,0x07,0x1d"
#endif
#define __force_inline inline __attribute__((__always_inline__))
#ifndef __HTM__
#define _TEXASRU_EXTRACT_BITS(TEXASR,BITNUM,SIZE) \
(((TEXASR) >> (31-(BITNUM))) & ((1<<(SIZE))-1))
#define _TEXASRU_FAILURE_PERSISTENT(TEXASRU) \
_TEXASRU_EXTRACT_BITS(TEXASRU, 7, 1)
#define _tbegin() \
({ unsigned int __ret; \
asm volatile ( \
TBEGIN "\t\n" \
"mfcr %0\t\n" \
"rlwinm %0,%0,3,1\t\n" \
"xori %0,%0,1\t\n" \
: "=r" (__ret) : \
: "cr0", "memory"); \
__ret; \
})
#define _tend() \
({ unsigned int __ret; \
asm volatile ( \
TEND "\t\n" \
"mfcr %0\t\n" \
"rlwinm %0,%0,3,1\t\n" \
"xori %0,%0,1\t\n" \
: "=r" (__ret) : \
: "cr0", "memory"); \
__ret; \
})
#define _tabort(__code) \
({ unsigned int __ret; \
asm volatile ( \
TABORT "\t\n" \
"mfcr %0\t\n" \
"rlwinm %0,%0,3,1\t\n" \
"xori %0,%0,1\t\n" \
: "=r" (__ret) : "r" (__code) \
: "cr0", "memory"); \
__ret; \
})
#define _texasru() \
({ unsigned long __ret; \
asm volatile ( \
"mfspr %0,131\t\n" \
: "=r" (__ret)); \
__ret; \
})
#define __builtin_tbegin(tdb) _tbegin ()
#define __builtin_tend(nested) _tend ()
#define __builtin_tabort(abortcode) _tabort (abortcode)
#define __builtin_get_texasru() _texasru ()
#else
# include <htmintrin.h>
#endif /* __HTM__ */
#endif /* __ASSEMBLER__ */
/* Definitions used for TEXASR Failure code (bits 0:7). If the failure
should be persistent, the abort code must be odd. 0xd0 through 0xff
are reserved for the kernel and potential hypervisor. */
#define _ABORT_PERSISTENT 0x01 /* An unspecified persistent abort. */
#define _ABORT_LOCK_BUSY 0x34 /* Busy lock, not persistent. */
#define _ABORT_NESTED_TRYLOCK (0x32 | _ABORT_PERSISTENT)
#define _ABORT_SYSCALL (0x30 | _ABORT_PERSISTENT)
#endif