From patchwork Thu Oct 6 17:54:05 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gilbert X-Patchwork-Id: 118146 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) by ozlabs.org (Postfix) with SMTP id CCFD7B6F9D for ; Fri, 7 Oct 2011 04:54:44 +1100 (EST) Received: (qmail 18751 invoked by alias); 6 Oct 2011 17:54:36 -0000 Received: (qmail 18742 invoked by uid 22791); 6 Oct 2011 17:54:33 -0000 X-SWARE-Spam-Status: No, hits=-2.5 required=5.0 tests=AWL, BAYES_00, RCVD_IN_DNSWL_LOW, TW_DM, TW_LN, T_HK_NAME_DR X-Spam-Check-By: sourceware.org Received: from mail-wy0-f175.google.com (HELO mail-wy0-f175.google.com) (74.125.82.175) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 06 Oct 2011 17:54:14 +0000 Received: by wyh5 with SMTP id 5so3455980wyh.20 for ; Thu, 06 Oct 2011 10:54:13 -0700 (PDT) Received: by 10.216.229.165 with SMTP id h37mr1253598weq.83.1317923651761; Thu, 06 Oct 2011 10:54:11 -0700 (PDT) Received: from davesworkthinkpad (gbibp9ph1--blueice2n1.emea.ibm.com. [195.212.29.75]) by mx.google.com with ESMTPS id ei16sm11424893wbb.21.2011.10.06.10.54.08 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 06 Oct 2011 10:54:09 -0700 (PDT) Date: Thu, 6 Oct 2011 18:54:05 +0100 From: "Dr. David Alan Gilbert" To: gcc-patches@gcc.gnu.org Cc: Ramana Radhakrishnan , rth@redhat.com, joseph@codesourcery.com, patches@linaro.org, mikestump@comcast.net, ro@CeBiTec.Uni-Bielefeld.DE Subject: [Patch 4/5] ARM 64 bit sync atomic operations [V3] Message-ID: <20111006175404.GE12770@davesworkthinkpad> References: <20110726085910.GA6925@davesworkthinkpad> <20110726090039.GB6925@davesworkthinkpad> <20111006174941.GA12770@davesworkthinkpad> <20111006175124.GB12770@davesworkthinkpad> <20111006175237.GC12770@davesworkthinkpad> <20111006175321.GD12770@davesworkthinkpad> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20111006175321.GD12770@davesworkthinkpad> User-Agent: Mutt/1.5.20 (2009-06-14) X-IsSubscribed: yes Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org Add ARM 64bit sync helpers for use on older ARMs. Based on 32bit versions but with check for sufficiently new kernel version. gcc/ * config/arm/linux-atomic-64bit.c: New (based on linux-atomic.c) * config/arm/linux-atomic.c: Change comment to point to 64bit version (SYNC_LOCK_RELEASE): Instantiate 64bit version. * config/arm/t-linux-eabi: Pull in linux-atomic-64bit.c diff --git a/gcc/config/arm/linux-atomic-64bit.c b/gcc/config/arm/linux-atomic-64bit.c new file mode 100644 index 0000000..6966e66 --- /dev/null +++ b/gcc/config/arm/linux-atomic-64bit.c @@ -0,0 +1,166 @@ +/* 64bit Linux-specific atomic operations for ARM EABI. + Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc. + Based on linux-atomic.c + + 64 bit additions david.gilbert@linaro.org + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC 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 General Public License +for more details. + +Under Section 7 of GPL version 3, you are granted additional +permissions described in the GCC Runtime Library Exception, version +3.1, as published by the Free Software Foundation. + +You should have received a copy of the GNU General Public License and +a copy of the GCC Runtime Library Exception along with this program; +see the files COPYING3 and COPYING.RUNTIME respectively. If not, see +. */ + +/* 64bit helper functions for atomic operations; the compiler will + call these when the code is compiled for a CPU without ldrexd/strexd. + (If the CPU had those then the compiler inlines the operation). + + These helpers require a kernel helper that's only present on newer + kernels; we check for that in an init section and bail out rather + unceremoneously. */ + +extern unsigned int __write (int fd, const void *buf, unsigned int count); +extern void abort (void); + +/* Kernel helper for compare-and-exchange. */ +typedef int (__kernel_cmpxchg64_t) (const long long* oldval, + const long long* newval, + long long *ptr); +#define __kernel_cmpxchg64 (*(__kernel_cmpxchg64_t *) 0xffff0f60) + +/* Kernel helper page version number. */ +#define __kernel_helper_version (*(unsigned int *)0xffff0ffc) + +/* Check that the kernel has a new enough version at load. */ +static void __check_for_sync8_kernelhelper (void) +{ + if (__kernel_helper_version < 5) + { + const char err[] = "A newer kernel is required to run this binary. " + "(__kernel_cmpxchg64 helper)\n"; + /* At this point we need a way to crash with some information + for the user - I'm not sure I can rely on much else being + available at this point, so do the same as generic-morestack.c + write () and abort (). */ + __write (2 /* stderr. */, err, sizeof (err)); + abort (); + } +}; + +static void (*__sync8_kernelhelper_inithook[]) (void) + __attribute__ ((used, section (".init_array"))) = { + &__check_for_sync8_kernelhelper +}; + +#define HIDDEN __attribute__ ((visibility ("hidden"))) + +#define FETCH_AND_OP_WORD64(OP, PFX_OP, INF_OP) \ + long long HIDDEN \ + __sync_fetch_and_##OP##_8 (long long *ptr, long long val) \ + { \ + int failure; \ + long long tmp,tmp2; \ + \ + do { \ + tmp = *ptr; \ + tmp2 = PFX_OP (tmp INF_OP val); \ + failure = __kernel_cmpxchg64 (&tmp, &tmp2, ptr); \ + } while (failure != 0); \ + \ + return tmp; \ + } + +FETCH_AND_OP_WORD64 (add, , +) +FETCH_AND_OP_WORD64 (sub, , -) +FETCH_AND_OP_WORD64 (or, , |) +FETCH_AND_OP_WORD64 (and, , &) +FETCH_AND_OP_WORD64 (xor, , ^) +FETCH_AND_OP_WORD64 (nand, ~, &) + +#define NAME_oldval(OP, WIDTH) __sync_fetch_and_##OP##_##WIDTH +#define NAME_newval(OP, WIDTH) __sync_##OP##_and_fetch_##WIDTH + +/* Implement both __sync__and_fetch and __sync_fetch_and_ for + subword-sized quantities. */ + +#define OP_AND_FETCH_WORD64(OP, PFX_OP, INF_OP) \ + long long HIDDEN \ + __sync_##OP##_and_fetch_8 (long long *ptr, long long val) \ + { \ + int failure; \ + long long tmp,tmp2; \ + \ + do { \ + tmp = *ptr; \ + tmp2 = PFX_OP (tmp INF_OP val); \ + failure = __kernel_cmpxchg64 (&tmp, &tmp2, ptr); \ + } while (failure != 0); \ + \ + return tmp2; \ + } + +OP_AND_FETCH_WORD64 (add, , +) +OP_AND_FETCH_WORD64 (sub, , -) +OP_AND_FETCH_WORD64 (or, , |) +OP_AND_FETCH_WORD64 (and, , &) +OP_AND_FETCH_WORD64 (xor, , ^) +OP_AND_FETCH_WORD64 (nand, ~, &) + +long long HIDDEN +__sync_val_compare_and_swap_8 (long long *ptr, long long oldval, + long long newval) +{ + int failure; + long long actual_oldval; + + while (1) + { + actual_oldval = *ptr; + + if (__builtin_expect (oldval != actual_oldval, 0)) + return actual_oldval; + + failure = __kernel_cmpxchg64 (&actual_oldval, &newval, ptr); + + if (__builtin_expect (!failure, 1)) + return oldval; + } +} + +typedef unsigned char bool; + +bool HIDDEN +__sync_bool_compare_and_swap_8 (long long *ptr, long long oldval, + long long newval) +{ + int failure = __kernel_cmpxchg64 (&oldval, &newval, ptr); + return (failure == 0); +} + +long long HIDDEN +__sync_lock_test_and_set_8 (long long *ptr, long long val) +{ + int failure; + long long oldval; + + do { + oldval = *ptr; + failure = __kernel_cmpxchg64 (&oldval, &val, ptr); + } while (failure != 0); + + return oldval; +} diff --git a/gcc/config/arm/linux-atomic.c b/gcc/config/arm/linux-atomic.c index 57065a6..80f161d 100644 --- a/gcc/config/arm/linux-atomic.c +++ b/gcc/config/arm/linux-atomic.c @@ -32,8 +32,8 @@ typedef void (__kernel_dmb_t) (void); #define __kernel_dmb (*(__kernel_dmb_t *) 0xffff0fa0) /* Note: we implement byte, short and int versions of atomic operations using - the above kernel helpers, but there is no support for "long long" (64-bit) - operations as yet. */ + the above kernel helpers; see linux-atomic-64bit.c for "long long" (64-bit) + operations. */ #define HIDDEN __attribute__ ((visibility ("hidden"))) @@ -273,6 +273,7 @@ SUBWORD_TEST_AND_SET (unsigned char, 1) *ptr = 0; \ } +SYNC_LOCK_RELEASE (long long, 8) SYNC_LOCK_RELEASE (int, 4) SYNC_LOCK_RELEASE (short, 2) SYNC_LOCK_RELEASE (char, 1) diff --git a/gcc/config/arm/t-linux-eabi b/gcc/config/arm/t-linux-eabi index a328a00..3814cc0 100644 --- a/gcc/config/arm/t-linux-eabi +++ b/gcc/config/arm/t-linux-eabi @@ -36,3 +36,4 @@ LIB1ASMFUNCS := $(filter-out _dvmd_tls,$(LIB1ASMFUNCS)) _dvmd_lnx _clear_cache EXTRA_MULTILIB_PARTS=crtbegin.o crtend.o crtbeginS.o crtendS.o crtbeginT.o LIB2FUNCS_STATIC_EXTRA += $(srcdir)/config/arm/linux-atomic.c +LIB2FUNCS_STATIC_EXTRA += $(srcdir)/config/arm/linux-atomic-64bit.c