From patchwork Sun Jan 10 14:20:50 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 7996471 Return-Path: X-Original-To: patchwork-xen-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id EC2149F1C0 for ; Sun, 10 Jan 2016 14:23:47 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2C8CC20265 for ; Sun, 10 Jan 2016 14:23:46 +0000 (UTC) Received: from lists.xen.org (lists.xenproject.org [50.57.142.19]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 036DB2025A for ; Sun, 10 Jan 2016 14:23:45 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xen.org) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aIGrf-0001pn-6H; Sun, 10 Jan 2016 14:21:03 +0000 Received: from mail6.bemta4.messagelabs.com ([85.158.143.247]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aIGre-0001od-Jw for xen-devel@lists.xenproject.org; Sun, 10 Jan 2016 14:21:02 +0000 Received: from [85.158.143.35] by server-1.bemta-4.messagelabs.com id AD/F6-09708-EC862965; Sun, 10 Jan 2016 14:21:02 +0000 X-Env-Sender: mst@redhat.com X-Msg-Ref: server-13.tower-21.messagelabs.com!1452435660!7664597!1 X-Originating-IP: [209.132.183.28] X-SpamReason: No, hits=0.0 required=7.0 tests=sa_preprocessor: VHJ1c3RlZCBJUDogMjA5LjEzMi4xODMuMjggPT4gNTQwNjQ=\n X-StarScan-Received: X-StarScan-Version: 7.35.1; banners=-,-,- X-VirusChecked: Checked Received: (qmail 52939 invoked from network); 10 Jan 2016 14:21:01 -0000 Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by server-13.tower-21.messagelabs.com with DHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 10 Jan 2016 14:21:01 -0000 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id B0EE37AE86; Sun, 10 Jan 2016 14:20:59 +0000 (UTC) Received: from redhat.com (vpn1-5-155.ams2.redhat.com [10.36.5.155]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id u0AEKoZH019373; Sun, 10 Jan 2016 09:20:51 -0500 Date: Sun, 10 Jan 2016 16:20:50 +0200 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Message-ID: <1452426622-4471-32-git-send-email-mst@redhat.com> References: <1452426622-4471-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1452426622-4471-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 Cc: linux-mips@linux-mips.org, Rich Felker , linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Peter Zijlstra , virtualization@lists.linux-foundation.org, "H. Peter Anvin" , sparclinux@vger.kernel.org, linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Russell King - ARM Linux , Arnd Bergmann , x86@kernel.org, xen-devel@lists.xenproject.org, Ingo Molnar , linux-xtensa@linux-xtensa.org, user-mode-linux-devel@lists.sourceforge.net, Stefano Stabellini , adi-buildroot-devel@lists.sourceforge.net, Thomas Gleixner , linux-metag@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Andrew Cooper , Joe Perches , linuxppc-dev@lists.ozlabs.org, David Miller Subject: [Xen-devel] [PATCH v3 31/41] sh: support 1 and 2 byte xchg X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This completes the xchg implementation for sh architecture. Note: The llsc variant is tricky since this only supports 4 byte atomics, the existing implementation of 1 byte xchg is wrong: we need to do a 4 byte cmpxchg and retry if any bytes changed meanwhile. Write this in C for clarity. Suggested-by: Rich Felker Signed-off-by: Michael S. Tsirkin --- arch/sh/include/asm/cmpxchg-grb.h | 22 +++++++++++++++ arch/sh/include/asm/cmpxchg-irq.h | 11 ++++++++ arch/sh/include/asm/cmpxchg-llsc.h | 58 +++++++++++++++++++++++--------------- arch/sh/include/asm/cmpxchg.h | 3 ++ 4 files changed, 72 insertions(+), 22 deletions(-) diff --git a/arch/sh/include/asm/cmpxchg-grb.h b/arch/sh/include/asm/cmpxchg-grb.h index f848dec..2ed557b 100644 --- a/arch/sh/include/asm/cmpxchg-grb.h +++ b/arch/sh/include/asm/cmpxchg-grb.h @@ -23,6 +23,28 @@ static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val) return retval; } +static inline unsigned long xchg_u16(volatile u16 *m, unsigned long val) +{ + unsigned long retval; + + __asm__ __volatile__ ( + " .align 2 \n\t" + " mova 1f, r0 \n\t" /* r0 = end point */ + " mov r15, r1 \n\t" /* r1 = saved sp */ + " mov #-6, r15 \n\t" /* LOGIN */ + " mov.w @%1, %0 \n\t" /* load old value */ + " extu.w %0, %0 \n\t" /* extend as unsigned */ + " mov.w %2, @%1 \n\t" /* store new value */ + "1: mov r1, r15 \n\t" /* LOGOUT */ + : "=&r" (retval), + "+r" (m), + "+r" (val) /* inhibit r15 overloading */ + : + : "memory" , "r0", "r1"); + + return retval; +} + static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val) { unsigned long retval; diff --git a/arch/sh/include/asm/cmpxchg-irq.h b/arch/sh/include/asm/cmpxchg-irq.h index bd11f63..f888772 100644 --- a/arch/sh/include/asm/cmpxchg-irq.h +++ b/arch/sh/include/asm/cmpxchg-irq.h @@ -14,6 +14,17 @@ static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val) return retval; } +static inline unsigned long xchg_u16(volatile u16 *m, unsigned long val) +{ + unsigned long flags, retval; + + local_irq_save(flags); + retval = *m; + *m = val; + local_irq_restore(flags); + return retval; +} + static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val) { unsigned long flags, retval; diff --git a/arch/sh/include/asm/cmpxchg-llsc.h b/arch/sh/include/asm/cmpxchg-llsc.h index 4713666..e754794 100644 --- a/arch/sh/include/asm/cmpxchg-llsc.h +++ b/arch/sh/include/asm/cmpxchg-llsc.h @@ -1,6 +1,9 @@ #ifndef __ASM_SH_CMPXCHG_LLSC_H #define __ASM_SH_CMPXCHG_LLSC_H +#include +#include + static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val) { unsigned long retval; @@ -22,29 +25,8 @@ static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val) return retval; } -static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val) -{ - unsigned long retval; - unsigned long tmp; - - __asm__ __volatile__ ( - "1: \n\t" - "movli.l @%2, %0 ! xchg_u8 \n\t" - "mov %0, %1 \n\t" - "mov %3, %0 \n\t" - "movco.l %0, @%2 \n\t" - "bf 1b \n\t" - "synco \n\t" - : "=&z"(tmp), "=&r" (retval) - : "r" (m), "r" (val & 0xff) - : "t", "memory" - ); - - return retval; -} - static inline unsigned long -__cmpxchg_u32(volatile int *m, unsigned long old, unsigned long new) +__cmpxchg_u32(volatile u32 *m, unsigned long old, unsigned long new) { unsigned long retval; unsigned long tmp; @@ -68,4 +50,36 @@ __cmpxchg_u32(volatile int *m, unsigned long old, unsigned long new) return retval; } +static inline u32 __xchg_cmpxchg(volatile void *ptr, u32 x, int size) +{ + int off = (unsigned long)ptr % sizeof(u32); + volatile u32 *p = ptr - off; +#ifdef __BIG_ENDIAN + int bitoff = (sizeof(u32) - 1 - off) * BITS_PER_BYTE; +#else + int bitoff = off * BITS_PER_BYTE; +#endif + u32 bitmask = ((0x1 << size * BITS_PER_BYTE) - 1) << bitoff; + u32 oldv, newv; + u32 ret; + + do { + oldv = READ_ONCE(*p); + ret = (oldv & bitmask) >> bitoff; + newv = (oldv & ~bitmask) | (x << bitoff); + } while (__cmpxchg_u32(p, oldv, newv) != oldv); + + return ret; +} + +static inline unsigned long xchg_u16(volatile u16 *m, unsigned long val) +{ + return __xchg_cmpxchg(m, val, sizeof *m); +} + +static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val) +{ + return __xchg_cmpxchg(m, val, sizeof *m); +} + #endif /* __ASM_SH_CMPXCHG_LLSC_H */ diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h index 85c97b18..5225916 100644 --- a/arch/sh/include/asm/cmpxchg.h +++ b/arch/sh/include/asm/cmpxchg.h @@ -27,6 +27,9 @@ extern void __xchg_called_with_bad_pointer(void); case 4: \ __xchg__res = xchg_u32(__xchg_ptr, x); \ break; \ + case 2: \ + __xchg__res = xchg_u16(__xchg_ptr, x); \ + break; \ case 1: \ __xchg__res = xchg_u8(__xchg_ptr, x); \ break; \