From patchwork Mon Jan 25 14:01:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 12043459 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A7A2C433DB for ; Mon, 25 Jan 2021 14:02:13 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B23BD230FD for ; Mon, 25 Jan 2021 14:02:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B23BD230FD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1731189DF7; Mon, 25 Jan 2021 14:02:00 +0000 (UTC) Received: from fireflyinternet.com (unknown [77.68.26.236]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5340589DBC for ; Mon, 25 Jan 2021 14:01:58 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from build.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 23693643-1500050 for multiple; Mon, 25 Jan 2021 14:01:39 +0000 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Mon, 25 Jan 2021 14:01:16 +0000 Message-Id: <20210125140136.10494-21-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210125140136.10494-1-chris@chris-wilson.co.uk> References: <20210125140136.10494-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 21/41] drm/i915: Wrap cmpxchg64 with try_cmpxchg64() helper X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thomas.hellstrom@intel.com, Chris Wilson Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Wrap cmpxchg64 with a try_cmpxchg()-esque helper. Hiding the old-value dance in the helper allows for cleaner code. Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_utils.h | 32 +++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h index abd4dcd9f79c..95ead6bb1ba6 100644 --- a/drivers/gpu/drm/i915/i915_utils.h +++ b/drivers/gpu/drm/i915/i915_utils.h @@ -461,4 +461,36 @@ static inline bool timer_expired(const struct timer_list *t) */ #define IS_ACTIVE(config) ((config) != 0) +#ifndef try_cmpxchg64 +#if IS_ENABLED(CONFIG_64BIT) +#define try_cmpxchg64(_ptr, _pold, _new) try_cmpxchg(_ptr, _pold, _new) +#else +#define try_cmpxchg64(_ptr, _pold, _new) \ +({ \ + __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \ + __typeof__(*(_ptr)) __old = *_old; \ + __typeof__(*(_ptr)) __cur = cmpxchg64(_ptr, __old, _new); \ + bool success = __cur == __old; \ + if (unlikely(!success)) \ + *_old = __cur; \ + likely(success); \ +}) +#endif +#endif + +#ifndef xchg64 +#if IS_ENABLED(CONFIG_64BIT) +#define xchg64(_ptr, _new) xchg(_ptr, _new) +#else +#define xchg64(_ptr, _new) \ +({ \ + __typeof__(_ptr) __ptr = (_ptr); \ + __typeof__(*(_ptr)) __old = *__ptr; \ + while (!try_cmpxchg64(__ptr, &__old, (_new))) \ + ; \ + __old; \ +}) +#endif +#endif + #endif /* !__I915_UTILS_H */