From patchwork Wed May 17 15:22:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Matthew Auld X-Patchwork-Id: 13245186 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 493B4C77B7F for ; Wed, 17 May 2023 15:23:43 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7D8EB10E447; Wed, 17 May 2023 15:23:42 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0E23310E446; Wed, 17 May 2023 15:23:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1684337020; x=1715873020; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=kkLqJ3cCJniWzST0mH4nTp9MHVf4aGt3b6XaZGdoT0Y=; b=DFIqxYwF4LTtta/MFCLee7FSHQn8k0r+pUhRh6vZ4ApVFtBV4F9oQ8rO x98ZDYrTB3WiE1WgO3J+kTWJd6sjlZGaGCZUyPP+UvBbyyOEJUfoT65NN 7VcCEYSparxZGvKYOvXDe51B2usRWU5uTay2gsvX4jM7kBw4sCVEH4Afu dQ8slotM3xD0QU8+VD5jeND5NNkb3LN/iuANA2oFLtpRsrTs3JmCtlRgz EAGf5dpaL33F+HRk6paJMVfT0RsPaxfx5NWpZvCtDtC3B3TbAxAZ4sAxp TzzZTjcNRVoVWiv5vNf33/Nb2b6TUEqvBkgheQfAbAvu9ycLGdnvdvh0H A==; X-IronPort-AV: E=McAfee;i="6600,9927,10713"; a="438132130" X-IronPort-AV: E=Sophos;i="5.99,282,1677571200"; d="scan'208";a="438132130" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 May 2023 08:23:39 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10713"; a="846129295" X-IronPort-AV: E=Sophos;i="5.99,282,1677571200"; d="scan'208";a="846129295" Received: from fskirtun-mobl-g8.ger.corp.intel.com (HELO mwauld-desk1.intel.com) ([10.252.15.194]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 May 2023 08:23:37 -0700 From: Matthew Auld To: intel-xe@lists.freedesktop.org Subject: [PATCH v5 1/7] drm: fix drmm_mutex_init() Date: Wed, 17 May 2023 16:22:38 +0100 Message-Id: <20230517152244.348171-1-matthew.auld@intel.com> X-Mailer: git-send-email 2.40.1 MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?utf-8?q?Thomas_Hellstr=C3=B6m?= , Jocelyn Falempe , dri-devel@lists.freedesktop.org, Thomas Zimmermann , Daniel Vetter Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" In mutex_init() lockdep seems to identify a lock by defining a static key for each lock class. However if we wrap the whole thing in a function the static key will be the same for everything calling that function, which looks to be the case for drmm_mutex_init(). This then results in impossible lockdep splats since lockdep thinks completely unrelated locks are the same lock class. The other issue is that when looking at splats we lose the actual lock name, where instead of seeing something like xe->mem_access.lock for the name, we just see something generic like lock#8. Attempt to fix this by converting drmm_mutex_init() into a macro, which should ensure that mutex_init() behaves as expected. Reported-by: Thomas Hellström Fixes: e13f13e039dc ("drm: Add DRM-managed mutex_init()") Cc: Thomas Zimmermann Cc: Jocelyn Falempe Cc: Daniel Vetter Cc: dri-devel@lists.freedesktop.org Signed-off-by: Matthew Auld --- drivers/gpu/drm/drm_managed.c | 26 -------------------------- include/drm/drm_managed.h | 23 ++++++++++++++++++++++- 2 files changed, 22 insertions(+), 27 deletions(-) diff --git a/drivers/gpu/drm/drm_managed.c b/drivers/gpu/drm/drm_managed.c index 4cf214de50c4..71c49819a7a2 100644 --- a/drivers/gpu/drm/drm_managed.c +++ b/drivers/gpu/drm/drm_managed.c @@ -263,29 +263,3 @@ void drmm_kfree(struct drm_device *dev, void *data) free_dr(dr_match); } EXPORT_SYMBOL(drmm_kfree); - -static void drmm_mutex_release(struct drm_device *dev, void *res) -{ - struct mutex *lock = res; - - mutex_destroy(lock); -} - -/** - * drmm_mutex_init - &drm_device-managed mutex_init() - * @dev: DRM device - * @lock: lock to be initialized - * - * Returns: - * 0 on success, or a negative errno code otherwise. - * - * This is a &drm_device-managed version of mutex_init(). The initialized - * lock is automatically destroyed on the final drm_dev_put(). - */ -int drmm_mutex_init(struct drm_device *dev, struct mutex *lock) -{ - mutex_init(lock); - - return drmm_add_action_or_reset(dev, drmm_mutex_release, lock); -} -EXPORT_SYMBOL(drmm_mutex_init); diff --git a/include/drm/drm_managed.h b/include/drm/drm_managed.h index 359883942612..01f977e91933 100644 --- a/include/drm/drm_managed.h +++ b/include/drm/drm_managed.h @@ -105,6 +105,27 @@ char *drmm_kstrdup(struct drm_device *dev, const char *s, gfp_t gfp); void drmm_kfree(struct drm_device *dev, void *data); -int drmm_mutex_init(struct drm_device *dev, struct mutex *lock); +static inline void __drmm_mutex_release(struct drm_device *dev, void *res) +{ + struct mutex *lock = res; + + mutex_destroy(lock); +} + +/** + * drmm_mutex_init - &drm_device-managed mutex_init() + * @dev: DRM device + * @lock: lock to be initialized + * + * Returns: + * 0 on success, or a negative errno code otherwise. + * + * This is a &drm_device-managed version of mutex_init(). The initialized + * lock is automatically destroyed on the final drm_dev_put(). + */ +#define drmm_mutex_init(dev, lock) ({ \ + mutex_init(lock); \ + drmm_add_action_or_reset(dev, __drmm_mutex_release, lock); \ +}) \ #endif