From patchwork Fri Nov 27 12:05:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Matthew Auld X-Patchwork-Id: 11935667 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=-16.7 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=unavailable 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 0C52EC63777 for ; Fri, 27 Nov 2020 12:09:53 +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 A692F21D81 for ; Fri, 27 Nov 2020 12:09:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A692F21D81 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A625B6EC53; Fri, 27 Nov 2020 12:08:57 +0000 (UTC) Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6F2786EC4C; Fri, 27 Nov 2020 12:08:43 +0000 (UTC) IronPort-SDR: TwfucVWeLdHt/vI4xRMVU88cpilv2eVPE/Z88jnqRpf7jhWCj+ajQW61/jb8NCM4bjxxVIKcPh yGE8/GonSuZw== X-IronPort-AV: E=McAfee;i="6000,8403,9817"; a="190544001" X-IronPort-AV: E=Sophos;i="5.78,374,1599548400"; d="scan'208";a="190544001" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Nov 2020 04:08:41 -0800 IronPort-SDR: zf8cX3Bl2lnGL1TQuxYDprnNZ2CXcBnilXQu2bc0Lo3Dy2iucMvwr0GHwFgqHOf7TFcYnoIlXe WXmytCRzbFHg== X-IronPort-AV: E=Sophos;i="5.78,374,1599548400"; d="scan'208";a="548028783" Received: from mjgleeso-mobl.ger.corp.intel.com (HELO mwauld-desk1.ger.corp.intel.com) ([10.251.85.2]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Nov 2020 04:08:39 -0800 From: Matthew Auld To: intel-gfx@lists.freedesktop.org Subject: [RFC PATCH 041/162] drm/i915: Prepare for obj->mm.lock removal Date: Fri, 27 Nov 2020 12:05:17 +0000 Message-Id: <20201127120718.454037-42-matthew.auld@intel.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201127120718.454037-1-matthew.auld@intel.com> References: <20201127120718.454037-1-matthew.auld@intel.com> 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?= , dri-devel@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Thomas Hellström Stolen objects need to lock, and we may call put_pages when refcount drops to 0, ensure all calls are handled correctly. Idea-from: Thomas Hellström Signed-off-by: Maarten Lankhorst Signed-off-by: Thomas Hellström --- drivers/gpu/drm/i915/gem/i915_gem_object.h | 13 +++++++++++++ drivers/gpu/drm/i915/gem/i915_gem_pages.c | 14 ++++++++++++-- drivers/gpu/drm/i915/gem/i915_gem_stolen.c | 10 +++++++++- 3 files changed, 34 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h index da7fd301fc8d..26ef37532f81 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_object.h +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h @@ -125,6 +125,19 @@ i915_gem_object_put(struct drm_i915_gem_object *obj) ((kref_read(&obj->base.refcount) == 1) && \ list_empty_careful(&obj->mm.link) && \ list_empty_careful(&obj->vma.list)))) +/* + * If more than one potential simultaneous locker, assert held. + */ +static inline void assert_object_held_shared(struct drm_i915_gem_object *obj) +{ + /* + * Note mm list lookup is protected by + * kref_get_unless_zero(). + */ + if (IS_ENABLED(CONFIG_LOCKDEP) && + kref_read(&obj->base.refcount) > 0) + lockdep_assert_held(&obj->mm.lock); +} static inline int __i915_gem_object_lock(struct drm_i915_gem_object *obj, struct i915_gem_ww_ctx *ww, diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c index b03e58106516..183aae046b68 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c @@ -18,7 +18,7 @@ void __i915_gem_object_set_pages(struct drm_i915_gem_object *obj, unsigned long supported = INTEL_INFO(i915)->page_sizes; int i; - lockdep_assert_held(&obj->mm.lock); + assert_object_held_shared(obj); if (i915_gem_object_is_volatile(obj)) obj->mm.madv = I915_MADV_DONTNEED; @@ -67,6 +67,7 @@ void __i915_gem_object_set_pages(struct drm_i915_gem_object *obj, struct list_head *list; unsigned long flags; + lockdep_assert_held(&obj->mm.lock); spin_lock_irqsave(&i915->mm.obj_lock, flags); i915->mm.shrink_count++; @@ -88,6 +89,8 @@ int ____i915_gem_object_get_pages(struct drm_i915_gem_object *obj) struct drm_i915_private *i915 = to_i915(obj->base.dev); int err; + assert_object_held_shared(obj); + if (unlikely(obj->mm.madv != I915_MADV_WILLNEED)) { drm_dbg(&i915->drm, "Attempting to obtain a purgeable object\n"); @@ -115,6 +118,8 @@ int __i915_gem_object_get_pages(struct drm_i915_gem_object *obj) if (err) return err; + assert_object_held_shared(obj); + if (unlikely(!i915_gem_object_has_pages(obj))) { GEM_BUG_ON(i915_gem_object_has_pinned_pages(obj)); @@ -142,7 +147,7 @@ void i915_gem_object_truncate(struct drm_i915_gem_object *obj) /* Try to discard unwanted pages */ void i915_gem_object_writeback(struct drm_i915_gem_object *obj) { - lockdep_assert_held(&obj->mm.lock); + assert_object_held_shared(obj); GEM_BUG_ON(i915_gem_object_has_pages(obj)); if (obj->ops->writeback) @@ -173,6 +178,8 @@ __i915_gem_object_unset_pages(struct drm_i915_gem_object *obj) { struct sg_table *pages; + assert_object_held_shared(obj); + pages = fetch_and_zero(&obj->mm.pages); if (IS_ERR_OR_NULL(pages)) return pages; @@ -200,6 +207,9 @@ int __i915_gem_object_put_pages_locked(struct drm_i915_gem_object *obj) if (i915_gem_object_has_pinned_pages(obj)) return -EBUSY; + /* May be called by shrinker from within get_pages() (on another bo) */ + assert_object_held_shared(obj); + i915_gem_object_release_mmap_offset(obj); /* diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c index 5372b888ba01..ce9086d3a647 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c @@ -643,11 +643,19 @@ __i915_gem_object_create_stolen(struct intel_memory_region *mem, cache_level = HAS_LLC(mem->i915) ? I915_CACHE_LLC : I915_CACHE_NONE; i915_gem_object_set_cache_coherency(obj, cache_level); + if (WARN_ON(!i915_gem_object_trylock(obj))) { + err = -EBUSY; + goto cleanup; + } + err = i915_gem_object_pin_pages(obj); - if (err) + if (err) { + i915_gem_object_unlock(obj); goto cleanup; + } i915_gem_object_init_memory_region(obj, mem); + i915_gem_object_unlock(obj); return obj;