From mboxrd@z Thu Jan 1 00:00:00 1970 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CC03EC3DA7A for ; Wed, 28 Dec 2022 15:33:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233858AbiL1Pde (ORCPT ); Wed, 28 Dec 2022 10:33:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233859AbiL1PdY (ORCPT ); Wed, 28 Dec 2022 10:33:24 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7BDB615FF2 for ; Wed, 28 Dec 2022 07:33:22 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id F3381B81647 for ; Wed, 28 Dec 2022 15:33:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6391DC433D2; Wed, 28 Dec 2022 15:33:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672241599; bh=4emUHXg+LQPCZGQcOikOvvBJYuFbgBXlACcVXZAmD2c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ml1joQloCojCw3SoRllhBgPuSV/+yhVOGhvvf5bXK13ZwXWCci98L8g1qfZl/ZHpy I+iYoF/lLfK8PdPD6Zyu0UxuDRCq9b0MCJejbfHFofpWoacDMcI2EMoN5hxoYvqfGZ yMXpn+d37C5igyMPeZ1o7GNl3oJmh+r2Z6lLV9mA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Matthew Auld , Anshuman Gupta , Sasha Levin Subject: [PATCH 6.1 0265/1146] drm/i915/dgfx: Grab wakeref at i915_ttm_unmap_virtual Date: Wed, 28 Dec 2022 15:30:04 +0100 Message-Id: <20221228144337.334310818@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144330.180012208@linuxfoundation.org> References: <20221228144330.180012208@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Anshuman Gupta [ Upstream commit 1cacd6894d5f4084f1581435e92d8a18d6721b25 ] We had already grabbed the rpm wakeref at obj destruction path, but it also required to grab the wakeref when object moves. When i915_gem_object_release_mmap_offset() gets called by i915_ttm_move_notify(), it will release the mmap offset without grabbing the wakeref. We want to avoid that therefore, grab the wakeref at i915_ttm_unmap_virtual() accordingly. While doing that also changed the lmem_userfault_lock from mutex to spinlock, as spinlock widely used for list. Also changed if (obj->userfault_count) to GEM_BUG_ON(!obj->userfault_count). v2: - Removed lmem_userfault_{list,lock} from intel_gt. [Matt Auld] Fixes: ad74457a6b5a ("drm/i915/dgfx: Release mmap on rpm suspend") Suggested-by: Matthew Auld Signed-off-by: Anshuman Gupta Reviewed-by: Matthew Auld Link: https://patchwork.freedesktop.org/patch/msgid/20221027092242.1476080-3-anshuman.gupta@intel.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/i915/gem/i915_gem_mman.c | 19 +++++------- drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 38 ++++++++++++++++-------- drivers/gpu/drm/i915/intel_runtime_pm.c | 2 +- drivers/gpu/drm/i915/intel_runtime_pm.h | 2 +- 4 files changed, 35 insertions(+), 26 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c index fd29a9053582..e63329bc8065 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c @@ -557,11 +557,13 @@ void i915_gem_object_runtime_pm_release_mmap_offset(struct drm_i915_gem_object * drm_vma_node_unmap(&bo->base.vma_node, bdev->dev_mapping); - if (obj->userfault_count) { - /* rpm wakeref provide exclusive access */ - list_del(&obj->userfault_link); - obj->userfault_count = 0; - } + /* + * We have exclusive access here via runtime suspend. All other callers + * must first grab the rpm wakeref. + */ + GEM_BUG_ON(!obj->userfault_count); + list_del(&obj->userfault_link); + obj->userfault_count = 0; } void i915_gem_object_release_mmap_offset(struct drm_i915_gem_object *obj) @@ -587,13 +589,6 @@ void i915_gem_object_release_mmap_offset(struct drm_i915_gem_object *obj) spin_lock(&obj->mmo.lock); } spin_unlock(&obj->mmo.lock); - - if (obj->userfault_count) { - mutex_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock); - list_del(&obj->userfault_link); - mutex_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock); - obj->userfault_count = 0; - } } static struct i915_mmap_offset * diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c index d6b447ae0a16..be4c081e7e13 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c @@ -509,18 +509,9 @@ static int i915_ttm_shrink(struct drm_i915_gem_object *obj, unsigned int flags) static void i915_ttm_delete_mem_notify(struct ttm_buffer_object *bo) { struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); - intel_wakeref_t wakeref = 0; if (bo->resource && !i915_ttm_is_ghost_object(bo)) { - /* ttm_bo_release() already has dma_resv_lock */ - if (i915_ttm_cpu_maps_iomem(bo->resource)) - wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm); - __i915_gem_object_pages_fini(obj); - - if (wakeref) - intel_runtime_pm_put(&to_i915(obj->base.dev)->runtime_pm, wakeref); - i915_ttm_free_cached_io_rsgt(obj); } } @@ -1056,12 +1047,15 @@ static vm_fault_t vm_fault_ttm(struct vm_fault *vmf) if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) goto out_rpm; - /* ttm_bo_vm_reserve() already has dma_resv_lock */ + /* + * ttm_bo_vm_reserve() already has dma_resv_lock. + * userfault_count is protected by dma_resv lock and rpm wakeref. + */ if (ret == VM_FAULT_NOPAGE && wakeref && !obj->userfault_count) { obj->userfault_count = 1; - mutex_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock); + spin_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock); list_add(&obj->userfault_link, &to_i915(obj->base.dev)->runtime_pm.lmem_userfault_list); - mutex_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock); + spin_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock); } if (wakeref & CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND) @@ -1127,7 +1121,27 @@ static u64 i915_ttm_mmap_offset(struct drm_i915_gem_object *obj) static void i915_ttm_unmap_virtual(struct drm_i915_gem_object *obj) { + struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); + intel_wakeref_t wakeref = 0; + + assert_object_held_shared(obj); + + if (i915_ttm_cpu_maps_iomem(bo->resource)) { + wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm); + + /* userfault_count is protected by obj lock and rpm wakeref. */ + if (obj->userfault_count) { + spin_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock); + list_del(&obj->userfault_link); + spin_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock); + obj->userfault_count = 0; + } + } + ttm_bo_unmap_virtual(i915_gem_to_ttm(obj)); + + if (wakeref) + intel_runtime_pm_put(&to_i915(obj->base.dev)->runtime_pm, wakeref); } static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = { diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c index bb74d4975cc8..129746713d07 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.c +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c @@ -655,6 +655,6 @@ void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm) init_intel_runtime_pm_wakeref(rpm); INIT_LIST_HEAD(&rpm->lmem_userfault_list); - mutex_init(&rpm->lmem_userfault_lock); + spin_lock_init(&rpm->lmem_userfault_lock); intel_wakeref_auto_init(&rpm->userfault_wakeref, rpm); } diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.h b/drivers/gpu/drm/i915/intel_runtime_pm.h index 9f50f109aa11..98b8b28baaa1 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.h +++ b/drivers/gpu/drm/i915/intel_runtime_pm.h @@ -64,7 +64,7 @@ struct intel_runtime_pm { * but instead has exclusive access by virtue of all other accesses requiring * holding the runtime pm wakeref. */ - struct mutex lmem_userfault_lock; + spinlock_t lmem_userfault_lock; /* * Keep list of userfaulted gem obj, which require to release their -- 2.35.1