From patchwork Sat Apr 10 18:59:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zack Rusin X-Patchwork-Id: 12195893 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,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 DD634C433ED for ; Sat, 10 Apr 2021 19:00:01 +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 82E5C6113A for ; Sat, 10 Apr 2021 19:00:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 82E5C6113A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=vmware.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 BE52F6E096; Sat, 10 Apr 2021 19:00:00 +0000 (UTC) Received: from EX13-EDG-OU-001.vmware.com (ex13-edg-ou-001.vmware.com [208.91.0.189]) by gabe.freedesktop.org (Postfix) with ESMTPS id F41586E096 for ; Sat, 10 Apr 2021 18:59:59 +0000 (UTC) Received: from sc9-mailhost2.vmware.com (10.113.161.72) by EX13-EDG-OU-001.vmware.com (10.113.208.155) with Microsoft SMTP Server id 15.0.1156.6; Sat, 10 Apr 2021 11:59:52 -0700 Received: from vertex.localdomain (unknown [10.16.119.48]) by sc9-mailhost2.vmware.com (Postfix) with ESMTP id 401D82034C; Sat, 10 Apr 2021 11:59:57 -0700 (PDT) From: Zack Rusin To: Subject: [PATCH v2] drm/vmwgfx: Make sure unpinning handles reservations Date: Sat, 10 Apr 2021 14:59:56 -0400 Message-ID: <20210410185956.720612-1-zackr@vmware.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Received-SPF: None (EX13-EDG-OU-001.vmware.com: zackr@vmware.com does not designate permitted sender hosts) 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: Martin Krastev , Roland Scheidegger Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Quite often it's a little hard to tell if reservations are already held in code paths that unpin bo's. While our pinning/unpinning code should be more explicit that requires a substential amount of work so instead we can avoid the issues by making sure we try to reserve before unpinning. Because we unpin those bo's only on destruction/error paths just that check tells us if we're already reserved or not and allows to cleanly unpin. Reviewed-by: Martin Krastev Reviewed-by: Roland Scheidegger Fixes: d1a73c641afd ("drm/vmwgfx: Make sure we unpin no longer needed buffers") Cc: dri-devel@lists.freedesktop.org Signed-off-by: Zack Rusin --- drivers/gpu/drm/vmwgfx/vmwgfx_drv.h | 11 +++++++++++ drivers/gpu/drm/vmwgfx/vmwgfx_mob.c | 18 ++++++++++++++---- 2 files changed, 25 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h index 8087a9013455..9a3133cb5cc1 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h @@ -1523,8 +1523,19 @@ static inline void vmw_bo_unreference(struct vmw_buffer_object **buf) *buf = NULL; if (tmp_buf != NULL) { + /* + * currently pinning requires a reservation to be held + * but unreference can be called either reserved or not. + * To avoid deadloacks we have to try to get a reservation. + * This is exlusively to satisfy the requirements of the + * unpin, ttm_bo_put will handle delayed deletion for us + * in case the bo is really busy. + */ + bool locked = dma_resv_trylock(tmp_buf->base.base.resv); if (tmp_buf->base.pin_count > 0) ttm_bo_unpin(&tmp_buf->base); + if (locked) + dma_resv_unlock(tmp_buf->base.base.resv); ttm_bo_put(&tmp_buf->base); } } diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c b/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c index a0b53141dded..f2d625415458 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c @@ -94,6 +94,16 @@ static void vmw_mob_pt_setup(struct vmw_mob *mob, struct vmw_piter data_iter, unsigned long num_data_pages); + +static inline void vmw_bo_unpin_unlocked(struct ttm_buffer_object *bo) +{ + int ret = ttm_bo_reserve(bo, false, true, NULL); + BUG_ON(ret != 0); + ttm_bo_unpin(bo); + ttm_bo_unreserve(bo); +} + + /* * vmw_setup_otable_base - Issue an object table base setup command to * the device @@ -277,7 +287,7 @@ static int vmw_otable_batch_setup(struct vmw_private *dev_priv, &batch->otables[i]); } - ttm_bo_unpin(batch->otable_bo); + vmw_bo_unpin_unlocked(batch->otable_bo); ttm_bo_put(batch->otable_bo); batch->otable_bo = NULL; return ret; @@ -341,9 +351,9 @@ static void vmw_otable_batch_takedown(struct vmw_private *dev_priv, BUG_ON(ret != 0); vmw_bo_fence_single(bo, NULL); + ttm_bo_unpin(bo); ttm_bo_unreserve(bo); - ttm_bo_unpin(batch->otable_bo); ttm_bo_put(batch->otable_bo); batch->otable_bo = NULL; } @@ -530,7 +540,7 @@ static void vmw_mob_pt_setup(struct vmw_mob *mob, void vmw_mob_destroy(struct vmw_mob *mob) { if (mob->pt_bo) { - ttm_bo_unpin(mob->pt_bo); + vmw_bo_unpin_unlocked(mob->pt_bo); ttm_bo_put(mob->pt_bo); mob->pt_bo = NULL; } @@ -646,7 +656,7 @@ int vmw_mob_bind(struct vmw_private *dev_priv, out_no_cmd_space: vmw_fifo_resource_dec(dev_priv); if (pt_set_up) { - ttm_bo_unpin(mob->pt_bo); + vmw_bo_unpin_unlocked(mob->pt_bo); ttm_bo_put(mob->pt_bo); mob->pt_bo = NULL; }