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 X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 8E77FC43381 for ; Fri, 8 Mar 2019 16:17:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 65EF92147A for ; Fri, 8 Mar 2019 16:17:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726600AbfCHQRY (ORCPT ); Fri, 8 Mar 2019 11:17:24 -0500 Received: from anholt.net ([50.246.234.109]:52528 "EHLO anholt.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726412AbfCHQRW (ORCPT ); Fri, 8 Mar 2019 11:17:22 -0500 Received: from localhost (localhost [127.0.0.1]) by anholt.net (Postfix) with ESMTP id 7AA1A10A2E21; Fri, 8 Mar 2019 08:17:21 -0800 (PST) X-Virus-Scanned: Debian amavisd-new at anholt.net Received: from anholt.net ([127.0.0.1]) by localhost (kingsolver.anholt.net [127.0.0.1]) (amavisd-new, port 10024) with LMTP id kK1gm7M7Otlv; Fri, 8 Mar 2019 08:17:19 -0800 (PST) Received: from eliezer.anholt.net (localhost [127.0.0.1]) by anholt.net (Postfix) with ESMTP id 5CF1510A2E2B; Fri, 8 Mar 2019 08:17:17 -0800 (PST) Received: by eliezer.anholt.net (Postfix, from userid 1000) id 243682FE4654; Fri, 8 Mar 2019 08:17:16 -0800 (PST) From: Eric Anholt To: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org, Rob Herring , david.emett@broadcom.com, thomas.spurden@broadcom.com, Eric Anholt Subject: [PATCH 1/4] drm: Add helpers for locking an array of BO reservations. Date: Fri, 8 Mar 2019 08:17:13 -0800 Message-Id: <20190308161716.2466-2-eric@anholt.net> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190308161716.2466-1-eric@anholt.net> References: <20190308161716.2466-1-eric@anholt.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now that we have the reservation object in the GEM object, it's easy to provide a helper for this common case. Noticed while reviewing panfrost and lima drivers. This particular version came out of v3d, which in turn was a copy from vc4. Signed-off-by: Eric Anholt --- drivers/gpu/drm/drm_gem.c | 76 +++++++++++++++++++++++++++++++++++++++ include/drm/drm_gem.h | 4 +++ 2 files changed, 80 insertions(+) diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index ad124f5a6f4d..9fd804f7d7ca 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -1233,3 +1233,79 @@ void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr) obj->dev->driver->gem_prime_vunmap(obj, vaddr); } EXPORT_SYMBOL(drm_gem_vunmap); + +/** + * drm_gem_lock_bo_reservations - Sets up the ww context and acquires + * the lock on an array of GEM objects. + * + * Once you've locked your reservations, you'll want to set up space + * for your shared fences (if applicable), submit your job, then + * drm_gem_unlock_reservations(). + * + * @acquire_ctx - struct ww_acquire_ctx that will be initialized as + * part of tracking this set of locked reservations. + */ +int +drm_gem_lock_reservations(struct drm_gem_object **objs, int count, + struct ww_acquire_ctx *acquire_ctx) +{ + int contended = -1; + int i, ret; + + ww_acquire_init(acquire_ctx, &reservation_ww_class); + +retry: + if (contended != -1) { + struct drm_gem_object *obj = objs[contended]; + + ret = ww_mutex_lock_slow_interruptible(&obj->resv->lock, + acquire_ctx); + if (ret) { + ww_acquire_done(acquire_ctx); + return ret; + } + } + + for (i = 0; i < count; i++) { + if (i == contended) + continue; + + ret = ww_mutex_lock_interruptible(&objs[i]->resv->lock, + acquire_ctx); + if (ret) { + int j; + + for (j = 0; j < i; j++) + ww_mutex_unlock(&objs[j]->resv->lock); + + if (contended != -1 && contended >= i) + ww_mutex_unlock(&objs[contended]->resv->lock); + + if (ret == -EDEADLK) { + contended = i; + goto retry; + } + + ww_acquire_done(acquire_ctx); + return ret; + } + } + + ww_acquire_done(acquire_ctx); + + return 0; +} +EXPORT_SYMBOL(drm_gem_lock_reservations); + +void +drm_gem_unlock_reservations(struct drm_gem_object **objs, int count, + struct ww_acquire_ctx *acquire_ctx) +{ + int i; + + for (i = 0; i < count; i++) + ww_mutex_unlock(&objs[i]->resv->lock); + + ww_acquire_fini(acquire_ctx); +} +EXPORT_SYMBOL(drm_gem_unlock_reservations); diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h index 25f1ff2df464..2955aaab3dca 100644 --- a/include/drm/drm_gem.h +++ b/include/drm/drm_gem.h @@ -384,6 +384,10 @@ void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages, struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle); long drm_gem_reservation_object_wait(struct drm_file *filep, u32 handle, bool wait_all, unsigned long timeout); +int drm_gem_lock_reservations(struct drm_gem_object **objs, int count, + struct ww_acquire_ctx *acquire_ctx); +void drm_gem_unlock_reservations(struct drm_gem_object **objs, int count, + struct ww_acquire_ctx *acquire_ctx); int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev, u32 handle, u64 *offset); int drm_gem_dumb_destroy(struct drm_file *file, -- 2.20.1