From patchwork Tue Aug 7 11:05:58 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10558557 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 63710139A for ; Tue, 7 Aug 2018 11:06:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4F9B7295DF for ; Tue, 7 Aug 2018 11:06:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 43A022961C; Tue, 7 Aug 2018 11:06:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id BDD4B295E6 for ; Tue, 7 Aug 2018 11:06:12 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F29AC6E0FE; Tue, 7 Aug 2018 11:06:11 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id 697926E0FE; Tue, 7 Aug 2018 11:06:10 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 12677510-1500050 for multiple; Tue, 07 Aug 2018 12:05:59 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org, amd-gfx@lists.freedesktop.org Date: Tue, 7 Aug 2018 12:05:58 +0100 Message-Id: <20180807110558.3298-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180807104500.31264-1-chris@chris-wilson.co.uk> References: <20180807104500.31264-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v3] drm/amdgpu: Transfer fences to dmabuf importer X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alex Deucher , =?utf-8?q?Christian_K=C3=B6nig?= , dri-devel@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP amdgpu only uses shared-fences internally, but dmabuf importers rely on implicit write hazard tracking via the reservation_object.fence_excl. For example, the importer use the write hazard for timing a page flip to only occur after the exporter has finished flushing its write into the surface. As such, on exporting a dmabuf, we must either flush all outstanding fences (for we do not know which are writes and should have been exclusive) or alternatively create a new exclusive fence that is the composite of all the existing shared fences, and so will only be signaled when all earlier fences are signaled (ensuring that we can not be signaled before the completion of any earlier write). v2: reservation_object is already locked by amdgpu_bo_reserve() Testcase: igt/amd_prime/amd-to-i915 Signed-off-by: Chris Wilson Cc: Alex Deucher Cc: "Christian König" --- drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c | 68 ++++++++++++++++++++--- 1 file changed, 60 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c index 1c5d97f4b4dd..576a83946c25 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c @@ -37,6 +37,7 @@ #include "amdgpu_display.h" #include #include +#include static const struct dma_buf_ops amdgpu_dmabuf_ops; @@ -188,6 +189,57 @@ amdgpu_gem_prime_import_sg_table(struct drm_device *dev, return ERR_PTR(ret); } +static int +__reservation_object_make_exclusive(struct reservation_object *obj) +{ + struct reservation_object_list *fobj; + struct dma_fence_array *array; + struct dma_fence **fences; + unsigned int count, i; + + fobj = reservation_object_get_list(obj); + if (!fobj) + return 0; + + count = !!rcu_access_pointer(obj->fence_excl); + count += fobj->shared_count; + + fences = kmalloc_array(count, sizeof(*fences), GFP_KERNEL); + if (!fences) + return -ENOMEM; + + for (i = 0; i < fobj->shared_count; i++) { + struct dma_fence *f = + rcu_dereference_protected(fobj->shared[i], + reservation_object_held(obj)); + + fences[i] = dma_fence_get(f); + } + + if (rcu_access_pointer(obj->fence_excl)) { + struct dma_fence *f = + rcu_dereference_protected(obj->fence_excl, + reservation_object_held(obj)); + + fences[i] = dma_fence_get(f); + } + + array = dma_fence_array_create(count, fences, + dma_fence_context_alloc(1), 0, + false); + if (!array) + goto err_fences_put; + + reservation_object_add_excl_fence(obj, &array->base); + return 0; + +err_fences_put: + for (i = 0; i < count; i++) + dma_fence_put(fences[i]); + kfree(fences); + return -ENOMEM; +} + /** * amdgpu_gem_map_attach - &dma_buf_ops.attach implementation * @dma_buf: shared DMA buffer @@ -219,16 +271,16 @@ static int amdgpu_gem_map_attach(struct dma_buf *dma_buf, if (attach->dev->driver != adev->dev->driver) { /* - * Wait for all shared fences to complete before we switch to future - * use of exclusive fence on this prime shared bo. + * We only create shared fences for internal use, but importers + * of the dmabuf rely on exclusive fences for implicitly + * tracking write hazards. As any of the current fences may + * correspond to a write, we need to convert all existing + * fences on the resevation object into a single exclusive + * fence. */ - r = reservation_object_wait_timeout_rcu(bo->tbo.resv, - true, false, - MAX_SCHEDULE_TIMEOUT); - if (unlikely(r < 0)) { - DRM_DEBUG_PRIME("Fence wait failed: %li\n", r); + r = __reservation_object_make_exclusive(bo->tbo.resv); + if (r) goto error_unreserve; - } } /* pin buffer into GTT */