From patchwork Thu Apr 8 09:42:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Stevens X-Patchwork-Id: 12190441 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 4536EC433B4 for ; Thu, 8 Apr 2021 09:42:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EE19861041 for ; Thu, 8 Apr 2021 09:42:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231210AbhDHJnB (ORCPT ); Thu, 8 Apr 2021 05:43:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45366 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231132AbhDHJnA (ORCPT ); Thu, 8 Apr 2021 05:43:00 -0400 Received: from mail-pg1-x534.google.com (mail-pg1-x534.google.com [IPv6:2607:f8b0:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06D5EC061761 for ; Thu, 8 Apr 2021 02:42:50 -0700 (PDT) Received: by mail-pg1-x534.google.com with SMTP id d10so1006926pgf.12 for ; Thu, 08 Apr 2021 02:42:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ALUujV6o8uZUngq4GI/5055uPf7G+D6LO8BfQLkVhv8=; b=GdvR0V0FiYIar4gyw7gyYI9kOGza4ogHCCNiZaajELJ+V5eJa5YWbVmzNvJqJ8oJ8v NWzJFxNR4tdSmsFasipzjdoWW08Ga++XtIp1aQAz+EzMWa5cMKlOtMD/4RGoCiHhx9YR K5zA8olmdgFv2/FO2icy4GMqLLZPIfxLp0/a8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ALUujV6o8uZUngq4GI/5055uPf7G+D6LO8BfQLkVhv8=; b=YFUhYjsQ9hMAnUb90TQewcgmTcCNdR5uO1UlCWll0AvfV3yn05Y/IXT61Vr0p0YS1Y 7bJHxvwFuld+GZh1xbxlhnsQdTQZhRqEQBHE8wUaSbW28whtBakkAIXCL+fjVbGxn+rV Z3vJMB95HomZNaXrW/kv3/MVnlDPYPDdXDx3mEZadNGRkuo9E+WCOVtfZbBIBPm7AyrV 8ErYFhYYixDFVVHaU2epn0nbgR+q+3Vh+wLvcAWoTnP5Zh+s0meDF/2Zxy506Jj70Ldk /frMdxuDRui2s9AQ1L0G2vbN37nXNUo+BOH+2q9ywhwRlyg6HZ4UP9aNk94MvILO4x7y b5lg== X-Gm-Message-State: AOAM532Zta39tpcIKH5prhZvHJ8lSqdW7L6ApXS26iIQ1jZSzHXK6r/P QH9DyZ8UTG/Zt9bpR05pZdhgCA== X-Google-Smtp-Source: ABdhPJy0S66jOMuDB9s93i4bwlleUxkBNZU7/7/Oxrd1NkSSq8mHh6D4dsnigRZ/rQYKXWAcB8aWHA== X-Received: by 2002:a05:6a00:1651:b029:241:afa4:92b1 with SMTP id m17-20020a056a001651b0290241afa492b1mr6756345pfc.12.1617874969534; Thu, 08 Apr 2021 02:42:49 -0700 (PDT) Received: from localhost ([2401:fa00:8f:203:25d8:8458:73e8:75ac]) by smtp.gmail.com with UTF8SMTPSA id f14sm25010791pfk.92.2021.04.08.02.42.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 08 Apr 2021 02:42:49 -0700 (PDT) From: David Stevens X-Google-Original-From: David Stevens To: =?utf-8?q?Christian_K=C3=B6nig?= Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Sumit Semwal , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, David Stevens Subject: [PATCH v2] drm/syncobj: use newly allocated stub fences Date: Thu, 8 Apr 2021 18:42:43 +0900 Message-Id: <20210408094243.3902013-1-stevensd@google.com> X-Mailer: git-send-email 2.31.0.208.g409f899ff0-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: David Stevens Allocate a new private stub fence in drm_syncobj_assign_null_handle, instead of using a static stub fence. When userspace creates a fence with DRM_SYNCOBJ_CREATE_SIGNALED or when userspace signals a fence via DRM_IOCTL_SYNCOBJ_SIGNAL, the timestamp obtained when the fence is exported and queried with SYNC_IOC_FILE_INFO should match when the fence's status was changed from the perspective of userspace, which is during the respective ioctl. When a static stub fence started being used in by these ioctls, this behavior changed. Instead, the timestamp returned by SYNC_IOC_FILE_INFO became the first time anything used the static stub fence, which has no meaning to userspace. Signed-off-by: David Stevens --- v1 -> v2: - checkpatch style fixes drivers/dma-buf/dma-fence.c | 33 ++++++++++++++++++++++++++++++++- drivers/gpu/drm/drm_syncobj.c | 25 +++++++++++++++++++------ include/linux/dma-fence.h | 1 + 3 files changed, 52 insertions(+), 7 deletions(-) diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index d64fc03929be..6081eb962490 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -26,6 +26,11 @@ EXPORT_TRACEPOINT_SYMBOL(dma_fence_signaled); static DEFINE_SPINLOCK(dma_fence_stub_lock); static struct dma_fence dma_fence_stub; +struct drm_fence_private_stub { + struct dma_fence base; + spinlock_t lock; +}; + /* * fence context counter: each execution context should have its own * fence context, this allows checking if fences belong to the same @@ -123,7 +128,9 @@ static const struct dma_fence_ops dma_fence_stub_ops = { /** * dma_fence_get_stub - return a signaled fence * - * Return a stub fence which is already signaled. + * Return a stub fence which is already signaled. The fence's + * timestamp corresponds to the first time after boot this + * function is called. */ struct dma_fence *dma_fence_get_stub(void) { @@ -141,6 +148,30 @@ struct dma_fence *dma_fence_get_stub(void) } EXPORT_SYMBOL(dma_fence_get_stub); +/** + * dma_fence_allocate_private_stub - return a private, signaled fence + * + * Return a newly allocated and signaled stub fence. + */ +struct dma_fence *dma_fence_allocate_private_stub(void) +{ + struct drm_fence_private_stub *fence; + + fence = kzalloc(sizeof(*fence), GFP_KERNEL); + if (fence == NULL) + return ERR_PTR(-ENOMEM); + + spin_lock_init(&fence->lock); + dma_fence_init(&fence->base, + &dma_fence_stub_ops, + &fence->lock, + 0, 0); + dma_fence_signal(&fence->base); + + return &fence->base; +} +EXPORT_SYMBOL(dma_fence_allocate_private_stub); + /** * dma_fence_context_alloc - allocate an array of fence contexts * @num: amount of contexts to allocate diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index 349146049849..a54aa850d143 100644 --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -350,12 +350,16 @@ EXPORT_SYMBOL(drm_syncobj_replace_fence); * * Assign a already signaled stub fence to the sync object. */ -static void drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj) +static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj) { - struct dma_fence *fence = dma_fence_get_stub(); + struct dma_fence *fence = dma_fence_allocate_private_stub(); + + if (IS_ERR(fence)) + return PTR_ERR(fence); drm_syncobj_replace_fence(syncobj, fence); dma_fence_put(fence); + return 0; } /* 5s default for wait submission */ @@ -469,6 +473,7 @@ EXPORT_SYMBOL(drm_syncobj_free); int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags, struct dma_fence *fence) { + int ret; struct drm_syncobj *syncobj; syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL); @@ -479,8 +484,13 @@ int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags, INIT_LIST_HEAD(&syncobj->cb_list); spin_lock_init(&syncobj->lock); - if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) - drm_syncobj_assign_null_handle(syncobj); + if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) { + ret = drm_syncobj_assign_null_handle(syncobj); + if (ret < 0) { + drm_syncobj_put(syncobj); + return ret; + } + } if (fence) drm_syncobj_replace_fence(syncobj, fence); @@ -1322,8 +1332,11 @@ drm_syncobj_signal_ioctl(struct drm_device *dev, void *data, if (ret < 0) return ret; - for (i = 0; i < args->count_handles; i++) - drm_syncobj_assign_null_handle(syncobjs[i]); + for (i = 0; i < args->count_handles; i++) { + ret = drm_syncobj_assign_null_handle(syncobjs[i]); + if (ret < 0) + break; + } drm_syncobj_array_free(syncobjs, args->count_handles); diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 9f12efaaa93a..6ffb4b2c6371 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -587,6 +587,7 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr) } struct dma_fence *dma_fence_get_stub(void); +struct dma_fence *dma_fence_allocate_private_stub(void); u64 dma_fence_context_alloc(unsigned num); #define DMA_FENCE_TRACE(f, fmt, args...) \