From patchwork Mon Jul 26 23:38:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rob Clark X-Patchwork-Id: 486085 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 601BAC4338F for ; Mon, 26 Jul 2021 23:34:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4699860F91 for ; Mon, 26 Jul 2021 23:34:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233965AbhGZWyV (ORCPT ); Mon, 26 Jul 2021 18:54:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42606 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233380AbhGZWyU (ORCPT ); Mon, 26 Jul 2021 18:54:20 -0400 Received: from mail-pl1-x634.google.com (mail-pl1-x634.google.com [IPv6:2607:f8b0:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 81F18C061757; Mon, 26 Jul 2021 16:34:47 -0700 (PDT) Received: by mail-pl1-x634.google.com with SMTP id f13so3114624plj.2; Mon, 26 Jul 2021 16:34:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Hr8TbT0NY8bhwRPFfOulQoFlLUKAkASJhK+Ly3YzODY=; b=j8LlgSPw1RFIs8exl6aXPn3feuweS/2CJIHKyHEB7xVGXTNTC85mtEg/Uq+42kAlt2 3QjXHcRqxRY2YLBc/jRGnCj71ESXb3kYFw4vm/zBJUYQ8kIHhxPNUw8U5SBxXsPeo0++ +0KYr1u29WW/FfVUqJJhz1n67eMRUY2pPWVlZ2NKZJ4YtMbcgkyjTi++nbRozr3VyCpB /Def4VylyfYnxhrjrlupA1NQ22I3TDfVPJqR6eoJLDGBYyvFR7ANRtd5Gu4fX47qDI8U T6fC5hASr8PoHrvYYtUpfai0fxI/yp8YrtOmOrPcSJnWieo53lWJRaIQyIskGWwapfcy PvRQ== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=Hr8TbT0NY8bhwRPFfOulQoFlLUKAkASJhK+Ly3YzODY=; b=Z/IHy8zzhnJnBdy4VhEziJVDv9xP90yM0H/JyltnXy/5XNgNi+4AyJqKW5YzRtfUYY /7dlX5SYkV4QgxfwYEhdkV9ZHFJ+hGsjEaPiAlokwREv5UZspghDwNSONQatYMpYtil4 gFB+QJG6zsQdKiUNMMDcYqzJ1Cu8prrDUtK6tyL2ZF3/T9A9DS98D7OhyeHNH5ppgAZ6 zaNxhSe1sHFIOvZqmQyOoFbjl5Pp8XLNy77weHoBtccJ0PJyDrR+HhM9njFfRtHuOi4g vD22o6f0GXwH9FbGnSH3236rRd8ol0Dicy/1sKEg1ARwOxklHyeikBB9PoUkQIGE00Bc tzyQ== X-Gm-Message-State: AOAM530Ua/axOy6z8fNbYcuUI1z8YK3hY+WOh7d75cYtO4h9dnn3zKgL RV3GAmZ4e7KiLq6680cm0ro= X-Google-Smtp-Source: ABdhPJzCJR1KRrhEUmpZNBEL+HoO6bZ9tT6NUdNFHH+pky+Hz4zM8T717wtK0Zidl77XkVjEvdhVFw== X-Received: by 2002:a17:90a:940e:: with SMTP id r14mr1342648pjo.41.1627342487091; Mon, 26 Jul 2021 16:34:47 -0700 (PDT) Received: from localhost ([2601:1c0:5200:a6:307:a401:7b76:c6e5]) by smtp.gmail.com with ESMTPSA id u190sm1212457pfb.95.2021.07.26.16.34.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jul 2021 16:34:46 -0700 (PDT) From: Rob Clark To: dri-devel@lists.freedesktop.org Cc: Daniel Vetter , Matthew Brost , =?utf-8?q?Christian_K=C3=B6n?= =?utf-8?q?ig?= , Rob Clark , Sumit Semwal , Gustavo Padovan , =?utf-8?q?Christian_K=C3=B6nig?= , linux-media@vger.kernel.org (open list:SYNC FILE FRAMEWORK), linaro-mm-sig@lists.linaro.org (moderated list:DMA BUFFER SHARING FRAMEWORK), linux-kernel@vger.kernel.org (open list) Subject: [RFC 1/4] dma-fence: Add deadline awareness Date: Mon, 26 Jul 2021 16:38:48 -0700 Message-Id: <20210726233854.2453899-2-robdclark@gmail.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210726233854.2453899-1-robdclark@gmail.com> References: <20210726233854.2453899-1-robdclark@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: Rob Clark Add a way to hint to the fence signaler of an upcoming deadline, such as vblank, which the fence waiter would prefer not to miss. This is to aid the fence signaler in making power management decisions, like boosting frequency as the deadline approaches and awareness of missing deadlines so that can be factored in to the frequency scaling. Signed-off-by: Rob Clark --- drivers/dma-buf/dma-fence.c | 39 +++++++++++++++++++++++++++++++++++++ include/linux/dma-fence.h | 17 ++++++++++++++++ 2 files changed, 56 insertions(+) diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index ce0f5eff575d..2e0d25ab457e 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -910,6 +910,45 @@ dma_fence_wait_any_timeout(struct dma_fence **fences, uint32_t count, } EXPORT_SYMBOL(dma_fence_wait_any_timeout); + +/** + * dma_fence_set_deadline - set desired fence-wait deadline + * @fence: the fence that is to be waited on + * @deadline: the time by which the waiter hopes for the fence to be + * signaled + * + * Inform the fence signaler of an upcoming deadline, such as vblank, by + * which point the waiter would prefer the fence to be signaled by. This + * is intended to give feedback to the fence signaler to aid in power + * management decisions, such as boosting GPU frequency if a periodic + * vblank deadline is approaching. + */ +void dma_fence_set_deadline(struct dma_fence *fence, ktime_t deadline) +{ + unsigned long flags; + + if (dma_fence_is_signaled(fence)) + return; + + spin_lock_irqsave(fence->lock, flags); + + /* If we already have an earlier deadline, keep it: */ + if (test_bit(DMA_FENCE_FLAG_HAS_DEADLINE_BIT, &fence->flags) && + ktime_before(fence->deadline, deadline)) { + spin_unlock_irqrestore(fence->lock, flags); + return; + } + + fence->deadline = deadline; + set_bit(DMA_FENCE_FLAG_HAS_DEADLINE_BIT, &fence->flags); + + spin_unlock_irqrestore(fence->lock, flags); + + if (fence->ops->set_deadline) + fence->ops->set_deadline(fence, deadline); +} +EXPORT_SYMBOL(dma_fence_set_deadline); + /** * dma_fence_init - Initialize a custom fence. * @fence: the fence to initialize diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 6ffb4b2c6371..4e6cfe4e6fbc 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -88,6 +88,7 @@ struct dma_fence { /* @timestamp replaced by @rcu on dma_fence_release() */ struct rcu_head rcu; }; + ktime_t deadline; u64 context; u64 seqno; unsigned long flags; @@ -99,6 +100,7 @@ enum dma_fence_flag_bits { DMA_FENCE_FLAG_SIGNALED_BIT, DMA_FENCE_FLAG_TIMESTAMP_BIT, DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, + DMA_FENCE_FLAG_HAS_DEADLINE_BIT, DMA_FENCE_FLAG_USER_BITS, /* must always be last member */ }; @@ -261,6 +263,19 @@ struct dma_fence_ops { */ void (*timeline_value_str)(struct dma_fence *fence, char *str, int size); + + /** + * @set_deadline: + * + * Callback to allow a fence waiter to inform the fence signaler of an + * upcoming deadline, such as vblank, by which point the waiter would + * prefer the fence to be signaled by. This is intended to give feedback + * to the fence signaler to aid in power management decisions, such as + * boosting GPU frequency. + * + * This callback is optional. + */ + void (*set_deadline)(struct dma_fence *fence, ktime_t deadline); }; void dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, @@ -586,6 +601,8 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr) return ret < 0 ? ret : 0; } +void dma_fence_set_deadline(struct dma_fence *fence, ktime_t deadline); + struct dma_fence *dma_fence_get_stub(void); struct dma_fence *dma_fence_allocate_private_stub(void); u64 dma_fence_context_alloc(unsigned num);