From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 09135A00C3; Thu, 12 May 2022 17:11:40 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id B5E2540E64; Thu, 12 May 2022 17:11:39 +0200 (CEST) Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by mails.dpdk.org (Postfix) with ESMTP id 3814240DDD for ; Thu, 12 May 2022 17:11:38 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1652368298; x=1683904298; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=JOFDVVVJRpeWS3vFDHRqrctejTDaoMMjRF3+iSVOvXc=; b=CR1bCUqkzJAvFZIUqU4/JTDdgRHjmwGwls3pUbjmNBCfnac3OKMUHLTl zVcCHanVPj20e7d7eEZC+wWKDr87JSJyGOgrAETmEQM2qONdXe7GOHbb7 myOVSa74TNupF9E7eZNhEkWuqteHypKVj01JvlN3KS9dkJbASnwf4APfU QzscUp44sGUqfPtLKpXmRos4M6Y7Lbqr+y3QYQEshMksYrDdo32w6vvS8 fWWqAHlMQTrV6fu4VArBb40ID/spCDvQYaoniwgmTKb2aKhQTw9x7zRa6 RG2E2e3hNHtLsnDfg1if7mjJANwsuUD6q12eh+8SIGm8kRi9/WAoyv9qV Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10345"; a="252078734" X-IronPort-AV: E=Sophos;i="5.91,220,1647327600"; d="scan'208";a="252078734" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 May 2022 08:11:37 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.91,220,1647327600"; d="scan'208";a="566727556" Received: from silpixa00401385.ir.intel.com (HELO silpixa00401385.ger.corp.intel.com.) ([10.237.222.117]) by orsmga007.jf.intel.com with ESMTP; 12 May 2022 08:11:35 -0700 From: Bruce Richardson To: dev@dpdk.org Cc: Radha Mohan Chintakuntla , Veerasenareddy Burru , Gagandeep Singh , Nipun Gupta , Chengwen Feng , Kevin Laatz , Conor Walsh , Bruce Richardson Subject: [PATCH] dmadev: clarify visibility of completed jobs Date: Thu, 12 May 2022 16:11:22 +0100 Message-Id: <20220512151122.20304-1-bruce.richardson@intel.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Clarify that once an operation has completed, the output of that operation is visible to all cores. Signed-off-by: Bruce Richardson --- This follows on from the discussion on-list[1]. Owing to the lack of replies stating that hardware doesn't guarantee this property, I'm taking the optimistic view and assuming that this is generally supported by the DMA drivers. If not, I can do a different patch for some capability flags to indicate the presence or not of this visibility guarantee. [1] https://lore.kernel.org/all/YkwxFZUqOfnL9cJC@bricha3-MOBL.ger.corp.intel.com/ --- lib/dmadev/rte_dmadev.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/dmadev/rte_dmadev.h b/lib/dmadev/rte_dmadev.h index ad9e7a0975..a7081e633c 100644 --- a/lib/dmadev/rte_dmadev.h +++ b/lib/dmadev/rte_dmadev.h @@ -1001,6 +1001,8 @@ rte_dma_submit(int16_t dev_id, uint16_t vchan) * @b EXPERIMENTAL: this API may change without prior notice. * * Return the number of operations that have been successfully completed. + * Once an operation has been reported as completed, the results of that + * operation will be visible to all cores on the system. * * @param dev_id * The identifier of the device. @@ -1058,6 +1060,8 @@ rte_dma_completed(int16_t dev_id, uint16_t vchan, const uint16_t nb_cpls, * * Return the number of operations that have been completed, and the operations * result may succeed or fail. + * Once an operation has been reported as completed successfully, the results of that + * operation will be visible to all cores on the system. * * @param dev_id * The identifier of the device. -- 2.34.1