From patchwork Fri Feb 22 17:00:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Jiang X-Patchwork-Id: 10826679 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 CD8FE922 for ; Fri, 22 Feb 2019 17:00:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B7E5B3288A for ; Fri, 22 Feb 2019 17:00:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AC7213211A; Fri, 22 Feb 2019 17:00:14 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3D04532924 for ; Fri, 22 Feb 2019 17:00:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727320AbfBVRAN (ORCPT ); Fri, 22 Feb 2019 12:00:13 -0500 Received: from mga02.intel.com ([134.134.136.20]:38701 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727196AbfBVRAL (ORCPT ); Fri, 22 Feb 2019 12:00:11 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Feb 2019 09:00:10 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,400,1544515200"; d="scan'208";a="277102447" Received: from djiang5-desk3.ch.intel.com ([143.182.136.93]) by orsmga004.jf.intel.com with ESMTP; 22 Feb 2019 09:00:10 -0800 Subject: [PATCH 4/4] dmaengine: ioatdma: support latency tolerance report (LTR) for v3.4 From: Dave Jiang To: vkoul@kernel.org Cc: dmaengine@vger.kernel.org Date: Fri, 22 Feb 2019 10:00:10 -0700 Message-ID: <155085481035.47403.17899583380233949363.stgit@djiang5-desk3.ch.intel.com> In-Reply-To: <155085455554.47403.4331874273102186275.stgit@djiang5-desk3.ch.intel.com> References: <155085455554.47403.4331874273102186275.stgit@djiang5-desk3.ch.intel.com> User-Agent: StGit/unknown-version MIME-Version: 1.0 Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP IOATDMA 3.4 supports PCIe LTR mechanism. The registers are non-standard PCIe LTR support. This needs to be setup in order to not suffer performance impact and provide proper power management. The channel is set to active when it is allocated, and to passive when it's freed. Signed-off-by: Dave Jiang --- drivers/dma/ioat/init.c | 27 +++++++++++++++++++++++++++ drivers/dma/ioat/registers.h | 14 ++++++++++++++ 2 files changed, 41 insertions(+) diff --git a/drivers/dma/ioat/init.c b/drivers/dma/ioat/init.c index 020bcdecb3fb..d41dc9a9ff68 100644 --- a/drivers/dma/ioat/init.c +++ b/drivers/dma/ioat/init.c @@ -638,6 +638,11 @@ static void ioat_free_chan_resources(struct dma_chan *c) ioat_stop(ioat_chan); ioat_reset_hw(ioat_chan); + /* Put LTR to idle */ + if (ioat_dma->version >= IOAT_VER_3_4) + writeb(IOAT_CHAN_LTR_SWSEL_IDLE, + ioat_chan->reg_base + IOAT_CHAN_LTR_SWSEL_OFFSET); + spin_lock_bh(&ioat_chan->cleanup_lock); spin_lock_bh(&ioat_chan->prep_lock); descs = ioat_ring_space(ioat_chan); @@ -727,6 +732,28 @@ static int ioat_alloc_chan_resources(struct dma_chan *c) spin_unlock_bh(&ioat_chan->prep_lock); spin_unlock_bh(&ioat_chan->cleanup_lock); + /* Setting up LTR values for 3.4 or later */ + if (ioat_chan->ioat_dma->version >= IOAT_VER_3_4) { + u32 lat_val; + + lat_val = IOAT_CHAN_LTR_ACTIVE_SNVAL | + IOAT_CHAN_LTR_ACTIVE_SNLATSCALE | + IOAT_CHAN_LTR_ACTIVE_SNREQMNT; + writel(lat_val, ioat_chan->reg_base + + IOAT_CHAN_LTR_ACTIVE_OFFSET); + + lat_val = IOAT_CHAN_LTR_IDLE_SNVAL | + IOAT_CHAN_LTR_IDLE_SNLATSCALE | + IOAT_CHAN_LTR_IDLE_SNREQMNT; + writel(lat_val, ioat_chan->reg_base + + IOAT_CHAN_LTR_IDLE_OFFSET); + + /* Select to active */ + writeb(IOAT_CHAN_LTR_SWSEL_ACTIVE, + ioat_chan->reg_base + + IOAT_CHAN_LTR_SWSEL_OFFSET); + } + ioat_start_null_desc(ioat_chan); /* check that we got off the ground */ diff --git a/drivers/dma/ioat/registers.h b/drivers/dma/ioat/registers.h index 2b517d6db5fd..99c1c24d465d 100644 --- a/drivers/dma/ioat/registers.h +++ b/drivers/dma/ioat/registers.h @@ -253,4 +253,18 @@ #define IOAT_CHAN_DRS_EN 0x0100 #define IOAT_CHAN_DRS_AUTOWRAP 0x0200 +#define IOAT_CHAN_LTR_SWSEL_OFFSET 0xBC +#define IOAT_CHAN_LTR_SWSEL_ACTIVE 0x0 +#define IOAT_CHAN_LTR_SWSEL_IDLE 0x1 + +#define IOAT_CHAN_LTR_ACTIVE_OFFSET 0xC0 +#define IOAT_CHAN_LTR_ACTIVE_SNVAL 0x0000 /* 0 us */ +#define IOAT_CHAN_LTR_ACTIVE_SNLATSCALE 0x0800 /* 1us scale */ +#define IOAT_CHAN_LTR_ACTIVE_SNREQMNT 0x8000 /* snoop req enable */ + +#define IOAT_CHAN_LTR_IDLE_OFFSET 0xC4 +#define IOAT_CHAN_LTR_IDLE_SNVAL 0x0258 /* 600 us */ +#define IOAT_CHAN_LTR_IDLE_SNLATSCALE 0x0800 /* 1us scale */ +#define IOAT_CHAN_LTR_IDLE_SNREQMNT 0x8000 /* snoop req enable */ + #endif /* _IOAT_REGISTERS_H_ */