From mboxrd@z Thu Jan 1 00:00:00 1970 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=-14.3 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,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 419B4C433E0 for ; Wed, 17 Mar 2021 22:48:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 09F6B64D9F for ; Wed, 17 Mar 2021 22:48:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229601AbhCQWsP (ORCPT ); Wed, 17 Mar 2021 18:48:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229608AbhCQWru (ORCPT ); Wed, 17 Mar 2021 18:47:50 -0400 Received: from mail-pg1-x531.google.com (mail-pg1-x531.google.com [IPv6:2607:f8b0:4864:20::531]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 94868C06174A; Wed, 17 Mar 2021 15:47:50 -0700 (PDT) Received: by mail-pg1-x531.google.com with SMTP id n11so168785pgm.12; Wed, 17 Mar 2021 15:47:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=AZQlG8sfqVYekS3pQFGKTyi8VGzITZR4qzf1zhijQFo=; b=ALZ1VE0LjbIRB2fJBolEdDSQVlBgdLAhjfQ1p0zidMdgRuoDdEOLIv71AdJPHgcRpo APFCzTCeWkr9e7pKMu+fcR3rRnukr2jgmZGNjF8fyXI2prnKkxIi3UvTu699wE5tVHIG NUkLBIvGP/iWfFVgnHwmUSONAB9K7yYkMU1AydYfN2cNlP+StfbLfB0m7PORlVILJdLW DWhJ/g8hVz8TPO7P++gO0qi9KvzX/K53qL+Fm1X+oA88bhpzc/urp73XR9/Je70D5ihC gxsmP1cve67ldDKV62WP4u6AKBvuUV/dEm20/LpFXhF0rk5CR4cgxFvLLOJEveUVE2dO NjUw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=AZQlG8sfqVYekS3pQFGKTyi8VGzITZR4qzf1zhijQFo=; b=laiUYcYelIXSFLSt9YlhJMabvTvyv86gJnieyUGohWr2IX4AOeedfH4VyLJH3MaWJ3 3MSboY7T+mFQrpixAE7ro6WSq6Rdp+UxTVrMvBK5EX26miZYUzSWLWsGZ4nWTmHlMLIX xn82Jk0Yim5JK/TN++dPKYafoEeKaKAnmgh44NsU/WTbUISPKGR6hbAaL3Vjw8VjImGN hFuhkDCO83EteSp0FBlK4fUGtJrULxM/LE4Q17pXU1jBj+Ko1Axcup+C9bZytz+EKxCO 6p+CvSLtMZ1f411dmawqjoDEVJyncS+IVacyEbQ9taA2TVfuHnosHddV+cxZiLTXXyAJ ZWow== X-Gm-Message-State: AOAM530UmjWk5S+q+d1idaugoURh6wvFsXDPiD9xxATMaCARtiq76pIB L2Lhm/HerZ8PovCXJY80TGpCFiK4FYs= X-Google-Smtp-Source: ABdhPJz69XyQa2AZP5IQXw/ofOSkrD2zxcYnwqOI1/2kpgk23ahjCbVqMpJQZtF3ZvO7hiST/ij+tw== X-Received: by 2002:a65:4942:: with SMTP id q2mr4332175pgs.34.1616021269760; Wed, 17 Mar 2021 15:47:49 -0700 (PDT) Received: from [10.230.29.202] ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id a19sm115940pfn.181.2021.03.17.15.47.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 17 Mar 2021 15:47:49 -0700 (PDT) Subject: Re: [PATCH net-next 2/4] net: ipa: introduce dma_addr_high32() To: Alex Elder , davem@davemloft.net, kuba@kernel.org Cc: bjorn.andersson@linaro.org, evgreen@chromium.org, cpratapa@codeaurora.org, subashab@codeaurora.org, elder@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210317222946.118125-1-elder@linaro.org> <20210317222946.118125-3-elder@linaro.org> From: Florian Fainelli Message-ID: <36b9977b-32b1-eb4a-0056-4f742e3fe4d6@gmail.com> Date: Wed, 17 Mar 2021 15:47:47 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210317222946.118125-3-elder@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/17/2021 3:29 PM, Alex Elder wrote: > Create a new helper function to encapsulate extracting the > high-order 32 bits of a DMA address. It returns 0 for builds > in which a DMA address is not 64 bits. > > This avoids doing a 32-position shift on a DMA address if it > happens not to be 64 bits wide. > > Signed-off-by: Alex Elder > --- > drivers/net/ipa/gsi.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c > index 2119367b93ea9..53698c64cf882 100644 > --- a/drivers/net/ipa/gsi.c > +++ b/drivers/net/ipa/gsi.c > @@ -688,6 +688,16 @@ static void gsi_evt_ring_doorbell(struct gsi *gsi, u32 evt_ring_id, u32 index) > iowrite32(val, gsi->virt + GSI_EV_CH_E_DOORBELL_0_OFFSET(evt_ring_id)); > } > > +/* Encapsulate extracting high-order 32 bits of DMA address */ > +static u32 dma_addr_high32(dma_addr_t addr) > +{ > +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT > + return (u32)(addr >> 32); You can probably use upper_32bits() here... > +#else /* !CONFIG_ARCH_DMA_ADDR_T_64BIT */ > + return 0; > +#endif /* !CONFIG_ARCH_DMA_ADDR_T_64BIT */ > +} > + > /* Program an event ring for use */ > static void gsi_evt_ring_program(struct gsi *gsi, u32 evt_ring_id) > { > @@ -711,7 +721,7 @@ static void gsi_evt_ring_program(struct gsi *gsi, u32 evt_ring_id) > val = evt_ring->ring.addr & GENMASK(31, 0); ...and you can use lower_32bits() here. > iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_2_OFFSET(evt_ring_id)); > > - val = evt_ring->ring.addr >> 32; > + val = dma_addr_high32(evt_ring->ring.addr); Does the compiler do a good job at eliminating the assignment when CONFIG_ARCH_DMA_ADDR_T_64BIT is not defined? > iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_3_OFFSET(evt_ring_id)); > > /* Enable interrupt moderation by setting the moderation delay */ > @@ -819,7 +829,7 @@ static void gsi_channel_program(struct gsi_channel *channel, bool doorbell) > val = channel->tre_ring.addr & GENMASK(31, 0); > iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_2_OFFSET(channel_id)); > > - val = channel->tre_ring.addr >> 32; > + val = dma_addr_high32(channel->tre_ring.addr); > iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_3_OFFSET(channel_id)); > > /* Command channel gets low weighted round-robin priority */ > -- Florian