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 Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 61B6EC433F5 for ; Mon, 22 Nov 2021 11:09:08 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 03867401BB; Mon, 22 Nov 2021 11:09:08 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id zBZEgb83QMDE; Mon, 22 Nov 2021 11:09:06 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp2.osuosl.org (Postfix) with ESMTPS id 9DF9A40010; Mon, 22 Nov 2021 11:09:05 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 7A73CC001E; Mon, 22 Nov 2021 11:09:05 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [IPv6:2605:bc80:3010::133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 7862AC0012 for ; Mon, 22 Nov 2021 11:09:04 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 6572140162 for ; Mon, 22 Nov 2021 11:09:04 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Qh4geacn0pMN for ; Mon, 22 Nov 2021 11:09:03 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by smtp2.osuosl.org (Postfix) with ESMTPS id E0A8E40010 for ; Mon, 22 Nov 2021 11:09:02 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: dafna) with ESMTPSA id 3733A1F44148 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=collabora.com; s=mail; t=1637579340; bh=6R7asC355cFNye6uYubFW2XAoicTdUQaddnkr60Th1A=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=EOTU3N8QBwwkYyW35oY3Di3R8mG0HV0HzKdn9Ts41UNH24Kgke3foLqvWEcwWzzmd J48fYH5waFC9ZxMLs1Uj6IEbLJ9qIU49oujVBZvkF7sH+ifARNhLX8ixB2jlTuC73g 2/xT3qgDmhZF0gg+T4V13kiuMvCEuu/ImhCSz2hyKvR1fFmJDnoIDHzD2JKyxHQHpP rUvbGY1+cMc27JGmNznYA6DbXmGdRTArl1fEmIb9YJ2/UfFopFGi+nG+Rm8AsRo3oA 7NJD6xw5MouUtInzMNPTGj4AKFPJ3T5RkRn/wu0sc36N27IY8+Y8UdnbzogS9SS0z5 aVMb85CpAgo7w== Subject: Re: [PATCH v3 12/33] iommu/mediatek: Always tlb_flush_all when each PM resume To: Yong Wu References: <20210923115840.17813-1-yong.wu@mediatek.com> <20210923115840.17813-13-yong.wu@mediatek.com> <5c4dd67ae7c81721d8cfd2c3b23b7c6df493cb5a.camel@mediatek.com> <4dd4cf8d-0f52-afae-f7d9-8e3cfdf3b729@collabora.com> From: Dafna Hirschfeld Message-ID: <40de67e6-e9c9-9c31-79fb-250ac8998513@collabora.com> Date: Mon, 22 Nov 2021 13:08:51 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Cc: youlin.pei@mediatek.com, anan.sun@mediatek.com, srv_heupstream@mediatek.com, Krzysztof Kozlowski , Will Deacon , sebastian.reichel@collabora.com, yf.wang@mediatek.com, yen-chang.chen@mediatek.com, Fabien Parent , iommu@lists.linux-foundation.org, Rob Herring , linux-mediatek@lists.infradead.org, Hsin-Yi Wang , Matthias Brugger , Collabora Kernel ML , Robin Murphy , mingyuan.ma@mediatek.com, linux-arm-kernel@lists.infradead.org, AngeloGioacchino Del Regno X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 22.11.21 09:05, Yong Wu wrote: > Hi Dafna, > > On Wed, 2021-11-10 at 15:50 +0800, Yong Wu wrote: >> On Wed, 2021-11-10 at 07:29 +0200, Dafna Hirschfeld wrote: >>> >>> On 10.11.21 04:20, Yong Wu wrote: >>>> On Tue, 2021-11-09 at 14:21 +0200, Dafna Hirschfeld wrote: >>>>> Hi >>>>> This patch is needed in order to update the tlb when a device >>>>> is >>>>> powered on. >>>>> Could you send this patch alone without the whole series so it >>>>> get >>>>> accepted easier? >>>> >>>> Which SoC are you testing on? In previous SoC, the IOMMU HW don't >>>> have >>>> power-domain, and we have a "has_pm"[1] in the tlb function for >>>> that >>>> case. The "has_pm" should be always 0 for the previous SoC like >>>> mt8173, >>>> it should always tlb synchronize. >>>> >>>> thus, Could you help share more about your issue? In which case >>>> it >>>> lack >>>> the necessary tlb operation. At least, We need confirm if it >>>> needs >>>> a >>>> "Fixes" tags if sending this patch alone. >>> >>> Hi, >>> I work with the mtk-vcodec driver on mt8173. As you wrote, the >>> iommu >>> doesn't >>> have a power-domain and so when allocating buffers before the >>> device >>> is powered >>> on, there is the warning >>> "Partial TLB flush timed out, falling back to full flush" >>> flooding the log buf. >> >> oh. Thanks very much for your information. Get it now. >> >> This issue should be introduced by the: >> >> b34ea31fe013 ("iommu/mediatek: Always enable the clk on resume") >> >> tlb failed due to the bclk is not enabled. Could you help try that >> after reverting this? >> >>> >>> Sebastian Reichel suggested to remove the 'if(has_pm)' check to >>> avoid >>> this warning, >>> and avoid flushing the tlb if the device is off: >>> >>> [1] http://ix.io/3Eyr >>> >>> This fixes the warning, but then the tlb is not flushed in sync, >>> Therefore the tlb should be flushed when the device is resumed. >>> >>> So the two patches (the one suggested in the link [1] and this >>> patch) >>> should be sent together as a 2-patch series. >> >> then this is reasonable. You could help this into a new patchset if >> you >> are free(add Fixes tag). >> >> Thanks. >> >>> >>> Thanks, >>> Dafna >>> >>>> >>>> Thanks. >>>> >>>> [1] >>>> >> >> > https://elixir.bootlin.com/linux/v5.15/source/drivers/iommu/mtk_iommu.c#L236 >>>> >>>>> I can resend the patch on your behalf if you want. > > What's your plan here? > > If you send the two as a independent patchset on v5.16, I will rebase > yours. > If you have no time for this, I could help this. Hi, just sent it in the patchset ` iommu/mediatek: fix tlb flush logic` Thanks, Dafna > > Thanks. > >>>>> >>>>> Thanks, >>>>> Dafna >>>>> >>>>> On 23.09.21 14:58, Yong Wu wrote: >>>>>> Prepare for 2 HWs that sharing pgtable in different power- >>>>>> domains. >>>>>> >>>>>> When there are 2 M4U HWs, it may has problem in the >>>>>> flush_range >>>>>> in >>>>>> which >>>>>> we get the pm_status via the m4u dev, BUT that function don't >>>>>> reflect the >>>>>> real power-domain status of the HW since there may be other >>>>>> HW >>>>>> also >>>>>> use >>>>>> that power-domain. >>>>>> >>>>>> The function dma_alloc_attrs help allocate the iommu buffer >>>>>> which >>>>>> need the corresponding power domain since tlb flush is needed >>>>>> when >>>>>> preparing iova. BUT this function only is for allocating >>>>>> buffer, >>>>>> we have no good reason to request the user always call >>>>>> pm_runtime_get >>>>>> before calling dma_alloc_xxx. Therefore, we add a >>>>>> tlb_flush_all >>>>>> in the pm_runtime_resume to make sure the tlb always is >>>>>> clean. >>>>>> >>>>>> Another solution is always call pm_runtime_get in the >>>>>> tlb_flush_range. >>>>>> This will trigger pm runtime resume/backup so often when the >>>>>> iommu >>>>>> power is not active at some time(means user don't call >>>>>> pm_runtime_get >>>>>> before calling dma_alloc_xxx), This may cause the performance >>>>>> drop. >>>>>> thus we don't use this. >>>>>> >>>>>> In other case, the iommu's power should always be active via >>>>>> device >>>>>> link with smi. >>>>>> >>>>>> The previous SoC don't have PM except mt8192. the mt8192 >>>>>> IOMMU >>>>>> is >>>>>> display's >>>>>> power-domain which nearly always is enabled. thus no need fix >>>>>> tags >>>>>> here. >>>>>> Prepare for mt8195. >>>>>> >>>>>> Signed-off-by: Yong Wu >>>>>> --- >>>>>> drivers/iommu/mtk_iommu.c | 11 +++++++++++ >>>>>> 1 file changed, 11 insertions(+) >>>>>> >>>>>> diff --git a/drivers/iommu/mtk_iommu.c >>>>>> b/drivers/iommu/mtk_iommu.c >>>>>> index 44cf5547d084..e9e94944ed91 100644 >>>>>> --- a/drivers/iommu/mtk_iommu.c >>>>>> +++ b/drivers/iommu/mtk_iommu.c >>>>>> @@ -984,6 +984,17 @@ static int __maybe_unused >>>>>> mtk_iommu_runtime_resume(struct device *dev) >>>>>> return ret; >>>>>> } >>>>>> >>>>>> + /* >>>>>> + * Users may allocate dma buffer before they call >>>>>> pm_runtime_get, then >>>>>> + * it will lack the necessary tlb flush. >>>>>> + * >>>>>> + * We have no good reason to request the users always >>>>>> call >>>>>> dma_alloc_xx >>>>>> + * after pm_runtime_get_sync. >>>>>> + * >>>>>> + * Thus, Make sure the tlb always is clean after each >>>>>> PM >>>>>> resume. >>>>>> + */ >>>>>> + mtk_iommu_tlb_do_flush_all(data); >>>>>> + >>>>>> /* >>>>>> * Uppon first resume, only enable the clk and return, >>>>>> since >>>>>> the values of the >>>>>> * registers are not yet set. >>>>>> >> >> _______________________________________________ >> iommu mailing list >> iommu@lists.linux-foundation.org >> https://lists.linuxfoundation.org/mailman/listinfo/iommu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu