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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 246B8C433FE for ; Sun, 9 Jan 2022 02:49:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Date:CC:To:From:Subject:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=CjaVgMnKwMjKQJNZzh6aSS/9M1O8LBGo0TdZdV22V6Q=; b=rdQb8r4NhCXZkk GKk+OdVBuv88Dvad1XHWlouL+pAEcjosImSJnvf9UbdUmzK7g/KsnWBaAO7I+/BUL6cRqhjvSCWBb YLYsUbQYoAfsEGQJP7eo8SdbX6ttoTRg0ZU5ay6fvCgeebzac5BRe93FcGgLmo4siDCbIBmRTIYet uVUizWqytUsSdTnj84r7sKuNTLXhTz3YANDlMEV7ZFhcQqao7KiW3deI27F3pSHZ+/kgqNM4ew+ys tnxZPWoxvDgaKhe1ib62kaEE7v8wX2Y0EoMySLPat/l8N0y8sJcxFccvWB+pd5CtuOqKC7uJNNqp/ 4mSFWXIqfso9zY+XtauQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n6OF5-007FdV-Ls; Sun, 09 Jan 2022 02:47:35 +0000 Received: from mailgw01.mediatek.com ([216.200.240.184]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n6OF1-007Fcb-NQ; Sun, 09 Jan 2022 02:47:33 +0000 X-UUID: 08a9b969ecbf47a3a33eb821f0c20b97-20220108 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Transfer-Encoding:MIME-Version:Content-Type:References:In-Reply-To:Date:CC:To:From:Subject:Message-ID; bh=J9ZI/3WENLpZwcgeYrX9to8Lu7F177ZXFy7u6/+ekks=; b=uaRnndrkJvY4Dzorc7INTidtZTp9nyVsEJfL4zqFkpBIyCHBCW57yIi7SWEJ8aRSVgGBC91YgQGiA4CJDORNauOEIlyyKyvIRR3xqjjUltJnvi72/0aHTYynTBfphDzTM+uKl0wX7NM0gqmCsiaKIfp6HP1XTZ2DO11Wwexmdm4=; X-UUID: 08a9b969ecbf47a3a33eb821f0c20b97-20220108 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw01.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 279442150; Sat, 08 Jan 2022 19:47:28 -0700 Received: from mtkmbs10n2.mediatek.inc (172.21.101.183) by MTKMBS62N1.mediatek.inc (172.29.193.41) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Sat, 8 Jan 2022 18:47:27 -0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs10n2.mediatek.inc (172.21.101.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.792.3; Sun, 9 Jan 2022 10:47:25 +0800 Received: from mhfsdcap04 (10.17.3.154) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Sun, 9 Jan 2022 10:47:24 +0800 Message-ID: Subject: Re: [PATCH v3 13/33] iommu/mediatek: Remove the power status checking in tlb flush all From: Yong Wu To: AngeloGioacchino Del Regno CC: Joerg Roedel , Rob Herring , Matthias Brugger , Will Deacon , Robin Murphy , Krzysztof Kozlowski , Tomasz Figa , , , , , , , Hsin-Yi Wang , , , , Date: Sun, 9 Jan 2022 10:47:24 +0800 In-Reply-To: <1cb7458d-a012-2e84-82bd-7e4f30ed9162@collabora.com> References: <20210923115840.17813-1-yong.wu@mediatek.com> <20210923115840.17813-14-yong.wu@mediatek.com> <1cb7458d-a012-2e84-82bd-7e4f30ed9162@collabora.com> X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220108_184731_789758_7FCE28DA X-CRM114-Status: GOOD ( 31.72 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 2022-01-04 at 16:55 +0100, AngeloGioacchino Del Regno wrote: > Il 23/09/21 13:58, Yong Wu ha scritto: > > To simplify the code, Remove the power status checking in the > > tlb_flush_all, remove this: > > if (pm_runtime_get_if_in_use(data->dev) <= 0) > > continue; > > > > After this patch, the mtk_iommu_tlb_flush_all will be called from > > a) isr > > b) pm runtime resume callback > > c) tlb flush range fail case > > d) iommu_create_device_direct_mappings > > -> iommu_flush_iotlb_all > > In first three cases, the power and clock always are enabled; d) is > > direct > > mapping, the tlb flush is unnecessay since we already have > > tlb_flush_all > > in the pm_runtime_resume callback. When the iommu's power status is > > changed to active, the tlb always is clean. > > > > In addition, there still are 2 reasons that don't add PM status > > checking > > in the tlb flush all: > > a) Write tlb flush all register also is ok even though the HW has > > no > > power and clocks. Write ignore. > > Do you mean that the register write seemingly succeeds but the > hardware discards it? > Please, reword the `a` sentence to be clearer. Yes. This is the "Write ignore" I tried to explain. By the way, the tlb operation patches were moved to this patchset[1] from Dafna. Would you help take a look at that one? I will send the next mt8195 version based on that patchset. [1] https://lore.kernel.org/linux-mediatek/20211208120744.2415-1-dafna.hirschfeld@collabora.com/ Thanks. > > > b) pm_runtime_get_if_in_use(m4udev) is 0 when the tlb_flush_all > > is called frm pm_runtime_resume cb. From this point, we can not add > > this code above in this tlb_flush_all. > > > > Signed-off-by: Yong Wu > > --- > > drivers/iommu/mtk_iommu.c | 20 +++++++------------- > > 1 file changed, 7 insertions(+), 13 deletions(-) > > > > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c > > index e9e94944ed91..4a33b6c6b1db 100644 > > --- a/drivers/iommu/mtk_iommu.c > > +++ b/drivers/iommu/mtk_iommu.c > > @@ -204,10 +204,14 @@ static struct mtk_iommu_domain > > *to_mtk_domain(struct iommu_domain *dom) > > return container_of(dom, struct mtk_iommu_domain, domain); > > } > > > > -static void mtk_iommu_tlb_do_flush_all(struct mtk_iommu_data > > *data) > > +static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data) > > { > > unsigned long flags; > > > > + /* > > + * No need get power status since the HW PM status nearly is > > active > > + * when entering here. > > Please reword this comment to explain the entire situation. > > > + */ > > spin_lock_irqsave(&data->tlb_lock, flags); > > writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, > > data->base + data->plat_data->inv_sel_reg); > > @@ -216,16 +220,6 @@ static void mtk_iommu_tlb_do_flush_all(struct > > mtk_iommu_data *data) > > spin_unlock_irqrestore(&data->tlb_lock, flags); > > } > > > > -static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data) > > -{ > > - if (pm_runtime_get_if_in_use(data->dev) <= 0) > > - return; > > - > > - mtk_iommu_tlb_do_flush_all(data); > > - > > - pm_runtime_put(data->dev); > > -} > > - > > static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, > > size_t size, > > struct mtk_iommu_data *data) > > { > > @@ -263,7 +257,7 @@ static void > > mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size, > > if (ret) { > > dev_warn(data->dev, > > "Partial TLB flush timed out, falling > > back to full flush\n"); > > - mtk_iommu_tlb_do_flush_all(data); > > + mtk_iommu_tlb_flush_all(data); > > } > > > > if (has_pm) > > @@ -993,7 +987,7 @@ static int __maybe_unused > > mtk_iommu_runtime_resume(struct device *dev) > > * > > * Thus, Make sure the tlb always is clean after each PM > > resume. > > */ > > - mtk_iommu_tlb_do_flush_all(data); > > + mtk_iommu_tlb_flush_all(data); > > > > /* > > * Uppon first resume, only enable the clk and return, since > > the values of the > > > > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel