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=-6.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED 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 73AC5C169C4 for ; Tue, 12 Feb 2019 02:58:01 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 40FCB2084D for ; Tue, 12 Feb 2019 02:58:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="i8iXmoXy" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 40FCB2084D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Date: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=d7tkpU4U/7wyVWSS+BNqCfSlceKm5JF+wcOIp3CrO0o=; b=i8iXmoXy2ABXYn Er6bbkkNCHs2ULsOygcKs2rGW1vm/dPE1/fP+mMbtzPDQBh7bb7L3xwqrdyE1StVBFNwG2h2t9Jgg LMsiC8YCZ7SePiHTM0FhWzzz/mEgbF2iWG6H9vNQToykMXf2ZaYXSectFmuDa4jXiySU86ug0whlo fPXd/SMbk87oSDCQxVJwBQ+2ojicF8LJjuXQ7rsznoLqNCccdmQdgcBe2EC2Ym/34MhuJPpwmvdO9 y1HIsq36Qb1EkZ2TyD88Loauv3XRJema2kVfd4Fql70/R4qSJNqqVZxllrJ2Buh/NM/SA1bpCKrsP fbfQCYLNe3VPRvLkeXQg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gtOGf-0006tK-W7; Tue, 12 Feb 2019 02:57:54 +0000 Received: from mailgw01.mediatek.com ([216.200.240.184]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gtOGb-0006ql-Jj; Tue, 12 Feb 2019 02:57:51 +0000 X-UUID: 2f98190efcc24032849f79a64d204ea3-20190211 X-UUID: 2f98190efcc24032849f79a64d204ea3-20190211 Received: from mtkcas67.mediatek.inc [(172.29.193.45)] by mailgw01.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLS) with ESMTP id 1685075918; Mon, 11 Feb 2019 18:57:34 -0800 Received: from MTKMBS31DR.mediatek.inc (172.27.6.102) by MTKMBS62DR.mediatek.inc (172.29.94.18) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Mon, 11 Feb 2019 18:57:32 -0800 Received: from MTKCAS32.mediatek.inc (172.27.4.184) by MTKMBS31DR.mediatek.inc (172.27.6.102) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Tue, 12 Feb 2019 10:57:29 +0800 Received: from [10.17.3.153] (10.17.3.153) by MTKCAS32.mediatek.inc (172.27.4.170) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Tue, 12 Feb 2019 10:57:29 +0800 Message-ID: <1549940249.4980.56.camel@mhfsdcap03> Subject: Re: [RFC PATCH] PCI/portdrv: Support for subtractive decode bridge From: Honghui Zhang To: Bjorn Helgaas Date: Tue, 12 Feb 2019 10:57:29 +0800 In-Reply-To: <20190207151816.GI7268@google.com> References: <1544758829-10327-1-git-send-email-honghui.zhang@mediatek.com> <20190207151816.GI7268@google.com> X-Mailer: Evolution 3.2.3-0ubuntu6 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190211_185749_661990_78A5349F X-CRM114-Status: GOOD ( 22.70 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: youlin.pei@mediatek.com, lorenzo.pieralisi@arm.com, poza@codeaurora.org, fred@fredlawl.com, linux-pci@vger.kernel.org, rafael.j.wysocki@intel.com, linux-kernel@vger.kernel.org, jianjun.wang@mediatek.com, ryder.lee@mediatek.com, linux-mediatek@lists.infradead.org, matthias.bgg@gmail.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, 2019-02-07 at 09:18 -0600, Bjorn Helgaas wrote: > Hi Honghui, > > On Fri, Dec 14, 2018 at 11:40:29AM +0800, honghui.zhang@mediatek.com wrote: > > From: Honghui Zhang > > > > The Class Code for subtractive decode PCI-to-PCI bridge is 060401h, > > change the class_mask values to make portdrv support this type bridge. > > I assume you have a Root Port or Switch Port that supports subtractive > decode? I'm trying to understand how such a device would work. > Hi, Bjorn, Yes, most of Mediatek's RC device have set the class type as 060401h as HW default values, include mt2712 and mt7622. Those RC device work fine with all I have tried EP device except that the portdrv was not attached to those device. But no scenario need those service as far as I know. > Out of curiosity, can you show the "lspci -vv" output for the device > and the downstream devices of interest? > lspci only read the class type 0604h, it does not care about the subordinate values of the class type. I will put the "lspci -vv" output at bottom of this mail. > Do you happen to know whether this functionality is configurable, > e.g., is there some way software can enable or disable subtractive > decode? I assume this would be some device-specific thing, because I > can't find anything in the Bridge Control register or similar. The > PCIe spec doesn't even contain the word "subtractive". > Those class type values for Mediatek's RC has a register which could be used to change its values. We never touch this backdoor register since without the portdrv attached is fine, nobody ask for the port service yet. I did some homework for the subtractive decode PCI-to-PCI bridge, and did not found much more information about that. I guess those port service should also support subtractive bridge since spec does not forbidden that. > The "PCI Express to PCI/PCI-X Bridge Specification", r1.0, says a PCI > Express bridge (which would include Root Ports and Switch Ports) has a > Class Code of 0x060400 (Non-Subtractive PCI-PCI Bridge) (sec 1.1). > > Sec 1.3.4 says subtractive decode on the primary interface is "not > applicable or outside the scope of this spec". > > Bjorn > # lspci -vvv 00:01.0 Class 0604: Device 14c3:5396 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- SERR- (64-bit, prefetchable) Bus: primary=00, secondary=01, subordinate=01, sec-latency=64 I/O behind bridge: 00000000-00000fff Memory behind bridge: 20000000-206fffff Prefetchable memory behind bridge: 00000000-000fffff Secondary status: 66MHz+ FastB2B- ParErr- DEVSEL=slow >TAbort- Reset- FastB2B- PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn- Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+ Address: 000000000807a0c0 Data: 0000 Capabilities: [78] Power Management version 3 Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0-,D1-,D2-,D3hot-,D3cold-) Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME- Capabilities: [80] Express (v2) Root Port (Slot+), MSI 01 DevCap: MaxPayload 256 bytes, PhantFunc 0 ExtTag- RBE+ DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+ MaxPayload 128 bytes, MaxReadReq 512 bytes DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr- TransPend+ LnkCap: Port #1, Speed 5GT/s, Width x2, ASPM L0s L1, Exit Latency L0s <64ns, L1 <2us ClockPM- Surprise- LLActRep- BwNot+ ASPMOptComp+ LnkCtl: ASPM L1 Enabled; RCB 128 bytes Disabled- CommClk + ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- LnkSta: Speed 5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt- SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug- Surprise- Slot #0, PowerLimit 0.000W; Interlock- NoCompl+ SltCtl: Enable: AttnBtn- PwrFlt- MRL- PresDet- CmdCplt- HPIrq- LinkChg- Control: AttnInd Unknown, PwrInd Unknown, Power- Interlock- SltSta: Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet- Interlock- Changed: MRL- PresDet- LinkState- RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna+ CRSVisible- RootCap: CRSVisible- RootSta: PME ReqID 0000, PMEStatus- PMEPending- DevCap2: Completion Timeout: Not Supported, TimeoutDis-, LTR+, OBFF Not Supported ARIFwd- DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-, LTR-, OBFF Disabled ARIFwd- LnkCtl2: Target Link Speed: 5GT/s, EnterCompliance- SpeedDis- Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS- Compliance De-emphasis: -6dB LnkSta2: Current De-emphasis Level: -6dB, EqualizationComplete-, EqualizationPhase1- EqualizationPhase2-, EqualizationPhase3-, LinkEqualizationRequest- Capabilities: [100 v1] Virtual Channel Caps: LPEVC=0 RefClk=100ns PATEntryBits=1 Arb: Fixed- WRR32- WRR64- WRR128- Ctrl: ArbSelect=Fixed Status: InProgress- VC0: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans- Arb: Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256- Ctrl: Enable+ ID=0 ArbSelect=Fixed TC/VC=ff Status: NegoPending- InProgress- Capabilities: [400 v1] L1 PM Substates L1SubCap: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+ ASPM_L1.1 + L1_PM_Substates+ PortCommonModeRestoreTime=30us PortTPowerOnTime=10us Capabilities: [600 v1] Latency Tolerance Reporting Max snoop latency: 0ns Max no snoop latency: 0ns Kernel driver in use: pcieport 01:00.0 Class 0200: Device 8086:1521 (rev 01) Subsystem: Device 1d1a:0000 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- SERR- TAbort- SERR- > Signed-off-by: Honghui Zhang > > --- > > drivers/pci/pcie/portdrv_pci.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c > > index eef22dc..86926ea 100644 > > --- a/drivers/pci/pcie/portdrv_pci.c > > +++ b/drivers/pci/pcie/portdrv_pci.c > > @@ -179,7 +179,7 @@ static void pcie_portdrv_err_resume(struct pci_dev *dev) > > */ > > static const struct pci_device_id port_pci_ids[] = { { > > /* handle any PCI-Express port */ > > - PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0), > > + PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0x01), > > }, { /* end: all zeroes */ } > > }; > > > > -- > > 2.6.4 > > > > > > _______________________________________________ > > linux-arm-kernel mailing list > > linux-arm-kernel@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel