From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-x230.google.com (mail-io0-x230.google.com [IPv6:2607:f8b0:4001:c06::230]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 1EC161A1E18 for ; Mon, 8 Aug 2016 03:44:37 -0700 (PDT) Received: by mail-io0-x230.google.com with SMTP id m101so353441539ioi.2 for ; Mon, 08 Aug 2016 03:44:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=pNjF8s9ph+3Y5X3M+0+rvrCikRy0WJAFQdxcHPjVksU=; b=InDhuRThYFjUqMZFIxBpM0RDdUuajo72m7X0uXcybE/mSKwTh1q9oMLN+KB2hLqfiC qsbij2eOz1OlgUsKuAy2IM0XbfZF3X08OBLmHOWm/HcMSKo57VdIrfHmHkFx14qeQ138 sEEUxQibFdri0TGULk4SXX14u76H2iWwLkMSs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=pNjF8s9ph+3Y5X3M+0+rvrCikRy0WJAFQdxcHPjVksU=; b=aYXdoAZ6fiy9IOePsRimH3frgryw64GApcGh7yiJ0sqQl9Zh7l05mTJluzvFS/2pFi 2iG+qrauyZDNMOmpQEOCVWMo/herP9OIyVCXsVRGMC+zkapt84RF4xwUdHTWghSNr4je 7PMRQXNCouYsGwuEq9QkYZxqBWIP/SBp8VaHty+cNKOhCHK8vLEJjnV08VghbC10pwo2 qiuAJP47W01H/IpPRJWO3E8v9swpQfgm61V+11KKjgXrA3eVS06aAnm8psQzb4/YMpow sy/lCTSO4n6A6Z0V+0KYa24qlx286q/aZjRkyoixyYEA0s9Oq6tjun8U5LuXF2YOBS8G uNBg== X-Gm-Message-State: AEkooutV/DNKYSa/90KUJe0Nx5UNBBo6woxZZxLB1DvyzcbSQST5gkJNLswFtlx5KSPjMLlmrrdURn9KWiZIKV31 X-Received: by 10.107.40.133 with SMTP id o127mr89178928ioo.183.1470653076360; Mon, 08 Aug 2016 03:44:36 -0700 (PDT) MIME-Version: 1.0 Received: by 10.36.204.195 with HTTP; Mon, 8 Aug 2016 03:44:35 -0700 (PDT) In-Reply-To: References: <20160805165911.14744-1-evan.lloyd@arm.com> From: Ard Biesheuvel Date: Mon, 8 Aug 2016 12:44:35 +0200 Message-ID: To: Alexei Fedorov Cc: Evan Lloyd , "Cohen, Eugene" , "edk2-devel@lists.01.org" , Heyi Guo , Leif Lindholm Subject: Re: [PATCH] ArmPkg: Fix double GIC EIOR write per interrupt X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 08 Aug 2016 10:44:37 -0000 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 8 August 2016 at 12:40, Alexei Fedorov wrote: > The interrupt is cleared in TimerInterruptHandler() (ArmPkg\Drivers\Timer= Dxe\TimerDxe.c) which is HARDWARE_INTERRUPT_HANDLER parameter passed to gI= nterrupt->RegisterInterruptSource(). Indeed. So now, the HARDWARE_INTERRUPT_HANDLER is clearing the interrupt in the interrupt routing hardware, while the spec clearly states that it is the GIC driver that should be doing it. > Spurious interrupts which don't have registered interrupt handlers are cl= eared in GicV(2|3)IrqInterruptHandler(). > Yes, that is correct according to the text you quoted. --=20 Ard. > > -----Original Message----- > From: Ard Biesheuvel [mailto:ard.biesheuvel@linaro.org] > Sent: 08 August 2016 11:32 > To: Alexei Fedorov > Cc: Evan Lloyd; Cohen, Eugene; edk2-devel@lists.01.org; Heyi Guo; Leif Li= ndholm > Subject: Re: [edk2] [PATCH] ArmPkg: Fix double GIC EIOR write per interru= pt > > On 8 August 2016 at 12:25, Alexei Fedorov wrote: >> >>> it does change the contract we have with registered interrupt >>> handlers >> >> Looks like it does not: >> From edk2\EmbeddedPkg\Include\Protocol\HardwareInterrupt.h: >> >> " Abstraction for hardware based interrupt routine >> >> ...The driver implementing >> this protocol is responsible for clearing the pending interrupt in the >> interrupt routing hardware. The HARDWARE_INTERRUPT_HANDLER is responsi= ble >> for clearing interrupt sources from individual devices." >> > > Thanks for digging that up! > > So after this change, the driver implementing the hardware interrupt prot= ocol no longer clears the pending interrupt in the interrupt routing hardwa= re. This means that we are not only changing the existing contract, we are = also violating the spec. > > >> >> -----Original Message----- >> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of >> Ard Biesheuvel >> Sent: 06 August 2016 09:25 >> To: Evan Lloyd; Cohen, Eugene >> Cc: edk2-devel@lists.01.org; Heyi Guo; Leif Lindholm >> Subject: Re: [edk2] [PATCH] ArmPkg: Fix double GIC EIOR write per >> interrupt >> >> (+ Eugene) >> >> On 5 August 2016 at 18:59, wrote: >>> From: Alexei >>> >>> This commit fixes a bug in the GIC v2 and v3 drivers where the >>> GICC_EOIR (End Of Interrupt Register) is written twice for a single int= errupt. >>> GicV(2|3)IrqInterruptHandler() calls the Interrupt Handler and then >>> GicV(2|3)EndOfInterrupt() on exit: >>> >>> InterruptHandler =3D gRegisteredInterruptHandlers[GicInterrupt]; >>> if (InterruptHandler !=3D NULL) { >>> // Call the registered interrupt handler. >>> InterruptHandler (GicInterrupt, SystemContext); } else { >>> DEBUG ((EFI_D_ERROR, "Spurious GIC interrupt: 0x%x\n", >>> GicInterrupt)); } >>> >>> GicV2EndOfInterrupt (&gHardwareInterruptV2Protocol, GicInterrupt); >>> >>> , although gInterrupt->EndOfInterrupt() has already been called by >>> InterruptHandler(). >>> >>> The fix moves the EndOfInterrupt() call inside the else case for >>> unregistered/spurious interrupts. This removes a potential race >>> condition that might have lost interrupts. >>> >> >> I understand that this solves the problem, but it does change the contra= ct we have with registered interrupt handlers, and we don't know how this m= ay be used out of tree. I know UEFI only supports polling for drivers, but = are there any other cases (debug?) where we may break other people's code b= y doing this? >> >> >>> Contributed-under: TianoCore Contribution Agreement 1.0 >>> Signed-off-by: Alexei Fedorov >>> Signed-off-by: Evan Lloyd >>> --- >>> >>> Code is available at: >>> https://github.com/EvanLloyd/tianocore/tree/EOIR_v1 >>> >>> ArmPkg/Drivers/ArmGic/GicV2/ArmGicV2Dxe.c | 5 ++--- >>> ArmPkg/Drivers/ArmGic/GicV3/ArmGicV3Dxe.c | 5 ++--- >>> 2 files changed, 4 insertions(+), 6 deletions(-) >>> >>> diff --git a/ArmPkg/Drivers/ArmGic/GicV2/ArmGicV2Dxe.c >>> b/ArmPkg/Drivers/ArmGic/GicV2/ArmGicV2Dxe.c >>> index >>> 036eb5cd6bf6845dd2b03b62c933c1dedaef7251..34d4be3867647e0fdad7356c949 >>> a >>> f8cd3ede7164 100644 >>> --- a/ArmPkg/Drivers/ArmGic/GicV2/ArmGicV2Dxe.c >>> +++ b/ArmPkg/Drivers/ArmGic/GicV2/ArmGicV2Dxe.c >>> @@ -2,7 +2,7 @@ >>> >>> Copyright (c) 2009, Hewlett-Packard Company. All rights >>> reserved.
Portions copyright (c) 2010, Apple Inc. All rights >>> reserved.
-Portions copyright (c) 2011-2015, ARM Ltd. All rights >>> reserved.
>>> +Portions copyright (c) 2011-2016, ARM Ltd. All rights reserved.
>>> >>> This program and the accompanying materials are licensed and made >>> available under the terms and conditions of the BSD License @@ -178,9 >>> +178,8 @@ GicV2IrqInterruptHandler ( >>> InterruptHandler (GicInterrupt, SystemContext); >>> } else { >>> DEBUG ((EFI_D_ERROR, "Spurious GIC interrupt: 0x%x\n", >>> GicInterrupt)); >>> + GicV2EndOfInterrupt (&gHardwareInterruptV2Protocol, >>> + GicInterrupt); >>> } >>> - >>> - GicV2EndOfInterrupt (&gHardwareInterruptV2Protocol, GicInterrupt); >>> } >>> >>> // >>> diff --git a/ArmPkg/Drivers/ArmGic/GicV3/ArmGicV3Dxe.c >>> b/ArmPkg/Drivers/ArmGic/GicV3/ArmGicV3Dxe.c >>> index >>> 106c669fcb8777dfaad609c0ce9f5b572727a3ff..983936f3738a74bb5d5e08e0129 >>> 7 >>> 3df240958a8b 100644 >>> --- a/ArmPkg/Drivers/ArmGic/GicV3/ArmGicV3Dxe.c >>> +++ b/ArmPkg/Drivers/ArmGic/GicV3/ArmGicV3Dxe.c >>> @@ -1,6 +1,6 @@ >>> /** @file >>> * >>> -* Copyright (c) 2011-2015, ARM Limited. All rights reserved. >>> +* Copyright (c) 2011-2016, ARM Limited. All rights reserved. >>> * >>> * This program and the accompanying materials >>> * are licensed and made available under the terms and conditions of >>> the BSD License @@ -169,9 +169,8 @@ GicV3IrqInterruptHandler ( >>> InterruptHandler (GicInterrupt, SystemContext); >>> } else { >>> DEBUG ((EFI_D_ERROR, "Spurious GIC interrupt: 0x%x\n", >>> GicInterrupt)); >>> + GicV3EndOfInterrupt (&gHardwareInterruptV3Protocol, >>> + GicInterrupt); >>> } >>> - >>> - GicV3EndOfInterrupt (&gHardwareInterruptV3Protocol, GicInterrupt); >>> } >>> >>> // >>> -- >>> Guid("CE165669-3EF3-493F-B85D-6190EE5B9759") >>> >> _______________________________________________ >> edk2-devel mailing list >> edk2-devel@lists.01.org >> https://lists.01.org/mailman/listinfo/edk2-devel >> >> IMPORTANT NOTICE: The contents of this email and any attachments are con= fidential and may also be privileged. If you are not the intended recipient= , please notify the sender immediately and do not disclose the contents to = any other person, use it for any purpose, or store or copy the information = in any medium. Thank you. >> > > IMPORTANT NOTICE: The contents of this email and any attachments are conf= idential and may also be privileged. If you are not the intended recipient,= please notify the sender immediately and do not disclose the contents to a= ny other person, use it for any purpose, or store or copy the information i= n any medium. Thank you.