Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755234AbbHQPjF (ORCPT ); Mon, 17 Aug 2015 11:39:05 -0400 Received: from mail-wi0-f179.google.com ([209.85.212.179]:36314 "EHLO mail-wi0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751317AbbHQPjE (ORCPT ); Mon, 17 Aug 2015 11:39:04 -0400 Message-ID: <55D1FFE8.9050104@linaro.org> Date: Mon, 17 Aug 2015 17:38:16 +0200 From: Eric Auger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.8.0 MIME-Version: 1.0 To: Alex Williamson CC: eric.auger@st.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, christoffer.dall@linaro.org, marc.zyngier@arm.com, feng.wu@intel.com, linux-kernel@vger.kernel.org, patches@linaro.org, pbonzini@redhat.com Subject: Re: [PATCH v3 04/10] VFIO: platform: add vfio_platform_set_automasked References: <1439212864-12954-1-git-send-email-eric.auger@linaro.org> <1439212864-12954-5-git-send-email-eric.auger@linaro.org> <1439405794.4023.528.camel@redhat.com> In-Reply-To: <1439405794.4023.528.camel@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2229 Lines: 73 On 08/12/2015 08:56 PM, Alex Williamson wrote: > On Mon, 2015-08-10 at 15:20 +0200, Eric Auger wrote: >> This function makes possible to change the automasked mode. >> >> Signed-off-by: Eric Auger >> >> --- >> >> v1 -> v2: >> - set forwarded flag >> --- >> drivers/vfio/platform/vfio_platform_irq.c | 19 +++++++++++++++++++ >> 1 file changed, 19 insertions(+) >> >> diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c >> index b31b1f0..a285384 100644 >> --- a/drivers/vfio/platform/vfio_platform_irq.c >> +++ b/drivers/vfio/platform/vfio_platform_irq.c >> @@ -186,6 +186,25 @@ static irqreturn_t vfio_handler(int irq, void *dev_id) >> return ret; >> } >> >> +static int vfio_platform_set_automasked(struct vfio_platform_irq *irq, >> + bool automasked) >> +{ >> + unsigned long flags; >> + >> + spin_lock_irqsave(&irq->lock, flags); >> + if (automasked) { >> + irq->forwarded = true; >> + irq->flags |= VFIO_IRQ_INFO_AUTOMASKED; >> + irq->handler = vfio_automasked_irq_handler; >> + } else { >> + irq->forwarded = false; >> + irq->flags &= ~VFIO_IRQ_INFO_AUTOMASKED; >> + irq->handler = vfio_irq_handler; >> + } >> + spin_unlock_irqrestore(&irq->lock, flags); >> + return 0; > > In vfio-speak, automasked means level and we're not magically changing > the IRQ from level to edge, we're simply able to handle level > differently based on a hardware optimization. Should the user visible > flags therefore change based on this? Aren't we really setting the > forwarded state rather than the automasked state? Well actually this was following the discussion we had a long time ago about that topic: http://lkml.iu.edu/hypermail/linux/kernel/1409.1/03659.html I did not really know how to conclude ... If it is preferred I can hide this to the userspace, no problem. Eric > >> +} >> + >> static void vfio_platform_irq_bypass_stop(struct irq_bypass_producer *prod) >> { >> } > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/