Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756042AbaJURrh (ORCPT ); Tue, 21 Oct 2014 13:47:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:30616 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750964AbaJURrf (ORCPT ); Tue, 21 Oct 2014 13:47:35 -0400 Message-ID: <1413913638.4202.153.camel@ul30vt.home> Subject: Re: [PATCH v8 13/18] vfio/platform: support for maskable and automasked interrupts From: Alex Williamson To: Antonios Motakis Cc: kvmarm@lists.cs.columbia.edu, iommu@lists.linux-foundation.org, will.deacon@arm.com, tech@virtualopensystems.com, christoffer.dall@linaro.org, eric.auger@linaro.org, kim.phillips@freescale.com, marc.zyngier@arm.com, "open list:VFIO DRIVER" , open list Date: Tue, 21 Oct 2014 11:47:18 -0600 In-Reply-To: <1413205825-6370-14-git-send-email-a.motakis@virtualopensystems.com> References: <1413205825-6370-1-git-send-email-a.motakis@virtualopensystems.com> <1413205825-6370-14-git-send-email-a.motakis@virtualopensystems.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2014-10-13 at 15:10 +0200, Antonios Motakis wrote: > Adds support to mask interrupts, and also for automasked interrupts. > Level sensitive interrupts are exposed as automasked interrupts and > are masked and disabled automatically when they fire. > > Signed-off-by: Antonios Motakis > --- > drivers/vfio/platform/vfio_platform_irq.c | 94 +++++++++++++++++++++++++-- > drivers/vfio/platform/vfio_platform_private.h | 2 + > 2 files changed, 91 insertions(+), 5 deletions(-) > > diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c > index 4359b9c..7620a17 100644 > --- a/drivers/vfio/platform/vfio_platform_irq.c > +++ b/drivers/vfio/platform/vfio_platform_irq.c > @@ -31,27 +31,103 @@ > > #include "vfio_platform_private.h" > > +static void vfio_platform_mask(struct vfio_platform_irq *irq_ctx) > +{ > + unsigned long flags; > + > + spin_lock_irqsave(&irq_ctx->lock, flags); > + > + if (!irq_ctx->masked) { > + disable_irq(irq_ctx->hwirq); > + irq_ctx->masked = true; > + } > + > + spin_unlock_irqrestore(&irq_ctx->lock, flags); > +} > + > static int vfio_platform_set_irq_mask(struct vfio_platform_device *vdev, > unsigned index, unsigned start, > unsigned count, uint32_t flags, void *data) > { > - return -EINVAL; > + if (start != 0 || count != 1) > + return -EINVAL; > + > + if (flags & VFIO_IRQ_SET_DATA_EVENTFD) > + return -EINVAL; /* not implemented yet */ > + > + if (flags & VFIO_IRQ_SET_DATA_NONE) { > + vfio_platform_mask(&vdev->irqs[index]); > + > + } else if (flags & VFIO_IRQ_SET_DATA_BOOL) { > + uint8_t mask = *(uint8_t *)data; > + > + if (mask) > + vfio_platform_mask(&vdev->irqs[index]); > + } > + > + return 0; > +} > + > +static void vfio_platform_unmask(struct vfio_platform_irq *irq_ctx) > +{ > + unsigned long flags; > + > + spin_lock_irqsave(&irq_ctx->lock, flags); > + > + if (irq_ctx->masked) { > + enable_irq(irq_ctx->hwirq); > + irq_ctx->masked = false; > + } > + > + spin_unlock_irqrestore(&irq_ctx->lock, flags); > } > > static int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev, > unsigned index, unsigned start, > unsigned count, uint32_t flags, void *data) > { > - return -EINVAL; > + if (start != 0 || count != 1) > + return -EINVAL; > + > + if (flags & VFIO_IRQ_SET_DATA_EVENTFD) > + return -EINVAL; /* not implemented yet */ > + > + if (flags & VFIO_IRQ_SET_DATA_NONE) { > + vfio_platform_unmask(&vdev->irqs[index]); > + > + } else if (flags & VFIO_IRQ_SET_DATA_BOOL) { > + uint8_t unmask = *(uint8_t *)data; > + > + if (unmask) > + vfio_platform_unmask(&vdev->irqs[index]); > + } > + > + return 0; > } > > static irqreturn_t vfio_irq_handler(int irq, void *dev_id) > { > struct vfio_platform_irq *irq_ctx = dev_id; > + unsigned long flags; > + int ret = IRQ_NONE; > > - eventfd_signal(irq_ctx->trigger, 1); > + spin_lock_irqsave(&irq_ctx->lock, flags); > + > + if (!irq_ctx->masked) { > + ret = IRQ_HANDLED; > + > + if (irq_ctx->flags & VFIO_IRQ_INFO_AUTOMASKED) { > + disable_irq_nosync(irq_ctx->hwirq); > + irq_ctx->masked = true; > + } > + } > > - return IRQ_HANDLED; > + spin_unlock_irqrestore(&irq_ctx->lock, flags); > + > + if (ret == IRQ_HANDLED) > + eventfd_signal(irq_ctx->trigger, 1); > + > + return ret; > } If you actually have edge interrupts, you're unnecessarily penalizing them with the spinlock here. You could do like vfio-pci and only advertise level interrupts as maskable then use separate edge vs level handlers. > > static int vfio_set_trigger(struct vfio_platform_device *vdev, > @@ -169,9 +245,17 @@ int vfio_platform_irq_init(struct vfio_platform_device *vdev) > if (hwirq < 0) > goto err; > > - vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD; > + spin_lock_init(&vdev->irqs[i].lock); > + > + vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD > + | VFIO_IRQ_INFO_MASKABLE; > + > + if (irq_get_trigger_type(hwirq) & IRQ_TYPE_LEVEL_MASK) > + vdev->irqs[i].flags |= VFIO_IRQ_INFO_AUTOMASKED; > + > vdev->irqs[i].count = 1; > vdev->irqs[i].hwirq = hwirq; > + vdev->irqs[i].masked = false; > } > > vdev->num_irqs = cnt; > diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h > index 47af6e0..65e80e7 100644 > --- a/drivers/vfio/platform/vfio_platform_private.h > +++ b/drivers/vfio/platform/vfio_platform_private.h > @@ -30,6 +30,8 @@ struct vfio_platform_irq { > int hwirq; > char *name; > struct eventfd_ctx *trigger; > + bool masked; > + spinlock_t lock; > }; > > struct vfio_platform_region { -- 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/