Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759343AbaJaThD (ORCPT ); Fri, 31 Oct 2014 15:37:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48237 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758148AbaJaThB (ORCPT ); Fri, 31 Oct 2014 15:37:01 -0400 Message-ID: <1414784196.27420.328.camel@ul30vt.home> Subject: Re: [PATCH v9 13/19] vfio/platform: support for level sensitive 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: Fri, 31 Oct 2014 13:36:36 -0600 In-Reply-To: <1414433284-31719-14-git-send-email-a.motakis@virtualopensystems.com> References: <1414433284-31719-1-git-send-email-a.motakis@virtualopensystems.com> <1414433284-31719-14-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, 2014-10-27 at 19:07 +0100, Antonios Motakis wrote: > Level sensitive interrupts are exposed as maskable and automasked > interrupts and are masked and disabled automatically when they fire. > > Signed-off-by: Antonios Motakis > --- > drivers/vfio/platform/vfio_platform_irq.c | 102 +++++++++++++++++++++++++- > drivers/vfio/platform/vfio_platform_private.h | 2 + > 2 files changed, 100 insertions(+), 4 deletions(-) > > diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c > index 2ac8ed7..563abf6 100644 > --- a/drivers/vfio/platform/vfio_platform_irq.c > +++ b/drivers/vfio/platform/vfio_platform_irq.c > @@ -31,18 +31,108 @@ > > #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 (!(vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE)) > + 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 (!(vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE)) > + 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_maskable_irq_handler(int irq, void *dev_id) > +{ > + struct vfio_platform_irq *irq_ctx = dev_id; > + unsigned long flags; > + int ret = IRQ_NONE; > + > + spin_lock_irqsave(&irq_ctx->lock, flags); > + > + if (!irq_ctx->masked) { > + ret = IRQ_HANDLED; > + > + /* automask maskable interrupts */ > + disable_irq_nosync(irq_ctx->hwirq); > + irq_ctx->masked = true; > + } > + > + spin_unlock_irqrestore(&irq_ctx->lock, flags); > + > + if (ret == IRQ_HANDLED) > + eventfd_signal(irq_ctx->trigger, 1); > + > + return ret; This is not just a maskable irq handler, but specifically a level (aka automasked) handler. So this should only be used for AUTOMASKED irqs. > } > > static irqreturn_t vfio_irq_handler(int irq, void *dev_id) > @@ -103,7 +193,7 @@ static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev, > irq_handler_t handler; > > if (vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE) > - return -EINVAL; /* not implemented */ > + handler = vfio_maskable_irq_handler; As noted in the previous patch, this should be a test for AUTOMASKED, not just MASKABLE. > else > handler = vfio_irq_handler; > > @@ -175,13 +265,17 @@ int vfio_platform_irq_init(struct vfio_platform_device *vdev) > if (hwirq < 0) > goto err; > > + spin_lock_init(&vdev->irqs[i].lock); > + > vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD; > > if (irq_get_trigger_type(hwirq) & IRQ_TYPE_LEVEL_MASK) > - vdev->irqs[i].flags |= VFIO_IRQ_INFO_MASKABLE; > + vdev->irqs[i].flags |= VFIO_IRQ_INFO_MASKABLE > + | 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 a3f2411..d25c4cd 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/