Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932497AbbENIjW (ORCPT ); Thu, 14 May 2015 04:39:22 -0400 Received: from mail-wg0-f41.google.com ([74.125.82.41]:36403 "EHLO mail-wg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752977AbbENIjR (ORCPT ); Thu, 14 May 2015 04:39:17 -0400 Message-ID: <55545F30.4090808@linaro.org> Date: Thu, 14 May 2015 10:39:12 +0200 From: Eric Auger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Alex Williamson CC: eric.auger@st.com, christoffer.dall@linaro.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, b.reynal@virtualopensystems.com, linux-kernel@vger.kernel.org, patches@linaro.org, agraf@suse.de, Bharat.Bhushan@freescale.com Subject: Re: [PATCH 3/5] VFIO: platform: add reset callback References: <1431008843-28411-1-git-send-email-eric.auger@linaro.org> <1431008843-28411-4-git-send-email-eric.auger@linaro.org> <1431541959.3625.54.camel@redhat.com> In-Reply-To: <1431541959.3625.54.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: 3314 Lines: 92 On 05/13/2015 08:32 PM, Alex Williamson wrote: > On Thu, 2015-05-07 at 16:27 +0200, Eric Auger wrote: >> A new reset callback is introduced. If this callback is populated, >> the reset is invoked on device release or upon userspace ioctl. The >> modality is exposed on VFIO_DEVICE_GET_INFO. >> >> Signed-off-by: Eric Auger >> >> --- >> >> v2 -> v3: >> - change patch title and commit message. Use IS_ERR_OR_NULL to >> anticipate for getter returned value. >> >> v1 -> v2: >> - On VFIO_DEVICE_RESET returns -EINVAL in case the callback is not >> populated (instead of -ENOTTY) >> --- >> drivers/vfio/platform/vfio_platform_common.c | 12 ++++++++++-- >> drivers/vfio/platform/vfio_platform_private.h | 1 + >> 2 files changed, 11 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c >> index edbf24c..0d10018 100644 >> --- a/drivers/vfio/platform/vfio_platform_common.c >> +++ b/drivers/vfio/platform/vfio_platform_common.c >> @@ -103,6 +103,8 @@ static void vfio_platform_release(void *device_data) >> mutex_lock(&driver_lock); >> >> if (!(--vdev->refcnt)) { >> + if (!IS_ERR_OR_NULL(vdev->reset)) >> + vdev->reset(vdev); > > > It seems sloppy to have a function pointer that could be ERR_PTR. The reset lookup function currently can return errors. I will change this. > > Should we also be trying to reset on device open? may be yes. I was influenced by qemu use case where reset is also explicitly invoked through iotcl by the reset notifier. If we do so we might have duplicated resets. - Eric > >> vfio_platform_regions_cleanup(vdev); >> vfio_platform_irq_cleanup(vdev); >> } >> @@ -162,6 +164,8 @@ static long vfio_platform_ioctl(void *device_data, >> if (info.argsz < minsz) >> return -EINVAL; >> >> + if (!IS_ERR_OR_NULL(vdev->reset)) >> + vdev->flags |= VFIO_DEVICE_FLAGS_RESET; >> info.flags = vdev->flags; >> info.num_regions = vdev->num_regions; >> info.num_irqs = vdev->num_irqs; >> @@ -255,8 +259,12 @@ static long vfio_platform_ioctl(void *device_data, >> >> return ret; >> >> - } else if (cmd == VFIO_DEVICE_RESET) >> - return -EINVAL; >> + } else if (cmd == VFIO_DEVICE_RESET) { >> + if (!IS_ERR_OR_NULL(vdev->reset)) >> + return vdev->reset(vdev); >> + else >> + return -EINVAL; >> + } >> >> return -ENOTTY; >> } >> diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h >> index 68909a4..84ccf6d 100644 >> --- a/drivers/vfio/platform/vfio_platform_private.h >> +++ b/drivers/vfio/platform/vfio_platform_private.h >> @@ -68,6 +68,7 @@ struct vfio_platform_device { >> (*get_resource)(struct vfio_platform_device *vdev, int i); >> int (*get_irq)(struct vfio_platform_device *vdev, int i); >> struct device *(*get_device)(struct vfio_platform_device *vdev); >> + int (*reset)(struct vfio_platform_device *vdev); >> }; >> >> typedef int (*vfio_platform_reset_fn_t)(struct vfio_platform_device *vdev); > > > -- 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/