From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ferruh Yigit Subject: Re: [RFC PATCH] igb_uio: issue FLR during open and release of device file Date: Wed, 31 May 2017 13:20:08 +0100 Message-ID: References: <1748341.rbpcFmWp0q@polaris> <1496228966-18573-1-git-send-email-shijith.thotton@caviumnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: Stephen Hemminger , dev@dpdk.org, Qi Zhang , Wenzhuo Lu , Thomas Monjalon , Jianfeng Tan To: Shijith Thotton , Gregory Etelson Return-path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id A9419292D for ; Wed, 31 May 2017 14:20:12 +0200 (CEST) In-Reply-To: <1496228966-18573-1-git-send-email-shijith.thotton@caviumnetworks.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 5/31/2017 12:09 PM, Shijith Thotton wrote: > Set UIO info device file operations open and release. Call pci reset > function inside open and release to clear device state at start and > end. Copied this behaviour from vfio_pci kernel module code. With this > change, it is not mandatory to issue FLR by PMD's during init and close. Cc: Jianfeng Tan Jianfeng also implemented following patch: http://dpdk.org/dev/patchwork/patch/17495/ Which also implements release and open ops, for slightly different reason (prevent DMA access after app exit), but mainly both are to gracefully handle application exit status. btw, for Jianfeng's case, can adding pci_clear_master() in release and moving pci_set_master() to open help preventing unwanted DMA? Gregory, Can you please check if this patch fixes your issue? Thanks, ferruh > > Signed-off-by: Shijith Thotton > --- > lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > > diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c > index b9d427c..5bc58d2 100644 > --- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c > +++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c > @@ -170,6 +170,34 @@ struct rte_uio_pci_dev { > return IRQ_HANDLED; > } > > +/** > + * This gets called while opening uio device file. It clears any previous state > + * associated with the pci device. > + */ > +static int > +igbuio_pci_open(struct uio_info *info, struct inode *inode) > +{ > + struct rte_uio_pci_dev *udev = info->priv; > + struct pci_dev *dev = udev->pdev; > + > + /* reset the pci device */ > + pci_reset_function(dev); > + > + return 0; > +} > + > +static int > +igbuio_pci_release(struct uio_info *info, struct inode *inode) > +{ > + struct rte_uio_pci_dev *udev = info->priv; > + struct pci_dev *dev = udev->pdev; > + > + /* try to reset the pci device */ > + pci_try_reset_function(dev); > + > + return 0; > +} > + > #ifdef CONFIG_XEN_DOM0 > static int > igbuio_dom0_mmap_phys(struct uio_info *info, struct vm_area_struct *vma) > @@ -372,6 +400,8 @@ struct rte_uio_pci_dev { > udev->info.version = "0.1"; > udev->info.handler = igbuio_pci_irqhandler; > udev->info.irqcontrol = igbuio_pci_irqcontrol; > + udev->info.open = igbuio_pci_open; > + udev->info.release = igbuio_pci_release; > #ifdef CONFIG_XEN_DOM0 > /* check if the driver run on Xen Dom0 */ > if (xen_initial_domain()) >