[dpdk-dev] [RFC PATCH] igb_uio: issue FLR during open and release of device file

Ferruh Yigit ferruh.yigit at intel.com
Wed May 31 14:20:08 CEST 2017


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.tan at intel.com>

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 <shijith.thotton at caviumnetworks.com>
> ---
>  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())
> 



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