Re: [PATCH 5/5] ixgbe: add driver set_max_vfs support

[Dan Carpenter <dan.carpenter@oracle.com>]

On Wed, Oct 03, 2012 at 10:51:35AM -0700, Yinghai Lu wrote:
> Need ixgbe guys to close the loop to use set_max_vfs instead
> kernel parameters.
> 
> Signed-off-by: Yinghai Lu <yinghai@kernel.org>
> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
> Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
> Cc: Greg Rose <gregory.v.rose@intel.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: John Fastabend <john.r.fastabend@intel.com>
> Cc: e1000-devel@lists.sourceforge.net
> Cc: netdev@vger.kernel.org
> ---
>  drivers/net/ethernet/intel/ixgbe/ixgbe.h      |    2 +
>  drivers/net/ethernet/intel/ixgbe/ixgbe_main.c |   44 +++++++++++++++++++-----
>  2 files changed, 37 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
> index b9623e9..d39d975 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
> @@ -558,6 +558,8 @@ struct ixgbe_adapter {
>  	u32 interrupt_event;
>  	u32 led_reg;
>  
> +	struct ixgbe_info *ixgbe_info;
> +
>  #ifdef CONFIG_IXGBE_PTP
>  	struct ptp_clock *ptp_clock;
>  	struct ptp_clock_info ptp_caps;
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> index ee61819..1c097c7 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> @@ -129,13 +129,6 @@ static struct notifier_block dca_notifier = {
>  };
>  #endif
>  
> -#ifdef CONFIG_PCI_IOV
> -static unsigned int max_vfs;
> -module_param(max_vfs, uint, 0);
> -MODULE_PARM_DESC(max_vfs,
> -		 "Maximum number of virtual functions to allocate per physical function - default is zero and maximum value is 63");
> -#endif /* CONFIG_PCI_IOV */
> -
>  static unsigned int allow_unsupported_sfp;
>  module_param(allow_unsupported_sfp, uint, 0);
>  MODULE_PARM_DESC(allow_unsupported_sfp,
> @@ -4496,7 +4489,7 @@ static int __devinit ixgbe_sw_init(struct ixgbe_adapter *adapter)
>  #ifdef CONFIG_PCI_IOV
>  	/* assign number of SR-IOV VFs */
>  	if (hw->mac.type != ixgbe_mac_82598EB)
> -		adapter->num_vfs = (max_vfs > 63) ? 0 : max_vfs;
> +		adapter->num_vfs = min_t(int, pdev->max_vfs, 63);

Could we make this min_t(uint, ...);

->max_vfs is type unsigned int. We take an unsigned long from sysfs.
We silently truncate it to an unsigned int.  Then we cast it to a
negative number and compare against 63 and take the minimum...

It's root only so it's not a problem but it's a hassle to audit.

regards,
dan carpenter