[Intel-wired-lan] [PATCH v1 03/13] ixgbevf: make use of BIT() macro to avoid shift of signed values

Keller, Jacob E jacob.e.keller at intel.com
Wed Apr 13 21:47:06 UTC 2016


On Wed, 2016-04-13 at 14:39 -0700, Alexander Duyck wrote:
> On Wed, Apr 13, 2016 at 2:31 PM, Jacob Keller <jacob.e.keller at intel.c
> om> wrote:
> > 
> > Also cleanup a case where we're bit shifting a value into place,
> > and use
> > an unsigned constant.
> > 
> > Signed-off-by: Jacob Keller <jacob.e.keller at intel.com>
> > ---
> >  drivers/net/ethernet/intel/ixgbevf/defines.h      | 22
> > +++++++++++-----------
> >  drivers/net/ethernet/intel/ixgbevf/ethtool.c      |  2 +-
> >  drivers/net/ethernet/intel/ixgbevf/ixgbevf.h      |  8 ++++----
> >  drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 18 +++++++++
> > ---------
> >  4 files changed, 25 insertions(+), 25 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/intel/ixgbevf/defines.h
> > b/drivers/net/ethernet/intel/ixgbevf/defines.h
> > index 58434584b16d..74901f7ef391 100644
> > --- a/drivers/net/ethernet/intel/ixgbevf/defines.h
> > +++ b/drivers/net/ethernet/intel/ixgbevf/defines.h
> > @@ -74,7 +74,7 @@ typedef u32 ixgbe_link_speed;
> >  #define IXGBE_RXDCTL_RLPML_EN  0x00008000
> > 
> >  /* DCA Control */
> > -#define IXGBE_DCA_TXCTRL_TX_WB_RO_EN (1 << 11) /* Tx Desc
> > writeback RO bit */
> > +#define IXGBE_DCA_TXCTRL_TX_WB_RO_EN BIT(11) /* Tx Desc writeback
> > RO bit */
> > 
> >  /* PSRTYPE bit definitions */
> >  #define IXGBE_PSRTYPE_TCPHDR   0x00000010
> > @@ -296,16 +296,16 @@ struct ixgbe_adv_tx_context_desc {
> >  #define IXGBE_TXDCTL_SWFLSH            0x04000000 /* Tx Desc. wr-
> > bk flushing */
> >  #define IXGBE_TXDCTL_WTHRESH_SHIFT     16         /* shift to
> > WTHRESH bits */
> > 
> > -#define IXGBE_DCA_RXCTRL_DESC_DCA_EN   (1 << 5)  /* Rx Desc enable
> > */
> > -#define IXGBE_DCA_RXCTRL_HEAD_DCA_EN   (1 << 6)  /* Rx Desc header
> > ena */
> > -#define IXGBE_DCA_RXCTRL_DATA_DCA_EN   (1 << 7)  /* Rx Desc
> > payload ena */
> > -#define IXGBE_DCA_RXCTRL_DESC_RRO_EN   (1 << 9)  /* Rx rd Desc
> > Relax Order */
> > -#define IXGBE_DCA_RXCTRL_DATA_WRO_EN   (1 << 13) /* Rx wr data
> > Relax Order */
> > -#define IXGBE_DCA_RXCTRL_HEAD_WRO_EN   (1 << 15) /* Rx wr header
> > RO */
> > +#define IXGBE_DCA_RXCTRL_DESC_DCA_EN   BIT(5)  /* Rx Desc enable
> > */
> > +#define IXGBE_DCA_RXCTRL_HEAD_DCA_EN   BIT(6)  /* Rx Desc header
> > ena */
> > +#define IXGBE_DCA_RXCTRL_DATA_DCA_EN   BIT(7)  /* Rx Desc payload
> > ena */
> > +#define IXGBE_DCA_RXCTRL_DESC_RRO_EN   BIT(9)  /* Rx rd Desc Relax
> > Order */
> > +#define IXGBE_DCA_RXCTRL_DATA_WRO_EN   BIT(13) /* Rx wr data Relax
> > Order */
> > +#define IXGBE_DCA_RXCTRL_HEAD_WRO_EN   BIT(15) /* Rx wr header RO
> > */
> > 
> > -#define IXGBE_DCA_TXCTRL_DESC_DCA_EN   (1 << 5)  /* DCA Tx Desc
> > enable */
> > -#define IXGBE_DCA_TXCTRL_DESC_RRO_EN   (1 << 9)  /* Tx rd Desc
> > Relax Order */
> > -#define IXGBE_DCA_TXCTRL_DESC_WRO_EN   (1 << 11) /* Tx Desc
> > writeback RO bit */
> > -#define IXGBE_DCA_TXCTRL_DATA_RRO_EN   (1 << 13) /* Tx rd data
> > Relax Order */
> > +#define IXGBE_DCA_TXCTRL_DESC_DCA_EN   BIT(5)  /* DCA Tx Desc
> > enable */
> > +#define IXGBE_DCA_TXCTRL_DESC_RRO_EN   BIT(9)  /* Tx rd Desc Relax
> > Order */
> > +#define IXGBE_DCA_TXCTRL_DESC_WRO_EN   BIT(11) /* Tx Desc
> > writeback RO bit */
> > +#define IXGBE_DCA_TXCTRL_DATA_RRO_EN   BIT(13) /* Tx rd data Relax
> > Order */
> > 
> >  #endif /* _IXGBEVF_DEFINES_H_ */
> > diff --git a/drivers/net/ethernet/intel/ixgbevf/ethtool.c
> > b/drivers/net/ethernet/intel/ixgbevf/ethtool.c
> > index 64d5c6e9343e..28954577fb59 100644
> > --- a/drivers/net/ethernet/intel/ixgbevf/ethtool.c
> > +++ b/drivers/net/ethernet/intel/ixgbevf/ethtool.c
> > @@ -166,7 +166,7 @@ static void ixgbevf_get_regs(struct net_device
> > *netdev,
> > 
> >         memset(p, 0, regs_len);
> > 
> > -       regs->version = (1 << 24) | hw->revision_id << 16 | hw-
> > >device_id;
> > +       regs->version = BIT(24) | hw->revision_id << 16 | hw-
> > >device_id;
> > 
> >         /* General Registers */
> >         regs_buff[0] = IXGBE_READ_REG(hw, IXGBE_VFCTRL);
> So the question I would have is what did the (1 << 24) mean?  I'm
> pretty sure it wasn't a bitmask.  It is supposed to be a version
> number.  You might want to restructure this bit so that it is more
> clear that what you are doing is converting the version, revision_id,
> and device_id into a version number for use by ethtool.
> 

This probably needs work. I just used a regular expression to convert
the 1 << x at first and didn't notice this in the review. I am not
really sure what the best way to do that would be, but this defintily
is less confusing. I'll think about it a little.

> > 
> > diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
> > b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
> > index 5ca3794aeb2e..aa28c4fb1a43 100644
> > --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
> > +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
> > @@ -166,10 +166,10 @@ struct ixgbevf_ring {
> > 
> >  #define MAXIMUM_ETHERNET_VLAN_SIZE (VLAN_ETH_FRAME_LEN +
> > ETH_FCS_LEN)
> > 
> > -#define IXGBE_TX_FLAGS_CSUM            (u32)(1)
> > -#define IXGBE_TX_FLAGS_VLAN            (u32)(1 << 1)
> > -#define IXGBE_TX_FLAGS_TSO             (u32)(1 << 2)
> > -#define IXGBE_TX_FLAGS_IPV4            (u32)(1 << 3)
> > +#define IXGBE_TX_FLAGS_CSUM            BIT(0)
> > +#define IXGBE_TX_FLAGS_VLAN            BIT(1)
> > +#define IXGBE_TX_FLAGS_TSO             BIT(2)
> > +#define IXGBE_TX_FLAGS_IPV4            BIT(3)
> >  #define IXGBE_TX_FLAGS_VLAN_MASK       0xffff0000
> >  #define IXGBE_TX_FLAGS_VLAN_PRIO_MASK  0x0000e000
> >  #define IXGBE_TX_FLAGS_VLAN_SHIFT      16
> > diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
> > b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
> > index 007cbe094990..ef127f46de23 100644
> > --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
> > +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
> > @@ -1056,7 +1056,7 @@ static int ixgbevf_poll(struct napi_struct
> > *napi, int budget)
> >         if (!test_bit(__IXGBEVF_DOWN, &adapter->state) &&
> >             !test_bit(__IXGBEVF_REMOVING, &adapter->state))
> >                 ixgbevf_irq_enable_queues(adapter,
> > -                                         1 << q_vector->v_idx);
> > +                                         BIT(q_vector->v_idx));
> > 
> >         return 0;
> >  }
> > @@ -1158,14 +1158,14 @@ static void ixgbevf_configure_msix(struct
> > ixgbevf_adapter *adapter)
> >                 }
> > 
> >                 /* add q_vector eims value to global
> > eims_enable_mask */
> > -               adapter->eims_enable_mask |= 1 << v_idx;
> > +               adapter->eims_enable_mask |= BIT(v_idx);
> > 
> >                 ixgbevf_write_eitr(q_vector);
> >         }
> > 
> >         ixgbevf_set_ivar(adapter, -1, 1, v_idx);
> >         /* setup eims_other and add value to global
> > eims_enable_mask */
> > -       adapter->eims_other = 1 << v_idx;
> > +       adapter->eims_other = BIT(v_idx);
> >         adapter->eims_enable_mask |= adapter->eims_other;
> >  }
> > 
> > @@ -1589,8 +1589,8 @@ static void ixgbevf_configure_tx_ring(struct
> > ixgbevf_adapter *adapter,
> >         txdctl |= (8 << 16);    /* WTHRESH = 8 */
> > 
> >         /* Setting PTHRESH to 32 both improves performance */
> > -       txdctl |= (1 << 8) |    /* HTHRESH = 1 */
> > -                 32;          /* PTHRESH = 32 */
> > +       txdctl |= (1u << 8) |    /* HTHRESH = 1 */
> > +                  32;           /* PTHRESH = 32 */
> > 
> >         clear_bit(__IXGBEVF_HANG_CHECK_ARMED, &ring->state);
> > 
> > @@ -1646,7 +1646,7 @@ static void ixgbevf_setup_psrtype(struct
> > ixgbevf_adapter *adapter)
> >                       IXGBE_PSRTYPE_L2HDR;
> > 
> >         if (adapter->num_rx_queues > 1)
> > -               psrtype |= 1 << 29;
> > +               psrtype |= BIT(29);
> > 
> >         IXGBE_WRITE_REG(hw, IXGBE_VFPSRTYPE, psrtype);
> >  }
> > @@ -2797,7 +2797,7 @@ static void ixgbevf_check_hang_subtask(struct
> > ixgbevf_adapter *adapter)
> >                 struct ixgbevf_q_vector *qv = adapter->q_vector[i];
> > 
> >                 if (qv->rx.ring || qv->tx.ring)
> > -                       eics |= 1 << i;
> > +                       eics |= BIT(i);
> >         }
> > 
> >         /* Cause software interrupt to ensure rings are cleaned */
> > @@ -3325,7 +3325,7 @@ static int ixgbevf_tso(struct ixgbevf_ring
> > *tx_ring,
> >         /* mss_l4len_id: use 1 as index for TSO */
> >         mss_l4len_idx = l4len << IXGBE_ADVTXD_L4LEN_SHIFT;
> >         mss_l4len_idx |= skb_shinfo(skb)->gso_size <<
> > IXGBE_ADVTXD_MSS_SHIFT;
> > -       mss_l4len_idx |= 1 << IXGBE_ADVTXD_IDX_SHIFT;
> > +       mss_l4len_idx |= BIT(IXGBE_ADVTXD_IDX_SHIFT);
> > 
> >         /* vlan_macip_lens: HEADLEN, MACLEN, VLAN tag */
> >         vlan_macip_lens = skb_network_header_len(skb);
> > @@ -3422,7 +3422,7 @@ static void ixgbevf_tx_olinfo_status(union
> > ixgbe_adv_tx_desc *tx_desc,
> > 
> >         /* use index 1 context for TSO/FSO/FCOE */
> >         if (tx_flags & IXGBE_TX_FLAGS_TSO)
> > -               olinfo_status |= cpu_to_le32(1 <<
> > IXGBE_ADVTXD_IDX_SHIFT);
> > +               olinfo_status |=
> > cpu_to_le32(BIT(IXGBE_ADVTXD_IDX_SHIFT));
> Same here.   This is a index value shifted by
> ADVTXD_IDX_SHIFT.  Maybe
> you should just invent a new bit so that you have IXGBE_ADVTXD_IDX1.
> It would be much more readable than converting a shift into a bit
> index.

Yea this should just be "1u" instead of BIT.

Thanks,
Jake


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