Re: [dpdk-dev] [PATCH RFC] mbuf: Adjust TX flags to start at bit 32

[Bruce Richardson <bruce.richardson@intel.com>]

On Tue, Sep 30, 2014 at 05:00:04PM +0100, Wiles, Roger Keith wrote:
> Hi Bruce,
> 
> I like the idea of the split, which should make it easier to do the testing of those bits.
> One comment below.
> 
> On Sep 30, 2014, at 10:33 AM, Bruce Richardson <bruce.richardson@intel.com> wrote:
> 
> > On Tue, Sep 30, 2014 at 04:26:02PM +0100, Bruce Richardson wrote:
> >> This patch takes the existing TX flags defined for the mbuf and shifts
> >> each uniquely defined one left so that additional RX flags can be
> >> defined without having RX and TX flags mixed together.
> >>
> >> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> >> ---
> >
> > This is just an RFC patch for now, as I'm looking for input to make sure
> > this is done right. Couple of opens, if people have input:
> > * is a 32/32 split for RX/TX flags appropriate? Are we likely to have about
> >  equal numbers of each?
> > * Doing a grep for the TX flag use, it seems the defines are commonly used,
> >  but if anyone is aware of anywhere where the code depends on the flags
> > having a particular value, please let me know.
> >
> > If I have time, I also hope to look at doing rework on the testpmd flag
> > handling based off Olivier's previous patches, but since that is not
> > affecting the public ABI, I consider it a bit lower priority.
> >
> > Thanks,
> > /Bruce
> >
> >> lib/librte_mbuf/rte_mbuf.h | 26 +++++++++++++-------------
> >> 1 file changed, 13 insertions(+), 13 deletions(-)
> >>
> >> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> >> index 1c6e115..c9fc4ec 100644
> >> --- a/lib/librte_mbuf/rte_mbuf.h
> >> +++ b/lib/librte_mbuf/rte_mbuf.h
> >> @@ -86,26 +86,26 @@ extern "C" {
> >> #define PKT_RX_IEEE1588_PTP  0x0200 /**< RX IEEE1588 L2 Ethernet PT Packet. */
> >> #define PKT_RX_IEEE1588_TMST 0x0400 /**< RX IEEE1588 L2/L4 timestamped packet.*/
> >>
> >> -#define PKT_TX_VLAN_PKT      0x0800 /**< TX packet is a 802.1q VLAN packet. */
> >> -#define PKT_TX_IP_CKSUM      0x1000 /**< IP cksum of TX pkt. computed by NIC. */
> >> -#define PKT_TX_IPV4_CSUM     0x1000 /**< Alias of PKT_TX_IP_CKSUM. */
> >> -#define PKT_TX_IPV4          PKT_RX_IPV4_HDR /**< IPv4 with no IP checksum offload. */
> >> -#define PKT_TX_IPV6          PKT_RX_IPV6_HDR /**< IPv6 packet */
> >> +#define PKT_TX_VLAN_PKT  (0x0001 << 32) /**< TX packet is a 802.1q VLAN packet. */
> >> +#define PKT_TX_IP_CKSUM  (0x0002 << 32) /**< IP cksum of TX pkt. computed by NIC. */
> 
> One little nit in the patch is does (0x0001 << 32) need to be (0x0001ULL << 32)? I have not tested it and just a thought.

Yes, indeed it does, good catch!

/Bruce

> 
> Thanks
> ++Keith
> >> +#define PKT_TX_IPV4_CSUM PKT_TX_IP_CKSUM /**< Alias of PKT_TX_IP_CKSUM. */
> >> +#define PKT_TX_IPV4      PKT_RX_IPV4_HDR /**< IPv4 with no IP checksum offload. */
> >> +#define PKT_TX_IPV6      PKT_RX_IPV6_HDR /**< IPv6 packet */
> >>
> >> /*
> >> - * Bit 14~13 used for L4 packet type with checksum enabled.
> >> + * Bit 35~34 used for L4 packet type with checksum enabled.
> >>  *     00: Reserved
> >>  *     01: TCP checksum
> >>  *     10: SCTP checksum
> >>  *     11: UDP checksum
> >>  */
> >> -#define PKT_TX_L4_MASK       0x6000 /**< Mask bits for L4 checksum offload request. */
> >> -#define PKT_TX_L4_NO_CKSUM   0x0000 /**< Disable L4 cksum of TX pkt. */
> >> -#define PKT_TX_TCP_CKSUM     0x2000 /**< TCP cksum of TX pkt. computed by NIC. */
> >> -#define PKT_TX_SCTP_CKSUM    0x4000 /**< SCTP cksum of TX pkt. computed by NIC. */
> >> -#define PKT_TX_UDP_CKSUM     0x6000 /**< UDP cksum of TX pkt. computed by NIC. */
> >> -/* Bit 15 */
> >> -#define PKT_TX_IEEE1588_TMST 0x8000 /**< TX IEEE1588 packet to timestamp. */
> >> +#define PKT_TX_L4_NO_CKSUM   (0x0000 << 32) /**< Disable L4 cksum of TX pkt. */
> >> +#define PKT_TX_TCP_CKSUM     (0x0004 << 32) /**< TCP cksum of TX pkt. computed by NIC. */
> >> +#define PKT_TX_SCTP_CKSUM    (0x0008 << 32) /**< SCTP cksum of TX pkt. computed by NIC. */
> >> +#define PKT_TX_UDP_CKSUM     (0x000C << 32) /**< UDP cksum of TX pkt. computed by NIC. */
> >> +#define PKT_TX_L4_MASK       (0x000C << 32) /**< Mask for L4 cksum offload request. */
> >> +/* Bit 36 */
> >> +#define PKT_TX_IEEE1588_TMST (0x0010 << 32) /**< TX IEEE1588 packet to timestamp. */
> >>
> >> /* Use final bit of flags to indicate a control mbuf */
> >> #define CTRL_MBUF_FLAG       (1ULL << 63)
> >> --
> >> 1.9.3
> >>
> 
> Keith Wiles, Principal Technologist with CTO office, Wind River mobile 972-213-5533
>