[dpdk-dev] [PATCH v8 3/3] ixgbe: Add LRO support

Ananyev, Konstantin konstantin.ananyev at intel.com
Tue Mar 31 12:25:40 CEST 2015



> -----Original Message-----
> From: Vlad Zolotarov [mailto:vladz at cloudius-systems.com]
> Sent: Monday, March 30, 2015 4:57 PM
> To: Ananyev, Konstantin; dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v8 3/3] ixgbe: Add LRO support
> 
> 
> 
> On 03/30/15 18:37, Vlad Zolotarov wrote:
> >
> >
> > On 03/30/15 17:18, Ananyev, Konstantin wrote:
> >> Hi Vlad,
> >>
> >>> -----Original Message-----
> >>> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Vlad Zolotarov
> >>> Sent: Wednesday, March 18, 2015 5:52 PM
> >>> To: dev at dpdk.org
> >>> Subject: [dpdk-dev] [PATCH v8 3/3] ixgbe: Add LRO support
> >>>
> >>>      - Only x540 and 82599 devices support LRO.
> >>>      - Add the appropriate HW configuration.
> >>>      - Add RSC aware rx_pkt_burst() handlers:
> >>>         - Implemented bulk allocation and non-bulk allocation versions.
> >>>         - Add LRO-specific fields to rte_eth_rxmode, to
> >>> rte_eth_dev_data
> >>>           and to ixgbe_rx_queue.
> >>>         - Use the appropriate handler when LRO is requested.
> >>>
> >>> Signed-off-by: Vlad Zolotarov <vladz at cloudius-systems.com>
> >>> ---
> >>> New in v8:
> >>>     - Took the RSC configuration code from ixgbe_dev_rx_init() into
> >>> a separate
> >>>       function - ixgbe_set_rsc().
> >>>     - Added some missing macros for HW configuration.
> >>>     - Styling adjustments:
> >>>        - Functions names.
> >>>        - Functions descriptions.
> >>>     - Reworked the ixgbe_free_rsc_cluster() code to make it more
> >>> readable.
> >>>     - Kill the HEADER_SPLIT flow in ixgbe_set_rsc() since it's not
> >>> supported by
> >>>       ixgbe PMD.
> >>>
> >>> New in v7:
> >>>     - Free not-yet-completed RSC aggregations in rte_eth_dev_stop()
> >>> flow.
> >>>     - Reset the sw_ring[].mbuf entry in a bulk allocation case.
> >>>       This is needed for ixgbe_rx_queue_release_mbufs().
> >>>     - _recv_pkts_lro(): added the missing memory barrier before RDT
> >>> update in a
> >>>       non-bulk allocation case.
> >>>     - Don't allow RSC when device is configured in an SR-IOV mode.
> >>>
> >>> New in v5:
> >>>     - Put the RTE_ETHDEV_HAS_LRO_SUPPORT definition at the beginning
> >>> of rte_ethdev.h.
> >>>     - Removed the "TODO: Remove me" comment near
> >>> RTE_ETHDEV_HAS_LRO_SUPPORT.
> >>>
> >>> New in v4:
> >>>     - Define RTE_ETHDEV_HAS_LRO_SUPPORT in rte_ethdev.h instead of
> >>>       RTE_ETHDEV_LRO_SUPPORT defined in config/common_linuxapp.
> >>>
> >>> New in v2:
> >>>     - Removed rte_eth_dev_data.lro_bulk_alloc.
> >>>     - Fixed a few styling and spelling issues.
> >>> ---
> >>>   lib/librte_ether/rte_ethdev.h           |   9 +-
> >>>   lib/librte_net/rte_ip.h                 |   3 +
> >>>   lib/librte_pmd_ixgbe/ixgbe/ixgbe_type.h |   6 +
> >>>   lib/librte_pmd_ixgbe/ixgbe_ethdev.c     |  11 +
> >>>   lib/librte_pmd_ixgbe/ixgbe_ethdev.h     |   5 +
> >>>   lib/librte_pmd_ixgbe/ixgbe_rxtx.c       | 610
> >>> +++++++++++++++++++++++++++++++-
> >>>   lib/librte_pmd_ixgbe/ixgbe_rxtx.h       |   6 +
> >>>   7 files changed, 642 insertions(+), 8 deletions(-)
> >>>
> >>> diff --git a/lib/librte_ether/rte_ethdev.h
> >>> b/lib/librte_ether/rte_ethdev.h
> >>> index 21aa359..61dc49a 100644
> >>> --- a/lib/librte_ether/rte_ethdev.h
> >>> +++ b/lib/librte_ether/rte_ethdev.h
> >>> @@ -172,6 +172,9 @@ extern "C" {
> >>>
> >>>   #include <stdint.h>
> >>>
> >>> +/* Use this macro to check if LRO API is supported */
> >>> +#define RTE_ETHDEV_HAS_LRO_SUPPORT
> >>> +
> >>>   #include <rte_log.h>
> >>>   #include <rte_interrupts.h>
> >>>   #include <rte_pci.h>
> >>> @@ -320,14 +323,15 @@ struct rte_eth_rxmode {
> >>>       enum rte_eth_rx_mq_mode mq_mode;
> >>>       uint32_t max_rx_pkt_len;  /**< Only used if jumbo_frame
> >>> enabled. */
> >>>       uint16_t split_hdr_size;  /**< hdr buf size (header_split
> >>> enabled).*/
> >>> -    uint8_t header_split : 1, /**< Header Split enable. */
> >>> +    uint16_t header_split : 1, /**< Header Split enable. */
> >>>           hw_ip_checksum   : 1, /**< IP/UDP/TCP checksum offload
> >>> enable. */
> >>>           hw_vlan_filter   : 1, /**< VLAN filter enable. */
> >>>           hw_vlan_strip    : 1, /**< VLAN strip enable. */
> >>>           hw_vlan_extend   : 1, /**< Extended VLAN enable. */
> >>>           jumbo_frame      : 1, /**< Jumbo Frame Receipt enable. */
> >>>           hw_strip_crc     : 1, /**< Enable CRC stripping by
> >>> hardware. */
> >>> -        enable_scatter   : 1; /**< Enable scatter packets rx
> >>> handler */
> >>> +        enable_scatter   : 1, /**< Enable scatter packets rx
> >>> handler */
> >>> +        enable_lro       : 1; /**< Enable LRO */
> >>>   };
> >>>
> >>>   /**
> >>> @@ -1515,6 +1519,7 @@ struct rte_eth_dev_data {
> >>>       uint8_t port_id;           /**< Device [external] port
> >>> identifier. */
> >>>       uint8_t promiscuous   : 1, /**< RX promiscuous mode ON(1) /
> >>> OFF(0). */
> >>>           scattered_rx : 1,  /**< RX of scattered packets is ON(1) /
> >>> OFF(0) */
> >>> +        lro          : 1,  /**< RX LRO is ON(1) / OFF(0) */
> >>>           all_multicast : 1, /**< RX all multicast mode ON(1) /
> >>> OFF(0). */
> >>>           dev_started : 1;   /**< Device state: STARTED(1) /
> >>> STOPPED(0). */
> >>>   };
> >>> diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h
> >>> index 64935d9..74c9ced 100644
> >>> --- a/lib/librte_net/rte_ip.h
> >>> +++ b/lib/librte_net/rte_ip.h
> >>> @@ -110,6 +110,9 @@ struct ipv4_hdr {
> >>>                          (((c) & 0xff) << 8)  | \
> >>>                          ((d) & 0xff))
> >>>
> >>> +/** Maximal IPv4 packet length (including a header) */
> >>> +#define IPV4_MAX_PKT_LEN        65535
> >>> +
> >>>   /** Internet header length mask for version_ihl field */
> >>>   #define IPV4_HDR_IHL_MASK    (0x0f)
> >>>   /**
> >>> diff --git a/lib/librte_pmd_ixgbe/ixgbe/ixgbe_type.h
> >>> b/lib/librte_pmd_ixgbe/ixgbe/ixgbe_type.h
> >>> index 9a66370..4998627 100644
> >>> --- a/lib/librte_pmd_ixgbe/ixgbe/ixgbe_type.h
> >>> +++ b/lib/librte_pmd_ixgbe/ixgbe/ixgbe_type.h
> >>> @@ -234,8 +234,14 @@ struct ixgbe_thermal_sensor_data {
> >>>   #define IXGBE_EITR(_i)        (((_i) <= 23) ? (0x00820 + ((_i) *
> >>> 4)) : \
> >>>                    (0x012300 + (((_i) - 24) * 4)))
> >>>   #define IXGBE_EITR_ITR_INT_MASK    0x00000FF8
> >>> +#define IXGBE_EITR_ITR_INT_SHIFT 3
> >>>   #define IXGBE_EITR_LLI_MOD    0x00008000
> >>>   #define IXGBE_EITR_CNT_WDIS    0x80000000
> >>> +/* EITR Inteval is in 2048ns uinits for 1G and 10G link */
> >>> +#define IXGBE_EITR_INTERVAL_UNIT_NS    2048
> >> Why is that? Why not just 2us as 82599 spec says?
> >> And then:
> >> +#define IXGBE_EITR_INTERVAL_US(us) (((us) /
> >> IXGBE_EITR_INTERVAL_UNIT_US << IXGBE_EITR_ITR_INT_SHIFT) &
> >> IXGBE_EITR_ITR_INT_MASK)
> >> ?
> >
> > Because spec doesn't say 2us but rather 2.048us - see 8.2.4.5.16
> > chapter of x540 spec.
> 
> The most confusing part is that 82599 Rev. 3.0 spec does say so. 

I see what you mean now.
Indeed that's a bit strange that in 82599 and X540 spec ITR_Interval units are different.
We sent a question about this to HW guys, but don't know when there will be an answer.
I suppose we can stick with 2.048 us case for now.
>From my understanding, even if 82599 uses 2us the difference in max timeout would be pretty small: 500 us vs 488 us
and shouldn't cause any performance drop. 
I wonder did try your LRO latest changes on 82599?
If yes, did you see any difference in performance vs previous version, when hardcoded value for 2us was used?    
Konstantin

>The  x540 spec I have is dated by March 2014 and 82599 spec is dated by
> November 2014 but according to changelog EITR description has never been
> updated. Therefore I conclude that the more recent device spec (x540)
> holds the most up to date content.
> 
> Pls., confirm.
> 
> thanks,
> vlad
> 
> >
> >>
> >>> +#define IXGBE_EITR_INTERVAL_US(us)    \
> >>> +   (((us) * 1000 / IXGBE_EITR_INTERVAL_UNIT_NS <<
> >>> IXGBE_EITR_ITR_INT_SHIFT) & \
> >>> +        IXGBE_EITR_ITR_INT_MASK)
> >>
> >> Unfortunately we are not supposed to change files under ixgbe
> >> subfirectory (except ixgbe_osdep.*).
> >> These files comes from ixgbe shared code and we treat them as read-only.
> >> You need to move these new macros you added into ixgbe_ethedev.h.
> >
> > Aha... Ok. No problem.
> >
> >>
> >> All other things look good to me.
> >> Konstantin
> >>
> >>>   #define IXGBE_IVAR(_i)        (0x00900 + ((_i) * 4)) /* 24 at
> >>> 0x900-0x960 */
> >>>   #define IXGBE_IVAR_MISC        0x00A00 /* misc MSI-X interrupt
> >>> causes */
> >>>   #define IXGBE_EITRSEL        0x00894
> >>> diff --git a/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> >>> b/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> >>> index 92d75db..923692e 100644
> >>> --- a/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> >>> +++ b/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> >>> @@ -1645,6 +1645,7 @@ ixgbe_dev_stop(struct rte_eth_dev *dev)
> >>>
> >>>       /* Clear stored conf */
> >>>       dev->data->scattered_rx = 0;
> >>> +    dev->data->lro = 0;
> >>>
> >>>       /* Clear recorded link status */
> >>>       memset(&link, 0, sizeof(link));
> >>> @@ -2013,6 +2014,16 @@ ixgbe_dev_info_get(struct rte_eth_dev *dev,
> >>> struct rte_eth_dev_info *dev_info)
> >>>           DEV_RX_OFFLOAD_IPV4_CKSUM |
> >>>           DEV_RX_OFFLOAD_UDP_CKSUM  |
> >>>           DEV_RX_OFFLOAD_TCP_CKSUM;
> >>> +
> >>> +    /*
> >>> +     * RSC is only supported by 82599 and x540 PF devices in a
> >>> non-SR-IOV
> >>> +     * mode.
> >>> +     */
> >>> +    if ((hw->mac.type == ixgbe_mac_82599EB ||
> >>> +         hw->mac.type == ixgbe_mac_X540) &&
> >>> +        !RTE_ETH_DEV_SRIOV(dev).active)
> >>> +        dev_info->rx_offload_capa |= DEV_RX_OFFLOAD_TCP_LRO;
> >>> +
> >>>       dev_info->tx_offload_capa =
> >>>           DEV_TX_OFFLOAD_VLAN_INSERT |
> >>>           DEV_TX_OFFLOAD_IPV4_CKSUM  |
> >>> diff --git a/lib/librte_pmd_ixgbe/ixgbe_ethdev.h
> >>> b/lib/librte_pmd_ixgbe/ixgbe_ethdev.h
> >>> index ffe3471..7050340 100644
> >>> --- a/lib/librte_pmd_ixgbe/ixgbe_ethdev.h
> >>> +++ b/lib/librte_pmd_ixgbe/ixgbe_ethdev.h
> >>> @@ -344,6 +344,11 @@ uint16_t ixgbe_recv_pkts(void *rx_queue, struct
> >>> rte_mbuf **rx_pkts,
> >>>   uint16_t ixgbe_recv_scattered_pkts(void *rx_queue,
> >>>           struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
> >>>
> >>> +uint16_t ixgbe_recv_pkts_lro_single_alloc(void *rx_queue,
> >>> +        struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
> >>> +uint16_t ixgbe_recv_pkts_lro_bulk_alloc(void *rx_queue,
> >>> +        struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
> >>> +
> >>>   uint16_t ixgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
> >>>           uint16_t nb_pkts);
> >>>
> >>> diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> >>> b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> >>> index a08ae6a..daa4c45 100644
> >>> --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> >>> +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> >>> @@ -70,6 +70,7 @@
> >>>   #include <rte_sctp.h>
> >>>   #include <rte_string_fns.h>
> >>>   #include <rte_errno.h>
> >>> +#include <rte_ip.h>
> >>>
> >>>   #include "ixgbe_logs.h"
> >>>   #include "ixgbe/ixgbe_api.h"
> >>> @@ -1422,6 +1423,295 @@ ixgbe_fill_cluster_head_buf(
> >>>       }
> >>>   }
> >>>
> >>> +/**
> >>> + * ixgbe_recv_pkts_lro - receive handler for and LRO case.
> >>> + *
> >>> + * @rx_queue Rx queue handle
> >>> + * @rx_pkts table of received packets
> >>> + * @nb_pkts size of rx_pkts table
> >>> + * @bulk_alloc if TRUE bulk allocation is used for a HW ring refilling
> >>> + *
> >>> + * Handles the Rx HW ring completions when RSC feature is
> >>> configured. Uses an
> >>> + * additional ring of ixgbe_rsc_entry's that will hold the relevant
> >>> RSC info.
> >>> + *
> >>> + * We use the same logic as in Lunux and in FreeBSD ixgbe drivers:
> >>> + * 1) When non-EOP RSC completion arrives:
> >>> + *    a) Update the HEAD of the current RSC aggregation cluster
> >>> with the new
> >>> + *       segment's data length.
> >>> + *    b) Set the "next" pointer of the current segment to point to
> >>> the segment
> >>> + *       at the NEXTP index.
> >>> + *    c) Pass the HEAD of RSC aggregation cluster on to the next
> >>> NEXTP entry
> >>> + *       in the sw_rsc_ring.
> >>> + * 2) When EOP arrives we just update the cluster's total length
> >>> and offload
> >>> + *    flags and deliver the cluster up to the upper layers. In our
> >>> case - put it
> >>> + *    in the rx_pkts table.
> >>> + *
> >>> + * Returns the number of received packets/clusters (according to
> >>> the "bulk
> >>> + * receive" interface).
> >>> + */
> >>> +static inline uint16_t
> >>> +ixgbe_recv_pkts_lro(void *rx_queue, struct rte_mbuf **rx_pkts,
> >>> uint16_t nb_pkts,
> >>> +            bool bulk_alloc)
> >>> +{
> >>> +    struct ixgbe_rx_queue *rxq = rx_queue;
> >>> +    volatile union ixgbe_adv_rx_desc *rx_ring = rxq->rx_ring;
> >>> +    struct ixgbe_rx_entry *sw_ring = rxq->sw_ring;
> >>> +    struct ixgbe_rsc_entry *sw_rsc_ring = rxq->sw_rsc_ring;
> >>> +    uint16_t rx_id = rxq->rx_tail;
> >>> +    uint16_t nb_rx = 0;
> >>> +    uint16_t nb_hold = rxq->nb_rx_hold;
> >>> +    uint16_t prev_id = rxq->rx_tail;
> >>> +
> >>> +    while (nb_rx < nb_pkts) {
> >>> +        bool eop;
> >>> +        struct ixgbe_rx_entry *rxe;
> >>> +        struct ixgbe_rsc_entry *rsc_entry;
> >>> +        struct ixgbe_rsc_entry *next_rsc_entry;
> >>> +        struct ixgbe_rx_entry *next_rxe;
> >>> +        struct rte_mbuf *first_seg;
> >>> +        struct rte_mbuf *rxm;
> >>> +        struct rte_mbuf *nmb;
> >>> +        union ixgbe_adv_rx_desc rxd;
> >>> +        uint16_t data_len;
> >>> +        uint16_t next_id;
> >>> +        volatile union ixgbe_adv_rx_desc *rxdp;
> >>> +        uint32_t staterr;
> >>> +
> >>> +next_desc:
> >>> +        /*
> >>> +         * The code in this whole file uses the volatile pointer to
> >>> +         * ensure the read ordering of the status and the rest of the
> >>> +         * descriptor fields (on the compiler level only!!!). This
> >>> is so
> >>> +         * UGLY - why not to just use the compiler barrier instead?
> >>> DPDK
> >>> +         * even has the rte_compiler_barrier() for that.
> >>> +         *
> >>> +         * But most importantly this is just wrong because this
> >>> doesn't
> >>> +         * ensure memory ordering in a general case at all. For
> >>> +         * instance, DPDK is supposed to work on Power CPUs where
> >>> +         * compiler barrier may just not be enough!
> >>> +         *
> >>> +         * I tried to write only this function properly to have a
> >>> +         * starting point (as a part of an LRO/RSC series) but the
> >>> +         * compiler cursed at me when I tried to cast away the
> >>> +         * "volatile" from rx_ring (yes, it's volatile too!!!). So,
> >>> I'm
> >>> +         * keeping it the way it is for now.
> >>> +         *
> >>> +         * The code in this file is broken in so many other places and
> >>> +         * will just not work on a big endian CPU anyway therefore the
> >>> +         * lines below will have to be revisited together with the
> >>> rest
> >>> +         * of the ixgbe PMD.
> >>> +         *
> >>> +         * TODO:
> >>> +         *    - Get rid of "volatile" crap and let the compiler do its
> >>> +         *      job.
> >>> +         *    - Use the proper memory barrier (rte_rmb()) to ensure
> >>> the
> >>> +         *      memory ordering below.
> >>> +         */
> >>> +        rxdp = &rx_ring[rx_id];
> >>> +        staterr = rte_le_to_cpu_32(rxdp->wb.upper.status_error);
> >>> +
> >>> +        if (!(staterr & IXGBE_RXDADV_STAT_DD))
> >>> +            break;
> >>> +
> >>> +        rxd = *rxdp;
> >>> +
> >>> +        PMD_RX_LOG(DEBUG, "port_id=%u queue_id=%u rx_id=%u "
> >>> +                  "staterr=0x%x data_len=%u",
> >>> +               rxq->port_id, rxq->queue_id, rx_id, staterr,
> >>> +               rte_le_to_cpu_16(rxd.wb.upper.length));
> >>> +
> >>> +        if (!bulk_alloc) {
> >>> +            nmb = rte_rxmbuf_alloc(rxq->mb_pool);
> >>> +            if (nmb == NULL) {
> >>> +                PMD_RX_LOG(DEBUG, "RX mbuf alloc failed "
> >>> +                          "port_id=%u queue_id=%u",
> >>> +                       rxq->port_id, rxq->queue_id);
> >>> +
> >>> +                rte_eth_devices[rxq->port_id].data->
> >>> +                            rx_mbuf_alloc_failed++;
> >>> +                break;
> >>> +            }
> >>> +        } else if (nb_hold > rxq->rx_free_thresh) {
> >>> +            uint16_t next_rdt = rxq->rx_free_trigger;
> >>> +
> >>> +            if (!ixgbe_rx_alloc_bufs(rxq, false)) {
> >>> +                rte_wmb();
> >>> +                IXGBE_PCI_REG_WRITE(rxq->rdt_reg_addr,
> >>> +                            next_rdt);
> >>> +                nb_hold -= rxq->rx_free_thresh;
> >>> +            } else {
> >>> +                PMD_RX_LOG(DEBUG, "RX bulk alloc failed "
> >>> +                          "port_id=%u queue_id=%u",
> >>> +                       rxq->port_id, rxq->queue_id);
> >>> +
> >>> +                rte_eth_devices[rxq->port_id].data->
> >>> +                            rx_mbuf_alloc_failed++;
> >>> +                break;
> >>> +            }
> >>> +        }
> >>> +
> >>> +        nb_hold++;
> >>> +        rxe = &sw_ring[rx_id];
> >>> +        eop = staterr & IXGBE_RXDADV_STAT_EOP;
> >>> +
> >>> +        next_id = rx_id + 1;
> >>> +        if (next_id == rxq->nb_rx_desc)
> >>> +            next_id = 0;
> >>> +
> >>> +        /* Prefetch next mbuf while processing current one. */
> >>> +        rte_ixgbe_prefetch(sw_ring[next_id].mbuf);
> >>> +
> >>> +        /*
> >>> +         * When next RX descriptor is on a cache-line boundary,
> >>> +         * prefetch the next 4 RX descriptors and the next 4 pointers
> >>> +         * to mbufs.
> >>> +         */
> >>> +        if ((next_id & 0x3) == 0) {
> >>> +            rte_ixgbe_prefetch(&rx_ring[next_id]);
> >>> +            rte_ixgbe_prefetch(&sw_ring[next_id]);
> >>> +        }
> >>> +
> >>> +        rxm = rxe->mbuf;
> >>> +
> >>> +        if (!bulk_alloc) {
> >>> +            __le64 dma =
> >>> + rte_cpu_to_le_64(RTE_MBUF_DATA_DMA_ADDR_DEFAULT(nmb));
> >>> +            /*
> >>> +             * Update RX descriptor with the physical address of the
> >>> +             * new data buffer of the new allocated mbuf.
> >>> +             */
> >>> +            rxe->mbuf = nmb;
> >>> +
> >>> +            rxm->data_off = RTE_PKTMBUF_HEADROOM;
> >>> +            rxdp->read.hdr_addr = dma;
> >>> +            rxdp->read.pkt_addr = dma;
> >>> +        } else
> >>> +            rxe->mbuf = NULL;
> >>> +
> >>> +        /*
> >>> +         * Set data length & data buffer address of mbuf.
> >>> +         */
> >>> +        data_len = rte_le_to_cpu_16(rxd.wb.upper.length);
> >>> +        rxm->data_len = data_len;
> >>> +
> >>> +        if (!eop) {
> >>> +            uint16_t nextp_id;
> >>> +            /*
> >>> +             * Get next descriptor index:
> >>> +             *  - For RSC it's in the NEXTP field.
> >>> +             *  - For a scattered packet - it's just a following
> >>> +             *    descriptor.
> >>> +             */
> >>> +            if (ixgbe_rsc_count(&rxd))
> >>> +                nextp_id =
> >>> +                    (staterr & IXGBE_RXDADV_NEXTP_MASK) >>
> >>> +                               IXGBE_RXDADV_NEXTP_SHIFT;
> >>> +            else
> >>> +                nextp_id = next_id;
> >>> +
> >>> +            next_rsc_entry = &sw_rsc_ring[nextp_id];
> >>> +            next_rxe = &sw_ring[nextp_id];
> >>> +            rte_ixgbe_prefetch(next_rxe);
> >>> +        }
> >>> +
> >>> +        rsc_entry = &sw_rsc_ring[rx_id];
> >>> +        first_seg = rsc_entry->fbuf;
> >>> +        rsc_entry->fbuf = NULL;
> >>> +
> >>> +        /*
> >>> +         * If this is the first buffer of the received packet,
> >>> +         * set the pointer to the first mbuf of the packet and
> >>> +         * initialize its context.
> >>> +         * Otherwise, update the total length and the number of
> >>> segments
> >>> +         * of the current scattered packet, and update the pointer to
> >>> +         * the last mbuf of the current packet.
> >>> +         */
> >>> +        if (first_seg == NULL) {
> >>> +            first_seg = rxm;
> >>> +            first_seg->pkt_len = data_len;
> >>> +            first_seg->nb_segs = 1;
> >>> +        } else {
> >>> +            first_seg->pkt_len += data_len;
> >>> +            first_seg->nb_segs++;
> >>> +        }
> >>> +
> >>> +        prev_id = rx_id;
> >>> +        rx_id = next_id;
> >>> +
> >>> +        /*
> >>> +         * If this is not the last buffer of the received packet,
> >>> update
> >>> +         * the pointer to the first mbuf at the NEXTP entry in the
> >>> +         * sw_rsc_ring and continue to parse the RX ring.
> >>> +         */
> >>> +        if (!eop) {
> >>> +            rxm->next = next_rxe->mbuf;
> >>> +            next_rsc_entry->fbuf = first_seg;
> >>> +            goto next_desc;
> >>> +        }
> >>> +
> >>> +        /*
> >>> +         * This is the last buffer of the received packet - return
> >>> +         * the current cluster to the user.
> >>> +         */
> >>> +        rxm->next = NULL;
> >>> +
> >>> +        /* Initialize the first mbuf of the returned packet */
> >>> +        ixgbe_fill_cluster_head_buf(first_seg, &rxd, rxq->port_id,
> >>> +                        staterr);
> >>> +
> >>> +        /* Prefetch data of first segment, if configured to do so. */
> >>> +        rte_packet_prefetch((char *)first_seg->buf_addr +
> >>> +            first_seg->data_off);
> >>> +
> >>> +        /*
> >>> +         * Store the mbuf address into the next entry of the array
> >>> +         * of returned packets.
> >>> +         */
> >>> +        rx_pkts[nb_rx++] = first_seg;
> >>> +    }
> >>> +
> >>> +    /*
> >>> +     * Record index of the next RX descriptor to probe.
> >>> +     */
> >>> +    rxq->rx_tail = rx_id;
> >>> +
> >>> +    /*
> >>> +     * If the number of free RX descriptors is greater than the RX
> >>> free
> >>> +     * threshold of the queue, advance the Receive Descriptor Tail
> >>> (RDT)
> >>> +     * register.
> >>> +     * Update the RDT with the value of the last processed RX
> >>> descriptor
> >>> +     * minus 1, to guarantee that the RDT register is never equal
> >>> to the
> >>> +     * RDH register, which creates a "full" ring situtation from the
> >>> +     * hardware point of view...
> >>> +     */
> >>> +    if (!bulk_alloc && nb_hold > rxq->rx_free_thresh) {
> >>> +        PMD_RX_LOG(DEBUG, "port_id=%u queue_id=%u rx_tail=%u "
> >>> +               "nb_hold=%u nb_rx=%u",
> >>> +               rxq->port_id, rxq->queue_id, rx_id, nb_hold, nb_rx);
> >>> +
> >>> +        rte_wmb();
> >>> +        IXGBE_PCI_REG_WRITE(rxq->rdt_reg_addr, prev_id);
> >>> +        nb_hold = 0;
> >>> +    }
> >>> +
> >>> +    rxq->nb_rx_hold = nb_hold;
> >>> +    return nb_rx;
> >>> +}
> >>> +
> >>> +uint16_t
> >>> +ixgbe_recv_pkts_lro_single_alloc(void *rx_queue, struct rte_mbuf
> >>> **rx_pkts,
> >>> +                 uint16_t nb_pkts)
> >>> +{
> >>> +    return ixgbe_recv_pkts_lro(rx_queue, rx_pkts, nb_pkts, false);
> >>> +}
> >>> +
> >>> +uint16_t
> >>> +ixgbe_recv_pkts_lro_bulk_alloc(void *rx_queue, struct rte_mbuf
> >>> **rx_pkts,
> >>> +                   uint16_t nb_pkts)
> >>> +{
> >>> +    return ixgbe_recv_pkts_lro(rx_queue, rx_pkts, nb_pkts, true);
> >>> +}
> >>> +
> >>>   uint16_t
> >>>   ixgbe_recv_scattered_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
> >>>                 uint16_t nb_pkts)
> >>> @@ -2005,6 +2295,31 @@ ixgbe_dev_tx_queue_setup(struct rte_eth_dev
> >>> *dev,
> >>>       return (0);
> >>>   }
> >>>
> >>> +/**
> >>> + * ixgbe_free_rsc_cluster - free the not-yet-completed RSC cluster
> >>> + *
> >>> + * The "next" pointer of the last segment of (not-yet-completed)
> >>> RSC clusters
> >>> + * in the sw_rsc_ring is not set to NULL but rather points to the next
> >>> + * mbuf of this RSC aggregation (that has not been completed yet
> >>> and still
> >>> + * resides on the HW ring). So, instead of calling for
> >>> rte_pktmbuf_free() we
> >>> + * will just free first "nb_segs" segments of the cluster
> >>> explicitly by calling
> >>> + * an rte_pktmbuf_free_seg().
> >>> + *
> >>> + * @m RSC cluster head
> >>> + */
> >>> +static void
> >>> +ixgbe_free_rsc_cluster(struct rte_mbuf *m)
> >>> +{
> >>> +    uint8_t i, nb_segs = m->nb_segs;
> >>> +    struct rte_mbuf *next_seg;
> >>> +
> >>> +    for (i = 0; i < nb_segs; i++) {
> >>> +        next_seg = m->next;
> >>> +        rte_pktmbuf_free_seg(m);
> >>> +        m = next_seg;
> >>> +    }
> >>> +}
> >>> +
> >>>   static void
> >>>   ixgbe_rx_queue_release_mbufs(struct ixgbe_rx_queue *rxq)
> >>>   {
> >>> @@ -2028,6 +2343,13 @@ ixgbe_rx_queue_release_mbufs(struct
> >>> ixgbe_rx_queue *rxq)
> >>>           }
> >>>   #endif
> >>>       }
> >>> +
> >>> +    if (rxq->sw_rsc_ring)
> >>> +        for (i = 0; i < rxq->nb_rx_desc; i++)
> >>> +            if (rxq->sw_rsc_ring[i].fbuf) {
> >>> + ixgbe_free_rsc_cluster(rxq->sw_rsc_ring[i].fbuf);
> >>> +                rxq->sw_rsc_ring[i].fbuf = NULL;
> >>> +            }
> >>>   }
> >>>
> >>>   static void
> >>> @@ -2036,6 +2358,7 @@ ixgbe_rx_queue_release(struct ixgbe_rx_queue
> >>> *rxq)
> >>>       if (rxq != NULL) {
> >>>           ixgbe_rx_queue_release_mbufs(rxq);
> >>>           rte_free(rxq->sw_ring);
> >>> +        rte_free(rxq->sw_rsc_ring);
> >>>           rte_free(rxq);
> >>>       }
> >>>   }
> >>> @@ -2158,6 +2481,7 @@ ixgbe_reset_rx_queue(struct ixgbe_hw *hw,
> >>> struct ixgbe_rx_queue *rxq)
> >>>       rxq->nb_rx_hold = 0;
> >>>       rxq->pkt_first_seg = NULL;
> >>>       rxq->pkt_last_seg = NULL;
> >>> +    rxq->rsc_en = 0;
> >>>   }
> >>>
> >>>   int
> >>> @@ -2172,6 +2496,14 @@ ixgbe_dev_rx_queue_setup(struct rte_eth_dev
> >>> *dev,
> >>>       struct ixgbe_rx_queue *rxq;
> >>>       struct ixgbe_hw     *hw;
> >>>       uint16_t len;
> >>> +    struct rte_eth_dev_info dev_info = { 0 };
> >>> +    struct rte_eth_rxmode *dev_rx_mode = &dev->data->dev_conf.rxmode;
> >>> +    bool rsc_requested = false;
> >>> +
> >>> +    dev->dev_ops->dev_infos_get(dev, &dev_info);
> >>> +    if ((dev_info.rx_offload_capa & DEV_RX_OFFLOAD_TCP_LRO) &&
> >>> +        dev_rx_mode->enable_lro)
> >>> +        rsc_requested = true;
> >>>
> >>>       PMD_INIT_FUNC_TRACE();
> >>>       hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> >>> @@ -2277,12 +2609,27 @@ ixgbe_dev_rx_queue_setup(struct rte_eth_dev
> >>> *dev,
> >>>       rxq->sw_ring = rte_zmalloc_socket("rxq->sw_ring",
> >>>                         sizeof(struct ixgbe_rx_entry) * len,
> >>>                         RTE_CACHE_LINE_SIZE, socket_id);
> >>> -    if (rxq->sw_ring == NULL) {
> >>> +    if (!rxq->sw_ring) {
> >>>           ixgbe_rx_queue_release(rxq);
> >>>           return (-ENOMEM);
> >>>       }
> >>> -    PMD_INIT_LOG(DEBUG, "sw_ring=%p hw_ring=%p dma_addr=0x%"PRIx64,
> >>> -             rxq->sw_ring, rxq->rx_ring, rxq->rx_ring_phys_addr);
> >>> +
> >>> +    if (rsc_requested) {
> >>> +        rxq->sw_rsc_ring =
> >>> +            rte_zmalloc_socket("rxq->sw_rsc_ring",
> >>> +                       sizeof(struct ixgbe_rsc_entry) * len,
> >>> +                       RTE_CACHE_LINE_SIZE, socket_id);
> >>> +        if (!rxq->sw_rsc_ring) {
> >>> +            ixgbe_rx_queue_release(rxq);
> >>> +            return (-ENOMEM);
> >>> +        }
> >>> +    } else
> >>> +        rxq->sw_rsc_ring = NULL;
> >>> +
> >>> +    PMD_INIT_LOG(DEBUG, "sw_ring=%p sw_rsc_ring=%p hw_ring=%p "
> >>> +                "dma_addr=0x%"PRIx64,
> >>> +             rxq->sw_ring, rxq->sw_rsc_ring, rxq->rx_ring,
> >>> +             rxq->rx_ring_phys_addr);
> >>>
> >>>       if (!rte_is_power_of_2(nb_desc)) {
> >>>           PMD_INIT_LOG(DEBUG, "queue[%d] doesn't meet Vector Rx "
> >>> @@ -3527,6 +3874,91 @@ ixgbe_dev_mq_tx_configure(struct rte_eth_dev
> >>> *dev)
> >>>       return 0;
> >>>   }
> >>>
> >>> +/**
> >>> + * ixgbe_get_rscctl_maxdesc - Calculate the RSCCTL[n].MAXDESC for PF
> >>> + *
> >>> + * Return the RSCCTL[n].MAXDESC for 82599 and x540 PF devices
> >>> according to the
> >>> + * spec rev. 3.0 chapter 8.2.3.8.13.
> >>> + *
> >>> + * @pool Memory pool of the Rx queue
> >>> + */
> >>> +static inline uint32_t
> >>> +ixgbe_get_rscctl_maxdesc(struct rte_mempool *pool)
> >>> +{
> >>> +    struct rte_pktmbuf_pool_private *mp_priv =
> >>> rte_mempool_get_priv(pool);
> >>> +
> >>> +    /* MAXDESC * SRRCTL.BSIZEPKT must not exceed 64 KB minus one */
> >>> +    uint16_t maxdesc =
> >>> +        IPV4_MAX_PKT_LEN /
> >>> +            (mp_priv->mbuf_data_room_size - RTE_PKTMBUF_HEADROOM);
> >>> +
> >>> +    if (maxdesc >= 16)
> >>> +        return IXGBE_RSCCTL_MAXDESC_16;
> >>> +    else if (maxdesc >= 8)
> >>> +        return IXGBE_RSCCTL_MAXDESC_8;
> >>> +    else if (maxdesc >= 4)
> >>> +        return IXGBE_RSCCTL_MAXDESC_4;
> >>> +    else
> >>> +        return IXGBE_RSCCTL_MAXDESC_1;
> >>> +}
> >>> +
> >>> +/**
> >>> + * ixgbe_set_ivar - Setup the correct IVAR register for a
> >>> particular MSIX
> >>> + * interrupt
> >>> + *
> >>> + * (Taken from FreeBSD tree)
> >>> + * (yes this is all very magic and confusing :)
> >>> + *
> >>> + * @dev port handle
> >>> + * @entry the register array entry
> >>> + * @vector the MSIX vector for this queue
> >>> + * @type RX/TX/MISC
> >>> + */
> >>> +static void
> >>> +ixgbe_set_ivar(struct rte_eth_dev *dev, u8 entry, u8 vector, s8 type)
> >>> +{
> >>> +    struct ixgbe_hw *hw =
> >>> IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> >>> +    u32 ivar, index;
> >>> +
> >>> +    vector |= IXGBE_IVAR_ALLOC_VAL;
> >>> +
> >>> +    switch (hw->mac.type) {
> >>> +
> >>> +    case ixgbe_mac_82598EB:
> >>> +        if (type == -1)
> >>> +            entry = IXGBE_IVAR_OTHER_CAUSES_INDEX;
> >>> +        else
> >>> +            entry += (type * 64);
> >>> +        index = (entry >> 2) & 0x1F;
> >>> +        ivar = IXGBE_READ_REG(hw, IXGBE_IVAR(index));
> >>> +        ivar &= ~(0xFF << (8 * (entry & 0x3)));
> >>> +        ivar |= (vector << (8 * (entry & 0x3)));
> >>> +        IXGBE_WRITE_REG(hw, IXGBE_IVAR(index), ivar);
> >>> +        break;
> >>> +
> >>> +    case ixgbe_mac_82599EB:
> >>> +    case ixgbe_mac_X540:
> >>> +        if (type == -1) { /* MISC IVAR */
> >>> +            index = (entry & 1) * 8;
> >>> +            ivar = IXGBE_READ_REG(hw, IXGBE_IVAR_MISC);
> >>> +            ivar &= ~(0xFF << index);
> >>> +            ivar |= (vector << index);
> >>> +            IXGBE_WRITE_REG(hw, IXGBE_IVAR_MISC, ivar);
> >>> +        } else {    /* RX/TX IVARS */
> >>> +            index = (16 * (entry & 1)) + (8 * type);
> >>> +            ivar = IXGBE_READ_REG(hw, IXGBE_IVAR(entry >> 1));
> >>> +            ivar &= ~(0xFF << index);
> >>> +            ivar |= (vector << index);
> >>> +            IXGBE_WRITE_REG(hw, IXGBE_IVAR(entry >> 1), ivar);
> >>> +        }
> >>> +
> >>> +        break;
> >>> +
> >>> +    default:
> >>> +        break;
> >>> +    }
> >>> +}
> >>> +
> >>>   void ixgbe_set_rx_function(struct rte_eth_dev *dev)
> >>>   {
> >>>       struct ixgbe_hw *hw =
> >>> IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> >>> @@ -3545,7 +3977,24 @@ void ixgbe_set_rx_function(struct rte_eth_dev
> >>> *dev)
> >>>           hw->rx_vec_allowed = false;
> >>>       }
> >>>
> >>> -    if (dev->data->scattered_rx) {
> >>> +    /*
> >>> +     * Initialize the appropriate LRO callback.
> >>> +     *
> >>> +     * If all queues satisfy the bulk allocation preconditions
> >>> +     * (hw->rx_bulk_alloc_allowed is TRUE) then we may use bulk
> >>> allocation.
> >>> +     * Otherwise use a single allocation version.
> >>> +     */
> >>> +    if (dev->data->lro) {
> >>> +        if (hw->rx_bulk_alloc_allowed) {
> >>> +            PMD_INIT_LOG(INFO, "LRO is requested. Using a bulk "
> >>> +                       "allocation version");
> >>> +            dev->rx_pkt_burst = ixgbe_recv_pkts_lro_bulk_alloc;
> >>> +        } else {
> >>> +            PMD_INIT_LOG(INFO, "LRO is requested. Using a single "
> >>> +                       "allocation version");
> >>> +            dev->rx_pkt_burst = ixgbe_recv_pkts_lro_single_alloc;
> >>> +        }
> >>> +    } else if (dev->data->scattered_rx) {
> >>>           /*
> >>>            * Set the non-LRO scattered callback: there are Vector and
> >>>            * single allocation versions.
> >>> @@ -3595,6 +4044,149 @@ void ixgbe_set_rx_function(struct
> >>> rte_eth_dev *dev)
> >>>       }
> >>>   }
> >>>
> >>> +/**
> >>> + * ixgbe_set_rsc - configure RSC related port HW registers
> >>> + *
> >>> + * Configures the port's RSC related registers according to the
> >>> 4.6.7.2 chapter
> >>> + * of 82599 Spec (x540 configuration is virtually the same).
> >>> + *
> >>> + * @dev port handle
> >>> + *
> >>> + * Returns 0 in case of success or a non-zero error code
> >>> + */
> >>> +static int
> >>> +ixgbe_set_rsc(struct rte_eth_dev *dev)
> >>> +{
> >>> +    struct rte_eth_rxmode *rx_conf = &dev->data->dev_conf.rxmode;
> >>> +    struct ixgbe_hw *hw =
> >>> IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> >>> +    struct rte_eth_dev_info dev_info = { 0 };
> >>> +    bool rsc_capable = false;
> >>> +    uint16_t i;
> >>> +    uint32_t rdrxctl;
> >>> +
> >>> +    /* Sanity check */
> >>> +    dev->dev_ops->dev_infos_get(dev, &dev_info);
> >>> +    if (dev_info.rx_offload_capa & DEV_RX_OFFLOAD_TCP_LRO)
> >>> +        rsc_capable = true;
> >>> +
> >>> +    if (!rsc_capable && rx_conf->enable_lro) {
> >>> +        PMD_INIT_LOG(CRIT, "LRO is requested on HW that doesn't "
> >>> +                   "support it");
> >>> +        return -EINVAL;
> >>> +    }
> >>> +
> >>> +    /* RSC global configuration (chapter 4.6.7.2.1 of 82599 Spec) */
> >>> +
> >>> +    if (!rx_conf->hw_strip_crc && rx_conf->enable_lro) {
> >>> +        /*
> >>> +         * According to chapter of 4.6.7.2.1 of the Spec Rev.
> >>> +         * 3.0 RSC configuration requires HW CRC stripping being
> >>> +         * enabled. If user requested both HW CRC stripping off
> >>> +         * and RSC on - return an error.
> >>> +         */
> >>> +        PMD_INIT_LOG(CRIT, "LRO can't be enabled when HW CRC "
> >>> +                    "is disabled");
> >>> +        return -EINVAL;
> >>> +    }
> >>> +
> >>> +    /* RFCTL configuration  */
> >>> +    if (rsc_capable) {
> >>> +        uint32_t rfctl = IXGBE_READ_REG(hw, IXGBE_RFCTL);
> >>> +        if (rx_conf->enable_lro)
> >>> +            /*
> >>> +             * Since NFS packets coalescing is not supported - clear
> >>> +             * RFCTL.NFSW_DIS and RFCTL.NFSR_DIS when RSC is
> >>> +             * enabled.
> >>> +             */
> >>> +            rfctl &= ~(IXGBE_RFCTL_RSC_DIS | IXGBE_RFCTL_NFSW_DIS |
> >>> +                   IXGBE_RFCTL_NFSR_DIS);
> >>> +        else
> >>> +            rfctl |= IXGBE_RFCTL_RSC_DIS;
> >>> +
> >>> +        IXGBE_WRITE_REG(hw, IXGBE_RFCTL, rfctl);
> >>> +    }
> >>> +
> >>> +    /* If LRO hasn't been requested - we are done here. */
> >>> +    if (!rx_conf->enable_lro)
> >>> +        return 0;
> >>> +
> >>> +    /* Set RDRXCTL.RSCACKC bit */
> >>> +    rdrxctl = IXGBE_READ_REG(hw, IXGBE_RDRXCTL);
> >>> +    rdrxctl |= IXGBE_RDRXCTL_RSCACKC;
> >>> +    IXGBE_WRITE_REG(hw, IXGBE_RDRXCTL, rdrxctl);
> >>> +
> >>> +    /* Per-queue RSC configuration (chapter 4.6.7.2.2 of 82599
> >>> Spec) */
> >>> +    for (i = 0; i < dev->data->nb_rx_queues; i++) {
> >>> +        struct ixgbe_rx_queue *rxq = dev->data->rx_queues[i];
> >>> +        uint32_t srrctl =
> >>> +            IXGBE_READ_REG(hw, IXGBE_SRRCTL(rxq->reg_idx));
> >>> +        uint32_t rscctl =
> >>> +            IXGBE_READ_REG(hw, IXGBE_RSCCTL(rxq->reg_idx));
> >>> +        uint32_t psrtype =
> >>> +            IXGBE_READ_REG(hw, IXGBE_PSRTYPE(rxq->reg_idx));
> >>> +        uint32_t eitr =
> >>> +            IXGBE_READ_REG(hw, IXGBE_EITR(rxq->reg_idx));
> >>> +
> >>> +        /*
> >>> +         * ixgbe PMD doesn't support header-split at the moment.
> >>> +         *
> >>> +         * Following the 4.6.7.2.1 chapter of the 82599/x540
> >>> +         * Spec if RSC is enabled the SRRCTL[n].BSIZEHEADER
> >>> +         * should be configured even if header split is not
> >>> +         * enabled. We will configure it 128 bytes following the
> >>> +         * recommendation in the spec.
> >>> +         */
> >>> +        srrctl &= ~IXGBE_SRRCTL_BSIZEHDR_MASK;
> >>> +        srrctl |= (128 << IXGBE_SRRCTL_BSIZEHDRSIZE_SHIFT) &
> >>> +                        IXGBE_SRRCTL_BSIZEHDR_MASK;
> >>> +
> >>> +        /*
> >>> +         * TODO: Consider setting the Receive Descriptor Minimum
> >>> +         * Threshold Size for an RSC case. This is not an obviously
> >>> +         * beneficiary option but the one worth considering...
> >>> +         */
> >>> +
> >>> +        rscctl |= IXGBE_RSCCTL_RSCEN;
> >>> +        rscctl |= ixgbe_get_rscctl_maxdesc(rxq->mb_pool);
> >>> +        psrtype |= IXGBE_PSRTYPE_TCPHDR;
> >>> +
> >>> +        /*
> >>> +         * RSC: Set ITR interval corresponding to 2K ints/s.
> >>> +         *
> >>> +         * Full-sized RSC aggregations for a 10Gb/s link will
> >>> +         * arrive at about 20K aggregation/s rate.
> >>> +         *
> >>> +         * 2K inst/s rate will make only 10% of the
> >>> +         * aggregations to be closed due to the interrupt timer
> >>> +         * expiration for a streaming at wire-speed case.
> >>> +         *
> >>> +         * For a sparse streaming case this setting will yield
> >>> +         * at most 500us latency for a single RSC aggregation.
> >>> +         */
> >>> +        eitr &= ~IXGBE_EITR_ITR_INT_MASK;
> >>> +        eitr |= IXGBE_EITR_INTERVAL_US(500) | IXGBE_EITR_CNT_WDIS;
> >>> +
> >>> +        IXGBE_WRITE_REG(hw, IXGBE_SRRCTL(rxq->reg_idx), srrctl);
> >>> +        IXGBE_WRITE_REG(hw, IXGBE_RSCCTL(rxq->reg_idx), rscctl);
> >>> +        IXGBE_WRITE_REG(hw, IXGBE_PSRTYPE(rxq->reg_idx), psrtype);
> >>> +        IXGBE_WRITE_REG(hw, IXGBE_EITR(rxq->reg_idx), eitr);
> >>> +
> >>> +        /*
> >>> +         * RSC requires the mapping of the queue to the
> >>> +         * interrupt vector.
> >>> +         */
> >>> +        ixgbe_set_ivar(dev, rxq->reg_idx, i, 0);
> >>> +
> >>> +        rxq->rsc_en = 1;
> >>> +    }
> >>> +
> >>> +    dev->data->lro = 1;
> >>> +
> >>> +    PMD_INIT_LOG(INFO, "enabling LRO mode");
> >>> +
> >>> +    return 0;
> >>> +}
> >>> +
> >>>   /*
> >>>    * Initializes Receive Unit.
> >>>    */
> >>> @@ -3615,6 +4207,7 @@ ixgbe_dev_rx_init(struct rte_eth_dev *dev)
> >>>       uint16_t buf_size;
> >>>       uint16_t i;
> >>>       struct rte_eth_rxmode *rx_conf = &dev->data->dev_conf.rxmode;
> >>> +    int rc;
> >>>
> >>>       PMD_INIT_FUNC_TRACE();
> >>>       hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> >>> @@ -3724,6 +4317,7 @@ ixgbe_dev_rx_init(struct rte_eth_dev *dev)
> >>>                          RTE_PKTMBUF_HEADROOM);
> >>>           srrctl |= ((buf_size >> IXGBE_SRRCTL_BSIZEPKT_SHIFT) &
> >>>                  IXGBE_SRRCTL_BSIZEPKT_MASK);
> >>> +
> >>>           IXGBE_WRITE_REG(hw, IXGBE_SRRCTL(rxq->reg_idx), srrctl);
> >>>
> >>>           buf_size = (uint16_t) ((srrctl &
> >>> IXGBE_SRRCTL_BSIZEPKT_MASK) <<
> >>> @@ -3738,8 +4332,6 @@ ixgbe_dev_rx_init(struct rte_eth_dev *dev)
> >>>       if (rx_conf->enable_scatter)
> >>>           dev->data->scattered_rx = 1;
> >>>
> >>> -    ixgbe_set_rx_function(dev);
> >>> -
> >>>       /*
> >>>        * Device configured with multiple RX queues.
> >>>        */
> >>> @@ -3770,6 +4362,12 @@ ixgbe_dev_rx_init(struct rte_eth_dev *dev)
> >>>           IXGBE_WRITE_REG(hw, IXGBE_RDRXCTL, rdrxctl);
> >>>       }
> >>>
> >>> +    rc = ixgbe_set_rsc(dev);
> >>> +    if (rc)
> >>> +        return rc;
> >>> +
> >>> +    ixgbe_set_rx_function(dev);
> >>> +
> >>>       return 0;
> >>>   }
> >>>
> >>> diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.h
> >>> b/lib/librte_pmd_ixgbe/ixgbe_rxtx.h
> >>> index 3937cf6..120bbbd 100644
> >>> --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.h
> >>> +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.h
> >>> @@ -79,6 +79,10 @@ struct ixgbe_rx_entry {
> >>>       struct rte_mbuf *mbuf; /**< mbuf associated with RX
> >>> descriptor. */
> >>>   };
> >>>
> >>> +struct ixgbe_rsc_entry {
> >>> +    struct rte_mbuf *fbuf; /**< First segment of the fragmented
> >>> packet. */
> >>> +};
> >>> +
> >>>   /**
> >>>    * Structure associated with each descriptor of the TX ring of a
> >>> TX queue.
> >>>    */
> >>> @@ -105,6 +109,7 @@ struct ixgbe_rx_queue {
> >>>       volatile uint32_t   *rdt_reg_addr; /**< RDT register address. */
> >>>       volatile uint32_t   *rdh_reg_addr; /**< RDH register address. */
> >>>       struct ixgbe_rx_entry *sw_ring; /**< address of RX software
> >>> ring. */
> >>> +    struct ixgbe_rsc_entry *sw_rsc_ring; /**< address of RSC
> >>> software ring. */
> >>>       struct rte_mbuf *pkt_first_seg; /**< First segment of current
> >>> packet. */
> >>>       struct rte_mbuf *pkt_last_seg; /**< Last segment of current
> >>> packet. */
> >>>       uint64_t            mbuf_initializer; /**< value to init mbufs */
> >>> @@ -126,6 +131,7 @@ struct ixgbe_rx_queue {
> >>>       uint8_t             port_id;  /**< Device port identifier. */
> >>>       uint8_t             crc_len;  /**< 0 if CRC stripped, 4
> >>> otherwise. */
> >>>       uint8_t             drop_en;  /**< If not 0, set
> >>> SRRCTL.Drop_En. */
> >>> +    uint8_t             rsc_en;   /**< If not 0, RSC is enabled. */
> >>>       uint8_t             rx_deferred_start; /**< not in global dev
> >>> start. */
> >>>   #ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
> >>>       /** need to alloc dummy mbuf, for wraparound when scanning hw
> >>> ring */
> >>> --
> >>> 2.1.0
> >



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