ceph/src/spdk/dpdk/drivers/net/sfc/sfc_tso.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  *
   3  * Copyright (c) 2016-2018 Solarflare Communications Inc.
   4  * All rights reserved.
   5  *
   6  * This software was jointly developed between OKTET Labs (under contract
   7  * for Solarflare) and Solarflare Communications, Inc.
   8  */
   9
  10 #include <rte_ip.h>
  11 #include <rte_tcp.h>
  12
  13 #include "sfc.h"
  14 #include "sfc_debug.h"
  15 #include "sfc_tx.h"
  16 #include "sfc_ev.h"
  17
  18 /** Standard TSO header length */
  19 #define SFC_TSOH_STD_LEN        256
  20
  21 /** The number of TSO option descriptors that precede the packet descriptors */
  22 #define SFC_TSO_OPDESCS_IDX_SHIFT       2
  23
  24 int
  25 sfc_efx_tso_alloc_tsoh_objs(struct sfc_efx_tx_sw_desc *sw_ring,
  26                             unsigned int txq_entries, unsigned int socket_id)
  27 {
  28         unsigned int i;
  29
  30         for (i = 0; i < txq_entries; ++i) {
  31                 sw_ring[i].tsoh = rte_malloc_socket("sfc-efx-txq-tsoh-obj",
  32                                                     SFC_TSOH_STD_LEN,
  33                                                     RTE_CACHE_LINE_SIZE,
  34                                                     socket_id);
  35                 if (sw_ring[i].tsoh == NULL)
  36                         goto fail_alloc_tsoh_objs;
  37         }
  38
  39         return 0;
  40
  41 fail_alloc_tsoh_objs:
  42         while (i > 0)
  43                 rte_free(sw_ring[--i].tsoh);
  44
  45         return ENOMEM;
  46 }
  47
  48 void
  49 sfc_efx_tso_free_tsoh_objs(struct sfc_efx_tx_sw_desc *sw_ring,
  50                            unsigned int txq_entries)
  51 {
  52         unsigned int i;
  53
  54         for (i = 0; i < txq_entries; ++i) {
  55                 rte_free(sw_ring[i].tsoh);
  56                 sw_ring[i].tsoh = NULL;
  57         }
  58 }
  59
  60 static void
  61 sfc_efx_tso_prepare_header(struct sfc_efx_txq *txq, struct rte_mbuf **in_seg,
  62                            size_t *in_off, unsigned int idx, size_t bytes_left)
  63 {
  64         struct rte_mbuf *m = *in_seg;
  65         size_t bytes_to_copy = 0;
  66         uint8_t *tsoh = txq->sw_ring[idx & txq->ptr_mask].tsoh;
  67
  68         do {
  69                 bytes_to_copy = MIN(bytes_left, m->data_len);
  70
  71                 rte_memcpy(tsoh, rte_pktmbuf_mtod(m, uint8_t *),
  72                            bytes_to_copy);
  73
  74                 bytes_left -= bytes_to_copy;
  75                 tsoh += bytes_to_copy;
  76
  77                 if (bytes_left > 0) {
  78                         m = m->next;
  79                         SFC_ASSERT(m != NULL);
  80                 }
  81         } while (bytes_left > 0);
  82
  83         if (bytes_to_copy == m->data_len) {
  84                 *in_seg = m->next;
  85                 *in_off = 0;
  86         } else {
  87                 *in_seg = m;
  88                 *in_off = bytes_to_copy;
  89         }
  90 }
  91
  92 int
  93 sfc_efx_tso_do(struct sfc_efx_txq *txq, unsigned int idx,
  94                struct rte_mbuf **in_seg, size_t *in_off, efx_desc_t **pend,
  95                unsigned int *pkt_descs, size_t *pkt_len)
  96 {
  97         uint8_t *tsoh;
  98         const struct tcp_hdr *th;
  99         efsys_dma_addr_t header_paddr;
 100         uint16_t packet_id;
 101         uint32_t sent_seq;
 102         struct rte_mbuf *m = *in_seg;
 103         size_t nh_off = m->l2_len; /* IP header offset */
 104         size_t tcph_off = m->l2_len + m->l3_len; /* TCP header offset */
 105         size_t header_len = m->l2_len + m->l3_len + m->l4_len;
 106         const efx_nic_cfg_t *encp = efx_nic_cfg_get(txq->evq->sa->nic);
 107
 108         idx += SFC_TSO_OPDESCS_IDX_SHIFT;
 109
 110         /* Packets which have too big headers should be discarded */
 111         if (unlikely(header_len > SFC_TSOH_STD_LEN))
 112                 return EMSGSIZE;
 113
 114         /*
 115          * The TCP header must start at most 208 bytes into the frame.
 116          * If it starts later than this then the NIC won't realise
 117          * it's a TCP packet and TSO edits won't be applied
 118          */
 119         if (unlikely(tcph_off > encp->enc_tx_tso_tcp_header_offset_limit))
 120                 return EMSGSIZE;
 121
 122         header_paddr = rte_pktmbuf_iova(m);
 123
 124         /*
 125          * Sometimes headers may be split across multiple mbufs. In such cases
 126          * we need to glue those pieces and store them in some temporary place.
 127          * Also, packet headers must be contiguous in memory, so that
 128          * they can be referred to with a single DMA descriptor. EF10 has no
 129          * limitations on address boundaries crossing by DMA descriptor data.
 130          */
 131         if (m->data_len < header_len) {
 132                 sfc_efx_tso_prepare_header(txq, in_seg, in_off, idx,
 133                                            header_len);
 134                 tsoh = txq->sw_ring[idx & txq->ptr_mask].tsoh;
 135
 136                 header_paddr = rte_malloc_virt2iova((void *)tsoh);
 137         } else {
 138                 if (m->data_len == header_len) {
 139                         *in_off = 0;
 140                         *in_seg = m->next;
 141                 } else {
 142                         *in_off = header_len;
 143                 }
 144
 145                 tsoh = rte_pktmbuf_mtod(m, uint8_t *);
 146         }
 147
 148         /* Handle IP header */
 149         if (m->ol_flags & PKT_TX_IPV4) {
 150                 const struct ipv4_hdr *iphe4;
 151
 152                 iphe4 = (const struct ipv4_hdr *)(tsoh + nh_off);
 153                 rte_memcpy(&packet_id, &iphe4->packet_id, sizeof(uint16_t));
 154                 packet_id = rte_be_to_cpu_16(packet_id);
 155         } else if (m->ol_flags & PKT_TX_IPV6) {
 156                 packet_id = 0;
 157         } else {
 158                 return EINVAL;
 159         }
 160
 161         /* Handle TCP header */
 162         th = (const struct tcp_hdr *)(tsoh + tcph_off);
 163
 164         rte_memcpy(&sent_seq, &th->sent_seq, sizeof(uint32_t));
 165         sent_seq = rte_be_to_cpu_32(sent_seq);
 166
 167         efx_tx_qdesc_tso2_create(txq->common, packet_id, 0, sent_seq,
 168                                  m->tso_segsz,
 169                                  *pend, EFX_TX_FATSOV2_OPT_NDESCS);
 170
 171         *pend += EFX_TX_FATSOV2_OPT_NDESCS;
 172         *pkt_descs += EFX_TX_FATSOV2_OPT_NDESCS;
 173
 174         efx_tx_qdesc_dma_create(txq->common, header_paddr, header_len,
 175                                 B_FALSE, (*pend)++);
 176         (*pkt_descs)++;
 177         *pkt_len -= header_len;
 178
 179         return 0;
 180 }