drivers/infiniband/hw/hfi1/vnic_sdma.c

   1 /*
   2  * Copyright(c) 2017 - 2018 Intel Corporation.
   3  *
   4  * This file is provided under a dual BSD/GPLv2 license.  When using or
   5  * redistributing this file, you may do so under either license.
   6  *
   7  * GPL LICENSE SUMMARY
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of version 2 of the GNU General Public License as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * BSD LICENSE
  19  *
  20  * Redistribution and use in source and binary forms, with or without
  21  * modification, are permitted provided that the following conditions
  22  * are met:
  23  *
  24  *  - Redistributions of source code must retain the above copyright
  25  *    notice, this list of conditions and the following disclaimer.
  26  *  - Redistributions in binary form must reproduce the above copyright
  27  *    notice, this list of conditions and the following disclaimer in
  28  *    the documentation and/or other materials provided with the
  29  *    distribution.
  30  *  - Neither the name of Intel Corporation nor the names of its
  31  *    contributors may be used to endorse or promote products derived
  32  *    from this software without specific prior written permission.
  33  *
  34  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  35  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  36  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  37  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  38  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  39  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  40  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  41  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  42  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  43  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  44  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  45  *
  46  */
  47
  48 /*
  49  * This file contains HFI1 support for VNIC SDMA functionality
  50  */
  51
  52 #include "sdma.h"
  53 #include "vnic.h"
  54
  55 #define HFI1_VNIC_SDMA_Q_ACTIVE   BIT(0)
  56 #define HFI1_VNIC_SDMA_Q_DEFERRED BIT(1)
  57
  58 #define HFI1_VNIC_TXREQ_NAME_LEN   32
  59 #define HFI1_VNIC_SDMA_DESC_WTRMRK 64
  60
  61 /*
  62  * struct vnic_txreq - VNIC transmit descriptor
  63  * @txreq: sdma transmit request
  64  * @sdma: vnic sdma pointer
  65  * @skb: skb to send
  66  * @pad: pad buffer
  67  * @plen: pad length
  68  * @pbc_val: pbc value
  69  */
  70 struct vnic_txreq {
  71         struct sdma_txreq       txreq;
  72         struct hfi1_vnic_sdma   *sdma;
  73
  74         struct sk_buff         *skb;
  75         unsigned char           pad[HFI1_VNIC_MAX_PAD];
  76         u16                     plen;
  77         __le64                  pbc_val;
  78 };
  79
  80 static void vnic_sdma_complete(struct sdma_txreq *txreq,
  81                                int status)
  82 {
  83         struct vnic_txreq *tx = container_of(txreq, struct vnic_txreq, txreq);
  84         struct hfi1_vnic_sdma *vnic_sdma = tx->sdma;
  85
  86         sdma_txclean(vnic_sdma->dd, txreq);
  87         dev_kfree_skb_any(tx->skb);
  88         kmem_cache_free(vnic_sdma->dd->vnic.txreq_cache, tx);
  89 }
  90
  91 static noinline int build_vnic_ulp_payload(struct sdma_engine *sde,
  92                                            struct vnic_txreq *tx)
  93 {
  94         int i, ret = 0;
  95
  96         ret = sdma_txadd_kvaddr(
  97                 sde->dd,
  98                 &tx->txreq,
  99                 tx->skb->data,
 100                 skb_headlen(tx->skb));
 101         if (unlikely(ret))
 102                 goto bail_txadd;
 103
 104         for (i = 0; i < skb_shinfo(tx->skb)->nr_frags; i++) {
 105                 skb_frag_t *frag = &skb_shinfo(tx->skb)->frags[i];
 106
 107                 /* combine physically continuous fragments later? */
 108                 ret = sdma_txadd_page(sde->dd,
 109                                       &tx->txreq,
 110                                       skb_frag_page(frag),
 111                                       skb_frag_off(frag),
 112                                       skb_frag_size(frag));
 113                 if (unlikely(ret))
 114                         goto bail_txadd;
 115         }
 116
 117         if (tx->plen)
 118                 ret = sdma_txadd_kvaddr(sde->dd, &tx->txreq,
 119                                         tx->pad + HFI1_VNIC_MAX_PAD - tx->plen,
 120                                         tx->plen);
 121
 122 bail_txadd:
 123         return ret;
 124 }
 125
 126 static int build_vnic_tx_desc(struct sdma_engine *sde,
 127                               struct vnic_txreq *tx,
 128                               u64 pbc)
 129 {
 130         int ret = 0;
 131         u16 hdrbytes = 2 << 2;  /* PBC */
 132
 133         ret = sdma_txinit_ahg(
 134                 &tx->txreq,
 135                 0,
 136                 hdrbytes + tx->skb->len + tx->plen,
 137                 0,
 138                 0,
 139                 NULL,
 140                 0,
 141                 vnic_sdma_complete);
 142         if (unlikely(ret))
 143                 goto bail_txadd;
 144
 145         /* add pbc */
 146         tx->pbc_val = cpu_to_le64(pbc);
 147         ret = sdma_txadd_kvaddr(
 148                 sde->dd,
 149                 &tx->txreq,
 150                 &tx->pbc_val,
 151                 hdrbytes);
 152         if (unlikely(ret))
 153                 goto bail_txadd;
 154
 155         /* add the ulp payload */
 156         ret = build_vnic_ulp_payload(sde, tx);
 157 bail_txadd:
 158         return ret;
 159 }
 160
 161 /* setup the last plen bypes of pad */
 162 static inline void hfi1_vnic_update_pad(unsigned char *pad, u8 plen)
 163 {
 164         pad[HFI1_VNIC_MAX_PAD - 1] = plen - OPA_VNIC_ICRC_TAIL_LEN;
 165 }
 166
 167 int hfi1_vnic_send_dma(struct hfi1_devdata *dd, u8 q_idx,
 168                        struct hfi1_vnic_vport_info *vinfo,
 169                        struct sk_buff *skb, u64 pbc, u8 plen)
 170 {
 171         struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[q_idx];
 172         struct sdma_engine *sde = vnic_sdma->sde;
 173         struct vnic_txreq *tx;
 174         int ret = -ECOMM;
 175
 176         if (unlikely(READ_ONCE(vnic_sdma->state) != HFI1_VNIC_SDMA_Q_ACTIVE))
 177                 goto tx_err;
 178
 179         if (unlikely(!sde || !sdma_running(sde)))
 180                 goto tx_err;
 181
 182         tx = kmem_cache_alloc(dd->vnic.txreq_cache, GFP_ATOMIC);
 183         if (unlikely(!tx)) {
 184                 ret = -ENOMEM;
 185                 goto tx_err;
 186         }
 187
 188         tx->sdma = vnic_sdma;
 189         tx->skb = skb;
 190         hfi1_vnic_update_pad(tx->pad, plen);
 191         tx->plen = plen;
 192         ret = build_vnic_tx_desc(sde, tx, pbc);
 193         if (unlikely(ret))
 194                 goto free_desc;
 195
 196         ret = sdma_send_txreq(sde, iowait_get_ib_work(&vnic_sdma->wait),
 197                               &tx->txreq, vnic_sdma->pkts_sent);
 198         /* When -ECOMM, sdma callback will be called with ABORT status */
 199         if (unlikely(ret && unlikely(ret != -ECOMM)))
 200                 goto free_desc;
 201
 202         if (!ret) {
 203                 vnic_sdma->pkts_sent = true;
 204                 iowait_starve_clear(vnic_sdma->pkts_sent, &vnic_sdma->wait);
 205         }
 206         return ret;
 207
 208 free_desc:
 209         sdma_txclean(dd, &tx->txreq);
 210         kmem_cache_free(dd->vnic.txreq_cache, tx);
 211 tx_err:
 212         if (ret != -EBUSY)
 213                 dev_kfree_skb_any(skb);
 214         else
 215                 vnic_sdma->pkts_sent = false;
 216         return ret;
 217 }
 218
 219 /*
 220  * hfi1_vnic_sdma_sleep - vnic sdma sleep function
 221  *
 222  * This function gets called from sdma_send_txreq() when there are not enough
 223  * sdma descriptors available to send the packet. It adds Tx queue's wait
 224  * structure to sdma engine's dmawait list to be woken up when descriptors
 225  * become available.
 226  */
 227 static int hfi1_vnic_sdma_sleep(struct sdma_engine *sde,
 228                                 struct iowait_work *wait,
 229                                 struct sdma_txreq *txreq,
 230                                 uint seq,
 231                                 bool pkts_sent)
 232 {
 233         struct hfi1_vnic_sdma *vnic_sdma =
 234                 container_of(wait->iow, struct hfi1_vnic_sdma, wait);
 235
 236         write_seqlock(&sde->waitlock);
 237         if (sdma_progress(sde, seq, txreq)) {
 238                 write_sequnlock(&sde->waitlock);
 239                 return -EAGAIN;
 240         }
 241
 242         vnic_sdma->state = HFI1_VNIC_SDMA_Q_DEFERRED;
 243         if (list_empty(&vnic_sdma->wait.list)) {
 244                 iowait_get_priority(wait->iow);
 245                 iowait_queue(pkts_sent, wait->iow, &sde->dmawait);
 246         }
 247         write_sequnlock(&sde->waitlock);
 248         return -EBUSY;
 249 }
 250
 251 /*
 252  * hfi1_vnic_sdma_wakeup - vnic sdma wakeup function
 253  *
 254  * This function gets called when SDMA descriptors becomes available and Tx
 255  * queue's wait structure was previously added to sdma engine's dmawait list.
 256  * It notifies the upper driver about Tx queue wakeup.
 257  */
 258 static void hfi1_vnic_sdma_wakeup(struct iowait *wait, int reason)
 259 {
 260         struct hfi1_vnic_sdma *vnic_sdma =
 261                 container_of(wait, struct hfi1_vnic_sdma, wait);
 262         struct hfi1_vnic_vport_info *vinfo = vnic_sdma->vinfo;
 263
 264         vnic_sdma->state = HFI1_VNIC_SDMA_Q_ACTIVE;
 265         if (__netif_subqueue_stopped(vinfo->netdev, vnic_sdma->q_idx))
 266                 netif_wake_subqueue(vinfo->netdev, vnic_sdma->q_idx);
 267 };
 268
 269 inline bool hfi1_vnic_sdma_write_avail(struct hfi1_vnic_vport_info *vinfo,
 270                                        u8 q_idx)
 271 {
 272         struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[q_idx];
 273
 274         return (READ_ONCE(vnic_sdma->state) == HFI1_VNIC_SDMA_Q_ACTIVE);
 275 }
 276
 277 void hfi1_vnic_sdma_init(struct hfi1_vnic_vport_info *vinfo)
 278 {
 279         int i;
 280
 281         for (i = 0; i < vinfo->num_tx_q; i++) {
 282                 struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[i];
 283
 284                 iowait_init(&vnic_sdma->wait, 0, NULL, NULL,
 285                             hfi1_vnic_sdma_sleep,
 286                             hfi1_vnic_sdma_wakeup, NULL, NULL);
 287                 vnic_sdma->sde = &vinfo->dd->per_sdma[i];
 288                 vnic_sdma->dd = vinfo->dd;
 289                 vnic_sdma->vinfo = vinfo;
 290                 vnic_sdma->q_idx = i;
 291                 vnic_sdma->state = HFI1_VNIC_SDMA_Q_ACTIVE;
 292
 293                 /* Add a free descriptor watermark for wakeups */
 294                 if (vnic_sdma->sde->descq_cnt > HFI1_VNIC_SDMA_DESC_WTRMRK) {
 295                         struct iowait_work *work;
 296
 297                         INIT_LIST_HEAD(&vnic_sdma->stx.list);
 298                         vnic_sdma->stx.num_desc = HFI1_VNIC_SDMA_DESC_WTRMRK;
 299                         work = iowait_get_ib_work(&vnic_sdma->wait);
 300                         list_add_tail(&vnic_sdma->stx.list, &work->tx_head);
 301                 }
 302         }
 303 }
 304
 305 int hfi1_vnic_txreq_init(struct hfi1_devdata *dd)
 306 {
 307         char buf[HFI1_VNIC_TXREQ_NAME_LEN];
 308
 309         snprintf(buf, sizeof(buf), "hfi1_%u_vnic_txreq_cache", dd->unit);
 310         dd->vnic.txreq_cache = kmem_cache_create(buf,
 311                                                  sizeof(struct vnic_txreq),
 312                                                  0, SLAB_HWCACHE_ALIGN,
 313                                                  NULL);
 314         if (!dd->vnic.txreq_cache)
 315                 return -ENOMEM;
 316         return 0;
 317 }
 318
 319 void hfi1_vnic_txreq_deinit(struct hfi1_devdata *dd)
 320 {
 321         kmem_cache_destroy(dd->vnic.txreq_cache);
 322         dd->vnic.txreq_cache = NULL;
 323 }