drivers/infiniband/hw/hfi1/vnic_sdma.c

   1 /*
   2  * Copyright(c) 2017 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 #define HFI1_VNIC_SDMA_RETRY_COUNT 1
  61
  62 /*
  63  * struct vnic_txreq - VNIC transmit descriptor
  64  * @txreq: sdma transmit request
  65  * @sdma: vnic sdma pointer
  66  * @skb: skb to send
  67  * @pad: pad buffer
  68  * @plen: pad length
  69  * @pbc_val: pbc value
  70  * @retry_count: tx retry count
  71  */
  72 struct vnic_txreq {
  73         struct sdma_txreq       txreq;
  74         struct hfi1_vnic_sdma   *sdma;
  75
  76         struct sk_buff         *skb;
  77         unsigned char           pad[HFI1_VNIC_MAX_PAD];
  78         u16                     plen;
  79         __le64                  pbc_val;
  80
  81         u32                     retry_count;
  82 };
  83
  84 static void vnic_sdma_complete(struct sdma_txreq *txreq,
  85                                int status)
  86 {
  87         struct vnic_txreq *tx = container_of(txreq, struct vnic_txreq, txreq);
  88         struct hfi1_vnic_sdma *vnic_sdma = tx->sdma;
  89
  90         sdma_txclean(vnic_sdma->dd, txreq);
  91         dev_kfree_skb_any(tx->skb);
  92         kmem_cache_free(vnic_sdma->dd->vnic.txreq_cache, tx);
  93 }
  94
  95 static noinline int build_vnic_ulp_payload(struct sdma_engine *sde,
  96                                            struct vnic_txreq *tx)
  97 {
  98         int i, ret = 0;
  99
 100         ret = sdma_txadd_kvaddr(
 101                 sde->dd,
 102                 &tx->txreq,
 103                 tx->skb->data,
 104                 skb_headlen(tx->skb));
 105         if (unlikely(ret))
 106                 goto bail_txadd;
 107
 108         for (i = 0; i < skb_shinfo(tx->skb)->nr_frags; i++) {
 109                 struct skb_frag_struct *frag = &skb_shinfo(tx->skb)->frags[i];
 110
 111                 /* combine physically continuous fragments later? */
 112                 ret = sdma_txadd_page(sde->dd,
 113                                       &tx->txreq,
 114                                       skb_frag_page(frag),
 115                                       frag->page_offset,
 116                                       skb_frag_size(frag));
 117                 if (unlikely(ret))
 118                         goto bail_txadd;
 119         }
 120
 121         if (tx->plen)
 122                 ret = sdma_txadd_kvaddr(sde->dd, &tx->txreq,
 123                                         tx->pad + HFI1_VNIC_MAX_PAD - tx->plen,
 124                                         tx->plen);
 125
 126 bail_txadd:
 127         return ret;
 128 }
 129
 130 static int build_vnic_tx_desc(struct sdma_engine *sde,
 131                               struct vnic_txreq *tx,
 132                               u64 pbc)
 133 {
 134         int ret = 0;
 135         u16 hdrbytes = 2 << 2;  /* PBC */
 136
 137         ret = sdma_txinit_ahg(
 138                 &tx->txreq,
 139                 0,
 140                 hdrbytes + tx->skb->len + tx->plen,
 141                 0,
 142                 0,
 143                 NULL,
 144                 0,
 145                 vnic_sdma_complete);
 146         if (unlikely(ret))
 147                 goto bail_txadd;
 148
 149         /* add pbc */
 150         tx->pbc_val = cpu_to_le64(pbc);
 151         ret = sdma_txadd_kvaddr(
 152                 sde->dd,
 153                 &tx->txreq,
 154                 &tx->pbc_val,
 155                 hdrbytes);
 156         if (unlikely(ret))
 157                 goto bail_txadd;
 158
 159         /* add the ulp payload */
 160         ret = build_vnic_ulp_payload(sde, tx);
 161 bail_txadd:
 162         return ret;
 163 }
 164
 165 /* setup the last plen bypes of pad */
 166 static inline void hfi1_vnic_update_pad(unsigned char *pad, u8 plen)
 167 {
 168         pad[HFI1_VNIC_MAX_PAD - 1] = plen - OPA_VNIC_ICRC_TAIL_LEN;
 169 }
 170
 171 int hfi1_vnic_send_dma(struct hfi1_devdata *dd, u8 q_idx,
 172                        struct hfi1_vnic_vport_info *vinfo,
 173                        struct sk_buff *skb, u64 pbc, u8 plen)
 174 {
 175         struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[q_idx];
 176         struct sdma_engine *sde = vnic_sdma->sde;
 177         struct vnic_txreq *tx;
 178         int ret = -ECOMM;
 179
 180         if (unlikely(READ_ONCE(vnic_sdma->state) != HFI1_VNIC_SDMA_Q_ACTIVE))
 181                 goto tx_err;
 182
 183         if (unlikely(!sde || !sdma_running(sde)))
 184                 goto tx_err;
 185
 186         tx = kmem_cache_alloc(dd->vnic.txreq_cache, GFP_ATOMIC);
 187         if (unlikely(!tx)) {
 188                 ret = -ENOMEM;
 189                 goto tx_err;
 190         }
 191
 192         tx->sdma = vnic_sdma;
 193         tx->skb = skb;
 194         hfi1_vnic_update_pad(tx->pad, plen);
 195         tx->plen = plen;
 196         ret = build_vnic_tx_desc(sde, tx, pbc);
 197         if (unlikely(ret))
 198                 goto free_desc;
 199         tx->retry_count = 0;
 200
 201         ret = sdma_send_txreq(sde, &vnic_sdma->wait, &tx->txreq,
 202                               vnic_sdma->pkts_sent);
 203         /* When -ECOMM, sdma callback will be called with ABORT status */
 204         if (unlikely(ret && unlikely(ret != -ECOMM)))
 205                 goto free_desc;
 206
 207         if (!ret) {
 208                 vnic_sdma->pkts_sent = true;
 209                 iowait_starve_clear(vnic_sdma->pkts_sent, &vnic_sdma->wait);
 210         }
 211         return ret;
 212
 213 free_desc:
 214         sdma_txclean(dd, &tx->txreq);
 215         kmem_cache_free(dd->vnic.txreq_cache, tx);
 216 tx_err:
 217         if (ret != -EBUSY)
 218                 dev_kfree_skb_any(skb);
 219         else
 220                 vnic_sdma->pkts_sent = false;
 221         return ret;
 222 }
 223
 224 /*
 225  * hfi1_vnic_sdma_sleep - vnic sdma sleep function
 226  *
 227  * This function gets called from sdma_send_txreq() when there are not enough
 228  * sdma descriptors available to send the packet. It adds Tx queue's wait
 229  * structure to sdma engine's dmawait list to be woken up when descriptors
 230  * become available.
 231  */
 232 static int hfi1_vnic_sdma_sleep(struct sdma_engine *sde,
 233                                 struct iowait *wait,
 234                                 struct sdma_txreq *txreq,
 235                                 uint seq,
 236                                 bool pkts_sent)
 237 {
 238         struct hfi1_vnic_sdma *vnic_sdma =
 239                 container_of(wait, struct hfi1_vnic_sdma, wait);
 240         struct hfi1_ibdev *dev = &vnic_sdma->dd->verbs_dev;
 241         struct vnic_txreq *tx = container_of(txreq, struct vnic_txreq, txreq);
 242
 243         if (sdma_progress(sde, seq, txreq))
 244                 if (tx->retry_count++ < HFI1_VNIC_SDMA_RETRY_COUNT)
 245                         return -EAGAIN;
 246
 247         vnic_sdma->state = HFI1_VNIC_SDMA_Q_DEFERRED;
 248         write_seqlock(&dev->iowait_lock);
 249         if (list_empty(&vnic_sdma->wait.list))
 250                 iowait_queue(pkts_sent, wait, &sde->dmawait);
 251         write_sequnlock(&dev->iowait_lock);
 252         return -EBUSY;
 253 }
 254
 255 /*
 256  * hfi1_vnic_sdma_wakeup - vnic sdma wakeup function
 257  *
 258  * This function gets called when SDMA descriptors becomes available and Tx
 259  * queue's wait structure was previously added to sdma engine's dmawait list.
 260  * It notifies the upper driver about Tx queue wakeup.
 261  */
 262 static void hfi1_vnic_sdma_wakeup(struct iowait *wait, int reason)
 263 {
 264         struct hfi1_vnic_sdma *vnic_sdma =
 265                 container_of(wait, struct hfi1_vnic_sdma, wait);
 266         struct hfi1_vnic_vport_info *vinfo = vnic_sdma->vinfo;
 267
 268         vnic_sdma->state = HFI1_VNIC_SDMA_Q_ACTIVE;
 269         if (__netif_subqueue_stopped(vinfo->netdev, vnic_sdma->q_idx))
 270                 netif_wake_subqueue(vinfo->netdev, vnic_sdma->q_idx);
 271 };
 272
 273 inline bool hfi1_vnic_sdma_write_avail(struct hfi1_vnic_vport_info *vinfo,
 274                                        u8 q_idx)
 275 {
 276         struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[q_idx];
 277
 278         return (READ_ONCE(vnic_sdma->state) == HFI1_VNIC_SDMA_Q_ACTIVE);
 279 }
 280
 281 void hfi1_vnic_sdma_init(struct hfi1_vnic_vport_info *vinfo)
 282 {
 283         int i;
 284
 285         for (i = 0; i < vinfo->num_tx_q; i++) {
 286                 struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[i];
 287
 288                 iowait_init(&vnic_sdma->wait, 0, NULL, hfi1_vnic_sdma_sleep,
 289                             hfi1_vnic_sdma_wakeup, NULL);
 290                 vnic_sdma->sde = &vinfo->dd->per_sdma[i];
 291                 vnic_sdma->dd = vinfo->dd;
 292                 vnic_sdma->vinfo = vinfo;
 293                 vnic_sdma->q_idx = i;
 294                 vnic_sdma->state = HFI1_VNIC_SDMA_Q_ACTIVE;
 295
 296                 /* Add a free descriptor watermark for wakeups */
 297                 if (vnic_sdma->sde->descq_cnt > HFI1_VNIC_SDMA_DESC_WTRMRK) {
 298                         INIT_LIST_HEAD(&vnic_sdma->stx.list);
 299                         vnic_sdma->stx.num_desc = HFI1_VNIC_SDMA_DESC_WTRMRK;
 300                         list_add_tail(&vnic_sdma->stx.list,
 301                                       &vnic_sdma->wait.tx_head);
 302                 }
 303         }
 304 }
 305
 306 int hfi1_vnic_txreq_init(struct hfi1_devdata *dd)
 307 {
 308         char buf[HFI1_VNIC_TXREQ_NAME_LEN];
 309
 310         snprintf(buf, sizeof(buf), "hfi1_%u_vnic_txreq_cache", dd->unit);
 311         dd->vnic.txreq_cache = kmem_cache_create(buf,
 312                                                  sizeof(struct vnic_txreq),
 313                                                  0, SLAB_HWCACHE_ALIGN,
 314                                                  NULL);
 315         if (!dd->vnic.txreq_cache)
 316                 return -ENOMEM;
 317         return 0;
 318 }
 319
 320 void hfi1_vnic_txreq_deinit(struct hfi1_devdata *dd)
 321 {
 322         kmem_cache_destroy(dd->vnic.txreq_cache);
 323         dd->vnic.txreq_cache = NULL;
 324 }