1 // SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause 2 /* 3 * Copyright(c) 2017 - 2018 Intel Corporation. 4 */ 5 6 /* 7 * This file contains HFI1 support for VNIC SDMA functionality 8 */ 9 10 #include "sdma.h" 11 #include "vnic.h" 12 13 #define HFI1_VNIC_SDMA_Q_ACTIVE BIT(0) 14 #define HFI1_VNIC_SDMA_Q_DEFERRED BIT(1) 15 16 #define HFI1_VNIC_TXREQ_NAME_LEN 32 17 #define HFI1_VNIC_SDMA_DESC_WTRMRK 64 18 19 /* 20 * struct vnic_txreq - VNIC transmit descriptor 21 * @txreq: sdma transmit request 22 * @sdma: vnic sdma pointer 23 * @skb: skb to send 24 * @pad: pad buffer 25 * @plen: pad length 26 * @pbc_val: pbc value 27 */ 28 struct vnic_txreq { 29 struct sdma_txreq txreq; 30 struct hfi1_vnic_sdma *sdma; 31 32 struct sk_buff *skb; 33 unsigned char pad[HFI1_VNIC_MAX_PAD]; 34 u16 plen; 35 __le64 pbc_val; 36 }; 37 38 static void vnic_sdma_complete(struct sdma_txreq *txreq, 39 int status) 40 { 41 struct vnic_txreq *tx = container_of(txreq, struct vnic_txreq, txreq); 42 struct hfi1_vnic_sdma *vnic_sdma = tx->sdma; 43 44 sdma_txclean(vnic_sdma->dd, txreq); 45 dev_kfree_skb_any(tx->skb); 46 kmem_cache_free(vnic_sdma->dd->vnic.txreq_cache, tx); 47 } 48 49 static noinline int build_vnic_ulp_payload(struct sdma_engine *sde, 50 struct vnic_txreq *tx) 51 { 52 int i, ret = 0; 53 54 ret = sdma_txadd_kvaddr( 55 sde->dd, 56 &tx->txreq, 57 tx->skb->data, 58 skb_headlen(tx->skb)); 59 if (unlikely(ret)) 60 goto bail_txadd; 61 62 for (i = 0; i < skb_shinfo(tx->skb)->nr_frags; i++) { 63 skb_frag_t *frag = &skb_shinfo(tx->skb)->frags[i]; 64 65 /* combine physically continuous fragments later? */ 66 ret = sdma_txadd_page(sde->dd, 67 &tx->txreq, 68 skb_frag_page(frag), 69 skb_frag_off(frag), 70 skb_frag_size(frag)); 71 if (unlikely(ret)) 72 goto bail_txadd; 73 } 74 75 if (tx->plen) 76 ret = sdma_txadd_kvaddr(sde->dd, &tx->txreq, 77 tx->pad + HFI1_VNIC_MAX_PAD - tx->plen, 78 tx->plen); 79 80 bail_txadd: 81 return ret; 82 } 83 84 static int build_vnic_tx_desc(struct sdma_engine *sde, 85 struct vnic_txreq *tx, 86 u64 pbc) 87 { 88 int ret = 0; 89 u16 hdrbytes = 2 << 2; /* PBC */ 90 91 ret = sdma_txinit_ahg( 92 &tx->txreq, 93 0, 94 hdrbytes + tx->skb->len + tx->plen, 95 0, 96 0, 97 NULL, 98 0, 99 vnic_sdma_complete); 100 if (unlikely(ret)) 101 goto bail_txadd; 102 103 /* add pbc */ 104 tx->pbc_val = cpu_to_le64(pbc); 105 ret = sdma_txadd_kvaddr( 106 sde->dd, 107 &tx->txreq, 108 &tx->pbc_val, 109 hdrbytes); 110 if (unlikely(ret)) 111 goto bail_txadd; 112 113 /* add the ulp payload */ 114 ret = build_vnic_ulp_payload(sde, tx); 115 bail_txadd: 116 return ret; 117 } 118 119 /* setup the last plen bypes of pad */ 120 static inline void hfi1_vnic_update_pad(unsigned char *pad, u8 plen) 121 { 122 pad[HFI1_VNIC_MAX_PAD - 1] = plen - OPA_VNIC_ICRC_TAIL_LEN; 123 } 124 125 int hfi1_vnic_send_dma(struct hfi1_devdata *dd, u8 q_idx, 126 struct hfi1_vnic_vport_info *vinfo, 127 struct sk_buff *skb, u64 pbc, u8 plen) 128 { 129 struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[q_idx]; 130 struct sdma_engine *sde = vnic_sdma->sde; 131 struct vnic_txreq *tx; 132 int ret = -ECOMM; 133 134 if (unlikely(READ_ONCE(vnic_sdma->state) != HFI1_VNIC_SDMA_Q_ACTIVE)) 135 goto tx_err; 136 137 if (unlikely(!sde || !sdma_running(sde))) 138 goto tx_err; 139 140 tx = kmem_cache_alloc(dd->vnic.txreq_cache, GFP_ATOMIC); 141 if (unlikely(!tx)) { 142 ret = -ENOMEM; 143 goto tx_err; 144 } 145 146 tx->sdma = vnic_sdma; 147 tx->skb = skb; 148 hfi1_vnic_update_pad(tx->pad, plen); 149 tx->plen = plen; 150 ret = build_vnic_tx_desc(sde, tx, pbc); 151 if (unlikely(ret)) 152 goto free_desc; 153 154 ret = sdma_send_txreq(sde, iowait_get_ib_work(&vnic_sdma->wait), 155 &tx->txreq, vnic_sdma->pkts_sent); 156 /* When -ECOMM, sdma callback will be called with ABORT status */ 157 if (unlikely(ret && unlikely(ret != -ECOMM))) 158 goto free_desc; 159 160 if (!ret) { 161 vnic_sdma->pkts_sent = true; 162 iowait_starve_clear(vnic_sdma->pkts_sent, &vnic_sdma->wait); 163 } 164 return ret; 165 166 free_desc: 167 sdma_txclean(dd, &tx->txreq); 168 kmem_cache_free(dd->vnic.txreq_cache, tx); 169 tx_err: 170 if (ret != -EBUSY) 171 dev_kfree_skb_any(skb); 172 else 173 vnic_sdma->pkts_sent = false; 174 return ret; 175 } 176 177 /* 178 * hfi1_vnic_sdma_sleep - vnic sdma sleep function 179 * 180 * This function gets called from sdma_send_txreq() when there are not enough 181 * sdma descriptors available to send the packet. It adds Tx queue's wait 182 * structure to sdma engine's dmawait list to be woken up when descriptors 183 * become available. 184 */ 185 static int hfi1_vnic_sdma_sleep(struct sdma_engine *sde, 186 struct iowait_work *wait, 187 struct sdma_txreq *txreq, 188 uint seq, 189 bool pkts_sent) 190 { 191 struct hfi1_vnic_sdma *vnic_sdma = 192 container_of(wait->iow, struct hfi1_vnic_sdma, wait); 193 194 write_seqlock(&sde->waitlock); 195 if (sdma_progress(sde, seq, txreq)) { 196 write_sequnlock(&sde->waitlock); 197 return -EAGAIN; 198 } 199 200 vnic_sdma->state = HFI1_VNIC_SDMA_Q_DEFERRED; 201 if (list_empty(&vnic_sdma->wait.list)) { 202 iowait_get_priority(wait->iow); 203 iowait_queue(pkts_sent, wait->iow, &sde->dmawait); 204 } 205 write_sequnlock(&sde->waitlock); 206 return -EBUSY; 207 } 208 209 /* 210 * hfi1_vnic_sdma_wakeup - vnic sdma wakeup function 211 * 212 * This function gets called when SDMA descriptors becomes available and Tx 213 * queue's wait structure was previously added to sdma engine's dmawait list. 214 * It notifies the upper driver about Tx queue wakeup. 215 */ 216 static void hfi1_vnic_sdma_wakeup(struct iowait *wait, int reason) 217 { 218 struct hfi1_vnic_sdma *vnic_sdma = 219 container_of(wait, struct hfi1_vnic_sdma, wait); 220 struct hfi1_vnic_vport_info *vinfo = vnic_sdma->vinfo; 221 222 vnic_sdma->state = HFI1_VNIC_SDMA_Q_ACTIVE; 223 if (__netif_subqueue_stopped(vinfo->netdev, vnic_sdma->q_idx)) 224 netif_wake_subqueue(vinfo->netdev, vnic_sdma->q_idx); 225 }; 226 227 inline bool hfi1_vnic_sdma_write_avail(struct hfi1_vnic_vport_info *vinfo, 228 u8 q_idx) 229 { 230 struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[q_idx]; 231 232 return (READ_ONCE(vnic_sdma->state) == HFI1_VNIC_SDMA_Q_ACTIVE); 233 } 234 235 void hfi1_vnic_sdma_init(struct hfi1_vnic_vport_info *vinfo) 236 { 237 int i; 238 239 for (i = 0; i < vinfo->num_tx_q; i++) { 240 struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[i]; 241 242 iowait_init(&vnic_sdma->wait, 0, NULL, NULL, 243 hfi1_vnic_sdma_sleep, 244 hfi1_vnic_sdma_wakeup, NULL, NULL); 245 vnic_sdma->sde = &vinfo->dd->per_sdma[i]; 246 vnic_sdma->dd = vinfo->dd; 247 vnic_sdma->vinfo = vinfo; 248 vnic_sdma->q_idx = i; 249 vnic_sdma->state = HFI1_VNIC_SDMA_Q_ACTIVE; 250 251 /* Add a free descriptor watermark for wakeups */ 252 if (vnic_sdma->sde->descq_cnt > HFI1_VNIC_SDMA_DESC_WTRMRK) { 253 struct iowait_work *work; 254 255 INIT_LIST_HEAD(&vnic_sdma->stx.list); 256 vnic_sdma->stx.num_desc = HFI1_VNIC_SDMA_DESC_WTRMRK; 257 work = iowait_get_ib_work(&vnic_sdma->wait); 258 list_add_tail(&vnic_sdma->stx.list, &work->tx_head); 259 } 260 } 261 } 262 263 int hfi1_vnic_txreq_init(struct hfi1_devdata *dd) 264 { 265 char buf[HFI1_VNIC_TXREQ_NAME_LEN]; 266 267 snprintf(buf, sizeof(buf), "hfi1_%u_vnic_txreq_cache", dd->unit); 268 dd->vnic.txreq_cache = kmem_cache_create(buf, 269 sizeof(struct vnic_txreq), 270 0, SLAB_HWCACHE_ALIGN, 271 NULL); 272 if (!dd->vnic.txreq_cache) 273 return -ENOMEM; 274 return 0; 275 } 276 277 void hfi1_vnic_txreq_deinit(struct hfi1_devdata *dd) 278 { 279 kmem_cache_destroy(dd->vnic.txreq_cache); 280 dd->vnic.txreq_cache = NULL; 281 } 282