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