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
vnic_sdma_complete(struct sdma_txreq * txreq,int status)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
build_vnic_ulp_payload(struct sdma_engine * sde,struct vnic_txreq * tx)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
build_vnic_tx_desc(struct sdma_engine * sde,struct vnic_txreq * tx,u64 pbc)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 */
hfi1_vnic_update_pad(unsigned char * pad,u8 plen)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
hfi1_vnic_send_dma(struct hfi1_devdata * dd,u8 q_idx,struct hfi1_vnic_vport_info * vinfo,struct sk_buff * skb,u64 pbc,u8 plen)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 */
hfi1_vnic_sdma_sleep(struct sdma_engine * sde,struct iowait_work * wait,struct sdma_txreq * txreq,uint seq,bool pkts_sent)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 */
hfi1_vnic_sdma_wakeup(struct iowait * wait,int reason)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
hfi1_vnic_sdma_write_avail(struct hfi1_vnic_vport_info * vinfo,u8 q_idx)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
hfi1_vnic_sdma_init(struct hfi1_vnic_vport_info * vinfo)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
hfi1_vnic_txreq_init(struct hfi1_devdata * dd)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
hfi1_vnic_txreq_deinit(struct hfi1_devdata * dd)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