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
vnic_sdma_complete(struct sdma_txreq * txreq,int status)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
build_vnic_ulp_payload(struct sdma_engine * sde,struct vnic_txreq * tx)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 NULL, NULL, NULL);
114 if (unlikely(ret))
115 goto bail_txadd;
116 }
117
118 if (tx->plen)
119 ret = sdma_txadd_kvaddr(sde->dd, &tx->txreq,
120 tx->pad + HFI1_VNIC_MAX_PAD - tx->plen,
121 tx->plen);
122
123 bail_txadd:
124 return ret;
125 }
126
build_vnic_tx_desc(struct sdma_engine * sde,struct vnic_txreq * tx,u64 pbc)127 static int build_vnic_tx_desc(struct sdma_engine *sde,
128 struct vnic_txreq *tx,
129 u64 pbc)
130 {
131 int ret = 0;
132 u16 hdrbytes = 2 << 2; /* PBC */
133
134 ret = sdma_txinit_ahg(
135 &tx->txreq,
136 0,
137 hdrbytes + tx->skb->len + tx->plen,
138 0,
139 0,
140 NULL,
141 0,
142 vnic_sdma_complete);
143 if (unlikely(ret))
144 goto bail_txadd;
145
146 /* add pbc */
147 tx->pbc_val = cpu_to_le64(pbc);
148 ret = sdma_txadd_kvaddr(
149 sde->dd,
150 &tx->txreq,
151 &tx->pbc_val,
152 hdrbytes);
153 if (unlikely(ret))
154 goto bail_txadd;
155
156 /* add the ulp payload */
157 ret = build_vnic_ulp_payload(sde, tx);
158 bail_txadd:
159 return ret;
160 }
161
162 /* setup the last plen bypes of pad */
hfi1_vnic_update_pad(unsigned char * pad,u8 plen)163 static inline void hfi1_vnic_update_pad(unsigned char *pad, u8 plen)
164 {
165 pad[HFI1_VNIC_MAX_PAD - 1] = plen - OPA_VNIC_ICRC_TAIL_LEN;
166 }
167
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)168 int hfi1_vnic_send_dma(struct hfi1_devdata *dd, u8 q_idx,
169 struct hfi1_vnic_vport_info *vinfo,
170 struct sk_buff *skb, u64 pbc, u8 plen)
171 {
172 struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[q_idx];
173 struct sdma_engine *sde = vnic_sdma->sde;
174 struct vnic_txreq *tx;
175 int ret = -ECOMM;
176
177 if (unlikely(READ_ONCE(vnic_sdma->state) != HFI1_VNIC_SDMA_Q_ACTIVE))
178 goto tx_err;
179
180 if (unlikely(!sde || !sdma_running(sde)))
181 goto tx_err;
182
183 tx = kmem_cache_alloc(dd->vnic.txreq_cache, GFP_ATOMIC);
184 if (unlikely(!tx)) {
185 ret = -ENOMEM;
186 goto tx_err;
187 }
188
189 tx->sdma = vnic_sdma;
190 tx->skb = skb;
191 hfi1_vnic_update_pad(tx->pad, plen);
192 tx->plen = plen;
193 ret = build_vnic_tx_desc(sde, tx, pbc);
194 if (unlikely(ret))
195 goto free_desc;
196
197 ret = sdma_send_txreq(sde, iowait_get_ib_work(&vnic_sdma->wait),
198 &tx->txreq, vnic_sdma->pkts_sent);
199 /* When -ECOMM, sdma callback will be called with ABORT status */
200 if (unlikely(ret && unlikely(ret != -ECOMM)))
201 goto free_desc;
202
203 if (!ret) {
204 vnic_sdma->pkts_sent = true;
205 iowait_starve_clear(vnic_sdma->pkts_sent, &vnic_sdma->wait);
206 }
207 return ret;
208
209 free_desc:
210 sdma_txclean(dd, &tx->txreq);
211 kmem_cache_free(dd->vnic.txreq_cache, tx);
212 tx_err:
213 if (ret != -EBUSY)
214 dev_kfree_skb_any(skb);
215 else
216 vnic_sdma->pkts_sent = false;
217 return ret;
218 }
219
220 /*
221 * hfi1_vnic_sdma_sleep - vnic sdma sleep function
222 *
223 * This function gets called from sdma_send_txreq() when there are not enough
224 * sdma descriptors available to send the packet. It adds Tx queue's wait
225 * structure to sdma engine's dmawait list to be woken up when descriptors
226 * become available.
227 */
hfi1_vnic_sdma_sleep(struct sdma_engine * sde,struct iowait_work * wait,struct sdma_txreq * txreq,uint seq,bool pkts_sent)228 static int hfi1_vnic_sdma_sleep(struct sdma_engine *sde,
229 struct iowait_work *wait,
230 struct sdma_txreq *txreq,
231 uint seq,
232 bool pkts_sent)
233 {
234 struct hfi1_vnic_sdma *vnic_sdma =
235 container_of(wait->iow, struct hfi1_vnic_sdma, wait);
236
237 write_seqlock(&sde->waitlock);
238 if (sdma_progress(sde, seq, txreq)) {
239 write_sequnlock(&sde->waitlock);
240 return -EAGAIN;
241 }
242
243 vnic_sdma->state = HFI1_VNIC_SDMA_Q_DEFERRED;
244 if (list_empty(&vnic_sdma->wait.list)) {
245 iowait_get_priority(wait->iow);
246 iowait_queue(pkts_sent, wait->iow, &sde->dmawait);
247 }
248 write_sequnlock(&sde->waitlock);
249 return -EBUSY;
250 }
251
252 /*
253 * hfi1_vnic_sdma_wakeup - vnic sdma wakeup function
254 *
255 * This function gets called when SDMA descriptors becomes available and Tx
256 * queue's wait structure was previously added to sdma engine's dmawait list.
257 * It notifies the upper driver about Tx queue wakeup.
258 */
hfi1_vnic_sdma_wakeup(struct iowait * wait,int reason)259 static void hfi1_vnic_sdma_wakeup(struct iowait *wait, int reason)
260 {
261 struct hfi1_vnic_sdma *vnic_sdma =
262 container_of(wait, struct hfi1_vnic_sdma, wait);
263 struct hfi1_vnic_vport_info *vinfo = vnic_sdma->vinfo;
264
265 vnic_sdma->state = HFI1_VNIC_SDMA_Q_ACTIVE;
266 if (__netif_subqueue_stopped(vinfo->netdev, vnic_sdma->q_idx))
267 netif_wake_subqueue(vinfo->netdev, vnic_sdma->q_idx);
268 };
269
hfi1_vnic_sdma_write_avail(struct hfi1_vnic_vport_info * vinfo,u8 q_idx)270 inline bool hfi1_vnic_sdma_write_avail(struct hfi1_vnic_vport_info *vinfo,
271 u8 q_idx)
272 {
273 struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[q_idx];
274
275 return (READ_ONCE(vnic_sdma->state) == HFI1_VNIC_SDMA_Q_ACTIVE);
276 }
277
hfi1_vnic_sdma_init(struct hfi1_vnic_vport_info * vinfo)278 void hfi1_vnic_sdma_init(struct hfi1_vnic_vport_info *vinfo)
279 {
280 int i;
281
282 for (i = 0; i < vinfo->num_tx_q; i++) {
283 struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[i];
284
285 iowait_init(&vnic_sdma->wait, 0, NULL, NULL,
286 hfi1_vnic_sdma_sleep,
287 hfi1_vnic_sdma_wakeup, NULL, NULL);
288 vnic_sdma->sde = &vinfo->dd->per_sdma[i];
289 vnic_sdma->dd = vinfo->dd;
290 vnic_sdma->vinfo = vinfo;
291 vnic_sdma->q_idx = i;
292 vnic_sdma->state = HFI1_VNIC_SDMA_Q_ACTIVE;
293
294 /* Add a free descriptor watermark for wakeups */
295 if (vnic_sdma->sde->descq_cnt > HFI1_VNIC_SDMA_DESC_WTRMRK) {
296 struct iowait_work *work;
297
298 INIT_LIST_HEAD(&vnic_sdma->stx.list);
299 vnic_sdma->stx.num_desc = HFI1_VNIC_SDMA_DESC_WTRMRK;
300 work = iowait_get_ib_work(&vnic_sdma->wait);
301 list_add_tail(&vnic_sdma->stx.list, &work->tx_head);
302 }
303 }
304 }
305
hfi1_vnic_txreq_init(struct hfi1_devdata * dd)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
hfi1_vnic_txreq_deinit(struct hfi1_devdata * dd)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 }
325