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 */
70struct 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
80static 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
91static 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
123bail_txadd:
124	return ret;
125}
126
127static 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);
158bail_txadd:
159	return ret;
160}
161
162/* setup the last plen bypes of pad */
163static 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
168int 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
209free_desc:
210	sdma_txclean(dd, &tx->txreq);
211	kmem_cache_free(dd->vnic.txreq_cache, tx);
212tx_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 */
228static 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 */
259static 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
270inline 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
278void 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
306int 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
320void 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