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 */
28struct 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
38static 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(dd: vnic_sdma->dd, tx: txreq);
45 dev_kfree_skb_any(skb: tx->skb);
46 kmem_cache_free(s: vnic_sdma->dd->vnic.txreq_cache, objp: tx);
47}
48
49static 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 dd: sde->dd,
56 tx: &tx->txreq,
57 kvaddr: tx->skb->data,
58 len: skb_headlen(skb: 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(dd: sde->dd,
67 tx: &tx->txreq,
68 page: skb_frag_page(frag),
69 offset: skb_frag_off(frag),
70 len: 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(dd: sde->dd, tx: &tx->txreq,
78 kvaddr: tx->pad + HFI1_VNIC_MAX_PAD - tx->plen,
79 len: tx->plen);
80
81bail_txadd:
82 return ret;
83}
84
85static 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: &tx->txreq,
94 flags: 0,
95 tlen: hdrbytes + tx->skb->len + tx->plen,
96 ahg_entry: 0,
97 num_ahg: 0,
98 NULL,
99 ahg_hlen: 0,
100 cb: 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 dd: sde->dd,
108 tx: &tx->txreq,
109 kvaddr: &tx->pbc_val,
110 len: hdrbytes);
111 if (unlikely(ret))
112 goto bail_txadd;
113
114 /* add the ulp payload */
115 ret = build_vnic_ulp_payload(sde, tx);
116bail_txadd:
117 return ret;
118}
119
120/* setup the last plen bypes of pad */
121static 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
126int 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(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, wait: iowait_get_ib_work(w: &vnic_sdma->wait),
156 tx: &tx->txreq, pkts_sent: 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(pkts_sent: vnic_sdma->pkts_sent, w: &vnic_sdma->wait);
164 }
165 return ret;
166
167free_desc:
168 sdma_txclean(dd, tx: &tx->txreq);
169 kmem_cache_free(s: dd->vnic.txreq_cache, objp: tx);
170tx_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 */
186static 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(sl: &sde->waitlock);
196 if (sdma_progress(sde, seq, tx: txreq)) {
197 write_sequnlock(sl: &sde->waitlock);
198 return -EAGAIN;
199 }
200
201 vnic_sdma->state = HFI1_VNIC_SDMA_Q_DEFERRED;
202 if (list_empty(head: &vnic_sdma->wait.list)) {
203 iowait_get_priority(w: wait->iow);
204 iowait_queue(pkts_sent, w: wait->iow, wait_head: &sde->dmawait);
205 }
206 write_sequnlock(sl: &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 */
217static 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(dev: vinfo->netdev, queue_index: vnic_sdma->q_idx))
225 netif_wake_subqueue(dev: vinfo->netdev, queue_index: vnic_sdma->q_idx);
226};
227
228inline 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
236void 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(wait: &vnic_sdma->wait, tx_limit: 0, NULL, NULL,
244 sleep: hfi1_vnic_sdma_sleep,
245 wakeup: 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(list: &vnic_sdma->stx.list);
257 vnic_sdma->stx.num_desc = HFI1_VNIC_SDMA_DESC_WTRMRK;
258 work = iowait_get_ib_work(w: &vnic_sdma->wait);
259 list_add_tail(new: &vnic_sdma->stx.list, head: &work->tx_head);
260 }
261 }
262}
263
264int hfi1_vnic_txreq_init(struct hfi1_devdata *dd)
265{
266 char buf[HFI1_VNIC_TXREQ_NAME_LEN];
267
268 snprintf(buf, size: sizeof(buf), fmt: "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
278void hfi1_vnic_txreq_deinit(struct hfi1_devdata *dd)
279{
280 kmem_cache_destroy(s: dd->vnic.txreq_cache);
281 dd->vnic.txreq_cache = NULL;
282}
283

source code of linux/drivers/infiniband/hw/hfi1/vnic_sdma.c