1// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
2/* Copyright (c) 2019 Mellanox Technologies. */
3
4#include "rx.h"
5#include "en/xdp.h"
6#include <net/xdp_sock_drv.h>
7#include <linux/filter.h>
8
9/* RX data path */
10
11static struct mlx5e_xdp_buff *xsk_buff_to_mxbuf(struct xdp_buff *xdp)
12{
13 /* mlx5e_xdp_buff shares its layout with xdp_buff_xsk
14 * and private mlx5e_xdp_buff fields fall into xdp_buff_xsk->cb
15 */
16 return (struct mlx5e_xdp_buff *)xdp;
17}
18
19int mlx5e_xsk_alloc_rx_mpwqe(struct mlx5e_rq *rq, u16 ix)
20{
21 struct mlx5e_mpw_info *wi = mlx5e_get_mpw_info(rq, i: ix);
22 struct mlx5e_icosq *icosq = rq->icosq;
23 struct mlx5_wq_cyc *wq = &icosq->wq;
24 struct mlx5e_umr_wqe *umr_wqe;
25 struct xdp_buff **xsk_buffs;
26 int batch, i;
27 u32 offset; /* 17-bit value with MTT. */
28 u16 pi;
29
30 if (unlikely(!xsk_buff_can_alloc(rq->xsk_pool, rq->mpwqe.pages_per_wqe)))
31 goto err;
32
33 XSK_CHECK_PRIV_TYPE(struct mlx5e_xdp_buff);
34 xsk_buffs = (struct xdp_buff **)wi->alloc_units.xsk_buffs;
35 batch = xsk_buff_alloc_batch(pool: rq->xsk_pool, xdp: xsk_buffs,
36 max: rq->mpwqe.pages_per_wqe);
37
38 /* If batch < pages_per_wqe, either:
39 * 1. Some (or all) descriptors were invalid.
40 * 2. dma_need_sync is true, and it fell back to allocating one frame.
41 * In either case, try to continue allocating frames one by one, until
42 * the first error, which will mean there are no more valid descriptors.
43 */
44 for (; batch < rq->mpwqe.pages_per_wqe; batch++) {
45 xsk_buffs[batch] = xsk_buff_alloc(pool: rq->xsk_pool);
46 if (unlikely(!xsk_buffs[batch]))
47 goto err_reuse_batch;
48 }
49
50 pi = mlx5e_icosq_get_next_pi(sq: icosq, size: rq->mpwqe.umr_wqebbs);
51 umr_wqe = mlx5_wq_cyc_get_wqe(wq, ix: pi);
52 memcpy(umr_wqe, &rq->mpwqe.umr_wqe, sizeof(struct mlx5e_umr_wqe));
53
54 if (likely(rq->mpwqe.umr_mode == MLX5E_MPWRQ_UMR_MODE_ALIGNED)) {
55 for (i = 0; i < batch; i++) {
56 struct mlx5e_xdp_buff *mxbuf = xsk_buff_to_mxbuf(xdp: xsk_buffs[i]);
57 dma_addr_t addr = xsk_buff_xdp_get_frame_dma(xdp: xsk_buffs[i]);
58
59 umr_wqe->inline_mtts[i] = (struct mlx5_mtt) {
60 .ptag = cpu_to_be64(addr | MLX5_EN_WR),
61 };
62 mxbuf->rq = rq;
63 }
64 } else if (unlikely(rq->mpwqe.umr_mode == MLX5E_MPWRQ_UMR_MODE_UNALIGNED)) {
65 for (i = 0; i < batch; i++) {
66 struct mlx5e_xdp_buff *mxbuf = xsk_buff_to_mxbuf(xdp: xsk_buffs[i]);
67 dma_addr_t addr = xsk_buff_xdp_get_frame_dma(xdp: xsk_buffs[i]);
68
69 umr_wqe->inline_ksms[i] = (struct mlx5_ksm) {
70 .key = rq->mkey_be,
71 .va = cpu_to_be64(addr),
72 };
73 mxbuf->rq = rq;
74 }
75 } else if (likely(rq->mpwqe.umr_mode == MLX5E_MPWRQ_UMR_MODE_TRIPLE)) {
76 u32 mapping_size = 1 << (rq->mpwqe.page_shift - 2);
77
78 for (i = 0; i < batch; i++) {
79 struct mlx5e_xdp_buff *mxbuf = xsk_buff_to_mxbuf(xdp: xsk_buffs[i]);
80 dma_addr_t addr = xsk_buff_xdp_get_frame_dma(xdp: xsk_buffs[i]);
81
82 umr_wqe->inline_ksms[i << 2] = (struct mlx5_ksm) {
83 .key = rq->mkey_be,
84 .va = cpu_to_be64(addr),
85 };
86 umr_wqe->inline_ksms[(i << 2) + 1] = (struct mlx5_ksm) {
87 .key = rq->mkey_be,
88 .va = cpu_to_be64(addr + mapping_size),
89 };
90 umr_wqe->inline_ksms[(i << 2) + 2] = (struct mlx5_ksm) {
91 .key = rq->mkey_be,
92 .va = cpu_to_be64(addr + mapping_size * 2),
93 };
94 umr_wqe->inline_ksms[(i << 2) + 3] = (struct mlx5_ksm) {
95 .key = rq->mkey_be,
96 .va = cpu_to_be64(rq->wqe_overflow.addr),
97 };
98 mxbuf->rq = rq;
99 }
100 } else {
101 __be32 pad_size = cpu_to_be32((1 << rq->mpwqe.page_shift) -
102 rq->xsk_pool->chunk_size);
103 __be32 frame_size = cpu_to_be32(rq->xsk_pool->chunk_size);
104
105 for (i = 0; i < batch; i++) {
106 struct mlx5e_xdp_buff *mxbuf = xsk_buff_to_mxbuf(xdp: xsk_buffs[i]);
107 dma_addr_t addr = xsk_buff_xdp_get_frame_dma(xdp: xsk_buffs[i]);
108
109 umr_wqe->inline_klms[i << 1] = (struct mlx5_klm) {
110 .key = rq->mkey_be,
111 .va = cpu_to_be64(addr),
112 .bcount = frame_size,
113 };
114 umr_wqe->inline_klms[(i << 1) + 1] = (struct mlx5_klm) {
115 .key = rq->mkey_be,
116 .va = cpu_to_be64(rq->wqe_overflow.addr),
117 .bcount = pad_size,
118 };
119 mxbuf->rq = rq;
120 }
121 }
122
123 bitmap_zero(dst: wi->skip_release_bitmap, nbits: rq->mpwqe.pages_per_wqe);
124 wi->consumed_strides = 0;
125
126 umr_wqe->ctrl.opmod_idx_opcode =
127 cpu_to_be32((icosq->pc << MLX5_WQE_CTRL_WQE_INDEX_SHIFT) | MLX5_OPCODE_UMR);
128
129 /* Optimized for speed: keep in sync with mlx5e_mpwrq_umr_entry_size. */
130 offset = ix * rq->mpwqe.mtts_per_wqe;
131 if (likely(rq->mpwqe.umr_mode == MLX5E_MPWRQ_UMR_MODE_ALIGNED))
132 offset = offset * sizeof(struct mlx5_mtt) / MLX5_OCTWORD;
133 else if (unlikely(rq->mpwqe.umr_mode == MLX5E_MPWRQ_UMR_MODE_OVERSIZED))
134 offset = offset * sizeof(struct mlx5_klm) * 2 / MLX5_OCTWORD;
135 else if (unlikely(rq->mpwqe.umr_mode == MLX5E_MPWRQ_UMR_MODE_TRIPLE))
136 offset = offset * sizeof(struct mlx5_ksm) * 4 / MLX5_OCTWORD;
137 umr_wqe->uctrl.xlt_offset = cpu_to_be16(offset);
138
139 icosq->db.wqe_info[pi] = (struct mlx5e_icosq_wqe_info) {
140 .wqe_type = MLX5E_ICOSQ_WQE_UMR_RX,
141 .num_wqebbs = rq->mpwqe.umr_wqebbs,
142 .umr.rq = rq,
143 };
144
145 icosq->pc += rq->mpwqe.umr_wqebbs;
146
147 icosq->doorbell_cseg = &umr_wqe->ctrl;
148
149 return 0;
150
151err_reuse_batch:
152 while (--batch >= 0)
153 xsk_buff_free(xdp: xsk_buffs[batch]);
154
155err:
156 rq->stats->buff_alloc_err++;
157 return -ENOMEM;
158}
159
160int mlx5e_xsk_alloc_rx_wqes_batched(struct mlx5e_rq *rq, u16 ix, int wqe_bulk)
161{
162 struct mlx5_wq_cyc *wq = &rq->wqe.wq;
163 struct xdp_buff **buffs;
164 u32 contig, alloc;
165 int i;
166
167 /* Each rq->wqe.frags->xskp is 1:1 mapped to an element inside the
168 * rq->wqe.alloc_units->xsk_buffs array allocated here.
169 */
170 buffs = rq->wqe.alloc_units->xsk_buffs;
171 contig = mlx5_wq_cyc_get_size(wq) - ix;
172 if (wqe_bulk <= contig) {
173 alloc = xsk_buff_alloc_batch(pool: rq->xsk_pool, xdp: buffs + ix, max: wqe_bulk);
174 } else {
175 alloc = xsk_buff_alloc_batch(pool: rq->xsk_pool, xdp: buffs + ix, max: contig);
176 if (likely(alloc == contig))
177 alloc += xsk_buff_alloc_batch(pool: rq->xsk_pool, xdp: buffs, max: wqe_bulk - contig);
178 }
179
180 for (i = 0; i < alloc; i++) {
181 int j = mlx5_wq_cyc_ctr2ix(wq, ctr: ix + i);
182 struct mlx5e_wqe_frag_info *frag;
183 struct mlx5e_rx_wqe_cyc *wqe;
184 dma_addr_t addr;
185
186 wqe = mlx5_wq_cyc_get_wqe(wq, ix: j);
187 /* Assumes log_num_frags == 0. */
188 frag = &rq->wqe.frags[j];
189
190 addr = xsk_buff_xdp_get_frame_dma(xdp: *frag->xskp);
191 wqe->data[0].addr = cpu_to_be64(addr + rq->buff.headroom);
192 frag->flags &= ~BIT(MLX5E_WQE_FRAG_SKIP_RELEASE);
193 }
194
195 return alloc;
196}
197
198int mlx5e_xsk_alloc_rx_wqes(struct mlx5e_rq *rq, u16 ix, int wqe_bulk)
199{
200 struct mlx5_wq_cyc *wq = &rq->wqe.wq;
201 int i;
202
203 for (i = 0; i < wqe_bulk; i++) {
204 int j = mlx5_wq_cyc_ctr2ix(wq, ctr: ix + i);
205 struct mlx5e_wqe_frag_info *frag;
206 struct mlx5e_rx_wqe_cyc *wqe;
207 dma_addr_t addr;
208
209 wqe = mlx5_wq_cyc_get_wqe(wq, ix: j);
210 /* Assumes log_num_frags == 0. */
211 frag = &rq->wqe.frags[j];
212
213 *frag->xskp = xsk_buff_alloc(pool: rq->xsk_pool);
214 if (unlikely(!*frag->xskp))
215 return i;
216
217 addr = xsk_buff_xdp_get_frame_dma(xdp: *frag->xskp);
218 wqe->data[0].addr = cpu_to_be64(addr + rq->buff.headroom);
219 frag->flags &= ~BIT(MLX5E_WQE_FRAG_SKIP_RELEASE);
220 }
221
222 return wqe_bulk;
223}
224
225static struct sk_buff *mlx5e_xsk_construct_skb(struct mlx5e_rq *rq, struct xdp_buff *xdp)
226{
227 u32 totallen = xdp->data_end - xdp->data_meta;
228 u32 metalen = xdp->data - xdp->data_meta;
229 struct sk_buff *skb;
230
231 skb = napi_alloc_skb(napi: rq->cq.napi, length: totallen);
232 if (unlikely(!skb)) {
233 rq->stats->buff_alloc_err++;
234 return NULL;
235 }
236
237 skb_put_data(skb, data: xdp->data_meta, len: totallen);
238
239 if (metalen) {
240 skb_metadata_set(skb, meta_len: metalen);
241 __skb_pull(skb, len: metalen);
242 }
243
244 return skb;
245}
246
247struct sk_buff *mlx5e_xsk_skb_from_cqe_mpwrq_linear(struct mlx5e_rq *rq,
248 struct mlx5e_mpw_info *wi,
249 struct mlx5_cqe64 *cqe,
250 u16 cqe_bcnt,
251 u32 head_offset,
252 u32 page_idx)
253{
254 struct mlx5e_xdp_buff *mxbuf = xsk_buff_to_mxbuf(xdp: wi->alloc_units.xsk_buffs[page_idx]);
255 struct bpf_prog *prog;
256
257 /* Check packet size. Note LRO doesn't use linear SKB */
258 if (unlikely(cqe_bcnt > rq->hw_mtu)) {
259 rq->stats->oversize_pkts_sw_drop++;
260 return NULL;
261 }
262
263 /* head_offset is not used in this function, because xdp->data and the
264 * DMA address point directly to the necessary place. Furthermore, in
265 * the current implementation, UMR pages are mapped to XSK frames, so
266 * head_offset should always be 0.
267 */
268 WARN_ON_ONCE(head_offset);
269
270 /* mxbuf->rq is set on allocation, but cqe is per-packet so set it here */
271 mxbuf->cqe = cqe;
272 xsk_buff_set_size(xdp: &mxbuf->xdp, size: cqe_bcnt);
273 xsk_buff_dma_sync_for_cpu(xdp: &mxbuf->xdp, pool: rq->xsk_pool);
274 net_prefetch(p: mxbuf->xdp.data);
275
276 /* Possible flows:
277 * - XDP_REDIRECT to XSKMAP:
278 * The page is owned by the userspace from now.
279 * - XDP_TX and other XDP_REDIRECTs:
280 * The page was returned by ZCA and recycled.
281 * - XDP_DROP:
282 * Recycle the page.
283 * - XDP_PASS:
284 * Allocate an SKB, copy the data and recycle the page.
285 *
286 * Pages to be recycled go to the Reuse Ring on MPWQE deallocation. Its
287 * size is the same as the Driver RX Ring's size, and pages for WQEs are
288 * allocated first from the Reuse Ring, so it has enough space.
289 */
290
291 prog = rcu_dereference(rq->xdp_prog);
292 if (likely(prog && mlx5e_xdp_handle(rq, prog, mxbuf))) {
293 if (likely(__test_and_clear_bit(MLX5E_RQ_FLAG_XDP_XMIT, rq->flags)))
294 __set_bit(page_idx, wi->skip_release_bitmap); /* non-atomic */
295 return NULL; /* page/packet was consumed by XDP */
296 }
297
298 /* XDP_PASS: copy the data from the UMEM to a new SKB and reuse the
299 * frame. On SKB allocation failure, NULL is returned.
300 */
301 return mlx5e_xsk_construct_skb(rq, xdp: &mxbuf->xdp);
302}
303
304struct sk_buff *mlx5e_xsk_skb_from_cqe_linear(struct mlx5e_rq *rq,
305 struct mlx5e_wqe_frag_info *wi,
306 struct mlx5_cqe64 *cqe,
307 u32 cqe_bcnt)
308{
309 struct mlx5e_xdp_buff *mxbuf = xsk_buff_to_mxbuf(xdp: *wi->xskp);
310 struct bpf_prog *prog;
311
312 /* wi->offset is not used in this function, because xdp->data and the
313 * DMA address point directly to the necessary place. Furthermore, the
314 * XSK allocator allocates frames per packet, instead of pages, so
315 * wi->offset should always be 0.
316 */
317 WARN_ON_ONCE(wi->offset);
318
319 /* mxbuf->rq is set on allocation, but cqe is per-packet so set it here */
320 mxbuf->cqe = cqe;
321 xsk_buff_set_size(xdp: &mxbuf->xdp, size: cqe_bcnt);
322 xsk_buff_dma_sync_for_cpu(xdp: &mxbuf->xdp, pool: rq->xsk_pool);
323 net_prefetch(p: mxbuf->xdp.data);
324
325 prog = rcu_dereference(rq->xdp_prog);
326 if (likely(prog && mlx5e_xdp_handle(rq, prog, mxbuf))) {
327 if (likely(__test_and_clear_bit(MLX5E_RQ_FLAG_XDP_XMIT, rq->flags)))
328 wi->flags |= BIT(MLX5E_WQE_FRAG_SKIP_RELEASE);
329 return NULL; /* page/packet was consumed by XDP */
330 }
331
332 /* XDP_PASS: copy the data from the UMEM to a new SKB. The frame reuse
333 * will be handled by mlx5e_free_rx_wqe.
334 * On SKB allocation failure, NULL is returned.
335 */
336 return mlx5e_xsk_construct_skb(rq, xdp: &mxbuf->xdp);
337}
338

source code of linux/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.c