xref: /linux/drivers/net/ethernet/netronome/nfp/bpf/main.c (revision 55f3538c4923e9dfca132e99ebec370e8094afda)
1 /*
2  * Copyright (C) 2017 Netronome Systems, Inc.
3  *
4  * This software is dual licensed under the GNU General License Version 2,
5  * June 1991 as shown in the file COPYING in the top-level directory of this
6  * source tree or the BSD 2-Clause License provided below.  You have the
7  * option to license this software under the complete terms of either license.
8  *
9  * The BSD 2-Clause License:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      1. Redistributions of source code must retain the above
16  *         copyright notice, this list of conditions and the following
17  *         disclaimer.
18  *
19  *      2. Redistributions in binary form must reproduce the above
20  *         copyright notice, this list of conditions and the following
21  *         disclaimer in the documentation and/or other materials
22  *         provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 
34 #include <net/pkt_cls.h>
35 
36 #include "../nfpcore/nfp_cpp.h"
37 #include "../nfpcore/nfp_nffw.h"
38 #include "../nfp_app.h"
39 #include "../nfp_main.h"
40 #include "../nfp_net.h"
41 #include "../nfp_port.h"
42 #include "fw.h"
43 #include "main.h"
44 
45 static bool nfp_net_ebpf_capable(struct nfp_net *nn)
46 {
47 #ifdef __LITTLE_ENDIAN
48 	if (nn->cap & NFP_NET_CFG_CTRL_BPF &&
49 	    nn_readb(nn, NFP_NET_CFG_BPF_ABI) == NFP_NET_BPF_ABI)
50 		return true;
51 #endif
52 	return false;
53 }
54 
55 static int
56 nfp_bpf_xdp_offload(struct nfp_app *app, struct nfp_net *nn,
57 		    struct bpf_prog *prog, struct netlink_ext_ack *extack)
58 {
59 	bool running, xdp_running;
60 	int ret;
61 
62 	if (!nfp_net_ebpf_capable(nn))
63 		return -EINVAL;
64 
65 	running = nn->dp.ctrl & NFP_NET_CFG_CTRL_BPF;
66 	xdp_running = running && nn->dp.bpf_offload_xdp;
67 
68 	if (!prog && !xdp_running)
69 		return 0;
70 	if (prog && running && !xdp_running)
71 		return -EBUSY;
72 
73 	ret = nfp_net_bpf_offload(nn, prog, running, extack);
74 	/* Stop offload if replace not possible */
75 	if (ret && prog)
76 		nfp_bpf_xdp_offload(app, nn, NULL, extack);
77 
78 	nn->dp.bpf_offload_xdp = prog && !ret;
79 	return ret;
80 }
81 
82 static const char *nfp_bpf_extra_cap(struct nfp_app *app, struct nfp_net *nn)
83 {
84 	return nfp_net_ebpf_capable(nn) ? "BPF" : "";
85 }
86 
87 static int
88 nfp_bpf_vnic_alloc(struct nfp_app *app, struct nfp_net *nn, unsigned int id)
89 {
90 	struct nfp_bpf_vnic *bv;
91 	int err;
92 
93 	bv = kzalloc(sizeof(*bv), GFP_KERNEL);
94 	if (!bv)
95 		return -ENOMEM;
96 	nn->app_priv = bv;
97 
98 	err = nfp_app_nic_vnic_alloc(app, nn, id);
99 	if (err)
100 		goto err_free_priv;
101 
102 	bv->start_off = nn_readw(nn, NFP_NET_CFG_BPF_START);
103 	bv->tgt_done = nn_readw(nn, NFP_NET_CFG_BPF_DONE);
104 
105 	return 0;
106 err_free_priv:
107 	kfree(nn->app_priv);
108 	return err;
109 }
110 
111 static void nfp_bpf_vnic_free(struct nfp_app *app, struct nfp_net *nn)
112 {
113 	struct nfp_bpf_vnic *bv = nn->app_priv;
114 
115 	WARN_ON(bv->tc_prog);
116 	kfree(bv);
117 }
118 
119 static int nfp_bpf_setup_tc_block_cb(enum tc_setup_type type,
120 				     void *type_data, void *cb_priv)
121 {
122 	struct tc_cls_bpf_offload *cls_bpf = type_data;
123 	struct nfp_net *nn = cb_priv;
124 	struct bpf_prog *oldprog;
125 	struct nfp_bpf_vnic *bv;
126 	int err;
127 
128 	if (type != TC_SETUP_CLSBPF) {
129 		NL_SET_ERR_MSG_MOD(cls_bpf->common.extack,
130 				   "only offload of BPF classifiers supported");
131 		return -EOPNOTSUPP;
132 	}
133 	if (!tc_cls_can_offload_and_chain0(nn->dp.netdev, &cls_bpf->common))
134 		return -EOPNOTSUPP;
135 	if (!nfp_net_ebpf_capable(nn)) {
136 		NL_SET_ERR_MSG_MOD(cls_bpf->common.extack,
137 				   "NFP firmware does not support eBPF offload");
138 		return -EOPNOTSUPP;
139 	}
140 	if (cls_bpf->common.protocol != htons(ETH_P_ALL)) {
141 		NL_SET_ERR_MSG_MOD(cls_bpf->common.extack,
142 				   "only ETH_P_ALL supported as filter protocol");
143 		return -EOPNOTSUPP;
144 	}
145 
146 	/* Only support TC direct action */
147 	if (!cls_bpf->exts_integrated ||
148 	    tcf_exts_has_actions(cls_bpf->exts)) {
149 		NL_SET_ERR_MSG_MOD(cls_bpf->common.extack,
150 				   "only direct action with no legacy actions supported");
151 		return -EOPNOTSUPP;
152 	}
153 
154 	if (cls_bpf->command != TC_CLSBPF_OFFLOAD)
155 		return -EOPNOTSUPP;
156 
157 	bv = nn->app_priv;
158 	oldprog = cls_bpf->oldprog;
159 
160 	/* Don't remove if oldprog doesn't match driver's state */
161 	if (bv->tc_prog != oldprog) {
162 		oldprog = NULL;
163 		if (!cls_bpf->prog)
164 			return 0;
165 	}
166 
167 	err = nfp_net_bpf_offload(nn, cls_bpf->prog, oldprog,
168 				  cls_bpf->common.extack);
169 	if (err)
170 		return err;
171 
172 	bv->tc_prog = cls_bpf->prog;
173 	return 0;
174 }
175 
176 static int nfp_bpf_setup_tc_block(struct net_device *netdev,
177 				  struct tc_block_offload *f)
178 {
179 	struct nfp_net *nn = netdev_priv(netdev);
180 
181 	if (f->binder_type != TCF_BLOCK_BINDER_TYPE_CLSACT_INGRESS)
182 		return -EOPNOTSUPP;
183 
184 	switch (f->command) {
185 	case TC_BLOCK_BIND:
186 		return tcf_block_cb_register(f->block,
187 					     nfp_bpf_setup_tc_block_cb,
188 					     nn, nn);
189 	case TC_BLOCK_UNBIND:
190 		tcf_block_cb_unregister(f->block,
191 					nfp_bpf_setup_tc_block_cb,
192 					nn);
193 		return 0;
194 	default:
195 		return -EOPNOTSUPP;
196 	}
197 }
198 
199 static int nfp_bpf_setup_tc(struct nfp_app *app, struct net_device *netdev,
200 			    enum tc_setup_type type, void *type_data)
201 {
202 	switch (type) {
203 	case TC_SETUP_BLOCK:
204 		return nfp_bpf_setup_tc_block(netdev, type_data);
205 	default:
206 		return -EOPNOTSUPP;
207 	}
208 }
209 
210 static bool nfp_bpf_tc_busy(struct nfp_app *app, struct nfp_net *nn)
211 {
212 	struct nfp_bpf_vnic *bv = nn->app_priv;
213 
214 	return !!bv->tc_prog;
215 }
216 
217 static int
218 nfp_bpf_change_mtu(struct nfp_app *app, struct net_device *netdev, int new_mtu)
219 {
220 	struct nfp_net *nn = netdev_priv(netdev);
221 	unsigned int max_mtu;
222 
223 	if (~nn->dp.ctrl & NFP_NET_CFG_CTRL_BPF)
224 		return 0;
225 
226 	max_mtu = nn_readb(nn, NFP_NET_CFG_BPF_INL_MTU) * 64 - 32;
227 	if (new_mtu > max_mtu) {
228 		nn_info(nn, "BPF offload active, MTU over %u not supported\n",
229 			max_mtu);
230 		return -EBUSY;
231 	}
232 	return 0;
233 }
234 
235 static int
236 nfp_bpf_parse_cap_adjust_head(struct nfp_app_bpf *bpf, void __iomem *value,
237 			      u32 length)
238 {
239 	struct nfp_bpf_cap_tlv_adjust_head __iomem *cap = value;
240 	struct nfp_cpp *cpp = bpf->app->pf->cpp;
241 
242 	if (length < sizeof(*cap)) {
243 		nfp_err(cpp, "truncated adjust_head TLV: %d\n", length);
244 		return -EINVAL;
245 	}
246 
247 	bpf->adjust_head.flags = readl(&cap->flags);
248 	bpf->adjust_head.off_min = readl(&cap->off_min);
249 	bpf->adjust_head.off_max = readl(&cap->off_max);
250 	bpf->adjust_head.guaranteed_sub = readl(&cap->guaranteed_sub);
251 	bpf->adjust_head.guaranteed_add = readl(&cap->guaranteed_add);
252 
253 	if (bpf->adjust_head.off_min > bpf->adjust_head.off_max) {
254 		nfp_err(cpp, "invalid adjust_head TLV: min > max\n");
255 		return -EINVAL;
256 	}
257 	if (!FIELD_FIT(UR_REG_IMM_MAX, bpf->adjust_head.off_min) ||
258 	    !FIELD_FIT(UR_REG_IMM_MAX, bpf->adjust_head.off_max)) {
259 		nfp_warn(cpp, "disabling adjust_head - driver expects min/max to fit in as immediates\n");
260 		memset(&bpf->adjust_head, 0, sizeof(bpf->adjust_head));
261 		return 0;
262 	}
263 
264 	return 0;
265 }
266 
267 static int
268 nfp_bpf_parse_cap_func(struct nfp_app_bpf *bpf, void __iomem *value, u32 length)
269 {
270 	struct nfp_bpf_cap_tlv_func __iomem *cap = value;
271 
272 	if (length < sizeof(*cap)) {
273 		nfp_err(bpf->app->cpp, "truncated function TLV: %d\n", length);
274 		return -EINVAL;
275 	}
276 
277 	switch (readl(&cap->func_id)) {
278 	case BPF_FUNC_map_lookup_elem:
279 		bpf->helpers.map_lookup = readl(&cap->func_addr);
280 		break;
281 	}
282 
283 	return 0;
284 }
285 
286 static int
287 nfp_bpf_parse_cap_maps(struct nfp_app_bpf *bpf, void __iomem *value, u32 length)
288 {
289 	struct nfp_bpf_cap_tlv_maps __iomem *cap = value;
290 
291 	if (length < sizeof(*cap)) {
292 		nfp_err(bpf->app->cpp, "truncated maps TLV: %d\n", length);
293 		return -EINVAL;
294 	}
295 
296 	bpf->maps.types = readl(&cap->types);
297 	bpf->maps.max_maps = readl(&cap->max_maps);
298 	bpf->maps.max_elems = readl(&cap->max_elems);
299 	bpf->maps.max_key_sz = readl(&cap->max_key_sz);
300 	bpf->maps.max_val_sz = readl(&cap->max_val_sz);
301 	bpf->maps.max_elem_sz = readl(&cap->max_elem_sz);
302 
303 	return 0;
304 }
305 
306 static int nfp_bpf_parse_capabilities(struct nfp_app *app)
307 {
308 	struct nfp_cpp *cpp = app->pf->cpp;
309 	struct nfp_cpp_area *area;
310 	u8 __iomem *mem, *start;
311 
312 	mem = nfp_rtsym_map(app->pf->rtbl, "_abi_bpf_capabilities", "bpf.cap",
313 			    8, &area);
314 	if (IS_ERR(mem))
315 		return PTR_ERR(mem) == -ENOENT ? 0 : PTR_ERR(mem);
316 
317 	start = mem;
318 	while (mem - start + 8 < nfp_cpp_area_size(area)) {
319 		u8 __iomem *value;
320 		u32 type, length;
321 
322 		type = readl(mem);
323 		length = readl(mem + 4);
324 		value = mem + 8;
325 
326 		mem += 8 + length;
327 		if (mem - start > nfp_cpp_area_size(area))
328 			goto err_release_free;
329 
330 		switch (type) {
331 		case NFP_BPF_CAP_TYPE_FUNC:
332 			if (nfp_bpf_parse_cap_func(app->priv, value, length))
333 				goto err_release_free;
334 			break;
335 		case NFP_BPF_CAP_TYPE_ADJUST_HEAD:
336 			if (nfp_bpf_parse_cap_adjust_head(app->priv, value,
337 							  length))
338 				goto err_release_free;
339 			break;
340 		case NFP_BPF_CAP_TYPE_MAPS:
341 			if (nfp_bpf_parse_cap_maps(app->priv, value, length))
342 				goto err_release_free;
343 			break;
344 		default:
345 			nfp_dbg(cpp, "unknown BPF capability: %d\n", type);
346 			break;
347 		}
348 	}
349 	if (mem - start != nfp_cpp_area_size(area)) {
350 		nfp_err(cpp, "BPF capabilities left after parsing, parsed:%zd total length:%zu\n",
351 			mem - start, nfp_cpp_area_size(area));
352 		goto err_release_free;
353 	}
354 
355 	nfp_cpp_area_release_free(area);
356 
357 	return 0;
358 
359 err_release_free:
360 	nfp_err(cpp, "invalid BPF capabilities at offset:%zd\n", mem - start);
361 	nfp_cpp_area_release_free(area);
362 	return -EINVAL;
363 }
364 
365 static int nfp_bpf_init(struct nfp_app *app)
366 {
367 	struct nfp_app_bpf *bpf;
368 	int err;
369 
370 	bpf = kzalloc(sizeof(*bpf), GFP_KERNEL);
371 	if (!bpf)
372 		return -ENOMEM;
373 	bpf->app = app;
374 	app->priv = bpf;
375 
376 	skb_queue_head_init(&bpf->cmsg_replies);
377 	init_waitqueue_head(&bpf->cmsg_wq);
378 	INIT_LIST_HEAD(&bpf->map_list);
379 
380 	err = nfp_bpf_parse_capabilities(app);
381 	if (err)
382 		goto err_free_bpf;
383 
384 	return 0;
385 
386 err_free_bpf:
387 	kfree(bpf);
388 	return err;
389 }
390 
391 static void nfp_bpf_clean(struct nfp_app *app)
392 {
393 	struct nfp_app_bpf *bpf = app->priv;
394 
395 	WARN_ON(!skb_queue_empty(&bpf->cmsg_replies));
396 	WARN_ON(!list_empty(&bpf->map_list));
397 	WARN_ON(bpf->maps_in_use || bpf->map_elems_in_use);
398 	kfree(bpf);
399 }
400 
401 const struct nfp_app_type app_bpf = {
402 	.id		= NFP_APP_BPF_NIC,
403 	.name		= "ebpf",
404 
405 	.ctrl_cap_mask	= 0,
406 
407 	.init		= nfp_bpf_init,
408 	.clean		= nfp_bpf_clean,
409 
410 	.change_mtu	= nfp_bpf_change_mtu,
411 
412 	.extra_cap	= nfp_bpf_extra_cap,
413 
414 	.vnic_alloc	= nfp_bpf_vnic_alloc,
415 	.vnic_free	= nfp_bpf_vnic_free,
416 
417 	.ctrl_msg_rx	= nfp_bpf_ctrl_msg_rx,
418 
419 	.setup_tc	= nfp_bpf_setup_tc,
420 	.tc_busy	= nfp_bpf_tc_busy,
421 	.bpf		= nfp_ndo_bpf,
422 	.xdp_offload	= nfp_bpf_xdp_offload,
423 };
424