xref: /openbmc/linux/drivers/net/ethernet/netronome/nfp/bpf/offload.c (revision 9dae47aba0a055f761176d9297371d5bb24289ec)
1 /*
2  * Copyright (C) 2016-2017 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 /*
35  * nfp_net_offload.c
36  * Netronome network device driver: TC offload functions for PF and VF
37  */
38 
39 #include <linux/kernel.h>
40 #include <linux/netdevice.h>
41 #include <linux/pci.h>
42 #include <linux/jiffies.h>
43 #include <linux/timer.h>
44 #include <linux/list.h>
45 
46 #include <net/pkt_cls.h>
47 #include <net/tc_act/tc_gact.h>
48 #include <net/tc_act/tc_mirred.h>
49 
50 #include "main.h"
51 #include "../nfp_app.h"
52 #include "../nfp_net_ctrl.h"
53 #include "../nfp_net.h"
54 
55 static int
56 nfp_prog_prepare(struct nfp_prog *nfp_prog, const struct bpf_insn *prog,
57 		 unsigned int cnt)
58 {
59 	struct nfp_insn_meta *meta;
60 	unsigned int i;
61 
62 	for (i = 0; i < cnt; i++) {
63 		meta = kzalloc(sizeof(*meta), GFP_KERNEL);
64 		if (!meta)
65 			return -ENOMEM;
66 
67 		meta->insn = prog[i];
68 		meta->n = i;
69 
70 		list_add_tail(&meta->l, &nfp_prog->insns);
71 	}
72 
73 	/* Another pass to record jump information. */
74 	list_for_each_entry(meta, &nfp_prog->insns, l) {
75 		u64 code = meta->insn.code;
76 
77 		if (BPF_CLASS(code) == BPF_JMP && BPF_OP(code) != BPF_EXIT &&
78 		    BPF_OP(code) != BPF_CALL) {
79 			struct nfp_insn_meta *dst_meta;
80 			unsigned short dst_indx;
81 
82 			dst_indx = meta->n + 1 + meta->insn.off;
83 			dst_meta = nfp_bpf_goto_meta(nfp_prog, meta, dst_indx,
84 						     cnt);
85 
86 			meta->jmp_dst = dst_meta;
87 			dst_meta->flags |= FLAG_INSN_IS_JUMP_DST;
88 		}
89 	}
90 
91 	return 0;
92 }
93 
94 static void nfp_prog_free(struct nfp_prog *nfp_prog)
95 {
96 	struct nfp_insn_meta *meta, *tmp;
97 
98 	list_for_each_entry_safe(meta, tmp, &nfp_prog->insns, l) {
99 		list_del(&meta->l);
100 		kfree(meta);
101 	}
102 	kfree(nfp_prog);
103 }
104 
105 int nfp_bpf_verifier_prep(struct nfp_app *app, struct nfp_net *nn,
106 			  struct netdev_bpf *bpf)
107 {
108 	struct bpf_prog *prog = bpf->verifier.prog;
109 	struct nfp_prog *nfp_prog;
110 	int ret;
111 
112 	nfp_prog = kzalloc(sizeof(*nfp_prog), GFP_KERNEL);
113 	if (!nfp_prog)
114 		return -ENOMEM;
115 	prog->aux->offload->dev_priv = nfp_prog;
116 
117 	INIT_LIST_HEAD(&nfp_prog->insns);
118 	nfp_prog->type = prog->type;
119 	nfp_prog->bpf = app->priv;
120 
121 	ret = nfp_prog_prepare(nfp_prog, prog->insnsi, prog->len);
122 	if (ret)
123 		goto err_free;
124 
125 	nfp_prog->verifier_meta = nfp_prog_first_meta(nfp_prog);
126 	bpf->verifier.ops = &nfp_bpf_analyzer_ops;
127 
128 	return 0;
129 
130 err_free:
131 	nfp_prog_free(nfp_prog);
132 
133 	return ret;
134 }
135 
136 int nfp_bpf_translate(struct nfp_app *app, struct nfp_net *nn,
137 		      struct bpf_prog *prog)
138 {
139 	struct nfp_prog *nfp_prog = prog->aux->offload->dev_priv;
140 	unsigned int stack_size;
141 	unsigned int max_instr;
142 
143 	stack_size = nn_readb(nn, NFP_NET_CFG_BPF_STACK_SZ) * 64;
144 	if (prog->aux->stack_depth > stack_size) {
145 		nn_info(nn, "stack too large: program %dB > FW stack %dB\n",
146 			prog->aux->stack_depth, stack_size);
147 		return -EOPNOTSUPP;
148 	}
149 
150 	nfp_prog->stack_depth = prog->aux->stack_depth;
151 	nfp_prog->start_off = nn_readw(nn, NFP_NET_CFG_BPF_START);
152 	nfp_prog->tgt_done = nn_readw(nn, NFP_NET_CFG_BPF_DONE);
153 
154 	max_instr = nn_readw(nn, NFP_NET_CFG_BPF_MAX_LEN);
155 	nfp_prog->__prog_alloc_len = max_instr * sizeof(u64);
156 
157 	nfp_prog->prog = kmalloc(nfp_prog->__prog_alloc_len, GFP_KERNEL);
158 	if (!nfp_prog->prog)
159 		return -ENOMEM;
160 
161 	return nfp_bpf_jit(nfp_prog);
162 }
163 
164 int nfp_bpf_destroy(struct nfp_app *app, struct nfp_net *nn,
165 		    struct bpf_prog *prog)
166 {
167 	struct nfp_prog *nfp_prog = prog->aux->offload->dev_priv;
168 
169 	kfree(nfp_prog->prog);
170 	nfp_prog_free(nfp_prog);
171 
172 	return 0;
173 }
174 
175 static int nfp_net_bpf_load(struct nfp_net *nn, struct bpf_prog *prog)
176 {
177 	struct nfp_prog *nfp_prog = prog->aux->offload->dev_priv;
178 	unsigned int max_mtu;
179 	dma_addr_t dma_addr;
180 	int err;
181 
182 	max_mtu = nn_readb(nn, NFP_NET_CFG_BPF_INL_MTU) * 64 - 32;
183 	if (max_mtu < nn->dp.netdev->mtu) {
184 		nn_info(nn, "BPF offload not supported with MTU larger than HW packet split boundary\n");
185 		return -EOPNOTSUPP;
186 	}
187 
188 	dma_addr = dma_map_single(nn->dp.dev, nfp_prog->prog,
189 				  nfp_prog->prog_len * sizeof(u64),
190 				  DMA_TO_DEVICE);
191 	if (dma_mapping_error(nn->dp.dev, dma_addr))
192 		return -ENOMEM;
193 
194 	nn_writew(nn, NFP_NET_CFG_BPF_SIZE, nfp_prog->prog_len);
195 	nn_writeq(nn, NFP_NET_CFG_BPF_ADDR, dma_addr);
196 
197 	/* Load up the JITed code */
198 	err = nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_BPF);
199 	if (err)
200 		nn_err(nn, "FW command error while loading BPF: %d\n", err);
201 
202 	dma_unmap_single(nn->dp.dev, dma_addr, nfp_prog->prog_len * sizeof(u64),
203 			 DMA_TO_DEVICE);
204 
205 	return err;
206 }
207 
208 static void nfp_net_bpf_start(struct nfp_net *nn)
209 {
210 	int err;
211 
212 	/* Enable passing packets through BPF function */
213 	nn->dp.ctrl |= NFP_NET_CFG_CTRL_BPF;
214 	nn_writel(nn, NFP_NET_CFG_CTRL, nn->dp.ctrl);
215 	err = nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_GEN);
216 	if (err)
217 		nn_err(nn, "FW command error while enabling BPF: %d\n", err);
218 }
219 
220 static int nfp_net_bpf_stop(struct nfp_net *nn)
221 {
222 	if (!(nn->dp.ctrl & NFP_NET_CFG_CTRL_BPF))
223 		return 0;
224 
225 	nn->dp.ctrl &= ~NFP_NET_CFG_CTRL_BPF;
226 	nn_writel(nn, NFP_NET_CFG_CTRL, nn->dp.ctrl);
227 
228 	return nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_GEN);
229 }
230 
231 int nfp_net_bpf_offload(struct nfp_net *nn, struct bpf_prog *prog,
232 			bool old_prog)
233 {
234 	int err;
235 
236 	if (prog) {
237 		struct bpf_dev_offload *offload = prog->aux->offload;
238 
239 		if (!offload)
240 			return -EINVAL;
241 		if (offload->netdev != nn->dp.netdev)
242 			return -EINVAL;
243 	}
244 
245 	if (prog && old_prog) {
246 		u8 cap;
247 
248 		cap = nn_readb(nn, NFP_NET_CFG_BPF_CAP);
249 		if (!(cap & NFP_NET_BPF_CAP_RELO)) {
250 			nn_err(nn, "FW does not support live reload\n");
251 			return -EBUSY;
252 		}
253 	}
254 
255 	/* Something else is loaded, different program type? */
256 	if (!old_prog && nn->dp.ctrl & NFP_NET_CFG_CTRL_BPF)
257 		return -EBUSY;
258 
259 	if (old_prog && !prog)
260 		return nfp_net_bpf_stop(nn);
261 
262 	err = nfp_net_bpf_load(nn, prog);
263 	if (err)
264 		return err;
265 
266 	if (!old_prog)
267 		nfp_net_bpf_start(nn);
268 
269 	return 0;
270 }
271