1 /*
2  * Copyright (C) 2016 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 #ifndef __NFP_BPF_H__
35 #define __NFP_BPF_H__ 1
36 
37 #include <linux/bitfield.h>
38 #include <linux/bpf.h>
39 #include <linux/list.h>
40 #include <linux/types.h>
41 
42 #include "../nfp_net.h"
43 
44 /* For branch fixup logic use up-most byte of branch instruction as scratch
45  * area.  Remember to clear this before sending instructions to HW!
46  */
47 #define OP_BR_SPECIAL	0xff00000000000000ULL
48 
49 enum br_special {
50 	OP_BR_NORMAL = 0,
51 	OP_BR_GO_OUT,
52 	OP_BR_GO_ABORT,
53 };
54 
55 enum static_regs {
56 	STATIC_REG_PKT		= 1,
57 #define REG_PKT_BANK	ALU_DST_A
58 	STATIC_REG_IMM		= 2, /* Bank AB */
59 };
60 
61 enum nfp_bpf_action_type {
62 	NN_ACT_TC_DROP,
63 	NN_ACT_TC_REDIR,
64 	NN_ACT_DIRECT,
65 	NN_ACT_XDP,
66 };
67 
68 /* Software register representation, hardware encoding in asm.h */
69 #define NN_REG_TYPE	GENMASK(31, 24)
70 #define NN_REG_VAL	GENMASK(7, 0)
71 
72 enum nfp_bpf_reg_type {
73 	NN_REG_GPR_A =	BIT(0),
74 	NN_REG_GPR_B =	BIT(1),
75 	NN_REG_NNR =	BIT(2),
76 	NN_REG_XFER =	BIT(3),
77 	NN_REG_IMM =	BIT(4),
78 	NN_REG_NONE =	BIT(5),
79 };
80 
81 #define NN_REG_GPR_BOTH	(NN_REG_GPR_A | NN_REG_GPR_B)
82 
83 #define reg_both(x)	((x) | FIELD_PREP(NN_REG_TYPE, NN_REG_GPR_BOTH))
84 #define reg_a(x)	((x) | FIELD_PREP(NN_REG_TYPE, NN_REG_GPR_A))
85 #define reg_b(x)	((x) | FIELD_PREP(NN_REG_TYPE, NN_REG_GPR_B))
86 #define reg_nnr(x)	((x) | FIELD_PREP(NN_REG_TYPE, NN_REG_NNR))
87 #define reg_xfer(x)	((x) | FIELD_PREP(NN_REG_TYPE, NN_REG_XFER))
88 #define reg_imm(x)	((x) | FIELD_PREP(NN_REG_TYPE, NN_REG_IMM))
89 #define reg_none()	(FIELD_PREP(NN_REG_TYPE, NN_REG_NONE))
90 
91 #define pkt_reg(np)	reg_a((np)->regs_per_thread - STATIC_REG_PKT)
92 #define imm_a(np)	reg_a((np)->regs_per_thread - STATIC_REG_IMM)
93 #define imm_b(np)	reg_b((np)->regs_per_thread - STATIC_REG_IMM)
94 #define imm_both(np)	reg_both((np)->regs_per_thread - STATIC_REG_IMM)
95 
96 #define NFP_BPF_ABI_FLAGS	reg_nnr(0)
97 #define   NFP_BPF_ABI_FLAG_MARK	1
98 #define NFP_BPF_ABI_MARK	reg_nnr(1)
99 #define NFP_BPF_ABI_PKT		reg_nnr(2)
100 #define NFP_BPF_ABI_LEN		reg_nnr(3)
101 
102 struct nfp_prog;
103 struct nfp_insn_meta;
104 typedef int (*instr_cb_t)(struct nfp_prog *, struct nfp_insn_meta *);
105 
106 #define nfp_prog_first_meta(nfp_prog)					\
107 	list_first_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
108 #define nfp_prog_last_meta(nfp_prog)					\
109 	list_last_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
110 #define nfp_meta_next(meta)	list_next_entry(meta, l)
111 #define nfp_meta_prev(meta)	list_prev_entry(meta, l)
112 
113 /**
114  * struct nfp_insn_meta - BPF instruction wrapper
115  * @insn: BPF instruction
116  * @off: index of first generated machine instruction (in nfp_prog.prog)
117  * @n: eBPF instruction number
118  * @skip: skip this instruction (optimized out)
119  * @double_cb: callback for second part of the instruction
120  * @l: link on nfp_prog->insns list
121  */
122 struct nfp_insn_meta {
123 	struct bpf_insn insn;
124 	unsigned int off;
125 	unsigned short n;
126 	bool skip;
127 	instr_cb_t double_cb;
128 
129 	struct list_head l;
130 };
131 
132 #define BPF_SIZE_MASK	0x18
133 
134 static inline u8 mbpf_class(const struct nfp_insn_meta *meta)
135 {
136 	return BPF_CLASS(meta->insn.code);
137 }
138 
139 static inline u8 mbpf_src(const struct nfp_insn_meta *meta)
140 {
141 	return BPF_SRC(meta->insn.code);
142 }
143 
144 static inline u8 mbpf_op(const struct nfp_insn_meta *meta)
145 {
146 	return BPF_OP(meta->insn.code);
147 }
148 
149 static inline u8 mbpf_mode(const struct nfp_insn_meta *meta)
150 {
151 	return BPF_MODE(meta->insn.code);
152 }
153 
154 /**
155  * struct nfp_prog - nfp BPF program
156  * @prog: machine code
157  * @prog_len: number of valid instructions in @prog array
158  * @__prog_alloc_len: alloc size of @prog array
159  * @act: BPF program/action type (TC DA, TC with action, XDP etc.)
160  * @num_regs: number of registers used by this program
161  * @regs_per_thread: number of basic registers allocated per thread
162  * @start_off: address of the first instruction in the memory
163  * @tgt_out: jump target for normal exit
164  * @tgt_abort: jump target for abort (e.g. access outside of packet buffer)
165  * @tgt_done: jump target to get the next packet
166  * @n_translated: number of successfully translated instructions (for errors)
167  * @error: error code if something went wrong
168  * @insns: list of BPF instruction wrappers (struct nfp_insn_meta)
169  */
170 struct nfp_prog {
171 	u64 *prog;
172 	unsigned int prog_len;
173 	unsigned int __prog_alloc_len;
174 
175 	enum nfp_bpf_action_type act;
176 
177 	unsigned int num_regs;
178 	unsigned int regs_per_thread;
179 
180 	unsigned int start_off;
181 	unsigned int tgt_out;
182 	unsigned int tgt_abort;
183 	unsigned int tgt_done;
184 
185 	unsigned int n_translated;
186 	int error;
187 
188 	struct list_head insns;
189 };
190 
191 struct nfp_bpf_result {
192 	unsigned int n_instr;
193 	bool dense_mode;
194 };
195 
196 int
197 nfp_bpf_jit(struct bpf_prog *filter, void *prog, enum nfp_bpf_action_type act,
198 	    unsigned int prog_start, unsigned int prog_done,
199 	    unsigned int prog_sz, struct nfp_bpf_result *res);
200 
201 int nfp_prog_verify(struct nfp_prog *nfp_prog, struct bpf_prog *prog);
202 
203 struct nfp_net;
204 struct tc_cls_bpf_offload;
205 
206 /**
207  * struct nfp_net_bpf_priv - per-vNIC BPF private data
208  * @rx_filter:		Filter offload statistics - dropped packets/bytes
209  * @rx_filter_prev:	Filter offload statistics - values from previous update
210  * @rx_filter_change:	Jiffies when statistics last changed
211  * @rx_filter_stats_timer:  Timer for polling filter offload statistics
212  * @rx_filter_lock:	Lock protecting timer state changes (teardown)
213  */
214 struct nfp_net_bpf_priv {
215 	struct nfp_stat_pair rx_filter, rx_filter_prev;
216 	unsigned long rx_filter_change;
217 	struct timer_list rx_filter_stats_timer;
218 	spinlock_t rx_filter_lock;
219 };
220 
221 int nfp_net_bpf_offload(struct nfp_net *nn, struct tc_cls_bpf_offload *cls_bpf);
222 void nfp_net_filter_stats_timer(unsigned long data);
223 
224 #endif
225