xref: /openbmc/linux/samples/bpf/ibumad_kern.c (revision 151f4e2b)
1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
2 
3 /**
4  * ibumad BPF sample kernel side
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of version 2 of the GNU General Public
8  * License as published by the Free Software Foundation.
9  *
10  * Copyright(c) 2018 Ira Weiny, Intel Corporation
11  */
12 
13 #define KBUILD_MODNAME "ibumad_count_pkts_by_class"
14 #include <uapi/linux/bpf.h>
15 
16 #include "bpf_helpers.h"
17 
18 
19 struct bpf_map_def SEC("maps") read_count = {
20 	.type        = BPF_MAP_TYPE_ARRAY,
21 	.key_size    = sizeof(u32), /* class; u32 required */
22 	.value_size  = sizeof(u64), /* count of mads read */
23 	.max_entries = 256, /* Room for all Classes */
24 };
25 
26 struct bpf_map_def SEC("maps") write_count = {
27 	.type        = BPF_MAP_TYPE_ARRAY,
28 	.key_size    = sizeof(u32), /* class; u32 required */
29 	.value_size  = sizeof(u64), /* count of mads written */
30 	.max_entries = 256, /* Room for all Classes */
31 };
32 
33 #undef DEBUG
34 #ifdef DEBUG
35 #define bpf_debug(fmt, ...)                         \
36 ({                                                  \
37 	char ____fmt[] = fmt;                       \
38 	bpf_trace_printk(____fmt, sizeof(____fmt),  \
39 			 ##__VA_ARGS__);            \
40 })
41 #else
42 #define bpf_debug(fmt, ...)
43 #endif
44 
45 /* Taken from the current format defined in
46  * include/trace/events/ib_umad.h
47  * and
48  * /sys/kernel/debug/tracing/events/ib_umad/ib_umad_read/format
49  * /sys/kernel/debug/tracing/events/ib_umad/ib_umad_write/format
50  */
51 struct ib_umad_rw_args {
52 	u64 pad;
53 	u8 port_num;
54 	u8 sl;
55 	u8 path_bits;
56 	u8 grh_present;
57 	u32 id;
58 	u32 status;
59 	u32 timeout_ms;
60 	u32 retires;
61 	u32 length;
62 	u32 qpn;
63 	u32 qkey;
64 	u8 gid_index;
65 	u8 hop_limit;
66 	u16 lid;
67 	u16 attr_id;
68 	u16 pkey_index;
69 	u8 base_version;
70 	u8 mgmt_class;
71 	u8 class_version;
72 	u8 method;
73 	u32 flow_label;
74 	u16 mad_status;
75 	u16 class_specific;
76 	u32 attr_mod;
77 	u64 tid;
78 	u8 gid[16];
79 	u32 dev_index;
80 	u8 traffic_class;
81 };
82 
83 SEC("tracepoint/ib_umad/ib_umad_read_recv")
84 int on_ib_umad_read_recv(struct ib_umad_rw_args *ctx)
85 {
86 	u64 zero = 0, *val;
87 	u8 class = ctx->mgmt_class;
88 
89 	bpf_debug("ib_umad read recv : class 0x%x\n", class);
90 
91 	val = bpf_map_lookup_elem(&read_count, &class);
92 	if (!val) {
93 		bpf_map_update_elem(&read_count, &class, &zero, BPF_NOEXIST);
94 		val = bpf_map_lookup_elem(&read_count, &class);
95 		if (!val)
96 			return 0;
97 	}
98 
99 	(*val) += 1;
100 
101 	return 0;
102 }
103 SEC("tracepoint/ib_umad/ib_umad_read_send")
104 int on_ib_umad_read_send(struct ib_umad_rw_args *ctx)
105 {
106 	u64 zero = 0, *val;
107 	u8 class = ctx->mgmt_class;
108 
109 	bpf_debug("ib_umad read send : class 0x%x\n", class);
110 
111 	val = bpf_map_lookup_elem(&read_count, &class);
112 	if (!val) {
113 		bpf_map_update_elem(&read_count, &class, &zero, BPF_NOEXIST);
114 		val = bpf_map_lookup_elem(&read_count, &class);
115 		if (!val)
116 			return 0;
117 	}
118 
119 	(*val) += 1;
120 
121 	return 0;
122 }
123 SEC("tracepoint/ib_umad/ib_umad_write")
124 int on_ib_umad_write(struct ib_umad_rw_args *ctx)
125 {
126 	u64 zero = 0, *val;
127 	u8 class = ctx->mgmt_class;
128 
129 	bpf_debug("ib_umad write : class 0x%x\n", class);
130 
131 	val = bpf_map_lookup_elem(&write_count, &class);
132 	if (!val) {
133 		bpf_map_update_elem(&write_count, &class, &zero, BPF_NOEXIST);
134 		val = bpf_map_lookup_elem(&write_count, &class);
135 		if (!val)
136 			return 0;
137 	}
138 
139 	(*val) += 1;
140 
141 	return 0;
142 }
143 
144 char _license[] SEC("license") = "GPL";
145