xref: /openbmc/linux/samples/bpf/ibumad_kern.c (revision b737eecd)
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/bpf_helpers.h>
17 
18 
19 struct {
20 	__uint(type, BPF_MAP_TYPE_ARRAY);
21 	__type(key, u32); /* class; u32 required */
22 	__type(value, u64); /* count of mads read */
23 	__uint(max_entries, 256); /* Room for all Classes */
24 } read_count SEC(".maps");
25 
26 struct {
27 	__uint(type, BPF_MAP_TYPE_ARRAY);
28 	__type(key, u32); /* class; u32 required */
29 	__type(value, u64); /* count of mads written */
30 	__uint(max_entries, 256); /* Room for all Classes */
31 } write_count SEC(".maps");
32 
33 #undef DEBUG
34 #ifndef DEBUG
35 #undef bpf_printk
36 #define bpf_printk(fmt, ...)
37 #endif
38 
39 /* Taken from the current format defined in
40  * include/trace/events/ib_umad.h
41  * and
42  * /sys/kernel/debug/tracing/events/ib_umad/ib_umad_read/format
43  * /sys/kernel/debug/tracing/events/ib_umad/ib_umad_write/format
44  */
45 struct ib_umad_rw_args {
46 	u64 pad;
47 	u8 port_num;
48 	u8 sl;
49 	u8 path_bits;
50 	u8 grh_present;
51 	u32 id;
52 	u32 status;
53 	u32 timeout_ms;
54 	u32 retires;
55 	u32 length;
56 	u32 qpn;
57 	u32 qkey;
58 	u8 gid_index;
59 	u8 hop_limit;
60 	u16 lid;
61 	u16 attr_id;
62 	u16 pkey_index;
63 	u8 base_version;
64 	u8 mgmt_class;
65 	u8 class_version;
66 	u8 method;
67 	u32 flow_label;
68 	u16 mad_status;
69 	u16 class_specific;
70 	u32 attr_mod;
71 	u64 tid;
72 	u8 gid[16];
73 	u32 dev_index;
74 	u8 traffic_class;
75 };
76 
77 SEC("tracepoint/ib_umad/ib_umad_read_recv")
78 int on_ib_umad_read_recv(struct ib_umad_rw_args *ctx)
79 {
80 	u64 zero = 0, *val;
81 	u8 class = ctx->mgmt_class;
82 
83 	bpf_printk("ib_umad read recv : class 0x%x\n", class);
84 
85 	val = bpf_map_lookup_elem(&read_count, &class);
86 	if (!val) {
87 		bpf_map_update_elem(&read_count, &class, &zero, BPF_NOEXIST);
88 		val = bpf_map_lookup_elem(&read_count, &class);
89 		if (!val)
90 			return 0;
91 	}
92 
93 	(*val) += 1;
94 
95 	return 0;
96 }
97 SEC("tracepoint/ib_umad/ib_umad_read_send")
98 int on_ib_umad_read_send(struct ib_umad_rw_args *ctx)
99 {
100 	u64 zero = 0, *val;
101 	u8 class = ctx->mgmt_class;
102 
103 	bpf_printk("ib_umad read send : class 0x%x\n", class);
104 
105 	val = bpf_map_lookup_elem(&read_count, &class);
106 	if (!val) {
107 		bpf_map_update_elem(&read_count, &class, &zero, BPF_NOEXIST);
108 		val = bpf_map_lookup_elem(&read_count, &class);
109 		if (!val)
110 			return 0;
111 	}
112 
113 	(*val) += 1;
114 
115 	return 0;
116 }
117 SEC("tracepoint/ib_umad/ib_umad_write")
118 int on_ib_umad_write(struct ib_umad_rw_args *ctx)
119 {
120 	u64 zero = 0, *val;
121 	u8 class = ctx->mgmt_class;
122 
123 	bpf_printk("ib_umad write : class 0x%x\n", class);
124 
125 	val = bpf_map_lookup_elem(&write_count, &class);
126 	if (!val) {
127 		bpf_map_update_elem(&write_count, &class, &zero, BPF_NOEXIST);
128 		val = bpf_map_lookup_elem(&write_count, &class);
129 		if (!val)
130 			return 0;
131 	}
132 
133 	(*val) += 1;
134 
135 	return 0;
136 }
137 
138 char _license[] SEC("license") = "GPL";
139