samples/bpf/ibumad_kern.c

0001 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
0002
0003 /*
0004  * ibumad BPF sample kernel side
0005  *
0006  * This program is free software; you can redistribute it and/or
0007  * modify it under the terms of version 2 of the GNU General Public
0008  * License as published by the Free Software Foundation.
0009  *
0010  * Copyright(c) 2018 Ira Weiny, Intel Corporation
0011  */
0012
0013 #define KBUILD_MODNAME "ibumad_count_pkts_by_class"
0014 #include <uapi/linux/bpf.h>
0015
0016 #include <bpf/bpf_helpers.h>
0017
0018
0019 struct {
0020     __uint(type, BPF_MAP_TYPE_ARRAY);
0021     __type(key, u32); /* class; u32 required */
0022     __type(value, u64); /* count of mads read */
0023     __uint(max_entries, 256); /* Room for all Classes */
0024 } read_count SEC(".maps");
0025
0026 struct {
0027     __uint(type, BPF_MAP_TYPE_ARRAY);
0028     __type(key, u32); /* class; u32 required */
0029     __type(value, u64); /* count of mads written */
0030     __uint(max_entries, 256); /* Room for all Classes */
0031 } write_count SEC(".maps");
0032
0033 #undef DEBUG
0034 #ifndef DEBUG
0035 #undef bpf_printk
0036 #define bpf_printk(fmt, ...)
0037 #endif
0038
0039 /* Taken from the current format defined in
0040  * include/trace/events/ib_umad.h
0041  * and
0042  * /sys/kernel/debug/tracing/events/ib_umad/ib_umad_read/format
0043  * /sys/kernel/debug/tracing/events/ib_umad/ib_umad_write/format
0044  */
0045 struct ib_umad_rw_args {
0046     u64 pad;
0047     u8 port_num;
0048     u8 sl;
0049     u8 path_bits;
0050     u8 grh_present;
0051     u32 id;
0052     u32 status;
0053     u32 timeout_ms;
0054     u32 retires;
0055     u32 length;
0056     u32 qpn;
0057     u32 qkey;
0058     u8 gid_index;
0059     u8 hop_limit;
0060     u16 lid;
0061     u16 attr_id;
0062     u16 pkey_index;
0063     u8 base_version;
0064     u8 mgmt_class;
0065     u8 class_version;
0066     u8 method;
0067     u32 flow_label;
0068     u16 mad_status;
0069     u16 class_specific;
0070     u32 attr_mod;
0071     u64 tid;
0072     u8 gid[16];
0073     u32 dev_index;
0074     u8 traffic_class;
0075 };
0076
0077 SEC("tracepoint/ib_umad/ib_umad_read_recv")
0078 int on_ib_umad_read_recv(struct ib_umad_rw_args *ctx)
0079 {
0080     u64 zero = 0, *val;
0081     u8 class = ctx->mgmt_class;
0082
0083     bpf_printk("ib_umad read recv : class 0x%x\n", class);
0084
0085     val = bpf_map_lookup_elem(&read_count, &class);
0086     if (!val) {
0087         bpf_map_update_elem(&read_count, &class, &zero, BPF_NOEXIST);
0088         val = bpf_map_lookup_elem(&read_count, &class);
0089         if (!val)
0090             return 0;
0091     }
0092
0093     (*val) += 1;
0094
0095     return 0;
0096 }
0097 SEC("tracepoint/ib_umad/ib_umad_read_send")
0098 int on_ib_umad_read_send(struct ib_umad_rw_args *ctx)
0099 {
0100     u64 zero = 0, *val;
0101     u8 class = ctx->mgmt_class;
0102
0103     bpf_printk("ib_umad read send : class 0x%x\n", class);
0104
0105     val = bpf_map_lookup_elem(&read_count, &class);
0106     if (!val) {
0107         bpf_map_update_elem(&read_count, &class, &zero, BPF_NOEXIST);
0108         val = bpf_map_lookup_elem(&read_count, &class);
0109         if (!val)
0110             return 0;
0111     }
0112
0113     (*val) += 1;
0114
0115     return 0;
0116 }
0117 SEC("tracepoint/ib_umad/ib_umad_write")
0118 int on_ib_umad_write(struct ib_umad_rw_args *ctx)
0119 {
0120     u64 zero = 0, *val;
0121     u8 class = ctx->mgmt_class;
0122
0123     bpf_printk("ib_umad write : class 0x%x\n", class);
0124
0125     val = bpf_map_lookup_elem(&write_count, &class);
0126     if (!val) {
0127         bpf_map_update_elem(&write_count, &class, &zero, BPF_NOEXIST);
0128         val = bpf_map_lookup_elem(&write_count, &class);
0129         if (!val)
0130             return 0;
0131     }
0132
0133     (*val) += 1;
0134
0135     return 0;
0136 }
0137
0138 char _license[] SEC("license") = "GPL";