samples/bpf/ibumad_kern.c

   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";