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/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/tracing/events/ib_umad/ib_umad_read/format
  43  * /sys/kernel/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";