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authorIra Weiny <ira.weiny@intel.com>2019-03-20 00:11:49 +0300
committerJason Gunthorpe <jgg@mellanox.com>2019-03-27 21:53:26 +0300
commit0ac01febd4753809d7d4d785f71cac2abde6b1c3 (patch)
treea00d8dd608774a56dc8bc02ed7192637ec429d8c /samples/bpf/ibumad_kern.c
parent2ccfbb70c2773ab0f257319c7e3b1cefb766d82e (diff)
downloadlinux-0ac01febd4753809d7d4d785f71cac2abde6b1c3.tar.xz
BPF: Add sample code for new ib_umad tracepoint
Provide a count of class types for a summary of MAD packets. The example shows one way to filter the trace data based on management class. Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'samples/bpf/ibumad_kern.c')
-rw-r--r--samples/bpf/ibumad_kern.c144
1 files changed, 144 insertions, 0 deletions
diff --git a/samples/bpf/ibumad_kern.c b/samples/bpf/ibumad_kern.c
new file mode 100644
index 000000000000..38b2b3f22049
--- /dev/null
+++ b/samples/bpf/ibumad_kern.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+
+/**
+ * ibumad BPF sample kernel side
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Copyright(c) 2018 Ira Weiny, Intel Corporation
+ */
+
+#define KBUILD_MODNAME "ibumad_count_pkts_by_class"
+#include <uapi/linux/bpf.h>
+
+#include "bpf_helpers.h"
+
+
+struct bpf_map_def SEC("maps") read_count = {
+ .type = BPF_MAP_TYPE_ARRAY,
+ .key_size = sizeof(u32), /* class; u32 required */
+ .value_size = sizeof(u64), /* count of mads read */
+ .max_entries = 256, /* Room for all Classes */
+};
+
+struct bpf_map_def SEC("maps") write_count = {
+ .type = BPF_MAP_TYPE_ARRAY,
+ .key_size = sizeof(u32), /* class; u32 required */
+ .value_size = sizeof(u64), /* count of mads written */
+ .max_entries = 256, /* Room for all Classes */
+};
+
+#undef DEBUG
+#ifdef DEBUG
+#define bpf_debug(fmt, ...) \
+({ \
+ char ____fmt[] = fmt; \
+ bpf_trace_printk(____fmt, sizeof(____fmt), \
+ ##__VA_ARGS__); \
+})
+#else
+#define bpf_debug(fmt, ...)
+#endif
+
+/* Taken from the current format defined in
+ * include/trace/events/ib_umad.h
+ * and
+ * /sys/kernel/debug/tracing/events/ib_umad/ib_umad_read/format
+ * /sys/kernel/debug/tracing/events/ib_umad/ib_umad_write/format
+ */
+struct ib_umad_rw_args {
+ u64 pad;
+ u8 port_num;
+ u8 sl;
+ u8 path_bits;
+ u8 grh_present;
+ u32 id;
+ u32 status;
+ u32 timeout_ms;
+ u32 retires;
+ u32 length;
+ u32 qpn;
+ u32 qkey;
+ u8 gid_index;
+ u8 hop_limit;
+ u16 lid;
+ u16 attr_id;
+ u16 pkey_index;
+ u8 base_version;
+ u8 mgmt_class;
+ u8 class_version;
+ u8 method;
+ u32 flow_label;
+ u16 mad_status;
+ u16 class_specific;
+ u32 attr_mod;
+ u64 tid;
+ u8 gid[16];
+ u32 dev_index;
+ u8 traffic_class;
+};
+
+SEC("tracepoint/ib_umad/ib_umad_read_recv")
+int on_ib_umad_read_recv(struct ib_umad_rw_args *ctx)
+{
+ u64 zero = 0, *val;
+ u8 class = ctx->mgmt_class;
+
+ bpf_debug("ib_umad read recv : class 0x%x\n", class);
+
+ val = bpf_map_lookup_elem(&read_count, &class);
+ if (!val) {
+ bpf_map_update_elem(&read_count, &class, &zero, BPF_NOEXIST);
+ val = bpf_map_lookup_elem(&read_count, &class);
+ if (!val)
+ return 0;
+ }
+
+ (*val) += 1;
+
+ return 0;
+}
+SEC("tracepoint/ib_umad/ib_umad_read_send")
+int on_ib_umad_read_send(struct ib_umad_rw_args *ctx)
+{
+ u64 zero = 0, *val;
+ u8 class = ctx->mgmt_class;
+
+ bpf_debug("ib_umad read send : class 0x%x\n", class);
+
+ val = bpf_map_lookup_elem(&read_count, &class);
+ if (!val) {
+ bpf_map_update_elem(&read_count, &class, &zero, BPF_NOEXIST);
+ val = bpf_map_lookup_elem(&read_count, &class);
+ if (!val)
+ return 0;
+ }
+
+ (*val) += 1;
+
+ return 0;
+}
+SEC("tracepoint/ib_umad/ib_umad_write")
+int on_ib_umad_write(struct ib_umad_rw_args *ctx)
+{
+ u64 zero = 0, *val;
+ u8 class = ctx->mgmt_class;
+
+ bpf_debug("ib_umad write : class 0x%x\n", class);
+
+ val = bpf_map_lookup_elem(&write_count, &class);
+ if (!val) {
+ bpf_map_update_elem(&write_count, &class, &zero, BPF_NOEXIST);
+ val = bpf_map_lookup_elem(&write_count, &class);
+ if (!val)
+ return 0;
+ }
+
+ (*val) += 1;
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";