aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/tools/perf/tests/bpf-script-example.c
diff options
context:
space:
mode:
authorDaniel Vetter <daniel.vetter@ffwll.ch>2015-11-23 09:04:05 +0100
committerDaniel Vetter <daniel.vetter@ffwll.ch>2015-11-23 09:04:05 +0100
commit92907cbbef8625bb3998d1eb385fc88f23c97a3f (patch)
tree15626ff9287e37c3cb81c7286d6db5a7fd77c854 /tools/perf/tests/bpf-script-example.c
parentdrm/i915: Update DRIVER_DATE to 20151120 (diff)
parentLinux 4.4-rc2 (diff)
downloadwireguard-linux-92907cbbef8625bb3998d1eb385fc88f23c97a3f.tar.xz
wireguard-linux-92907cbbef8625bb3998d1eb385fc88f23c97a3f.zip
Merge tag 'v4.4-rc2' into drm-intel-next-queued
Linux 4.4-rc2 Backmerge to get at commit 1b0e3a049efe471c399674fd954500ce97438d30 Author: Imre Deak <imre.deak@intel.com> Date: Thu Nov 5 23:04:11 2015 +0200 drm/i915/skl: disable display side power well support for now so that we can proplery re-eanble skl power wells in -next. Conflicts are just adjacent lines changed, except for intel_fbdev.c where we need to interleave the changs. Nothing nefarious. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Diffstat (limited to '')
-rw-r--r--tools/perf/tests/bpf-script-example.c48
1 files changed, 48 insertions, 0 deletions
diff --git a/tools/perf/tests/bpf-script-example.c b/tools/perf/tests/bpf-script-example.c
new file mode 100644
index 000000000000..0ec9c2c03164
--- /dev/null
+++ b/tools/perf/tests/bpf-script-example.c
@@ -0,0 +1,48 @@
+/*
+ * bpf-script-example.c
+ * Test basic LLVM building
+ */
+#ifndef LINUX_VERSION_CODE
+# error Need LINUX_VERSION_CODE
+# error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig'
+#endif
+#define BPF_ANY 0
+#define BPF_MAP_TYPE_ARRAY 2
+#define BPF_FUNC_map_lookup_elem 1
+#define BPF_FUNC_map_update_elem 2
+
+static void *(*bpf_map_lookup_elem)(void *map, void *key) =
+ (void *) BPF_FUNC_map_lookup_elem;
+static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) =
+ (void *) BPF_FUNC_map_update_elem;
+
+struct bpf_map_def {
+ unsigned int type;
+ unsigned int key_size;
+ unsigned int value_size;
+ unsigned int max_entries;
+};
+
+#define SEC(NAME) __attribute__((section(NAME), used))
+struct bpf_map_def SEC("maps") flip_table = {
+ .type = BPF_MAP_TYPE_ARRAY,
+ .key_size = sizeof(int),
+ .value_size = sizeof(int),
+ .max_entries = 1,
+};
+
+SEC("func=sys_epoll_pwait")
+int bpf_func__sys_epoll_pwait(void *ctx)
+{
+ int ind =0;
+ int *flag = bpf_map_lookup_elem(&flip_table, &ind);
+ int new_flag;
+ if (!flag)
+ return 0;
+ /* flip flag and store back */
+ new_flag = !*flag;
+ bpf_map_update_elem(&flip_table, &ind, &new_flag, BPF_ANY);
+ return new_flag;
+}
+char _license[] SEC("license") = "GPL";
+int _version SEC("version") = LINUX_VERSION_CODE;