bpf: move time in state struct definitions into a single shared header

Key and value formats for time in state related BPF maps currently
have to be kept in sync between the BPF prog and
libtimeinstate. Add a new bpf_timeinstate.h header file in a directory
that already gets added to the include path for BPF progs, and add
this file to a cc_library_headers module so it can be used from
libtimeinstate as well.

Test: build libtimeinstate and time_in_state.o
Bug: 138317993
Change-Id: Ic56b2b64746f2211f3c802e074339750f26303c0
Merged-In: Ic56b2b64746f2211f3c802e074339750f26303c0
Signed-off-by: Connor O'Brien <connoro@google.com>
(cherry picked from commit badb20f528bbddb3a8806371a7f1169e3c4a0d89)
diff --git a/progs/include/bpf_timeinstate.h b/progs/include/bpf_timeinstate.h
new file mode 100644
index 0000000..6cbc4e1
--- /dev/null
+++ b/progs/include/bpf_timeinstate.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <inttypes.h>
+
+#define BPF_FS_PATH "/sys/fs/bpf/"
+
+// Number of frequencies for which a UID's times can be tracked in a single map entry. If some CPUs
+// have more than 32 freqs available, a single UID is tracked using 2 or more entries.
+#define FREQS_PER_ENTRY 32
+// Number of distinct CPU counts for which a UID's concurrent time stats can be tracked in a single
+// map entry. On systems with more than 8 CPUs, a single UID is tracked using 2 or more entries.
+#define CPUS_PER_ENTRY 8
+
+typedef struct {
+    uint32_t uid;
+    uint32_t bucket;
+} time_key_t;
+
+typedef struct {
+    uint64_t ar[FREQS_PER_ENTRY];
+} tis_val_t;
+
+typedef struct {
+    uint64_t active[CPUS_PER_ENTRY];
+    uint64_t policy[CPUS_PER_ENTRY];
+} concurrent_val_t;
+
+typedef struct {
+    uint32_t policy;
+    uint32_t freq;
+} freq_idx_key_t;