// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2023. Huawei Technologies Co., Ltd */
#include <vmlinux.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_helpers.h>

#include "bpf_experimental.h"
#include "bpf_misc.h"

struct generic_map_value {
	void *data;
};

char _license[] SEC("license") = "GPL";

const unsigned int data_sizes[] = {16, 32, 64, 96, 128, 192, 256, 512, 1024, 2048, 4096};
const volatile unsigned int data_btf_ids[ARRAY_SIZE(data_sizes)] = {};

const unsigned int percpu_data_sizes[] = {8, 16, 32, 64, 96, 128, 192, 256, 512};
const volatile unsigned int percpu_data_btf_ids[ARRAY_SIZE(data_sizes)] = {};

int err = 0;
u32 pid = 0;

#define DEFINE_ARRAY_WITH_KPTR(_size) \
	struct bin_data_##_size { \
		char data[_size - sizeof(void *)]; \
	}; \
	/* See Commit 5d8d6634ccc, force btf generation for type bin_data_##_size */	\
	struct bin_data_##_size *__bin_data_##_size; \
	struct map_value_##_size { \
		struct bin_data_##_size __kptr * data; \
	}; \
	struct { \
		__uint(type, BPF_MAP_TYPE_ARRAY); \
		__type(key, int); \
		__type(value, struct map_value_##_size); \
		__uint(max_entries, 128); \
	} array_##_size SEC(".maps")

#define DEFINE_ARRAY_WITH_PERCPU_KPTR(_size) \
	struct percpu_bin_data_##_size { \
		char data[_size]; \
	}; \
	struct percpu_bin_data_##_size *__percpu_bin_data_##_size; \
	struct map_value_percpu_##_size { \
		struct percpu_bin_data_##_size __percpu_kptr * data; \
	}; \
	struct { \
		__uint(type, BPF_MAP_TYPE_ARRAY); \
		__type(key, int); \
		__type(value, struct map_value_percpu_##_size); \
		__uint(max_entries, 128); \
	} array_percpu_##_size SEC(".maps")

static __always_inline void batch_alloc(struct bpf_map *map, unsigned int batch, unsigned int idx)
{
	struct generic_map_value *value;
	unsigned int i, key;
	void *old, *new;

	for (i = 0; i < batch; i++) {
		key = i;
		value = bpf_map_lookup_elem(map, &key);
		if (!value) {
			err = 1;
			return;
		}
		new = bpf_obj_new_impl(data_btf_ids[idx], NULL);
		if (!new) {
			err = 2;
			return;
		}
		old = bpf_kptr_xchg(&value->data, new);
		if (old) {
			bpf_obj_drop(old);
			err = 3;
			return;
		}
	}
}

static __always_inline void batch_free(struct bpf_map *map, unsigned int batch, unsigned int idx)
{
	struct generic_map_value *value;
	unsigned int i, key;
	void *old;

	for (i = 0; i < batch; i++) {
		key = i;
		value = bpf_map_lookup_elem(map, &key);
		if (!value) {
			err = 4;
			return;
		}
		old = bpf_kptr_xchg(&value->data, NULL);
		if (!old) {
			err = 5;
			return;
		}
		bpf_obj_drop(old);
	}
}

static __always_inline void batch_percpu_alloc(struct bpf_map *map, unsigned int batch,
					       unsigned int idx)
{
	struct generic_map_value *value;
	unsigned int i, key;
	void *old, *new;

	for (i = 0; i < batch; i++) {
		key = i;
		value = bpf_map_lookup_elem(map, &key);
		if (!value) {
			err = 1;
			return;
		}
		/* per-cpu allocator may not be able to refill in time */
		new = bpf_percpu_obj_new_impl(percpu_data_btf_ids[idx], NULL);
		if (!new)
			continue;

		old = bpf_kptr_xchg(&value->data, new);
		if (old) {
			bpf_percpu_obj_drop(old);
			err = 2;
			return;
		}
	}
}

static __always_inline void batch_percpu_free(struct bpf_map *map, unsigned int batch,
					      unsigned int idx)
{
	struct generic_map_value *value;
	unsigned int i, key;
	void *old;

	for (i = 0; i < batch; i++) {
		key = i;
		value = bpf_map_lookup_elem(map, &key);
		if (!value) {
			err = 3;
			return;
		}
		old = bpf_kptr_xchg(&value->data, NULL);
		if (!old)
			continue;
		bpf_percpu_obj_drop(old);
	}
}

#define CALL_BATCH_ALLOC(size, batch, idx) \
	batch_alloc((struct bpf_map *)(&array_##size), batch, idx)

#define CALL_BATCH_ALLOC_FREE(size, batch, idx) \
	do { \
		batch_alloc((struct bpf_map *)(&array_##size), batch, idx); \
		batch_free((struct bpf_map *)(&array_##size), batch, idx); \
	} while (0)

#define CALL_BATCH_PERCPU_ALLOC(size, batch, idx) \
	batch_percpu_alloc((struct bpf_map *)(&array_percpu_##size), batch, idx)

#define CALL_BATCH_PERCPU_ALLOC_FREE(size, batch, idx) \
	do { \
		batch_percpu_alloc((struct bpf_map *)(&array_percpu_##size), batch, idx); \
		batch_percpu_free((struct bpf_map *)(&array_percpu_##size), batch, idx); \
	} while (0)

/* kptr doesn't support bin_data_8 which is a zero-sized array */
DEFINE_ARRAY_WITH_KPTR(16);
DEFINE_ARRAY_WITH_KPTR(32);
DEFINE_ARRAY_WITH_KPTR(64);
DEFINE_ARRAY_WITH_KPTR(96);
DEFINE_ARRAY_WITH_KPTR(128);
DEFINE_ARRAY_WITH_KPTR(192);
DEFINE_ARRAY_WITH_KPTR(256);
DEFINE_ARRAY_WITH_KPTR(512);
DEFINE_ARRAY_WITH_KPTR(1024);
DEFINE_ARRAY_WITH_KPTR(2048);
DEFINE_ARRAY_WITH_KPTR(4096);

DEFINE_ARRAY_WITH_PERCPU_KPTR(8);
DEFINE_ARRAY_WITH_PERCPU_KPTR(16);
DEFINE_ARRAY_WITH_PERCPU_KPTR(32);
DEFINE_ARRAY_WITH_PERCPU_KPTR(64);
DEFINE_ARRAY_WITH_PERCPU_KPTR(96);
DEFINE_ARRAY_WITH_PERCPU_KPTR(128);
DEFINE_ARRAY_WITH_PERCPU_KPTR(192);
DEFINE_ARRAY_WITH_PERCPU_KPTR(256);
DEFINE_ARRAY_WITH_PERCPU_KPTR(512);

SEC("?fentry/" SYS_PREFIX "sys_nanosleep")
int test_batch_alloc_free(void *ctx)
{
	if ((u32)bpf_get_current_pid_tgid() != pid)
		return 0;

	/* Alloc 128 16-bytes objects in batch to trigger refilling,
	 * then free 128 16-bytes objects in batch to trigger freeing.
	 */
	CALL_BATCH_ALLOC_FREE(16, 128, 0);
	CALL_BATCH_ALLOC_FREE(32, 128, 1);
	CALL_BATCH_ALLOC_FREE(64, 128, 2);
	CALL_BATCH_ALLOC_FREE(96, 128, 3);
	CALL_BATCH_ALLOC_FREE(128, 128, 4);
	CALL_BATCH_ALLOC_FREE(192, 128, 5);
	CALL_BATCH_ALLOC_FREE(256, 128, 6);
	CALL_BATCH_ALLOC_FREE(512, 64, 7);
	CALL_BATCH_ALLOC_FREE(1024, 32, 8);
	CALL_BATCH_ALLOC_FREE(2048, 16, 9);
	CALL_BATCH_ALLOC_FREE(4096, 8, 10);

	return 0;
}

SEC("?fentry/" SYS_PREFIX "sys_nanosleep")
int test_free_through_map_free(void *ctx)
{
	if ((u32)bpf_get_current_pid_tgid() != pid)
		return 0;

	/* Alloc 128 16-bytes objects in batch to trigger refilling,
	 * then free these objects through map free.
	 */
	CALL_BATCH_ALLOC(16, 128, 0);
	CALL_BATCH_ALLOC(32, 128, 1);
	CALL_BATCH_ALLOC(64, 128, 2);
	CALL_BATCH_ALLOC(96, 128, 3);
	CALL_BATCH_ALLOC(128, 128, 4);
	CALL_BATCH_ALLOC(192, 128, 5);
	CALL_BATCH_ALLOC(256, 128, 6);
	CALL_BATCH_ALLOC(512, 64, 7);
	CALL_BATCH_ALLOC(1024, 32, 8);
	CALL_BATCH_ALLOC(2048, 16, 9);
	CALL_BATCH_ALLOC(4096, 8, 10);

	return 0;
}

SEC("?fentry/" SYS_PREFIX "sys_nanosleep")
int test_batch_percpu_alloc_free(void *ctx)
{
	if ((u32)bpf_get_current_pid_tgid() != pid)
		return 0;

	/* Alloc 128 8-bytes per-cpu objects in batch to trigger refilling,
	 * then free 128 8-bytes per-cpu objects in batch to trigger freeing.
	 */
	CALL_BATCH_PERCPU_ALLOC_FREE(8, 128, 0);
	CALL_BATCH_PERCPU_ALLOC_FREE(16, 128, 1);
	CALL_BATCH_PERCPU_ALLOC_FREE(32, 128, 2);
	CALL_BATCH_PERCPU_ALLOC_FREE(64, 128, 3);
	CALL_BATCH_PERCPU_ALLOC_FREE(96, 128, 4);
	CALL_BATCH_PERCPU_ALLOC_FREE(128, 128, 5);
	CALL_BATCH_PERCPU_ALLOC_FREE(192, 128, 6);
	CALL_BATCH_PERCPU_ALLOC_FREE(256, 128, 7);
	CALL_BATCH_PERCPU_ALLOC_FREE(512, 64, 8);

	return 0;
}

SEC("?fentry/" SYS_PREFIX "sys_nanosleep")
int test_percpu_free_through_map_free(void *ctx)
{
	if ((u32)bpf_get_current_pid_tgid() != pid)
		return 0;

	/* Alloc 128 8-bytes per-cpu objects in batch to trigger refilling,
	 * then free these object through map free.
	 */
	CALL_BATCH_PERCPU_ALLOC(8, 128, 0);
	CALL_BATCH_PERCPU_ALLOC(16, 128, 1);
	CALL_BATCH_PERCPU_ALLOC(32, 128, 2);
	CALL_BATCH_PERCPU_ALLOC(64, 128, 3);
	CALL_BATCH_PERCPU_ALLOC(96, 128, 4);
	CALL_BATCH_PERCPU_ALLOC(128, 128, 5);
	CALL_BATCH_PERCPU_ALLOC(192, 128, 6);
	CALL_BATCH_PERCPU_ALLOC(256, 128, 7);
	CALL_BATCH_PERCPU_ALLOC(512, 64, 8);

	return 0;
}