/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Define struct user_exit_info which is shared between BPF and userspace parts
 * to communicate exit status and other information.
 *
 * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
 * Copyright (c) 2022 Tejun Heo <tj@kernel.org>
 * Copyright (c) 2022 David Vernet <dvernet@meta.com>
 */
#ifndef __USER_EXIT_INFO_H
#define __USER_EXIT_INFO_H

#include <stdio.h>
#include <stdbool.h>

#include "user_exit_info_common.h"

/* no need to call the following explicitly if SCX_OPS_LOAD() is used */
#define UEI_SET_SIZE(__skel, __ops_name, __uei_name) ({                                 \
        u32 __len = (__skel)->struct_ops.__ops_name->exit_dump_len ?: UEI_DUMP_DFL_LEN; \
        (__skel)->rodata->__uei_name##_dump_len = __len;                                \
        RESIZE_ARRAY((__skel), data, __uei_name##_dump, __len);                         \
})

#define UEI_EXITED(__skel, __uei_name) ({                                       \
        /* use __sync to force memory barrier */                                \
        __sync_val_compare_and_swap(&(__skel)->data->__uei_name.kind, -1, -1);  \
})

#define UEI_REPORT(__skel, __uei_name) ({                                       \
        struct user_exit_info *__uei = &(__skel)->data->__uei_name;             \
        char *__uei_dump = (__skel)->data_##__uei_name##_dump->__uei_name##_dump; \
        if (__uei_dump[0] != '\0') {                                            \
                fputs("\nDEBUG DUMP\n", stderr);                                \
                fputs("================================================================================\n\n", stderr); \
                fputs(__uei_dump, stderr);                                      \
                fputs("\n================================================================================\n\n", stderr); \
        }                                                                       \
        fprintf(stderr, "EXIT: %s", __uei->reason);                             \
        if (__uei->msg[0] != '\0')                                              \
                fprintf(stderr, " (%s)", __uei->msg);                           \
        fputs("\n", stderr);                                                    \
        __uei->exit_code;                                                       \
})

/*
 * We can't import vmlinux.h while compiling user C code. Let's duplicate
 * scx_exit_code definition.
 */
enum scx_exit_code {
        /* Reasons */
        SCX_ECODE_RSN_HOTPLUG           = 1LLU << 32,

        /* Actions */
        SCX_ECODE_ACT_RESTART           = 1LLU << 48,
};

enum uei_ecode_mask {
        UEI_ECODE_USER_MASK             = ((1LLU << 32) - 1),
        UEI_ECODE_SYS_RSN_MASK          = ((1LLU << 16) - 1) << 32,
        UEI_ECODE_SYS_ACT_MASK          = ((1LLU << 16) - 1) << 48,
};

/*
 * These macro interpret the ecode returned from UEI_REPORT().
 */
#define UEI_ECODE_USER(__ecode)         ((__ecode) & UEI_ECODE_USER_MASK)
#define UEI_ECODE_SYS_RSN(__ecode)      ((__ecode) & UEI_ECODE_SYS_RSN_MASK)
#define UEI_ECODE_SYS_ACT(__ecode)      ((__ecode) & UEI_ECODE_SYS_ACT_MASK)

#define UEI_ECODE_RESTART(__ecode)      (UEI_ECODE_SYS_ACT((__ecode)) == SCX_ECODE_ACT_RESTART)

#endif  /* __USER_EXIT_INFO_H */