/*
 * Copyright (c) 2005 The DragonFly Project.  All rights reserved.
 * 
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.com>
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
/*
 * Generic Kernel trace buffer support.  
 *
 */

#ifndef _SYS_KTR_H_
#define _SYS_KTR_H_

#include <sys/types.h>
#include <sys/sysctl.h>
#include <sys/cpputil.h>

#ifdef _KERNEL
#include "opt_ktr.h"
#endif

/*
 * Conveniently auto-enable KTRs when particular KTRs are specified
 * in kernel options.  This way we can get logging during boot.
 * However, if KTR_ALL is optioned, just disable everything by default.
 * The user can enable individual masks via sysctl.
 */
#if defined(KTR_ALL)
#define KTR_AUTO_ENABLE         0
#else
#define KTR_ALL                 0
#define KTR_AUTO_ENABLE         -1
#endif

#define KTR_BUFSIZE             192
#define KTR_VERSION             4

#define KTR_VERSION_WITH_FREQ   3
#define KTR_VERSION_KTR_CPU     4

#ifndef LOCORE

struct ktr_info {
        const char *kf_name;    /* human-interpreted subsystem name */
        int32_t *kf_master_enable; /* the master enable variable */
        const char * const kf_format;   /* data format */
        int kf_data_size;       /* relevance of the data buffer */
};

struct ktr_entry {
        u_int64_t ktr_timestamp;
        struct ktr_info *ktr_info;
        const   char *ktr_file;
        void    *ktr_caller1;
        void    *ktr_caller2;
        int32_t ktr_line;
        int32_t ktr_unused;
        int32_t ktr_data[KTR_BUFSIZE / sizeof(int32_t)];
};

struct ktr_cpu_core {
        struct ktr_entry *ktr_buf;
        int              ktr_idx;
};

struct ktr_cpu {
        struct ktr_cpu_core core;
} __cachealign;

#ifdef _KERNEL

struct ktr_entry * ktr_begin_write_entry(struct ktr_info *,
                                         const char *, int);
int ktr_finish_write_entry(struct ktr_info *, struct ktr_entry *);
void    cpu_ktr_caller(struct ktr_entry *ktr);

#endif

/*
 * Take advantage of constant integer optimizations by the compiler
 * to optimize-out disabled code at compile-time.  If KTR_ENABLE_<name>
 * is 0, the compiler avoids generating all related code when KTR is enabled.
 */

#ifdef KTR

SYSCTL_DECL(_debug_ktr);

#define KTR_INFO_MASTER(master)                                             \
            SYSCTL_NODE(_debug_ktr, OID_AUTO, master, CTLFLAG_RW, 0, "");   \
            int ktr_ ## master ## _enable = KTR_AUTO_ENABLE;                \
            SYSCTL_INT(_debug_ktr, OID_AUTO, master ## _enable, CTLFLAG_RW, \
                &ktr_ ## master ## _enable, 0,                              \
                "Bit mask to control " __XSTRING(master) "'s event logging")

#define KTR_INFO_MASTER_EXTERN(master)                                  \
            SYSCTL_DECL(_debug_ktr_ ## master);                         \
            extern int ktr_ ## master ## _enable                        \

/*
 * This creates a read-only sysctl so the user knows what the mask
 * definitions are and a number of static const int's which are used
 * by the compiler to optimize the trace logging at compile-time and
 * run-time.
 * You're supposed to specify any arguments to the format as you would in
 * a function prototype.
 * We automagically create a struct for the arguments and a throwaway
 * function that will be called with the format and the actual arguments
 * at the KTR_LOG site. This makes sure that the compiler will typecheck
 * the arguments against the format string. On gcc, this requires -Wformat
 * (which is included in -Wall) and -O1 at least. Note that using
 * ktr_info.kf_format will not work, hence we need to define another
 * throwaway const wariable for the format.
 */
#define KTR_INFO(compile, master, name, maskbit, format, ...)           \
        static const int ktr_ ## master ## _ ## name ## _mask =         \
                1 << (maskbit);                                         \
        static const int ktr_ ## master ## _ ##name ## _enable =        \
                compile;                                                \
        static int ktr_ ## master ## _ ## name ## _mask_ro =            \
                1 << (maskbit);                                         \
        SYSCTL_INT(_debug_ktr_ ## master, OID_AUTO, name ## _mask,      \
                   CTLFLAG_RD, &ktr_ ## master ## _ ## name ## _mask_ro, \
                   0, "Value of the " __XSTRING(name) " event in " __XSTRING(master) "'s mask"); \
        __GENSTRUCT(ktr_info_ ## master ## _ ## name ## _args, __VA_ARGS__) \
                __packed;                                               \
        CTASSERT(sizeof(struct ktr_info_ ## master ## _ ## name ## _args) <= KTR_BUFSIZE); \
        static inline void                                              \
        __ktr_info_ ## master ## _ ## name ## _fmtcheck(const char *fmt, \
                                                        ...) __printf0like(1, 2); \
        static inline void                                              \
        __ktr_info_ ## master ## _ ## name ## _fmtcheck(const char *fmt __unused, \
                                                        ...)            \
        {}                                                              \
        static const char * const __ktr_ ## master ## _ ## name ## _fmt = format; \
        static struct ktr_info ktr_info_ ## master ## _ ## name = {     \
                .kf_name = #master "_" #name,                           \
                .kf_master_enable = &ktr_ ## master ## _enable,         \
                .kf_format = format,                                    \
                .kf_data_size = sizeof(struct ktr_info_ ## master ## _ ## name ## _args), \
        }




/*
 * Call ktr_begin_write_entry() that sets up the entry for us; use
 * a struct copy to give as max flexibility as possible to the compiler.
 * In higher optimization levels, it will copy the arguments directly from
 * registers to the destination buffer. Call our dummy function that will
 * typecheck the arguments against the format string.
 */
#define KTR_LOG(name, ...)                                              \
        do {                                                            \
                __ktr_info_ ## name ## _fmtcheck (__ktr_ ## name ## _fmt, \
                                                  ##__VA_ARGS__);       \
                if (__predict_false(ktr_ ## name ## _enable &&          \
                    (ktr_ ## name ## _mask &                            \
                     *ktr_info_ ## name .kf_master_enable))) {          \
                        struct ktr_entry *entry;                        \
                        entry = ktr_begin_write_entry(                  \
                                &ktr_info_ ## name, __FILE__, __LINE__); \
                        if (!entry)                                     \
                                break;                                  \
                        *(struct ktr_info_  ## name ## _args *)&entry->ktr_data[0] = \
                                (struct ktr_info_  ## name ## _args){ __VA_ARGS__}; \
                        if (ktr_finish_write_entry(&ktr_info_ ## name, entry)) { \
                                kprintf(ktr_info_ ## name .kf_format, ##__VA_ARGS__); \
                                kprintf("\n");                          \
                        }                                               \
                }                                                       \
        }  while(0)

#define KTR_COND_LOG(name, cond, ...)                                   \
        do {                                                            \
                __ktr_info_ ## name ## _fmtcheck (__ktr_ ## name ## _fmt, ##__VA_ARGS__);       \
                if (__predict_false((cond) &&                           \
                    ktr_ ## name ## _enable &&                          \
                    (ktr_ ## name ## _mask &                            \
                     *ktr_info_ ## name .kf_master_enable))) {          \
                        struct ktr_entry *entry;                        \
                        entry = ktr_begin_write_entry(                  \
                                &ktr_info_ ## name, __FILE__, __LINE__); \
                        if (!entry)                                     \
                                break;                                  \
                        *(struct ktr_info_  ## name ## _args *)&entry->ktr_data[0] = \
                                (struct ktr_info_  ## name ## _args){ __VA_ARGS__}; \
                        if (ktr_finish_write_entry(&ktr_info_ ## name, entry)) { \
                                kprintf(ktr_info_ ## name .kf_format, ##__VA_ARGS__); \
                                kprintf("\n");                          \
                        }                                               \
                }                                                       \
        }  while(0)

#else

#define KTR_INFO_MASTER(master)
#define KTR_INFO_MASTER_EXTERN(master)
#define KTR_INFO(compile, master, name, maskbit, format, ...)
#define KTR_LOG(info, args...)          do { } while (0)
#define KTR_COND_LOG(info, args...)     do { } while (0)

#endif

#endif /* !LOCORE */
#endif /* !_SYS_KTR_H_ */