/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
 */
#include <sys/types.h>
#include <sys/varargs.h>
#include <sys/cmn_err.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/time.h>
#include <sys/ib/clients/rdsv3/rdsv3_debug.h>

/*
 * This file contains the debug defines and routines.
 * Debugging information is collected in a circular kernel buffer. Debug
 * messages with level lower than rdsv3dbglvl are ignored. The size of the
 * of the debug buffer can be changed by setting 'rdsv3_debug_buf_size' in
 * bytes in /etc/system.
 *
 * The debug buffer can be cleared by setting 'rdsv3_clear_debug_buf_flag = 1'
 * on a running system.
 */

#define RDSV3_DEBUG_SIZE_EXTRA_ALLOC    8
#define RDSV3_MIN_DEBUG_BUF_SIZE                0x1000
#define RDSV3_FUNCNAME_LEN              40
#define RDSV3_PRINTBUF_LEN              4096
#ifdef  DEBUG
#define RDSV3_DEBUG_BUF_SIZE            0x200000        /* 2M size */
#else
#define RDSV3_DEBUG_BUF_SIZE            0x2000
#endif  /* DEBUG */

/* Max length of a debug statement */
#define RDSV3_PRINT_BUF_LEN     4096

static int rdsv3_suppress_dprintf;      /* Suppress debug printing */
static int rdsv3_buffer_dprintf = 1;    /* Use debug buffer (0 == console) */
static int rdsv3_debug_buf_size = RDSV3_DEBUG_BUF_SIZE; /* Sz of Debug buf */
static int rdsv3_allow_intr_msgs = 0;   /* log "intr" messages */
char *rdsv3_debug_buf = NULL;   /* The Debug Buf */
char *rdsv3_buf_sptr, *rdsv3_buf_eptr;  /* debug buffer temp pointer */
int rdsv3_clear_debug_buf_flag = 0;     /* Clear debug buffer */
uint_t  rdsv3dbglvl = RDSV3_LOG_L4;

/*
 * Print Buffer protected by mutex for debug stuff. The mutex also
 * ensures serializing debug messages.
 */
static kmutex_t rdsv3_debug_mutex;
static char     rdsv3_print_buf[RDSV3_PRINT_BUF_LEN];

/* Function Prototypes */
static void     rdsv3_clear_print_buf();

/* RDS logging init */
void
rdsv3_logging_initialization()
{
        boolean_t flag = B_FALSE;

        mutex_init(&rdsv3_debug_mutex, NULL, MUTEX_DRIVER, NULL);
        mutex_enter(&rdsv3_debug_mutex);

        if (rdsv3_debug_buf_size <= RDSV3_DEBUG_SIZE_EXTRA_ALLOC) {
                rdsv3_debug_buf_size = RDSV3_MIN_DEBUG_BUF_SIZE;
                flag = B_TRUE;
        }

        /* if it is less that RDSV3_MIN_DEBUG_BUF_SIZE, adjust it */
        rdsv3_debug_buf_size = max(RDSV3_MIN_DEBUG_BUF_SIZE,
            rdsv3_debug_buf_size);

        rdsv3_debug_buf = (char *)kmem_alloc(rdsv3_debug_buf_size, KM_SLEEP);
        rdsv3_clear_print_buf();
        mutex_exit(&rdsv3_debug_mutex);

        if (flag == B_TRUE) {
                RDSV3_DPRINTF2("RDS", "rdsv3_debug_buf_size was too small, "
                    "adjusted to %x", rdsv3_debug_buf_size);
        }
}


/* RDS logging destroy */
void
rdsv3_logging_destroy()
{
        mutex_enter(&rdsv3_debug_mutex);
        if (rdsv3_debug_buf) {
                kmem_free(rdsv3_debug_buf, rdsv3_debug_buf_size);
                rdsv3_debug_buf = NULL;
        }
        mutex_exit(&rdsv3_debug_mutex);
        mutex_destroy(&rdsv3_debug_mutex);
}


/*
 * debug, log, and console message handling
 */

/*
 * clear the RDS debug buffer
 */
static void
rdsv3_clear_print_buf()
{
        ASSERT(MUTEX_HELD(&rdsv3_debug_mutex));
        if (rdsv3_debug_buf) {
                rdsv3_buf_sptr = rdsv3_debug_buf;
                rdsv3_buf_eptr = rdsv3_debug_buf + rdsv3_debug_buf_size -
                    RDSV3_DEBUG_SIZE_EXTRA_ALLOC;

                bzero(rdsv3_debug_buf, rdsv3_debug_buf_size);
        }
}


static void
rdsv3_vlog(char *name, uint_t level, char *fmt, va_list ap)
{
        char    *label = (name == NULL) ? "rds" : name;
        char    *msg_ptr;
        size_t  len;

        mutex_enter(&rdsv3_debug_mutex);

        /* if not using logging scheme; quit */
        if (rdsv3_suppress_dprintf || (rdsv3_debug_buf == NULL)) {
                mutex_exit(&rdsv3_debug_mutex);
                return;
        }

        /* If user requests to clear debug buffer, go ahead */
        if (rdsv3_clear_debug_buf_flag != 0) {
                rdsv3_clear_print_buf();
                rdsv3_clear_debug_buf_flag = 0;
        }

        /*
         * put "label" into the buffer
         */
        len = snprintf(rdsv3_print_buf, RDSV3_FUNCNAME_LEN, "%s:\t", label);

        msg_ptr = rdsv3_print_buf + len;
        len += vsnprintf(msg_ptr, RDSV3_PRINT_BUF_LEN - len - 2, fmt, ap);

        len = min(len, RDSV3_PRINT_BUF_LEN - 2);
        ASSERT(len == strlen(rdsv3_print_buf));
        rdsv3_print_buf[len++] = '\n';
        rdsv3_print_buf[len] = '\0';

        /*
         * stuff the message in the debug buf
         */
        if (rdsv3_buffer_dprintf) {

                /*
                 * overwrite >>>> that might be over the end of the
                 * the buffer
                 */
                *rdsv3_buf_sptr = '\0';

                if (rdsv3_buf_sptr + len > rdsv3_buf_eptr) {
                        size_t left = (uintptr_t)rdsv3_buf_eptr -
                            (uintptr_t)rdsv3_buf_sptr;

                        bcopy((caddr_t)rdsv3_print_buf,
                            (caddr_t)rdsv3_buf_sptr, left);
                        bcopy((caddr_t)rdsv3_print_buf + left,
                            (caddr_t)rdsv3_debug_buf, len - left);
                        rdsv3_buf_sptr = rdsv3_debug_buf + len - left;
                } else {
                        bcopy((caddr_t)rdsv3_print_buf, rdsv3_buf_sptr, len);
                        rdsv3_buf_sptr += len;
                }

                /* add marker */
                (void) sprintf(rdsv3_buf_sptr, ">>>>");
        }

        /*
         * LINTR, L5-L2 message may go to the rdsv3_debug_buf
         * L1 messages will go to the /var/adm/messages (debug & non-debug).
         * L0 messages will go to console (debug & non-debug).
         */
        switch (level) {
        case RDSV3_LOG_LINTR:
        case RDSV3_LOG_L5:
        case RDSV3_LOG_L4:
        case RDSV3_LOG_L3:
        case RDSV3_LOG_L2:
                if (!rdsv3_buffer_dprintf) {
                        cmn_err(CE_CONT, "^%s", rdsv3_print_buf);
                }
                break;
        case RDSV3_LOG_L1:
                if (!rdsv3_buffer_dprintf) {
                        cmn_err(CE_CONT, "^%s", rdsv3_print_buf);
                } else {
                        /* go to messages file */
                        cmn_err(CE_CONT, "!%s", rdsv3_print_buf);
                }
                break;
        case RDSV3_LOG_L0:
                /* Strip the "\n" added earlier */
                if (rdsv3_print_buf[len - 1] == '\n') {
                        rdsv3_print_buf[len - 1] = '\0';
                }
                if (msg_ptr[len - 1] == '\n') {
                        msg_ptr[len - 1] = '\0';
                }
                /* go to console */
                cmn_err(CE_CONT, "^%s", rdsv3_print_buf);
                break;
        }

        mutex_exit(&rdsv3_debug_mutex);
}

void
rdsv3_dprintf_intr(char *name, char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        rdsv3_vlog(name, RDSV3_LOG_LINTR, fmt, ap);
        va_end(ap);
}

/*
 * Check individual subsystem err levels
 */
#define RDSV3_CHECK_ERR_LEVEL(level)            \
        if (rdsv3dbglvl < level)                \
                return;                         \

void
rdsv3_dprintf5(char *name, char *fmt, ...)
{
        va_list ap;

        RDSV3_CHECK_ERR_LEVEL(RDSV3_LOG_L5);

        va_start(ap, fmt);
        rdsv3_vlog(name, RDSV3_LOG_L5, fmt, ap);
        va_end(ap);
}

void
rdsv3_dprintf4(char *name, char *fmt, ...)
{
        va_list ap;

        RDSV3_CHECK_ERR_LEVEL(RDSV3_LOG_L4);

        va_start(ap, fmt);
        rdsv3_vlog(name, RDSV3_LOG_L4, fmt, ap);
        va_end(ap);
}

void
rdsv3_dprintf3(char *name, char *fmt, ...)
{
        va_list ap;

        RDSV3_CHECK_ERR_LEVEL(RDSV3_LOG_L3);

        va_start(ap, fmt);
        rdsv3_vlog(name, RDSV3_LOG_L3, fmt, ap);
        va_end(ap);
}

void
rdsv3_dprintf2(char *name, char *fmt, ...)
{
        va_list ap;

        RDSV3_CHECK_ERR_LEVEL(RDSV3_LOG_L2);

        va_start(ap, fmt);
        rdsv3_vlog(name, RDSV3_LOG_L2, fmt, ap);
        va_end(ap);
}

void
rdsv3_dprintf1(char *name, char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        rdsv3_vlog(name, RDSV3_LOG_L1, fmt, ap);
        va_end(ap);
}


/*
 * Function:
 *      rdsv3_dprintf0
 * Input:
 *      name    - Name of the function generating the debug message
 *      fmt     - The message to be displayed.
 * Output:
 *      none
 * Returns:
 *      none
 * Description:
 *      A generic log function to display RDS debug messages.
 */
void
rdsv3_dprintf0(char *name, char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        rdsv3_vlog(name, RDSV3_LOG_L0, fmt, ap);
        va_end(ap);
}

/* For ofed rdstrace */
void
rdsv3_trace(char *name, uint8_t lvl, char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        rdsv3_vlog(name, lvl, fmt, ap);
        va_end(ap);
}

#define DEFAULT_RATELIMIT_INTERVAL      5
#define DEFAULT_RATELIMIT_BURST 10

struct ratelimit_state {
        clock_t interval;
        int burst;
        int printed;
        int missed;
        hrtime_t begin;
        kmutex_t lock;
};

#define DEFINE_RATELIMIT_STATE(name, interval, burst)           \
        static struct ratelimit_state name = {interval, burst, }

DEFINE_RATELIMIT_STATE(rdsv3_printk_ratelimit_state,
    DEFAULT_RATELIMIT_INTERVAL,
    DEFAULT_RATELIMIT_BURST);

int
rdsv3_printk_ratelimit(void)
{
        struct ratelimit_state *rs = &rdsv3_printk_ratelimit_state;
        hrtime_t current = gethrtime();
        int rtn = 0;

        if (rs->interval) {
                return (1);
        }
        mutex_enter(&rs->lock);
        if (!rs->begin) {
                rs->begin = current;
        }
        if (current < rs->begin + TICK_TO_NSEC(rs->interval)) {
                if (rs->missed) {
                        RDSV3_DPRINTF0("rdsv3_printk_ratelimit: ",
                            "%d callbacks suppressed\n", rs->missed);
                        rs->begin = 0;
                        rs->printed = 0;
                        rs->missed = 0;
                }
        }
        if (rs->burst && rs->burst > rs->printed) {
                rs->printed++;
                rtn = 1;
        } else {
                rs->missed++;
        }
        mutex_exit(&rs->lock);
        return (rtn);
}