OpenSolaris kernel development BKM

1. to enter the debugger (mdb)

#include <sys/debug.h>

debug_enter(char *);

2. timer in the device driver

     #include <sys/types.h>
     #include <sys/conf.h>

     timeout_id_t timeout(void (* func)(void *), void *arg,
         clock_t  ticks);


SEE ALSO
     bufcall(9F), cv_timedwait(9F), ddi_in_panic(9F),  delay(9F),
     drv_usectohz(9F), untimeout(9F)

3. interrupt clean and restore

intr_clean()
intr_restore()

4. cpu cache line flush

wbinvd
clflush

5. conditional print sample

#ifdef ZFS_DEBUG
extern void __dprintf(const char *file, const char *func,
    int line, const char *fmt, ...);
#define dprintf(...) /
        if (zfs_flags & ZFS_DEBUG_DPRINTF) /
                __dprintf(__FILE__, __func__, __LINE__, __VA_ARGS__)
#else
#define dprintf(...) ((void)0)
#endif /* ZFS_DEBUG */

========================

/* _NOTE(PRINTFLIKE(4)) - this is printf-like, but lint is too whiney */
void
__dprintf(const char *file, const char *func, int line, const char *fmt, ...)
{
        const char *newfile;
        char buf[256];
        va_list adx;

        /*
         * Get rid of annoying "../common/" prefix to filename.
         */
        newfile = strrchr(file, '/');
        if (newfile != NULL) {
                newfile = newfile + 1; /* Get rid of leading / */
        } else {
                newfile = file;
        }

        va_start(adx, fmt);
        (void) vsnprintf(buf, sizeof (buf), fmt, adx);
        va_end(adx);

        /*
         * To get this data, use the zfs-dprintf probe as so:
         * dtrace -q -n 'zfs-dprintf /
         *      /stringof(arg0) == "dbuf.c"/ /
         *      {printf("%s: %s", stringof(arg1), stringof(arg3))}'
         * arg0 = file name
         * arg1 = function name
         * arg2 = line number
         * arg3 = message
         */
        DTRACE_PROBE4(zfs__dprintf,
            char *, newfile, char *, func, int, line, char *, buf);
}

6. get the kernel tick

     #include <sys/types.h>
     #include <sys/ddi.h>
     #include <sys/sunddi.h>

     clock_t ddi_get_lbolt(void);

     #include <sys/types.h>
     #include <sys/ddi.h>

     clock_t drv_usectohz(clock_t microsecs);

7. walk a dip tree

/*
 * collect_pci_mmio()
 *   walk through the pci device tree, and collect the mmio resources
 */
static int
collect_pci_mmio(dev_info_t *pdip)
{
        int count;
        ASSERT(pdip);

        /*
         * walk through the device tree under pdip
         * normally, pdip should be the pci root nexus
         */
        ndi_devi_enter(pdip, &count);
        ddi_walk_devs(ddi_get_child(pdip),
            collect_pci_mmio_walk, NULL);
        ndi_devi_exit(pdip, count);

        return (DDI_SUCCESS);
}