drv_getparm(9f) [debian man page]

drv_getparm(9F) 					   Kernel Functions for Drivers 					   drv_getparm(9F)

NAME

       drv_getparm - retrieve kernel state information

SYNOPSIS

       #include <sys/ddi.h>

       int drv_getparm(unsigned int parm, void *value_p);

INTERFACE LEVEL

       Architecture independent level 1 (DDI/DKI).

PARAMETERS

       parm	       The kernel parameter to be obtained.  Possible values are:

       "small and bold"ReadLTthe  value  of  lbolt.  lbolt is a clock_t that is unconditionally incremented by one at each clock tick.	No special
		       treatment is applied when this value overflows the maximum value of the signed integral type clock_t. When this occurs, its
		       value  will  be	negative,  and its magnitude will be decreasing until it again passes zero. It can therefore not be relied
		       upon to provide an indication of the amount of time that passes since the last system reboot, nor should it be used to mark
		       an  absolute  time  in the system. Only the difference between two measurements of lbolt is significant. It is used in this
		       way inside the system kernel for timing purposes.

       PPGRP	       Read the process group identification number.  This number determines which processes should receive a	HANGUP	or   BREAK
		       signal when detected by a driver.

       UPROCP	       Read the process table token value.

       PPID	       Read process identification number.

       PSID	       Read process session identification number.

       TIME	       Read time in seconds.

       UCRED	       Return a pointer to the caller's credential structure.

       value_p	       A pointer to the data space in which the value of the parameter is to be copied.

DESCRIPTION

       Since  the  release  of	the  Solaris  2.6  operating  environment,  the  drv_getparm()	function  has  been replaced by ddi_get_lbolt(9F),
       ddi_get_time(9F), and ddi_get_pid(9F).

       drv_getparm() function verifies that  parm corresponds to a kernel parameter that may be read.  If the value of	parm does  not	correspond
       to a parameter or corresponds to a parameter that may not be read,  -1 is returned.  Otherwise, the value of the parameter is stored in the
       data space pointed to by  value_p.

       drv_getparm() does not explicitly check to see whether the device has the appropriate context when the function is called and the  function
       does  not  check  for  correct alignment in the data space pointed to by value_p. It is the responsibility of the driver writer to use this
       function only when it is appropriate to do so and to correctly  declare the data space needed by the driver.

RETURN VALUES

       drv_getparm() returns 0 to indicate success,  -1 to indicate failure.  The value stored in the space pointed to by  value_p is the value of
       the  parameter  if  0  is  returned, or undefined if  -1 is returned. -1 is returned if you specify a value other than  LBOLT, PPGRP, PPID,
       PSID, TIME, UCRED, or  UPROCP.  Always check the return code when using this function.

CONTEXT

       drv_getparm() can be called from user context only when using PPGRP, PPID, PSID, UCRED, or UPROCP.  It can be called from user or interrupt
       context when using the LBOLT or TIME argument.

SEE ALSO

       ddi_get_lbolt(9F), ddi_get_pid(9F), ddi_get_time(9F),  buf(9S)

       Writing Device Drivers

SunOS 5.10							    24 Jun 1997 						   drv_getparm(9F)

Check Out this Related Man Page

putctl(9F)						   Kernel Functions for Drivers 						putctl(9F)

NAME

       putctl - send a control message to a queue

SYNOPSIS

       #include <sys/stream.h>

       int putctl(queue_t *q, int type);

INTERFACE LEVEL

       Architecture independent level 1 (DDI/DKI).

PARAMETERS

       q       Queue to which the message is to be sent.

       type    Message type (must be control, not data type).

DESCRIPTION

       The  putctl()  function	tests  the  type argument to make sure a data type has not been specified, and then attempts to allocate a message
       block. putctl() fails if type is M_DATA, M_PROTO, or M_PCPROTO, or if a message block cannot be allocated. If successful,   putctl()  calls
       the put(9E) routine of the queue pointed to by q with the newly allocated and initialized messages.

RETURN VALUES

       On success, 1 is returned. If type is a data type, or if a message block cannot be allocated, 0 is returned.

CONTEXT

       The putctl() function can be called from user, interrupt, or kernel context.

EXAMPLES

       Example 1 Using putctl()

       The send_ctl() routine is used to pass control messages downstream. M_BREAK messages are handled with putctl() (line 11). putctl1(9F) (line
       16) is used for M_DELAY messages, so that parm can be used to specify the length of the delay. In either case, if a message block cannot be
       allocated  a  variable  recording  the number of allocation failures is incremented (lines 12, 17). If an invalid message type is detected,
       cmn_err(9F) panics the system (line 21).

	 1  void
	  2  send_ctl(wrq, type, parm)
	  3	 queue_t *wrq;
	  4	 uchar_t type;
	  5	 uchar_t parm;
	  6  {
	  7	    extern int num_alloc_fail;
	  8
	  9	  switch (type) {
	 10	    case M_BREAK:
	 11		if (!putctl(wrq->q_next, M_BREAK))
	 12			 num_alloc_fail++;
	 13		  break;
	 14
	 15	  case M_DELAY:
	 16		if (!putctl1(wrq->q_next, M_DELAY, parm))
	 17			 num_alloc_fail++;
	 18		break;
	 19
	 20	  default:
	 21		cmn_err(CE_PANIC, "send_ctl: bad message type passed");
	 22		  break;
	 23	    }
	 24  }

SEE ALSO

       put(9E), cmn_err(9F), datamsg(9F), putctl1(9F), putnextctl(9F)

       Writing Device Drivers

       STREAMS Programming Guide

SunOS 5.11							    16 Jan 2006 							putctl(9F)

Linux and UNIX Man Pages

drv_getparm(9f) [debian man page]

Check Out this Related Man Page