ddi_copyout(9f) 맨 페이지 - 윈디하나의 솔라나라

개요

섹션
맨 페이지 이름
검색(S)

ddi_copyout(9f)

ddi_copyout(9F)                Kernel Functions                ddi_copyout(9F)



NAME
       ddi_copyout - copy data from a driver

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

       int ddi_copyout(const void *driverbuf, void *buf, size_t cn, int flags);

INTERFACE LEVEL
       Solaris DDI specific (Solaris DDI).

PARAMETERS
       driverbuf    Source address in the driver from which the data is trans‐
                    ferred.


       buf          Destination address to which the data is transferred.


       cn           Number of bytes to copy.


       flags        Set of flag bits that provide  address  space  information
                    about buf.


DESCRIPTION
       This routine is designed for use in driver ioctl(9E) routines for driv‐
       ers that support layered  ioctls.  ddi_copyout()  copies  data  from  a
       driver buffer to a destination address, buf.


       The  flags argument determines the address space information about buf.
       If the FKIOCTL flag is  set,  this  indicates  that  buf  is  a  kernel
       address,  and  ddi_copyout()  behaves like bcopy(9F). Otherwise, buf is
       interpreted as a user buffer address, and  ddi_copyout()  behaves  like
       copyout(9F).


       Addresses  that  are  word-aligned are moved most efficiently. However,
       the driver developer is not obliged to ensure alignment. This  function
       automatically  finds  the  most  efficient  move algorithm according to
       address alignment.

RETURN VALUES
       Under normal conditions, 0 is returned to indicate a  successful  copy.
       Otherwise, −1 is returned if one of the following occurs:

           o      Paging  fault;  the  driver tried to access a page of memory
                  for which it did not have read or write access.


           o      Invalid user address, such as a user area or stack area.


           o      Invalid address that  would  have  resulted  in  data  being
                  copied into the user block.


           o      Hardware  fault;  a  hardware  error prevented access to the
                  specified user memory. For example, an uncorrectable  parity
                  or ECC error occurred.


           o      ADI  version  mismatch;  the  hardware  detected  a mismatch
                  between the version specified for  the  destination  address
                  and  the actual in-memory version. For more information, see
                  the adi(3C) man page.



       If −1 is returned to the caller, driver  entry  point  routines  should
       return EFAULT.

CONTEXT
       ddi_copyout() can be called from user or kernel context only.

EXAMPLES
       Example 1 ddi_copyout() example



       A  driver  ioctl(9E) routine (line 12) can be used to get or set device
       attributes or registers. In the XX_GETREGS  condition  (line  25),  the
       driver  copies the current device register values to another data area.
       If the specified argument contains an invalid address, an error code is
       returned.


         1  struct device  {        /* layout of physical device registers  */
          2     int      control;    /* physical device control word  */
          3     int      status;     /* physical device status word   */
          4     short    recv_char;  /* receive character from device */
          5     short    xmit_char;  /* transmit character to device  */
          6  };

          7  struct device_state {
          8     volatile struct device *regsp;   /* pointer to device registers */
          9     kmutex_t reg_mutex;              /* protect device registers */
                . . .
         10  };

         11  static void *statep; /* for soft state routines */

         12  xxioctl(dev_t dev, int cmd, int arg, int mode,
         13      cred_t *cred_p, int *rval_p)
         14  {
         15      struct device_state *sp;
         16      volatile struct device *rp;
         17      struct device reg_buf;     /* temporary buffer for registers */
         18      int instance;

         19      instance = getminor(dev);
         20      sp = ddi_get_soft_state(statep, instance);
         21      if (sp == NULL)
         22          return (ENXIO);
         23      rp = sp->regsp;
                 . . .
         24      switch (cmd)  {

         25      case XX_GETREGS:   /* copy registers to arg */
         26            mutex_enter(&sp->reg_mutex);
         27            /*
         28             * Copy data from device registers to
         29             * temporary device register buffer
         30             * e.g. reg_buf.control = rp->control;
         31             */
         32            mutex_exit(&sp->reg_mutex);
         33            if (ddi_copyout(&reg_buf, arg,
         34                sizeof (struct device), mode) != 0) {
         35                    return (EFAULT);
         36            }

         37            break;
         38      }
         39  }


SEE ALSO
       ioctl(9E),    bcopy(9F),   copyin(9F),   copyout(9F),   ddi_copyin(9F),
       uiomove(9F)


       Writing Device Drivers in Oracle Solaris 11.4

NOTES
       The value of the flags  argument  to  ddi_copyout()  should  be  passed
       through directly from the mode argument of ioctl() untranslated.


       Driver defined locks should not be held across calls to this function.


       ddi_copyout() should not be used from a streams driver. For more infor‐
       mation, see M_COPYIN and M_COPYOUT in STREAMS Programming Guide.



Oracle Solaris 11.4               30 Sep 2015                  ddi_copyout(9F)
맨 페이지 내용의 저작권은 맨 페이지 작성자에게 있습니다.
RSS ATOM XHTML 5 CSS3