ddi_copyin(9F)

NAME

ddi_copyin − copy data to a driver buffer

SYNOPSIS

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

int ddi_copyin(caddr_t buf, caddr_t driverbuf, size_t cn, int flags);

ARGUMENTS

buf Source address from which data is transferred.

driverbuf Driver destination address to which data is transferred.

cn Number of bytes transferred.

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

INTERFACE LEVEL

Sun hardware specific (SunDDI).

DESCRIPTION

This routine is designed for use in driver ioctl(9E) routines for drivers that support layered ioctls. ddi_copyin() copies data from a source address to a driver buffer. The driver developer must ensure that adequate space is allocated for the destination address.

The flags argument is used to determine the address space information about buf. If the FKIOCTL flag is set, this indicates that buf is a kernel address, and ddi_copyin() behaves like bcopy(9F). Otherwise buf is interpreted as a user buffer address, and ddi_copyin() behaves like copyin(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 according to address alignment.

RETURN VALUES

ddi_copyin() returns 0, indicating a successful copy. It returns −1 if one of the following occurs:

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

• invalid user area or stack area

• invalid address that would have resulted in data being copied into the user block

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

CONTEXT

ddi_copyin() can be called from user context only.

NOTES

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

SunOS 5.1 — Last change: 29 Sep 1992

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