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physio(9r)
NAME
  physio - Implements raw I/O

SYNOPSIS
  int physio(
	  int (*strategy) (),
	  register struct buf *bp,
	  dev_t device,
	  int rwflag,
	  void (*mincnt) (),
	  register struct uio *uio );

ARGUMENTS
  strategy
      Specifies the block device driver's strategy interface for the device.

  bp  Specifies a pointer to a buf structure.  This structure contains
      information such as the binary status flags, the major/minor device
      numbers, and the address of the associated buffer. This buffer is
      always a special buffer header owned exclusively by the device for
      handling I/O requests.

  device
      Specifies the device number.

  rwflag
      Specifies the read/write flag.

  mincnt
      Specifies a pointer to a minphys interface.

  uio Specifies a pointer to a uio structure.

DESCRIPTION
  The physio interface implements raw I/O. This interface maps the raw I/O
  request directly into the user buffer, without using bcopy. The memory
  pages in the user address space are locked while the transfer is processed.

RETURN VALUES
  The physio interface can return one of the following values:

  EAIO	  The internal Alpha I/O operation completed.

  EFAULT  An error occurred in mapping the raw I/O request.

  EIO	  There is no such device or address on which to perform the I/O
	  request.


EXAMPLE
  See Writing Device Drivers: Tutorial for a code example of the physio
  interface.


SEE ALSO
  Kernel Interfaces: minphys(9r)

Index for Section 9

Alphabetical listing for P

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