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/* A handle on a mach device.
Copyright (C) 1995 Free Software Foundation, Inc.
Written by Miles Bader <miles@gnu.ai.mit.edu>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#ifndef __DEV_H__
#define __DEV_H__
#include <mach.h>
#include <device/device.h>
#include "iostate.h"
/* #define FAKE */
#define MSG
#ifdef MSG
#include <stdio.h>
#include <string.h>
#include <unistd.h>
extern FILE *debug;
extern struct mutex debug_lock;
#endif
/* ---------------------------------------------------------------- */
/* Information about a kernel device. */
struct dev
{
/* The device port for the kernel device we're doing paging on. */
device_t port;
/* The mach device name which we opened. */
char *name;
/* The total size of DEV. */
vm_size_t size;
/* The block size of DEV. I/O to DEV must occur in multiples of
block_size. */
int dev_block_size;
/* The block size in which we will do I/O; this must be a multiple of
DEV_BLOCK_SIZE. */
int block_size;
/* Various attributes of this device (see below for the DEV_ flag bits).
This field is constant. */
int flags;
/* Current state of our output stream -- location and the buffer used to do
buffered i/o. */
struct io_state io_state;
/* The pager we're using to do disk i/o for us. If NULL, a pager hasn't
been allocated yet. Lock the lock in IO_STATE if you want to update
this field. */
struct pager *pager;
/* The port_bucket for paging ports. */
struct port_bucket *pager_port_bucket;
/* The current owner of the open device. For terminals, this affects
controlling terminal behavior (see term_become_ctty). For all objects
this affects old-style async IO. Negative values represent pgrps. This
has nothing to do with the owner of a file (as returned by io_stat, and
as used for various permission checks by filesystems). An owner of 0
indicates that there is no owner. */
pid_t owner;
};
/* Various bits to be set in the flags field. */
/* True if this device should be used in `block' mode, with buffering of
sub-block-size i/o. */
#define DEV_BUFFERED 0x1
/* True if this device only supports serial i/o (that is, there's only one
read/write location, which must explicitly be moved to do i/o elsewhere.*/
#define DEV_SERIAL 0x2
/* True if we can change the current i/o location of a serial device. */
#define DEV_SEEKABLE 0x4
/* True if a device cannot be written on. */
#define DEV_READONLY 0x8
/* Returns TRUE if any of the flags in BITS are set for DEV. */
#define dev_is(dev, bits) ((dev)->flags & (bits))
/* Returns true if it's ok to call dev_write on these arguments, without
first copying BUF to a page-aligned buffer. */
#define dev_write_valid(dev, buf, len, offs) \
((len) <= IO_INBAND_MAX || (buf) % vm_page_size == 0)
/* Returns a pointer to a new device structure in DEV for the kernel device
NAME, with the given FLAGS. If BLOCK_SIZE is non-zero, it should be the
desired block size, and must be a multiple of the device block size.
If an error occurs, the error code is returned, otherwise 0. */
error_t dev_open(char *name, int flags, int block_size, struct dev **dev);
/* Free DEV and any resources it consumes. */
void dev_close(struct dev *dev);
/* Reads AMOUNT bytes from DEV and returns it in BUF and BUF_LEN (using the
standard mach out-array convention). *OFFS is incremented to reflect the
amount read/written. Both LEN and *OFFS must be multiples of DEV's block
size. If an error occurs, the error code is returned, otherwise 0. */
error_t dev_read(struct dev *dev,
vm_address_t *buf, vm_size_t *buf_len, vm_size_t amount,
vm_offset_t *offs);
/* Writes AMOUNT bytes from the buffer pointed to by BUF to the device DEV.
*OFFS is incremented to reflect the amount read/written. Both AMOUNT and
*OFFS must be multiples of DEV's block size, and either BUF must be
page-aligned, or dev_write_valid() must return true for these arguments.
If an error occurs, the error code is returned, otherwise 0. */
error_t dev_write(struct dev *dev,
vm_address_t buf, vm_size_t amount, vm_offset_t *offs);
/* Returns in MEMOBJ the port for a memory object backed by the storage on
DEV. Returns 0 or the error code if an error occurred. */
error_t dev_get_memory_object(struct dev *dev, memory_object_t *memobj);
/* Try to stop all paging activity on DEV, returning true if we were
successful. If NOSYNC is true, then we won't write back any (kernel)
cached pages to the device. */
int dev_stop_paging (struct dev *dev, int nosync);
/* Try and write out any pending writes to DEV. If WAIT is true, will wait
for any paging activity to cease. */
error_t dev_sync(struct dev *dev, int wait);
#ifdef MSG
char *brep(vm_address_t buf, vm_size_t len);
#endif
#endif /* !__DEV_H__ */
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