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author | Miles Bader <miles@gnu.org> | 1995-04-05 00:54:58 +0000 |
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committer | Miles Bader <miles@gnu.org> | 1995-04-05 00:54:58 +0000 |
commit | 28630f6da0ab09f1a87852b7221f7b99bc2ef21c (patch) | |
tree | bbec9dc8f3c59b5dba5f7f9ef48a524d916923b7 /devio/dev.h | |
parent | 5360e84d14494a6bc105edca255dcd3afe327848 (diff) |
Initial revision
Diffstat (limited to 'devio/dev.h')
-rw-r--r-- | devio/dev.h | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/devio/dev.h b/devio/dev.h new file mode 100644 index 00000000..7244c91e --- /dev/null +++ b/devio/dev.h @@ -0,0 +1,138 @@ +/* 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 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 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 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__ */ |