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/*
* Mach Operating System
* Copyright (c) 1991,1990,1989,1988 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
/*
* Author: David B. Golub, Carnegie Mellon University
* Date: 10/88
*/
#ifndef _IO_REQ_
#define _IO_REQ_
#include <mach/boolean.h>
#include <mach/port.h>
#include <mach/message.h>
#include <mach/vm_param.h>
#include <kern/slab.h>
#include <kern/kalloc.h>
#include <kern/lock.h>
#include <vm/vm_page.h>
#include <device/device_types.h>
#include <device/dev_hdr.h>
#include <kern/macros.h>
/*
* IO request element, queued on device for delayed replies.
*/
typedef struct io_req *io_req_t;
struct io_req {
struct io_req * io_next; /* next, ... */
struct io_req * io_prev; /* prev pointers: link in done,
defered, or in-progress list */
mach_device_t io_device; /* pointer to open-device structure */
char * io_dev_ptr; /* pointer to driver structure -
filled in by driver if necessary */
int io_unit; /* unit number ('minor') of device */
int io_op; /* IO operation */
dev_mode_t io_mode; /* operation mode (wait, truncate) */
recnum_t io_recnum; /* starting record number for
random-access devices */
union io_un {
io_buf_ptr_t data; /* data, for IO requests */
} io_un;
#define io_data io_un.data
long io_count; /* amount requested */
vm_size_t io_alloc_size; /* amount allocated */
long io_residual; /* amount NOT done */
io_return_t io_error; /* error code */
/* call when done - returns TRUE if IO really finished */
boolean_t (*io_done)(io_req_t);
struct ipc_port *io_reply_port; /* reply port, for asynchronous
messages */
mach_msg_type_name_t io_reply_port_type;
/* send or send-once right? */
struct io_req * io_link; /* forward link (for driver header) */
struct io_req * io_rlink; /* reverse link (for driver header) */
vm_map_copy_t io_copy; /* vm_map_copy obj. for this op. */
long io_total; /* total op size, for write */
decl_simple_lock_data(,io_req_lock)
/* Lock for this structure */
long io_physrec; /* mapping to the physical block
number */
long io_rectotal; /* total number of blocks to move */
};
/*
* LOCKING NOTE: Operations on io_req's are in general single threaded by
* the invoking code, obviating the need for a lock. The usual IO_CALL
* path through the code is: Initiating thread hands io_req to device driver,
* driver passes it to io_done thread, io_done thread sends reply message. No
* locking is needed in this sequence. Unfortunately, a synchronous wait
* for a buffer requires a lock to avoid problems if the wait and interrupt
* happen simultaneously on different processors.
*/
#define ior_lock(ior) simple_lock(&(ior)->io_req_lock)
#define ior_unlock(ior) simple_unlock(&(ior)->io_req_lock)
/*
* Flags and operations
*/
#define IO_WRITE 0x00000000 /* operation is write */
#define IO_READ 0x00000001 /* operation is read */
#define IO_OPEN 0x00000002 /* operation is open */
#define IO_DONE 0x00000100 /* operation complete */
#define IO_ERROR 0x00000200 /* error on operation */
#define IO_BUSY 0x00000400 /* operation in progress */
#define IO_WANTED 0x00000800 /* wakeup when no longer BUSY */
#define IO_BAD 0x00001000 /* bad disk block */
#define IO_CALL 0x00002000 /* call io_done_thread when done */
#define IO_INBAND 0x00004000 /* mig call was inband */
#define IO_INTERNAL 0x00008000 /* internal, device-driver specific */
#define IO_LOANED 0x00010000 /* ior loaned by another module */
#define IO_SPARE_START 0x00020000 /* start of spare flags */
/*
* Standard completion routine for io_requests.
*/
void iodone(io_req_t);
/*
* Macros to allocate and free IORs - will convert to caches later.
*/
#define io_req_alloc(ior,size) \
MACRO_BEGIN \
(ior) = (io_req_t)kalloc(sizeof(struct io_req)); \
simple_lock_init(&(ior)->io_req_lock); \
MACRO_END
#define io_req_free(ior) \
(kfree((vm_offset_t)(ior), sizeof(struct io_req)))
extern struct kmem_cache io_inband_cache; /* for inband reads */
#endif /* _IO_REQ_ */
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