#ifndef _SCSI_GENERIC_H
#define _SCSI_GENERIC_H
+#include <linux/compiler.h>
+
/*
History:
Started: Aug 9 by Lawrence Foard (entropy@world.std.com), to allow user
Original driver (sg.h):
* Copyright (C) 1992 Lawrence Foard
Version 2 and 3 extensions to driver:
-* Copyright (C) 1998 - 2003 Douglas Gilbert
-
- Version: 3.5.29 (20030529)
- This version is for 2.5 series kernels.
-
- Changes since 3.5.28 (20030308)
- - fix bug introduced in version 3.1.24 (last segment of sgat list)
- Changes since 3.5.27 (20020812)
- - remove procfs entries: hosts, host_hdr + host_strs (now in sysfs)
- - add sysfs sg driver params: def_reserved_size, allow_dio, version
- - new boot option: "sg_allow_dio" and module parameter: "allow_dio"
- - multiple internal changes due to scsi subsystem rework
- Changes since 3.5.26 (20020708)
- - re-add direct IO using Kai Makisara's work
- - re-tab to 8, start using C99-isms
- - simplify memory management
- Changes since 3.5.25 (20020504)
- - driverfs additions
- - copy_to/from_user() fixes [William Stinson]
- - disable kiobufs support
+* Copyright (C) 1998 - 2006 Douglas Gilbert
+
+ Version: 3.5.34 (20060920)
+ This version is for 2.6 series kernels.
For a full changelog see http://www.torque.net/sg
2.1.40 2.2.20
3.0.x optional version 3 sg driver for 2.2 series
3.1.17++ 2.4.0++
- 3.5.23++ 2.5.0++
+ 3.5.30++ 2.6.0++
Major new features in SG 3.x driver (cf SG 2.x drivers)
- SG_IO ioctl() combines function if write() and read()
data into kernel buffers and then use the CPU to copy the data into the
user space (vice versa for writes). That is called "indirect" IO due to
the double handling of data. There are two methods offered to remove the
- redundant copy: 1) direct IO which uses the kernel kiobuf mechanism and
- 2) using the mmap() system call to map the reserve buffer (this driver has
- one reserve buffer per fd) into the user space. Both have their advantages.
+ redundant copy: 1) direct IO and 2) using the mmap() system call to map
+ the reserve buffer (this driver has one reserve buffer per fd) into the
+ user space. Both have their advantages.
In terms of absolute speed mmap() is faster. If speed is not a concern,
indirect IO should be fine. Read the documentation for more information.
- ** N.B. To use direct IO 'echo 1 > /proc/scsi/sg/allow_dio' may be
- needed. That pseudo file's content is defaulted to 0. **
+ ** N.B. To use direct IO 'echo 1 > /proc/scsi/sg/allow_dio' or
+ 'echo 1 > /sys/module/sg/parameters/allow_dio' is needed.
+ That attribute is 0 by default. **
Historical note: this SCSI pass-through driver has been known as "sg" for
a decade. In broader kernel discussions "sg" is used to refer to scatter
http://www.torque.net/sg/p/sg_v3_ho.html
This is a rendering from DocBook source [change the extension to "sgml"
or "xml"]. There are renderings in "ps", "pdf", "rtf" and "txt" (soon).
+ The SG_IO ioctl is now found in other parts kernel (e.g. the block layer).
+ For more information see http://www.torque.net/sg/sg_io.html
The older, version 2 documents discuss the original sg interface in detail:
http://www.torque.net/sg/p/scsi-generic.txt
http://www.torque.net/sg/p/scsi-generic_long.txt
- A version of this document (potentially out of date) may also be found in
- the kernel source tree, probably at:
- /usr/src/linux/Documentation/scsi/scsi-generic.txt .
+ Also available: <kernel_source>/Documentation/scsi/scsi-generic.txt
Utility and test programs are available at the sg web site. They are
- bundled as sg_utils (for the lk 2.2 series) and sg3_utils (for the
- lk 2.4 series).
-
- There is a HOWTO on the Linux SCSI subsystem in the lk 2.4 series at:
- http://www.linuxdoc.org/HOWTO/SCSI-2.4-HOWTO
+ packaged as sg3_utils (for the lk 2.4 and 2.6 series) and sg_utils
+ (for the lk 2.2 series).
*/
typedef struct sg_iovec /* same structure as used by readv() Linux system */
{ /* call. It defines one scatter-gather element. */
- void * iov_base; /* Starting address */
+ void __user *iov_base; /* Starting address */
size_t iov_len; /* Length in bytes */
} sg_iovec_t;
unsigned char mx_sb_len; /* [i] max length to write to sbp */
unsigned short iovec_count; /* [i] 0 implies no scatter gather */
unsigned int dxfer_len; /* [i] byte count of data transfer */
- void * dxferp; /* [i], [*io] points to data transfer memory
+ void __user *dxferp; /* [i], [*io] points to data transfer memory
or scatter gather list */
- unsigned char * cmdp; /* [i], [*i] points to command to perform */
- unsigned char * sbp; /* [i], [*o] points to sense_buffer memory */
+ unsigned char __user *cmdp; /* [i], [*i] points to command to perform */
+ void __user *sbp; /* [i], [*o] points to sense_buffer memory */
unsigned int timeout; /* [i] MAX_UINT->no timeout (unit: millisec) */
unsigned int flags; /* [i] 0 -> default, see SG_FLAG... */
int pack_id; /* [i->o] unused internally (normally) */
- void * usr_ptr; /* [i->o] unused internally */
+ void __user * usr_ptr; /* [i->o] unused internally */
unsigned char status; /* [o] scsi status */
unsigned char masked_status;/* [o] shifted, masked scsi status */
unsigned char msg_status; /* [o] messaging level data (optional) */
char sg_io_owned; /* 0 -> complete with read(), 1 -> owned by SG_IO */
char problem; /* 0 -> no problem detected, 1 -> error to report */
int pack_id; /* pack_id associated with request */
- void * usr_ptr; /* user provided pointer (in new interface) */
+ void __user *usr_ptr; /* user provided pointer (in new interface) */
unsigned int duration; /* millisecs elapsed since written (req_state==1)
or request duration (req_state==2) */
int unused;
#define SG_GET_ACCESS_COUNT 0x2289
-#define SG_SCATTER_SZ (8 * 4096) /* PAGE_SIZE not available to user */
+#define SG_SCATTER_SZ (8 * 4096)
/* Largest size (in bytes) a single scatter-gather list element can have.
- The value must be a power of 2 and <= (PAGE_SIZE * 32) [131072 bytes on
- i386]. The minimum value is PAGE_SIZE. If scatter-gather not supported
- by adapter then this value is the largest data block that can be
- read/written by a single scsi command. The user can find the value of
- PAGE_SIZE by calling getpagesize() defined in unistd.h . */
+ The value used by the driver is 'max(SG_SCATTER_SZ, PAGE_SIZE)'.
+ This value should be a power of 2 (and may be rounded up internally).
+ If scatter-gather is not supported by adapter then this value is the
+ largest data block that can be read/written by a single scsi command. */
#define SG_DEFAULT_RETRIES 0
git://git.onelab.eu / linux-2.6.git / blobdiff