--- /dev/null
+ Summary of HDIO_ ioctl calls.
+ ============================
+
+ Edward A. Falk <efalk@google.com>
+
+ November, 2004
+
+This document attempts to describe the ioctl(2) calls supported by
+the HD/IDE layer. These are by-and-large implemented (as of Linux 2.6)
+in drivers/ide/ide.c and drivers/block/scsi_ioctl.c
+
+ioctl values are listed in <linux/hdreg.h>. As of this writing, they
+are as follows:
+
+ ioctls that pass argument pointers to user space:
+
+ HDIO_GETGEO get device geometry
+ HDIO_GET_UNMASKINTR get current unmask setting
+ HDIO_GET_MULTCOUNT get current IDE blockmode setting
+ HDIO_GET_QDMA get use-qdma flag
+ HDIO_SET_XFER set transfer rate via proc
+ HDIO_OBSOLETE_IDENTITY OBSOLETE, DO NOT USE
+ HDIO_GET_KEEPSETTINGS get keep-settings-on-reset flag
+ HDIO_GET_32BIT get current io_32bit setting
+ HDIO_GET_NOWERR get ignore-write-error flag
+ HDIO_GET_DMA get use-dma flag
+ HDIO_GET_NICE get nice flags
+ HDIO_GET_IDENTITY get IDE identification info
+ HDIO_GET_WCACHE get write cache mode on|off
+ HDIO_GET_ACOUSTIC get acoustic value
+ HDIO_GET_ADDRESS get sector addressing mode
+ HDIO_GET_BUSSTATE get the bus state of the hwif
+ HDIO_TRISTATE_HWIF execute a channel tristate
+ HDIO_DRIVE_RESET execute a device reset
+ HDIO_DRIVE_TASKFILE execute raw taskfile
+ HDIO_DRIVE_TASK execute task and special drive command
+ HDIO_DRIVE_CMD execute a special drive command
+ HDIO_DRIVE_CMD_AEB HDIO_DRIVE_TASK
+
+ ioctls that pass non-pointer values:
+
+ HDIO_SET_MULTCOUNT change IDE blockmode
+ HDIO_SET_UNMASKINTR permit other irqs during I/O
+ HDIO_SET_KEEPSETTINGS keep ioctl settings on reset
+ HDIO_SET_32BIT change io_32bit flags
+ HDIO_SET_NOWERR change ignore-write-error flag
+ HDIO_SET_DMA change use-dma flag
+ HDIO_SET_PIO_MODE reconfig interface to new speed
+ HDIO_SCAN_HWIF register and (re)scan interface
+ HDIO_SET_NICE set nice flags
+ HDIO_UNREGISTER_HWIF unregister interface
+ HDIO_SET_WCACHE change write cache enable-disable
+ HDIO_SET_ACOUSTIC change acoustic behavior
+ HDIO_SET_BUSSTATE set the bus state of the hwif
+ HDIO_SET_QDMA change use-qdma flag
+ HDIO_SET_ADDRESS change lba addressing modes
+
+ HDIO_SET_IDE_SCSI Set scsi emulation mode on/off
+ HDIO_SET_SCSI_IDE not implemented yet
+
+
+The information that follows was determined from reading kernel source
+code. It is likely that some corrections will be made over time.
+
+
+
+
+
+
+
+General:
+
+ Unless otherwise specified, all ioctl calls return 0 on success
+ and -1 with errno set to an appropriate value on error.
+
+ Unless otherwise specified, all ioctl calls return -1 and set
+ errno to EFAULT on a failed attempt to copy data to or from user
+ address space.
+
+ Unless otherwise specified, all data structures and constants
+ are defined in <linux/hdreg.h>
+
+
+
+HDIO_GETGEO get device geometry
+
+ usage:
+
+ struct hd_geometry geom;
+ ioctl(fd, HDIO_GETGEO, &geom);
+
+
+ inputs: none
+
+ outputs:
+
+ hd_geometry structure containing:
+
+ heads number of heads
+ sectors number of sectors/track
+ cylinders number of cylinders, mod 65536
+ start starting sector of this partition.
+
+
+ error returns:
+ EINVAL if the device is not a disk drive or floppy drive,
+ or if the user passes a null pointer
+
+
+ notes:
+
+ Not particularly useful with modern disk drives, whose geometry
+ is a polite fiction anyway. Modern drives are addressed
+ purely by sector number nowadays (lba addressing), and the
+ drive geometry is an abstraction which is actually subject
+ to change. Currently (as of Nov 2004), the geometry values
+ are the "bios" values -- presumably the values the drive had
+ when Linux first booted.
+
+ In addition, the cylinders field of the hd_geometry is an
+ unsigned short, meaning that on most architectures, this
+ ioctl will not return a meaningful value on drives with more
+ than 65535 tracks.
+
+ The start field is unsigned long, meaning that it will not
+ contain a meaningful value for disks over 219 Gb in size.
+
+
+
+
+HDIO_GET_UNMASKINTR get current unmask setting
+
+ usage:
+
+ long val;
+ ioctl(fd, HDIO_GET_UNMASKINTR, &val);
+
+ inputs: none
+
+ outputs:
+ The value of the drive's current unmask setting
+
+
+
+HDIO_SET_UNMASKINTR permit other irqs during I/O
+
+ usage:
+
+ unsigned long val;
+ ioctl(fd, HDIO_SET_UNMASKINTR, val);
+
+ inputs:
+ New value for unmask flag
+
+ outputs: none
+
+ error return:
+ EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ EACCES Access denied: requires CAP_SYS_ADMIN
+ EINVAL value out of range [0 1]
+ EBUSY Controller busy
+
+
+
+
+HDIO_GET_MULTCOUNT get current IDE blockmode setting
+
+ usage:
+
+ long val;
+ ioctl(fd, HDIO_GET_MULTCOUNT, &val);
+
+ inputs: none
+
+ outputs:
+ The value of the current IDE block mode setting. This
+ controls how many sectors the drive will transfer per
+ interrupt.
+
+
+
+HDIO_SET_MULTCOUNT change IDE blockmode
+
+ usage:
+
+ int val;
+ ioctl(fd, HDIO_SET_MULTCOUNT, val);
+
+ inputs:
+ New value for IDE block mode setting. This controls how many
+ sectors the drive will transfer per interrupt.
+
+ outputs: none
+
+ error return:
+ EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ EACCES Access denied: requires CAP_SYS_ADMIN
+ EINVAL value out of range supported by disk.
+ EBUSY Controller busy or blockmode already set.
+ EIO Drive did not accept new block mode.
+
+ notes:
+
+ Source code comments read:
+
+ This is tightly woven into the driver->do_special can not
+ touch. DON'T do it again until a total personality rewrite
+ is committed.
+
+ If blockmode has already been set, this ioctl will fail with
+ EBUSY
+
+
+
+HDIO_GET_QDMA get use-qdma flag
+
+ Not implemented, as of 2.6.8.1
+
+
+
+HDIO_SET_XFER set transfer rate via proc
+
+ Not implemented, as of 2.6.8.1
+
+
+
+HDIO_OBSOLETE_IDENTITY OBSOLETE, DO NOT USE
+
+ Same as HDIO_GET_IDENTITY (see below), except that it only
+ returns the first 142 bytes of drive identity information.
+
+
+
+HDIO_GET_IDENTITY get IDE identification info
+
+ usage:
+
+ unsigned char identity[512];
+ ioctl(fd, HDIO_GET_IDENTITY, identity);
+
+ inputs: none
+
+ outputs:
+
+ ATA drive identity information. For full description, see
+ the IDENTIFY DEVICE and IDENTIFY PACKET DEVICE commands in
+ the ATA specification.
+
+ error returns:
+ EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ ENOMSG IDENTIFY DEVICE information not available
+
+ notes:
+
+ Returns information that was obtained when the drive was
+ probed. Some of this information is subject to change, and
+ this ioctl does not re-probe the drive to update the
+ information.
+
+ This information is also available from /proc/ide/hdX/identify
+
+
+
+HDIO_GET_KEEPSETTINGS get keep-settings-on-reset flag
+
+ usage:
+
+ long val;
+ ioctl(fd, HDIO_GET_KEEPSETTINGS, &val);
+
+ inputs: none
+
+ outputs:
+ The value of the current "keep settings" flag
+
+ notes:
+
+ When set, indicates that kernel should restore settings
+ after a drive reset.
+
+
+
+HDIO_SET_KEEPSETTINGS keep ioctl settings on reset
+
+ usage:
+
+ long val;
+ ioctl(fd, HDIO_SET_KEEPSETTINGS, val);
+
+ inputs:
+ New value for keep_settings flag
+
+ outputs: none
+
+ error return:
+ EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ EACCES Access denied: requires CAP_SYS_ADMIN
+ EINVAL value out of range [0 1]
+ EBUSY Controller busy
+
+
+
+HDIO_GET_32BIT get current io_32bit setting
+
+ usage:
+
+ long val;
+ ioctl(fd, HDIO_GET_32BIT, &val);
+
+ inputs: none
+
+ outputs:
+ The value of the current io_32bit setting
+
+ notes:
+
+ 0=16-bit, 1=32-bit, 2,3 = 32bit+sync
+
+
+
+HDIO_GET_NOWERR get ignore-write-error flag
+
+ usage:
+
+ long val;
+ ioctl(fd, HDIO_GET_NOWERR, &val);
+
+ inputs: none
+
+ outputs:
+ The value of the current ignore-write-error flag
+
+
+
+HDIO_GET_DMA get use-dma flag
+
+ usage:
+
+ long val;
+ ioctl(fd, HDIO_GET_DMA, &val);
+
+ inputs: none
+
+ outputs:
+ The value of the current use-dma flag
+
+
+
+HDIO_GET_NICE get nice flags
+
+ usage:
+
+ long nice;
+ ioctl(fd, HDIO_GET_NICE, &nice);
+
+ inputs: none
+
+ outputs:
+
+ The drive's "nice" values.
+
+ notes:
+
+ Per-drive flags which determine when the system will give more
+ bandwidth to other devices sharing the same IDE bus.
+ See <linux/hdreg.h>, near symbol IDE_NICE_DSC_OVERLAP.
+
+
+
+
+HDIO_SET_NICE set nice flags
+
+ usage:
+
+ unsigned long nice;
+ ...
+ ioctl(fd, HDIO_SET_NICE, nice);
+
+ inputs:
+ bitmask of nice flags.
+
+ outputs: none
+
+ error returns:
+ EACCES Access denied: requires CAP_SYS_ADMIN
+ EPERM Flags other than DSC_OVERLAP and NICE_1 set.
+ EPERM DSC_OVERLAP specified but not supported by drive
+
+ notes:
+
+ This ioctl sets the DSC_OVERLAP and NICE_1 flags from values
+ provided by the user.
+
+ Nice flags are listed in <linux/hdreg.h>, starting with
+ IDE_NICE_DSC_OVERLAP. These values represent shifts.
+
+
+
+
+
+HDIO_GET_WCACHE get write cache mode on|off
+
+ usage:
+
+ long val;
+ ioctl(fd, HDIO_GET_WCACHE, &val);
+
+ inputs: none
+
+ outputs:
+ The value of the current write cache mode
+
+
+
+HDIO_GET_ACOUSTIC get acoustic value
+
+ usage:
+
+ long val;
+ ioctl(fd, HDIO_GET_ACOUSTIC, &val);
+
+ inputs: none
+
+ outputs:
+ The value of the current acoustic settings
+
+ notes:
+
+ See HDIO_SET_ACOUSTIC
+
+
+
+HDIO_GET_ADDRESS
+
+ usage:
+
+ long val;
+ ioctl(fd, HDIO_GET_ADDRESS, &val);
+
+ inputs: none
+
+ outputs:
+ The value of the current addressing mode:
+ 0 = 28-bit
+ 1 = 48-bit
+ 2 = 48-bit doing 28-bit
+ 3 = 64-bit
+
+
+
+HDIO_GET_BUSSTATE get the bus state of the hwif
+
+ usage:
+
+ long state;
+ ioctl(fd, HDIO_SCAN_HWIF, &state);
+
+ inputs: none
+
+ outputs:
+ Current power state of the IDE bus. One of BUSSTATE_OFF,
+ BUSSTATE_ON, or BUSSTATE_TRISTATE
+
+ error returns:
+ EACCES Access denied: requires CAP_SYS_ADMIN
+
+
+
+
+HDIO_SET_BUSSTATE set the bus state of the hwif
+
+ usage:
+
+ int state;
+ ...
+ ioctl(fd, HDIO_SCAN_HWIF, state);
+
+ inputs:
+ Desired IDE power state. One of BUSSTATE_OFF, BUSSTATE_ON,
+ or BUSSTATE_TRISTATE
+
+ outputs: none
+
+ error returns:
+ EACCES Access denied: requires CAP_SYS_RAWIO
+ EOPNOTSUPP Hardware interface does not support bus power control
+
+
+
+
+HDIO_TRISTATE_HWIF execute a channel tristate
+
+ Not implemented, as of 2.6.8.1. See HDIO_SET_BUSSTATE
+
+
+
+HDIO_DRIVE_RESET execute a device reset
+
+ usage:
+
+ int args[3]
+ ...
+ ioctl(fd, HDIO_DRIVE_RESET, args);
+
+ inputs: none
+
+ outputs: none
+
+ error returns:
+ EACCES Access denied: requires CAP_SYS_ADMIN
+
+ notes:
+
+ Abort any current command, prevent anything else from being
+ queued, execute a reset on the device, and issue BLKRRPART
+ ioctl on the block device.
+
+ Executes an ATAPI soft reset if applicable, otherwise
+ executes an ATA soft reset on the controller.
+
+
+
+HDIO_DRIVE_TASKFILE execute raw taskfile
+
+ Note: If you don't have a copy of the ANSI ATA specification
+ handy, you should probably ignore this ioctl.
+
+ Execute an ATA disk command directly by writing the "taskfile"
+ registers of the drive. Requires ADMIN and RAWIO access
+ privileges.
+
+ usage:
+
+ struct {
+ ide_task_request_t req_task;
+ u8 outbuf[OUTPUT_SIZE];
+ u8 inbuf[INPUT_SIZE];
+ } task;
+ memset(&task.req_task, 0, sizeof(task.req_task));
+ task.req_task.out_size = sizeof(task.outbuf);
+ task.req_task.in_size = sizeof(task.inbuf);
+ ...
+ ioctl(fd, HDIO_DRIVE_TASKFILE, &task);
+ ...
+
+ inputs:
+
+ (See below for details on memory area passed to ioctl.)
+
+ io_ports[8] values to be written to taskfile registers
+ hob_ports[8] high-order bytes, for extended commands.
+ out_flags flags indicating which registers are valid
+ in_flags flags indicating which registers should be returned
+ data_phase see below
+ req_cmd command type to be executed
+ out_size size of output buffer
+ outbuf buffer of data to be transmitted to disk
+ inbuf buffer of data to be received from disk (see [1])
+
+ outputs:
+
+ io_ports[] values returned in the taskfile registers
+ hob_ports[] high-order bytes, for extended commands.
+ out_flags flags indicating which registers are valid (see [2])
+ in_flags flags indicating which registers should be returned
+ outbuf buffer of data to be transmitted to disk (see [1])
+ inbuf buffer of data to be received from disk
+
+ error returns:
+ EACCES CAP_SYS_ADMIN or CAP_SYS_RAWIO privilege not set.
+ ENOMSG Device is not a disk drive.
+ ENOMEM Unable to allocate memory for task
+ EFAULT req_cmd == TASKFILE_IN_OUT (not implemented as of 2.6.8)
+ EPERM req_cmd == TASKFILE_MULTI_OUT and drive
+ multi-count not yet set.
+
+
+ notes:
+
+ [1] Currently (2.6.8), both the input and output buffers are
+ copied from the user and written back to the user, even when
+ not used. This may be a bug.
+
+ [2] The out_flags and in_flags are returned to the user after
+ the ioctl completes. Currently (2.6.8) these are the same
+ as the input values, unchanged. In the future, they may have
+ more significance.
+
+ Extreme caution should be used with using this ioctl. A
+ mistake can easily corrupt data or hang the system.
+
+ The argument to the ioctl is a pointer to a region of memory
+ containing a ide_task_request_t structure, followed by an
+ optional buffer of data to be transmitted to the drive,
+ followed by an optional buffer to receive data from the drive.
+
+ Command is passed to the disk drive via the ide_task_request_t
+ structure, which contains these fields:
+
+ io_ports[8] values for the taskfile registers
+ hob_ports[8] high-order bytes, for extended commands
+ out_flags flags indicating which entries in the
+ io_ports[] and hob_ports[] arrays
+ contain valid values. Type ide_reg_valid_t.
+ in_flags flags indicating which entries in the
+ io_ports[] and hob_ports[] arrays
+ are expected to contain valid values
+ on return.
+ data_phase See below
+ req_cmd Command type, see below
+ out_size output (user->drive) buffer size, bytes
+ in_size input (drive->user) buffer size, bytes
+
+ This ioctl does not necessarily respect all flags in the
+ out_flags and in_flags values -- some taskfile registers
+ may be written or read even if not requested in the flags.
+ Unused fields of io_ports[] and hob_ports[] should be set
+ to zero.
+
+ The data_phase field describes the data transfer to be
+ performed. Value is one of:
+
+ TASKFILE_IN
+ TASKFILE_MULTI_IN
+ TASKFILE_OUT
+ TASKFILE_MULTI_OUT
+ TASKFILE_IN_OUT
+ TASKFILE_IN_DMA
+ TASKFILE_IN_DMAQ
+ TASKFILE_OUT_DMA
+ TASKFILE_OUT_DMAQ
+ TASKFILE_P_IN
+ TASKFILE_P_IN_DMA
+ TASKFILE_P_IN_DMAQ
+ TASKFILE_P_OUT
+ TASKFILE_P_OUT_DMA
+ TASKFILE_P_OUT_DMAQ
+
+ The req_cmd field classifies the command type. It may be
+ one of:
+
+ IDE_DRIVE_TASK_NO_DATA
+ IDE_DRIVE_TASK_SET_XFER
+ IDE_DRIVE_TASK_IN
+ IDE_DRIVE_TASK_OUT
+ IDE_DRIVE_TASK_RAW_WRITE
+
+
+
+
+
+
+HDIO_DRIVE_CMD execute a special drive command
+
+ Note: If you don't have a copy of the ANSI ATA specification
+ handy, you should probably ignore this ioctl.
+
+ usage:
+
+ u8 args[4+XFER_SIZE];
+ ...
+ ioctl(fd, HDIO_DRIVE_CMD, args);
+
+ inputs:
+
+ Taskfile register values:
+ args[0] COMMAND
+ args[1] SECTOR
+ args[2] FEATURE
+ args[3] NSECTOR
+
+ outputs:
+
+ args[] buffer is filled with register values followed by any
+ data returned by the disk.
+ args[0] status
+ args[1] error
+ args[2] NSECTOR
+ args[3] undefined
+ args[4+] NSECTOR * 512 bytes of data returned by the command.
+
+ error returns:
+ EACCES Access denied: requires CAP_SYS_RAWIO
+ ENOMEM Unable to allocate memory for task
+
+ notes:
+
+ Taskfile registers IDE_LCYL, IDE_HCYL, and IDE_SELECT are
+ set to zero before executing the command.
+
+
+
+HDIO_DRIVE_TASK execute task and special drive command
+
+ Note: If you don't have a copy of the ANSI ATA specification
+ handy, you should probably ignore this ioctl.
+
+ usage:
+
+ u8 args[7];
+ ...
+ ioctl(fd, HDIO_DRIVE_TASK, args);
+
+ inputs:
+
+ Taskfile register values:
+ args[0] COMMAND
+ args[1] FEATURE
+ args[2] NSECTOR
+ args[3] SECTOR
+ args[4] LCYL
+ args[5] HCYL
+ args[6] SELECT
+
+ outputs:
+
+ Taskfile register values:
+ args[0] status
+ args[1] error
+ args[2] NSECTOR
+ args[3] SECTOR
+ args[4] LCYL
+ args[5] HCYL
+ args[6] SELECT
+
+ error returns:
+ EACCES Access denied: requires CAP_SYS_RAWIO
+ ENOMEM Unable to allocate memory for task
+
+
+
+
+HDIO_DRIVE_CMD_AEB HDIO_DRIVE_TASK
+
+ Not implemented, as of 2.6.8.1
+
+
+
+HDIO_SET_32BIT change io_32bit flags
+
+ usage:
+
+ int val;
+ ioctl(fd, HDIO_SET_32BIT, val);
+
+ inputs:
+ New value for io_32bit flag
+
+ outputs: none
+
+ error return:
+ EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ EACCES Access denied: requires CAP_SYS_ADMIN
+ EINVAL value out of range [0 3]
+ EBUSY Controller busy
+
+
+
+
+HDIO_SET_NOWERR change ignore-write-error flag
+
+ usage:
+
+ int val;
+ ioctl(fd, HDIO_SET_NOWERR, val);
+
+ inputs:
+ New value for ignore-write-error flag. Used for ignoring
+ WRERR_STAT
+
+ outputs: none
+
+ error return:
+ EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ EACCES Access denied: requires CAP_SYS_ADMIN
+ EINVAL value out of range [0 1]
+ EBUSY Controller busy
+
+
+
+HDIO_SET_DMA change use-dma flag
+
+ usage:
+
+ long val;
+ ioctl(fd, HDIO_SET_DMA, val);
+
+ inputs:
+ New value for use-dma flag
+
+ outputs: none
+
+ error return:
+ EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ EACCES Access denied: requires CAP_SYS_ADMIN
+ EINVAL value out of range [0 1]
+ EBUSY Controller busy
+
+
+
+HDIO_SET_PIO_MODE reconfig interface to new speed
+
+ usage:
+
+ long val;
+ ioctl(fd, HDIO_SET_PIO_MODE, val);
+
+ inputs:
+ New interface speed.
+
+ outputs: none
+
+ error return:
+ EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ EACCES Access denied: requires CAP_SYS_ADMIN
+ EINVAL value out of range [0 255]
+ EBUSY Controller busy
+
+
+
+HDIO_SCAN_HWIF register and (re)scan interface
+
+ usage:
+
+ int args[3]
+ ...
+ ioctl(fd, HDIO_SCAN_HWIF, args);
+
+ inputs:
+ args[0] io address to probe
+ args[1] control address to probe
+ args[2] irq number
+
+ outputs: none
+
+ error returns:
+ EACCES Access denied: requires CAP_SYS_RAWIO
+ EIO Probe failed.
+
+ notes:
+
+ This ioctl initializes the addresses and irq for a disk
+ controller, probes for drives, and creates /proc/ide
+ interfaces as appropiate.
+
+
+
+HDIO_UNREGISTER_HWIF unregister interface
+
+ usage:
+
+ int index;
+ ioctl(fd, HDIO_UNREGISTER_HWIF, index);
+
+ inputs:
+ index index of hardware interface to unregister
+
+ outputs: none
+
+ error returns:
+ EACCES Access denied: requires CAP_SYS_RAWIO
+
+ notes:
+
+ This ioctl removes a hardware interface from the kernel.
+
+ Currently (2.6.8) this ioctl silently fails if any drive on
+ the interface is busy.
+
+
+
+HDIO_SET_WCACHE change write cache enable-disable
+
+ usage:
+
+ int val;
+ ioctl(fd, HDIO_SET_WCACHE, val);
+
+ inputs:
+ New value for write cache enable
+
+ outputs: none
+
+ error return:
+ EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ EACCES Access denied: requires CAP_SYS_ADMIN
+ EINVAL value out of range [0 1]
+ EBUSY Controller busy
+
+
+
+HDIO_SET_ACOUSTIC change acoustic behavior
+
+ usage:
+
+ int val;
+ ioctl(fd, HDIO_SET_ACOUSTIC, val);
+
+ inputs:
+ New value for drive acoustic settings
+
+ outputs: none
+
+ error return:
+ EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ EACCES Access denied: requires CAP_SYS_ADMIN
+ EINVAL value out of range [0 254]
+ EBUSY Controller busy
+
+
+
+HDIO_SET_QDMA change use-qdma flag
+
+ Not implemented, as of 2.6.8.1
+
+
+
+HDIO_SET_ADDRESS change lba addressing modes
+
+ usage:
+
+ int val;
+ ioctl(fd, HDIO_SET_ADDRESS, val);
+
+ inputs:
+ New value for addressing mode
+ 0 = 28-bit
+ 1 = 48-bit
+ 2 = 48-bit doing 28-bit
+
+ outputs: none
+
+ error return:
+ EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ EACCES Access denied: requires CAP_SYS_ADMIN
+ EINVAL value out of range [0 2]
+ EBUSY Controller busy
+ EIO Drive does not support lba48 mode.
+
+
+HDIO_SET_IDE_SCSI
+
+ usage:
+
+ long val;
+ ioctl(fd, HDIO_SET_IDE_SCSI, val);
+
+ inputs:
+ New value for scsi emulation mode (?)
+
+ outputs: none
+
+ error return:
+ EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ EACCES Access denied: requires CAP_SYS_ADMIN
+ EINVAL value out of range [0 1]
+ EBUSY Controller busy
+
+
+
+HDIO_SET_SCSI_IDE
+
+ Not implemented, as of 2.6.8.1
+
+