1 files changed, 1342 insertions, 0 deletions

diff --git a/Documentation/ioctl/hdio.rst b/Documentation/ioctl/hdio.rst
new file mode 100644
index 000000000000..e822e3dff176
--- /dev/null
+++ b/Documentation/ioctl/hdio.rst
@@ -0,0 +1,1342 @@
+==============================
+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 cannot
+            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
+          - ENXIO       No such device: phy dead or ctl_addr == 0
+          - EIO         I/O error:      reset timed out or hardware error
+
+        notes:
+
+          - Execute a reset on the device as soon as the current IO
+            operation has completed.
+
+          - 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.
+          - EIO         Drive failed the command.
+
+        notes:
+
+          [1] READ THE FOLLOWING NOTES *CAREFULLY*.  THIS IOCTL IS
+          FULL OF GOTCHAS.  Extreme caution should be used with using
+          this ioctl.  A mistake can easily corrupt data or hang the
+          system.
+
+          [2] Both the input and output buffers are copied from the
+          user and written back to the user, even when not used.
+
+          [3] If one or more bits are set in out_flags and in_flags is
+          zero, the following values are used for in_flags.all and
+          written back into in_flags on completion.
+
+           * IDE_TASKFILE_STD_IN_FLAGS | (IDE_HOB_STD_IN_FLAGS << 8)
+             if LBA48 addressing is enabled for the drive
+           * IDE_TASKFILE_STD_IN_FLAGS
+             if CHS/LBA28
+
+          The association between in_flags.all and each enable
+          bitfield flips depending on endianness; fortunately, TASKFILE
+          only uses inflags.b.data bit and ignores all other bits.
+          The end result is that, on any endian machines, it has no
+          effect other than modifying in_flags on completion.
+
+          [4] The default value of SELECT is (0xa0|DEV_bit|LBA_bit)
+          except for four drives per port chipsets.  For four drives
+          per port chipsets, it's (0xa0|DEV_bit|LBA_bit) for the first
+          pair and (0x80|DEV_bit|LBA_bit) for the second pair.
+
+          [5] 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
+            ============        ===============================================
+
+          When out_flags is zero, the following registers are loaded.
+
+            ============        ===============================================
+            HOB_FEATURE         If the drive supports LBA48
+            HOB_NSECTOR         If the drive supports LBA48
+            HOB_SECTOR          If the drive supports LBA48
+            HOB_LCYL            If the drive supports LBA48
+            HOB_HCYL            If the drive supports LBA48
+            FEATURE
+            NSECTOR
+            SECTOR
+            LCYL
+            HCYL
+            SELECT              First, masked with 0xE0 if LBA48, 0xEF
+                                otherwise; then, or'ed with the default
+                                value of SELECT.
+            ============        ===============================================
+
+          If any bit in out_flags is set, the following registers are loaded.
+
+            ============        ===============================================
+            HOB_DATA            If out_flags.b.data is set.  HOB_DATA will
+                                travel on DD8-DD15 on little endian machines
+                                and on DD0-DD7 on big endian machines.
+            DATA                If out_flags.b.data is set.  DATA will
+                                travel on DD0-DD7 on little endian machines
+                                and on DD8-DD15 on big endian machines.
+            HOB_NSECTOR         If out_flags.b.nsector_hob is set
+            HOB_SECTOR          If out_flags.b.sector_hob is set
+            HOB_LCYL            If out_flags.b.lcyl_hob is set
+            HOB_HCYL            If out_flags.b.hcyl_hob is set
+            FEATURE             If out_flags.b.feature is set
+            NSECTOR             If out_flags.b.nsector is set
+            SECTOR              If out_flags.b.sector is set
+            LCYL                If out_flags.b.lcyl is set
+            HCYL                If out_flags.b.hcyl is set
+            SELECT              Or'ed with the default value of SELECT and
+                                loaded regardless of out_flags.b.select.
+            ============        ===============================================
+
+          Taskfile registers are read back from the drive into
+          {io|hob}_ports[] after the command completes iff one of the
+          following conditions is met; otherwise, the original values
+          will be written back, unchanged.
+
+            1. The drive fails the command (EIO).
+            2. One or more than one bits are set in out_flags.
+            3. The requested data_phase is TASKFILE_NO_DATA.
+
+            ============        ===============================================
+            HOB_DATA            If in_flags.b.data is set.  It will contain
+                                DD8-DD15 on little endian machines and
+                                DD0-DD7 on big endian machines.
+            DATA                If in_flags.b.data is set.  It will contain
+                                DD0-DD7 on little endian machines and
+                                DD8-DD15 on big endian machines.
+            HOB_FEATURE         If the drive supports LBA48
+            HOB_NSECTOR         If the drive supports LBA48
+            HOB_SECTOR          If the drive supports LBA48
+            HOB_LCYL            If the drive supports LBA48
+            HOB_HCYL            If the drive supports LBA48
+            NSECTOR
+            SECTOR
+            LCYL
+            HCYL
+            ============        ===============================================
+
+          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            == IN_DMA (queueing not supported)
+            TASKFILE_OUT_DMA
+            TASKFILE_OUT_DMAQ           == OUT_DMA (queueing not supported)
+            TASKFILE_P_IN               unimplemented
+            TASKFILE_P_IN_DMA           unimplemented
+            TASKFILE_P_IN_DMAQ          unimplemented
+            TASKFILE_P_OUT              unimplemented
+            TASKFILE_P_OUT_DMA          unimplemented
+            TASKFILE_P_OUT_DMAQ         unimplemented
+            ===================        ========================================
+
+          The req_cmd field classifies the command type.  It may be
+          one of:
+
+            ========================    =======================================
+            IDE_DRIVE_TASK_NO_DATA
+            IDE_DRIVE_TASK_SET_XFER     unimplemented
+            IDE_DRIVE_TASK_IN
+            IDE_DRIVE_TASK_OUT          unimplemented
+            IDE_DRIVE_TASK_RAW_WRITE
+            ========================    =======================================
+
+          [6] Do not access {in|out}_flags->all except for resetting
+          all the bits.  Always access individual bit fields.  ->all
+          value will flip depending on endianness.  For the same
+          reason, do not use IDE_{TASKFILE|HOB}_STD_{OUT|IN}_FLAGS
+          constants defined in hdreg.h.
+
+
+
+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:
+            Commands other than WIN_SMART:
+
+            =======     =======
+            args[0]     COMMAND
+            args[1]     NSECTOR
+            args[2]     FEATURE
+            args[3]     NSECTOR
+            =======     =======
+
+            WIN_SMART:
+
+            =======     =======
+            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
+          - EIO         Drive reports error
+
+        notes:
+
+          [1] For commands other than WIN_SMART, args[1] should equal
+          args[3].  SECTOR, LCYL and HCYL are undefined.  For
+          WIN_SMART, 0x4f and 0xc2 are loaded into LCYL and HCYL
+          respectively.  In both cases SELECT will contain the default
+          value for the drive.  Please refer to HDIO_DRIVE_TASKFILE
+          notes for the default value of SELECT.
+
+          [2] If NSECTOR value is greater than zero and the drive sets
+          DRQ when interrupting for the command, NSECTOR * 512 bytes
+          are read from the device into the area following NSECTOR.
+          In the above example, the area would be
+          args[4..4+XFER_SIZE].  16bit PIO is used regardless of
+          HDIO_SET_32BIT setting.
+
+          [3] If COMMAND == WIN_SETFEATURES && FEATURE == SETFEATURES_XFER
+          && NSECTOR >= XFER_SW_DMA_0 && the drive supports any DMA
+          mode, IDE driver will try to tune the transfer mode of the
+          drive accordingly.
+
+
+
+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
+          - ENOMSG      Device is not a disk drive.
+          - EIO         Drive failed the command.
+
+        notes:
+
+          [1] DEV bit (0x10) of SELECT register is ignored and the
+          appropriate value for the drive is used.  All other bits
+          are used unaltered.
+
+
+
+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 appropriate.
+
+
+
+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