ide: remove 'command_type' field from ide_task_t

* Add 'data_buf' and 'nsect' variables in ide_taskfile_ioctl()
  to cache data buffer pointer and number of sectors to transfer
  (this allows us to have only one ide_diag_taskfile() call).

* Add IDE_TFLAG_WRITE taskfile flag and use it to check whether
  the REQ_RW request flag should be set.

* Move ->command_type handling from ide_diag_taskfile() to
  ide_taskfile_ioctl() and use ->req_cmd instead of ->command_type.

* Add 'nsect' parameter to ide_raw_taskfile().

* Merge ide_diag_taskfile() into ide_raw_taskfile().

* Initialize ->data_phase explicitly in idedisk_prepare_flush(),
  ide_start_power_step() and ide_disk_special().

* Remove no longer needed 'command_type' field from ide_task_t.

* Add #ifndef/#endif __KERNEL__ to <linux/hdreg.h> around no
  longer used by kernel IDE_DRIVE_TASK_* and TASKFILE_* defines.

There should be no functionality changes caused by this patch.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

include/linux/hdreg.h

@@ -73,13 +73,13 @@
 #define HDIO_DRIVE_HOB_HDR_SIZE		(8 * sizeof(__u8))
 #define HDIO_DRIVE_TASK_HDR_SIZE	(8 * sizeof(__u8))
 
-#define IDE_DRIVE_TASK_INVALID		-1
 #define IDE_DRIVE_TASK_NO_DATA		0
+#ifndef __KERNEL__
+#define IDE_DRIVE_TASK_INVALID		-1
 #define IDE_DRIVE_TASK_SET_XFER		1
-
 #define IDE_DRIVE_TASK_IN		2
-
 #define IDE_DRIVE_TASK_OUT		3
+#endif
 #define IDE_DRIVE_TASK_RAW_WRITE	4
 
 /*
@@ -166,9 +166,6 @@ typedef struct hd_drive_hob_hdr {
 } hob_struct_t;
 #endif
 
-#define TASKFILE_INVALID		0x7fff
-#define TASKFILE_48			0x8000
-
 #define TASKFILE_NO_DATA		0x0000
 
 #define TASKFILE_IN			0x0001
@@ -183,12 +180,16 @@ typedef struct hd_drive_hob_hdr {
 #define TASKFILE_IN_DMAQ		0x0080
 #define TASKFILE_OUT_DMAQ		0x0100
 
+#ifndef __KERNEL__
 #define TASKFILE_P_IN			0x0200
 #define TASKFILE_P_OUT			0x0400
 #define TASKFILE_P_IN_DMA		0x0800
 #define TASKFILE_P_OUT_DMA		0x1000
 #define TASKFILE_P_IN_DMAQ		0x2000
 #define TASKFILE_P_OUT_DMAQ		0x4000
+#define TASKFILE_48			0x8000
+#define TASKFILE_INVALID		0x7fff
+#endif
 
 /* ATA/ATAPI Commands pre T13 Spec */
 #define WIN_NOP				0x00