ide-disk: use do_rw_taskfile() (take 2)

* Add IDE_TFLAG_DMA_PIO_FALLBACK taskfile flag to indicate the need
  to skip loading taskfile registers in do_rw_taskfile().

* Export do_rw_taskfile().

* Convert __ide_do_rw_disk() to use do_rw_taskfile().

* Unexport ide_tf_load().

* Unexport {pre_task_out,task_in}_intr() and make it static.

* Remove incorrect comment about do_rw_taskfile() from <linux/ide.h>.

There should be no functionality changes caused by this patch.

v2:
* Add missing blk_fs_request() check to task_dma_ok() (for VDMA).

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 721c9d8..c333a75 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -912,6 +912,7 @@
 	IDE_TFLAG_FLAGGED_SET_IN_FLAGS	= (1 << 16),
 	IDE_TFLAG_IN_DATA		= (1 << 17),
 	IDE_TFLAG_CUSTOM_HANDLER	= (1 << 18),
+	IDE_TFLAG_DMA_PIO_FALLBACK	= (1 << 19),
 };
 
 struct ide_taskfile {
@@ -965,13 +966,7 @@
 
 void ide_pktcmd_tf_load(ide_drive_t *, u32, u16, u8);
 
-/*
- * taskfile io for disks for now...and builds request from ide_ioctl
- */
-extern ide_startstop_t do_rw_taskfile(ide_drive_t *, ide_task_t *);
-
-extern ide_startstop_t task_in_intr(ide_drive_t *);
-extern ide_startstop_t pre_task_out_intr(ide_drive_t *, struct request *);
+ide_startstop_t do_rw_taskfile(ide_drive_t *, ide_task_t *);
 
 int ide_raw_taskfile(ide_drive_t *, ide_task_t *, u8 *, u16);
 int ide_no_data_taskfile(ide_drive_t *, ide_task_t *);