ide-gd: implement block device ->set_capacity method (v2)

* Use ->probed_capacity to store native device capacity for ATA disks.

* Add ->set_capacity method to struct ide_disk_ops.

* Implement disk device ->set_capacity method for ATA disks.

* Implement block device ->set_capacity method.

v2:
* Check if LBA and HPA are supported in ide_disk_set_capacity().

* According to the spec the SET MAX ADDRESS command shall be
  immediately preceded by a READ NATIVE MAX ADDRESS command.

* Add ide_disk_hpa_{get_native,set}_capacity() helpers.

Together with the previous patch adding ->set_capacity block device
method this allows automatic disabling of Host Protected Area (HPA)
if any partitions overlapping HPA are detected.

Cc: Robert Hancock <hancockrwd@gmail.com>
Cc: Frans Pop <elendil@planet.nl>
Cc: "Andries E. Brouwer" <Andries.Brouwer@cwi.nl>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Emphatically-Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 9fed365..e96ace1 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -397,6 +397,7 @@
 struct ide_disk_ops {
 	int		(*check)(struct ide_drive_s *, const char *);
 	int		(*get_capacity)(struct ide_drive_s *);
+	u64		(*set_capacity)(struct ide_drive_s *, u64);
 	void		(*setup)(struct ide_drive_s *);
 	void		(*flush)(struct ide_drive_s *);
 	int		(*init_media)(struct ide_drive_s *, struct gendisk *);
@@ -568,8 +569,7 @@
 	unsigned int	drive_data;	/* used by set_pio_mode/dev_select() */
 	unsigned int	failures;	/* current failure count */
 	unsigned int	max_failures;	/* maximum allowed failure count */
-	u64		probed_capacity;/* initial reported media capacity (ide-cd only currently) */
-
+	u64		probed_capacity;/* initial/native media capacity */
 	u64		capacity64;	/* total number of sectors */
 
 	int		lun;		/* logical unit */