ide: dynamic allocation of device structures

Allocate device structures dynamically instead of having them embedded
in ide_hwif_t:

* Remove needless zeroing of port structure from ide_init_port_data().

* Add ide_hwif_t.devices[MAX_DRIVES] (table of pointers to the devices).

* Add ide_port_{alloc,free}_devices() helpers and use them respectively
  in ide_{host,free}_alloc().

* Convert all users of ->drives[] to use ->devices[] instead.

While at it:

* Use drive->dn for the slave device check in scc_pata.c.

As a nice side-effect this patch cuts ~1kB (x86-32) from the resulting
code size:

   text    data     bss     dec     hex filename
  53963    1244     237   55444    d894 drivers/ide/ide-core.o.before
  52981    1244     237   54462    d4be drivers/ide/ide-core.o.after

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/ide.h b/include/linux/ide.h
index 9f6fe1fe7a6c..f00086b10be3 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -753,7 +753,7 @@ typedef struct hwif_s {
 
         unsigned long   sata_scr[SATA_NR_PORTS];
 
-        ide_drive_t     drives[MAX_DRIVES];     /* drive info */
+        ide_drive_t     *devices[MAX_DRIVES];
 
         u8 major;       /* our major number */
         u8 index;       /* 0 for ide0; 1 for ide1; ... */
@@ -1600,7 +1600,7 @@ static inline int hwif_to_node(ide_hwif_t *hwif)
 
 static inline ide_drive_t *ide_get_pair_dev(ide_drive_t *drive)
 {
-        ide_drive_t *peer = &drive->hwif->drives[(drive->dn ^ 1) & 1];
+        ide_drive_t *peer = drive->hwif->devices[(drive->dn ^ 1) & 1];
 
         return (peer->dev_flags & IDE_DFLAG_PRESENT) ? peer : NULL;
 }