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, 3 insertions, 2 deletions

diff --git a/drivers/ide/scc_pata.c b/drivers/ide/scc_pata.c
index 90574ab76345..841164d7d3b9 100644
--- a/drivers/ide/scc_pata.c
+++ b/drivers/ide/scc_pata.c
@@ -259,7 +259,7 @@ static void scc_set_dma_mode(ide_drive_t *drive, const u8 speed)
         unsigned long scrcst_port = ctl_base + 0x014;
         unsigned long udenvt_port = ctl_base + 0x018;
         unsigned long tdvhsel_port   = ctl_base + 0x020;
-        int is_slave = (&hwif->drives[1] == drive);
+        int is_slave = drive->dn & 1;
         int offset, idx;
         unsigned long reg;
         unsigned long jcactsel;
@@ -413,7 +413,8 @@ static int scc_dma_end(ide_drive_t *drive)
                                 if (rq)
                                         rq->errors |= ERROR_RESET;
                                 for (unit = 0; unit < MAX_DRIVES; unit++) {
-                                        ide_drive_t *drive = &hwif->drives[unit];
+                                        ide_drive_t *drive = hwif->devices[unit];
+
                                         drive->crc_count++;
                                 }
                         }