Table of interleaving modes supported in cpu/8xxx/ddr/
======================================================
  +-------------+---------------------------------------------------------+
  |             |                   Rank Interleaving                     |
  |             +--------+-----------+-----------+------------+-----------+
  |Memory       |        |           |           |    2x2     |    4x1    |
  |Controller   |  None  | 2x1 lower | 2x1 upper | {CS0+CS1}, | {CS0+CS1+ |
  |Interleaving |        | {CS0+CS1} | {CS2+CS3} | {CS2+CS3}  |  CS2+CS3} |
  +-------------+--------+-----------+-----------+------------+-----------+
  |None         |  Yes   | Yes       | Yes       | Yes        | Yes       |
  +-------------+--------+-----------+-----------+------------+-----------+
  |Cacheline    |  Yes   | Yes       | No        | No, Only(*)| Yes       |
  |             |CS0 Only|           |           | {CS0+CS1}  |           |
  +-------------+--------+-----------+-----------+------------+-----------+
  |Page         |  Yes   | Yes       | No        | No, Only(*)| Yes       |
  |             |CS0 Only|           |           | {CS0+CS1}  |           |
  +-------------+--------+-----------+-----------+------------+-----------+
  |Bank         |  Yes   | Yes       | No        | No, Only(*)| Yes       |
  |             |CS0 Only|           |           | {CS0+CS1}  |           |
  +-------------+--------+-----------+-----------+------------+-----------+
  |Superbank    |  No    | Yes       | No        | No, Only(*)| Yes       |
  |             |        |           |           | {CS0+CS1}  |           |
  +-------------+--------+-----------+-----------+------------+-----------+
 (*) Although the hardware can be configured with memory controller
 interleaving using "2x2" rank interleaving, it only interleaves {CS0+CS1}
 from each controller. {CS2+CS3} on each controller are only rank
 interleaved on that controller.

The ways to configure the ddr interleaving mode
==============================================
1. In board header file(e.g.MPC8572DS.h), add default interleaving setting
   under "CONFIG_EXTRA_ENV_SETTINGS", like:
	#define CONFIG_EXTRA_ENV_SETTINGS				\
	 "memctl_intlv_ctl=2\0"						\
	 ......

2. Run u-boot "setenv" command to configure the memory interleaving mode.
   Either numerical or string value is accepted.

  # disable memory controller interleaving
  setenv memctl_intlv_ctl

  # cacheline interleaving
  setenv memctl_intlv_ctl 0 or setenv memctl_intlv_ctl cacheline

  # page interleaving
  setenv memctl_intlv_ctl 1 or setenv memctl_intlv_ctl page

  # bank interleaving
  setenv memctl_intlv_ctl 2 or setenv memctl_intlv_ctl bank

  # superbank
  setenv memctl_intlv_ctl 3 or setenv memctl_intlv_ctl superbank

  # disable bank (chip-select) interleaving
  setenv ba_intlv_ctl

  # bank(chip-select) interleaving cs0+cs1
  setenv ba_intlv_ctl 0x40 or setenv ba_intlv_ctl cs0_cs1

  # bank(chip-select) interleaving cs2+cs3
  setenv ba_intlv_ctl 0x20 or setenv ba_intlv_ctl cs2_cs3

  # bank(chip-select) interleaving (cs0+cs1) and (cs2+cs3)  (2x2)
  setenv ba_intlv_ctl 0x60 or setenv ba_intlv_ctl cs0_cs1_and_cs2_cs3

  # bank(chip-select) interleaving (cs0+cs1+cs2+cs3) (4x1)
  setenv ba_intlv_ctl 0x04 or setenv ba_intlv_ctl cs0_cs1_cs2_cs3