Memory barrier

[Leonardo Fogel]

Hi.
Please, what are the correct barriers for the following cases?

Case 1:
   bus_write_1(region_0, ...);
   /* barrier here */
   DELAY(some_time);

Case 2:
   bus_write_1(region_0, ...);
   /* barrier here */
   bus_write_1(region_2, ...);

In the first one, I want the write to reach the device before the thread busy-waits. As I understand it, bus_space_barrier(9) is not adequate, because it does not prevent the processor from executing instructions (or load/store to RAM) before the write completes.

In the second one, I want the write to a device (e.g. power management) to complete before the write to another starts/completes. Again, bus_space_barrier() seems not to be adequate because it can not cover two regions.

Thank you for your time.

Leonardo