tree 10a3622d6a57fe02b45112fd512297238ad93dc5
parent 806af56c4dd0b58ed3afac0a80a95eeea44b5970
author Andrew Thoelke <andrew.thoelke@arm.com> 1398684519 +0100
committer Andrew Thoelke <andrew.thoelke@arm.com> 1399457987 +0100

Correct usage of data and instruction barriers

The current code does not always use data and instruction
barriers as required by the architecture and frequently uses
barriers excessively due to their inclusion in all of the
write_*() helper functions.

Barriers should be used explicitly in assembler or C code
when modifying processor state that requires the barriers in
order to enable review of correctness of the code.

This patch removes the barriers from the helper functions and
introduces them as necessary elsewhere in the code.

PORTING NOTE: check any port of Trusted Firmware for use of
system register helper functions for reliance on the previous
barrier behaviour and add explicit barriers as necessary.

Fixes ARM-software/tf-issues#92

Change-Id: Ie63e187404ff10e0bdcb39292dd9066cb84c53bf