tree 6a81a6b7d549bcbc75cc1b78119046d2f46d75b9
parent 2e7e42c49a3dab6fa94b007e1278bde90cc6c8da
author David Horstmann <david.horstmann@arm.com> 1602685069 +0100
committer David Horstmann <david.horstmann@arm.com> 1603907929 +0000

Use constant stack size with RECLAIM_INIT_CODE

Currently, when RECLAIM_INIT_CODE is set, the
stacks are scaled to ensure that the entirety
of the init section can be reclaimed as stack.

This causes an issue in lib/psci/aarch64/psci_helpers.S,
where the stack size is used for cache operations in
psci_do_pwrdown_cache_maintenance(). If the stacks
are scaled, then the PSCI code may fail to invalidate
some of the stack memory before power down.

Resizing stacks is also not good for stability in general,
since code that works with a small number of cores may
overflow the stack when the number of cores is increased.

Change to make every stack be PLATFORM_STACK_SIZE big,
and allow the total stack to be smaller than the
init section.

Any pages of the init section not reclaimed as
stack will be set to read-only and execute-never,
for security.

Change-Id: I10b3884981006431f2fcbec3864c81d4a8c246e8
Signed-off-by: David Horstmann <david.horstmann@arm.com>