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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>

BL31 binary size is aligned to 4KB because of the
code in include\plat\arm\common\arm_reclaim_init.ld.S:
    __INIT_CODE_UNALIGNED__ = .;
    . = ALIGN(PAGE_SIZE);
    __INIT_CODE_END__ = .;
with all the zero data after the last instruction of
BL31 code to the end of the page.
This causes increase in size of BL31 binary stored in FIP
and its loading time by BL2.
This patch reduces the size of BL31 image by moving
page alignment from __INIT_CODE_END__ to __STACKS_END__
which also increases the stack size for secondary CPUs.

Change-Id: Ie2ec503fc774c22c12ec506d74fd3ef2b0b183a9
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

The patch fixes BL31 linker script error
"Init code ends past the end of the stacks"
for platforms with number of CPUs less than 4,
which is caused by __STACKS_END__ address being
lower than __INIT_CODE_END__.
The modified BL31 linker script detects such cases
and increases the total amount of stack memory,
setting __STACKS_END__ = __INIT_CODE_END__, and
CPUs' stacks are calculated by BL31 'plat_get_my_stack'
function accordingly. For platforms with more than 4 CPUs
and __INIT_CODE_END__ < __STACKS_END__ stack memory does not
increase and allocated CPUs' stacks match the existing
implementation.
The patch removes exclusion of PSCI initialization
functions from the reclaimed .init section in
'arm_reclaim_init.ld.S' script, which increases the
size of reclaimed memory region.

Change-Id: I927773e00dd84e1ffe72f9ee534f4f2fc7b6153c
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

Previously the .init section was created even when the reclaim flag was
manually set to 0.

Change-Id: Ia9e7c7997261f54a4eca725d7ea605192f60bcf8
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>
	       Zelalem Aweke <zelalem.aweke@arm.com>

Map the initialization code for BL31 to overlap with the memory
required for the secondary cores stack. Once BL31 has been
initialized the memory can be remapped to RW data so that it can
be used for secondary cores stacks. By moving code from .text to
.text.init the size of the BL31 image is decreased by a page.

Split arm_common.ld.S into two linker scripts, one for tzc_dram
(arm_tzc_dram.ld.S) and one for reclaiming initialization code
(arm_reclaim_init.ld.S) so that platforms can chose which memory
regions they wish to include.

Change-Id: I648e88f3eda1aa71765744cf34343ecda9320b32
Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>