[coreboot-gerrit] Change in coreboot[master]: arch/x86: Reserve some CAR memory for FSP single stack requirement

[Subrata Banik (Code Review)]

Hello Kyösti Mälkki, Aaron Durbin, Patrick Rudolph, Nathaniel L Desimone, Julius Werner, Angel Pons, Kane Chen, Aamir Bohra, build bot (Jenkins), Furquan Shaikh, Meera Ravindranath, Usha P, Tim Wawrzynczak, Philipp Deppenwiese, V Sowmya,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/35165

to look at the new patch set (#9).

Change subject: arch/x86: Reserve some CAR memory for FSP single stack requirement
......................................................................

arch/x86: Reserve some CAR memory for FSP single stack requirement

From FSP2.1 onwards stack and heap requirement has changed
(For documentation on this feature, please see page 25 of the
FSP v2.1 specification (https://cdrdv2.intel.com/v1/dl/getContent/611786))

arch_upd->StackBase will refer as Heap Start for HOB and arch_upd->StackSize
will be heap size.

As FSP and coreboot will share same stack hence FSP doesn't need dedicated
UPD to pass stack start information.

But FSP might need to know where to keep HOB heap and for the same purpose
it uses StackBase and StackSize UPDs (names are confusing!)

Proposed to reserve a small region above _car_global_end with platform
given FSP_DCACHE_HEAP_SIZE for FSP to keep HOB heap.

+--------------+ _car_region_end
                 |              |
 FSP heap end    +--------------+ _car_fsp_heap_end
                 |heap          |
 FSP heap base   +--------------+ _car_fsp_heap_start/_car_global_end
                 |car global    |
                 +--------------+ _car_global_start
                 +--------------+ _car_relocatable_data_start
                 +--------------+ _car_stack_end
                 |              |
                 +--------------+
                 |stack_guard   |
                 +--------------+ _car_stack_start
                 |vboot         |
                 +--------------+
                 +--------------+ _car_region_start

Set default value for FSP_DCACHE_HEAP_SIZE is 64KB for now. Platform should
override the default value from soc/intel/<platform>/Kconfig if required.

(Right now CML & ICL, FSP requires at least heap size is 64KB and stack is 128KB)

BUG=b:140268415
TEST=Build and boot CML-Hatch and ICL.

With this CL
No "Smashed stack detected in romstage" msg in serial log.

Change-Id: I943eff1225b976dc4440a6ca6d02ceea378319f8
Signed-off-by: Subrata Banik 
---
M src/arch/x86/car.ld
M src/arch/x86/include/arch/symbols.h
M src/drivers/intel/fsp2_0/Kconfig
M src/drivers/intel/fsp2_0/memory_init.c
4 files changed, 62 insertions(+), 12 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/65/35165/9