[coreboot-gerrit] Change in coreboot[master]: soc/intel/common/block/systemagent/memmap.c: Align cached region

[Angel Pons (Code Review)]

Angel Pons has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/45930 )

Change subject: soc/intel/common/block/systemagent/memmap.c: Align cached region
......................................................................

Patch Set 4:

(1 comment)

https://review.coreboot.org/c/coreboot/+/45930/4/src/soc/intel/common/block/... 
File src/soc/intel/common/block/systemagent/memmap.c:

https://review.coreboot.org/c/coreboot/+/45930/4/src/soc/intel/common/block/... 
PS4, Line 59: FSP does not seem to bother w.r.t. alignment when asked to place cbmem_top()
> Just curious, what platforms have you seen the issue and how bad is it?

I've seen it happen with the Kaby and Coffee Lake FSPs. I don't have any other platforms to test on. On Kaby Lake, I saw that it tries to use 0x79fff000 as top_of_ram which fails miserably, and then `postcar_enable_tseg_cache` fails miserably as well. On Whiskey Lake, this more or less halves the time for a fast boot (800-ish milliseconds down to 400-ish milliseconds).