[XS] Change in coreboot[main]: intel/cmm/block: use CONFIG_SMM_TSEG_SIZE in sa_get_tseg_size function

[Subrata Banik (Code Review)]

Attention is currently required from: Anil Kumar K, Bora Guvendik, Jamie Ryu, Jeremy Compostella, Jérémy Compostella, Paul Menzel, Wonkyu Kim.

Subrata Banik has posted comments on this change by Wonkyu Kim. ( https://review.coreboot.org/c/coreboot/+/84210?usp=email )

Change subject: intel/cmm/block: use CONFIG_SMM_TSEG_SIZE in sa_get_tseg_size function
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Patch Set 3:

(2 comments)

File src/soc/intel/common/block/systemagent/systemagent_early.c:

https://review.coreboot.org/c/coreboot/+/84210/comment/f7932282_04e98890?usp... :
PS2, Line 155: 	return sa_get_gsm_base() - sa_get_tseg_base();
> We checked internally and got recommendation not to calculate it as CONFIG_SMM_TSEG_SIZE is passed to FSP and memory map which based on calculation can be changed later.

Sorry, I'm unable to follow your statement.

I'm asking to relying on `sa_get_gsm_size` to know if IGD is present. if IGD is there, the sa_get_gsm_size() should return non-zero value and we can calculate the TSEG size considering it as base. Otherwise, we can pass the fixed CONFIG_SMM_TSEG_SIZE

File src/soc/intel/common/block/systemagent/systemagent_early.c:

https://review.coreboot.org/c/coreboot/+/84210/comment/e150b849_b2856816?usp... :
PS3, Line 151: 	if (CONFIG_SMM_TSEG_SIZE) {
             : 		return CONFIG_SMM_TSEG_SIZE;
             : 	}
             : 
what is this for ?