[M] Change in coreboot[main]: soc/intel/cse: Add function to get cse_bp_info early

[Subrata Banik (Code Review)]

Attention is currently required from: Krishna P Bhat D, Rizwan Qureshi.

Subrata Banik has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/78053?usp=email )

Change subject: soc/intel/cse: Add function to get cse_bp_info early
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Patch Set 3:

(4 comments)

File src/soc/intel/common/block/cse/cse_lite.c:

https://review.coreboot.org/c/coreboot/+/78053/comment/d0d2666b_e2688ef0 :
PS1, Line 468: is_cse_bp_info_valid
> > anyway had introduced the boot time impact (which we don't measure today) across the global reset but user will feel the same
>
> the impact is across cold reset. This change will nullify the impact across warm/global resets.
> > There is no benefit of sending CSE cmd on every boot if u know the CBMEM data is persistent and CSE version can't be changed across warm reboot
>
> we can take it up as a follow-up patch, if you insist.

lets do that later

File src/soc/intel/common/block/cse/cse_lite.c:

https://review.coreboot.org/c/coreboot/+/78053/comment/61486147_6f827529 :
PS2, Line 424: store_cse_bp_info_in_cbmem
> store_cse_bp_info_in_cbmem() is being called by https://review.coreboot.org/c/coreboot/+/78053/2/src/soc/intel/common/block/... to store response in the case of late romstage cse_fw_sync() and also called by https://review.coreboot.org/c/coreboot/+/78053/2/src/soc/intel/common/block/... in CBMEM_CREATION_HOOK. 
> cbmem_find(CBMEM_ID_CSE_BP_INFO) is only used at https://review.coreboot.org/c/coreboot/+/78053/2/src/soc/intel/common/block/..., better not to move it to common function.

i'm unable to follow the concern ?

you are trying to fetch the cse bp info from cbmem. if the information is readily available then fetch it or else, prepare the data into the cbmem. I don't understand why it's better not to move things into an unified function ?

take a look into cbmem_add implementation, it first do cbmem_find and on failure it makes a new entry.

https://review.coreboot.org/c/coreboot/+/78053/comment/f8582ac9_90bb7bae :
PS2, Line 470: cse_bp_info_in_cbmem
> https://review.coreboot.org/c/coreboot/+/78053/comment/2f9f5241_046c81c8/ As Rizwan suggested.

lets do that later as discussed https://review.coreboot.org/c/coreboot/+/78053/comment/2f9f5241_046c81c8/

https://review.coreboot.org/c/coreboot/+/78053/comment/96f90ffd_35143c41 :
PS2, Line 507: 	if (cbmem_online())
             : 		store_cse_bp_info_in_cbmem();
> We have to consider the case of cse_fw_sync() being called in late romstage also like in JSL, TGL. The cbmem init hooks would have been run prior to cse_get_bp_info being called (after fsp memory init) and we would have to then copy the get_bp_info_rsp to cbmem.

Calling fetch_cse_bp_info_from_cbmem() from line 469 would eliminate the need to store the cse bp info later (basically do the cbmem add, like what this function is doing).