[M] Change in coreboot[main]: soc/intel/alderlake: Add function to force disable memory channels

[Kapil Porwal (Code Review)]

Attention is currently required from: Angel Pons, Christian Walter, Dinesh Gehlot, Eric Lai, Jayvik Desai, Jeremy Soller, Lean Sheng Tan, Michał Kopeć, Michał Żygowski, Nick Vaccaro, Piotr Król, Sean Rhodes, Subrata Banik, Tim Crawford.

Kapil Porwal has posted comments on this change by Kapil Porwal. ( https://review.coreboot.org/c/coreboot/+/85529?usp=email )

Change subject: soc/intel/alderlake: Add function to force disable memory channels
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Patch Set 6:

(5 comments)

File src/soc/intel/alderlake/include/soc/meminit.h:

https://review.coreboot.org/c/coreboot/+/85529/comment/b3fee309_cd6660c8?usp... :
PS6, Line 120: mb_fill_override_channel_mask
> +1 […]

Acknowledged

File src/soc/intel/alderlake/meminit.c:

https://review.coreboot.org/c/coreboot/+/85529/comment/97ba0f76_0ff17196?usp... :
PS1, Line 264: void memcfg_init(FSPM_UPD *memupd, const struct mb_cfg *mb_cfg,
             : 		 const struct mem_spd *spd_info, bool half_populated,
             : 		 uint32_t ch_disable_mask)
> Looks good to me.

Acknowledged

File src/soc/intel/alderlake/meminit.c:

https://review.coreboot.org/c/coreboot/+/85529/comment/35969fdd_c6cf4156?usp... :
PS6, Line 260: if ((ch_disable_mask & BIT(0)) &&
             : 		!((ch_disable_mask & 0xf) == (BIT(0) | BIT(1)))
             : 		) {
> I'm confused about this check. […]

That is correct.

Also check https://review.coreboot.org/c/coreboot/+/85529/comment/9166abbc_80078807/

https://review.coreboot.org/c/coreboot/+/85529/comment/38a9e8ae_3abcc3cd?usp... :
PS6, Line 269:  {
> Sharing some thoughts on this, but I don't have a strong opinion. […]

I also prefer using braces to avoid the cases where we use a macro which expands into multiple lines of code. In this case, we can safely remove them.

Ack.

https://review.coreboot.org/c/coreboot/+/85529/comment/a1cf4503_f73c4111?usp... :
PS6, Line 325: 	mem_init_override_channel_mask(mem_cfg, mb_fill_override_channel_mask());
> nit: You can call `mb_fill_override_channel_mask()` inside `mem_init_override_channel_mask()`

Acknowledged