[S] Change in coreboot[main]: cpu/x86/mtrr: Exclude ranges above 4G if temporary MTRRs exhausted

[Matt DeVillier (Code Review)]

Attention is currently required from: Jérémy Compostella, Shuo Liu.

Matt DeVillier has posted comments on this change by Matt DeVillier. ( https://review.coreboot.org/c/coreboot/+/86941?usp=email )

Change subject: cpu/x86/mtrr: Exclude ranges above 4G if temporary MTRRs exhausted
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Patch Set 2:

(2 comments)

File src/cpu/x86/mtrr/mtrr.c:

https://review.coreboot.org/c/coreboot/+/86941/comment/e3a82c34_529deaa0?usp... :
PS2, Line 664: int
> should be `bool`

this will be a somewhat extensive change, I'll do it in a separate patch and rebase this one top

https://review.coreboot.org/c/coreboot/+/86941/comment/888366d2_f7149378?usp... :
PS2, Line 893: 		sol.mtrr_default_type = calc_var_mtrrs(&addr_space, above4gb, address_bits, &num_mtrrs_used);
> Shouldn't you print a message if `num_mtrrs_used > total_mtrrs condition` still isn't met ?

sure, I can rework it to skip `prepare_var_mtrrs` altogether since we know it will fail, and just print an error instead