cpu/x86: Make 1GB paging the default

This patch flips the polarity of CONFIG_USE_1G_PAGES_TLB into
CONFIG_NEED_SMALL_2MB_PAGE_TABLES which is off by default, meaning
CPUs added in the future will automatically build the smaller 1GB pages.
We can expect support for this feature to be available on all future CPU
generations (with the possible exception of embedded edge cases), so
this default setting should make mistakes less likely and keep
maintenance effort lower. (Besides, enabling the support where it
doesn't work fails fast, whereas keeping it disabled where it could work
is an inefficiency that can easily go overlooked for a long time.)

While this is technically a CPU feature, not a northbridge feature, we
support a lot more individual CPUs than northbridges in the pre-SoC era,
and they tend to be closely coupled anyway. So select the option at the
northbridge level for older CPUs to keep things simpler.

Change-Id: I2cf1237a7fb63b8904c2a3d57fead162c66bacde
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82792
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/cpu/qemu-x86/Kconfig b/src/cpu/qemu-x86/Kconfig
index b5ff6f09a5..221a7bae45 100644
--- a/src/cpu/qemu-x86/Kconfig
+++ b/src/cpu/qemu-x86/Kconfig
@@ -7,6 +7,7 @@ config CPU_QEMU_X86
 	select UDELAY_TSC
 	select TSC_MONOTONIC_TIMER
 	select UNKNOWN_TSC_RATE
+	select NEED_SMALL_2MB_PAGE_TABLES	# QEMU doesn't support 1GB pages
 
 if CPU_QEMU_X86