[coreboot-gerrit] [S] Change in coreboot[master]: soc/intel/tigerlake: Enable early caching of RAMTOP region

[Lean Sheng Tan (Code Review)]

Lean Sheng Tan has submitted this change. ( https://review.coreboot.org/c/coreboot/+/73738 )

(

4 is the latest approved patch-set.
No files were changed between the latest approved patch-set and the submitted one.
 )Change subject: soc/intel/tigerlake: Enable early caching of RAMTOP region
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soc/intel/tigerlake: Enable early caching of RAMTOP region

Enable early caching of the TOM region to optimize the boot time by
selecting `SOC_INTEL_COMMON_BASECODE_RAMTOP` config.

Purpose of this feature is to cache the TOM (with a fixed size of
16MB) for all consecutive boots even before calling into the FSP.
Otherwise, this range remains un-cached until postcar boot stage
updates the MTRR programming. FSP-M and late romstage uses this
uncached TOM range for various purposes (like relocating services
between SPI mapped cached memory to DRAM based uncache memory) hence
having the ability to cache this range beforehand would help to
optimize the boot time (more than 50ms as applicable).

Signed-off-by: Lean Sheng Tan 
Change-Id: I3b68d13aa414e69c0a80122021e6755352db32fd
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73738
Reviewed-by: Subrata Banik 
Reviewed-by: Sean Rhodes 
Tested-by: build bot (Jenkins) 
---
M src/soc/intel/tigerlake/Kconfig
1 file changed, 28 insertions(+), 1 deletion(-)

Approvals:
  build bot (Jenkins): Verified
  Sean Rhodes: Looks good to me, approved
  Subrata Banik: Looks good to me, approved

diff --git a/src/soc/intel/tigerlake/Kconfig b/src/soc/intel/tigerlake/Kconfig
index fca4f79..9928591 100644
--- a/src/soc/intel/tigerlake/Kconfig
+++ b/src/soc/intel/tigerlake/Kconfig
@@ -93,7 +93,8 @@
    select USE_FSP_NOTIFY_PHASE_POST_PCI_ENUM
    select USE_FSP_NOTIFY_PHASE_READY_TO_BOOT
    select USE_FSP_NOTIFY_PHASE_END_OF_FIRMWARE
-	select SOC_INTEL_COMMON_BASECODE if SOC_INTEL_CSE_LITE_SKU
+	select SOC_INTEL_COMMON_BASECODE
+	select SOC_INTEL_COMMON_BASECODE_RAMTOP
    select CR50_USE_LONG_INTERRUPT_PULSES if TPM_GOOGLE_CR50
    select X86_CLFLUSH_CAR