[coreboot-gerrit] Change in coreboot[master]: soc/intel/xeon_sp: Fix final MTRR usage

[Arthur Heymans (Code Review)]

Arthur Heymans has submitted this change. ( https://review.coreboot.org/c/coreboot/+/47868 )

Change subject: soc/intel/xeon_sp: Fix final MTRR usage
......................................................................

soc/intel/xeon_sp: Fix final MTRR usage

The region top_of_ram -> cbmem_top is used by FSP and cbmem, but is
also just regular DRAM. Marking it as such improves the final MTRR
solution a lot and fixes MTRR starvation depending on the setup.

Change-Id: I19ff7cf2d699b4cc34caccd91cafd6a284d699d3
Signed-off-by: Arthur Heymans 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47868
Reviewed-by: Christian Walter 
Reviewed-by: Angel Pons 
Reviewed-by: Jonathan Zhang 
Tested-by: build bot (Jenkins) 
---
M src/soc/intel/xeon_sp/uncore.c
1 file changed, 5 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Angel Pons: Looks good to me, approved
  Jonathan Zhang: Looks good to me, but someone else must approve
  Christian Walter: Looks good to me, approved

diff --git a/src/soc/intel/xeon_sp/uncore.c b/src/soc/intel/xeon_sp/uncore.c
index de29dea..8965b3b 100644
--- a/src/soc/intel/xeon_sp/uncore.c
+++ b/src/soc/intel/xeon_sp/uncore.c
@@ -200,6 +200,11 @@
    LOG_MEM_RESOURCE("low_ram", dev, index, base_kb, size_kb);
    ram_resource(dev, index++, base_kb, size_kb);

+	/* fsp_mem_base -> cbmem_top */
+	base_kb = top_of_ram / KiB;
+	size_kb = ((uintptr_t)cbmem_top() - top_of_ram) / KiB;
+	reserved_ram_resource(dev, index++, base_kb, size_kb);
+
    /*
     * FSP meomoy, CBMem regions are already added as reserved
     * Add TSEG and MESEG Regions as reserved memory