From 4b4c0c6016fb1be88b770077c00e788421bef2fe Mon Sep 17 00:00:00 2001 From: Furquan Shaikh Date: Mon, 1 Jun 2020 13:47:28 -0700 Subject: [PATCH] northbridge/intel/sandybridge: Mask lower 20 bits of TOLUD and TOLM in hostbridge.asl Lower 20bits of TOLUD and TOLM registers include 19 reserved bits and 1 lock bit. If lock bit is set, then systemagent.asl would end up reporting the base address of low MMIO incorrectly i.e. off by 1. This change masks the lower 20 bits of TOLUD and TOM registers when exposing it in the ACPI tables to ensure that the base address of low MMIO region is reported correctly. Change-Id: Ib0ffd9a332fa9590de63f8828d30daa710fe50db Signed-off-by: Furquan Shaikh Reviewed-on: https://review.coreboot.org/c/coreboot/+/41979 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Rudolph --- src/northbridge/intel/sandybridge/acpi/hostbridge.asl | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/northbridge/intel/sandybridge/acpi/hostbridge.asl b/src/northbridge/intel/sandybridge/acpi/hostbridge.asl index c8efc982f9..0f70f8c9d5 100644 --- a/src/northbridge/intel/sandybridge/acpi/hostbridge.asl +++ b/src/northbridge/intel/sandybridge/acpi/hostbridge.asl @@ -342,13 +342,17 @@ Method (_CRS, 0, Serialized) // Fix up PCI memory region // Start with Top of Lower Usable DRAM - Local0 = ^MCHC.TLUD + // Lower 20 bits of TOLUD register need to be masked since they contain lock and + // reserved bits. + Local0 = ^MCHC.TLUD & (0xfff << 20) Local1 = ^MCHC.MEBA // Check if ME base is equal If (Local0 == Local1) { // Use Top Of Memory instead - Local0 = ^MCHC.TOM + // Lower 20 bits of TOM register need to be masked since they contain lock and + // reserved bits. + Local0 = ^MCHC.TOM & (0x7ffff << 20) } PMIN = Local0