[coreboot-gerrit] Patch set updated for coreboot: 6d84a26 ACPI: Fix corrupt SSDT table on multiprocessor AMD Family 10h systems

[Timothy Pearson (tpearson@raptorengineeringinc.com)]

Timothy Pearson (tpearson at raptorengineeringinc.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/8259

-gerrit

commit 6d84a266b74e805b6beb57413d0dad20f1c44e3b
Author: Timothy Pearson <tpearson at raptorengineeringinc.com>
Date:   Fri Jan 23 20:18:56 2015 -0600

    ACPI: Fix corrupt SSDT table on multiprocessor AMD Family 10h systems
    
    Signed-off-by: Timothy Pearson <tpearson at raptorengineeringinc.com>
    Change-Id: I3175c8b29e94a27a2db6b11f8fc9e1d91bde11f9
---
 src/northbridge/amd/amdfam10/acpi.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/northbridge/amd/amdfam10/acpi.c b/src/northbridge/amd/amdfam10/acpi.c
index 463fb7c..9ffea36 100644
--- a/src/northbridge/amd/amdfam10/acpi.c
+++ b/src/northbridge/amd/amdfam10/acpi.c
@@ -1,6 +1,7 @@
 /*
  * This file is part of the coreboot project.
  *
+ * Copyright (C) 2015 Timothy Pearson <tpearson at raptorengineeringinc.com>, Raptor Engineering
  * Copyright (C) 2007 Advanced Micro Devices, Inc.
  *
  * This program is free software; you can redistribute it and/or modify
@@ -187,6 +188,22 @@ void update_ssdtx(void *ssdtx, int i)
 
 void northbridge_acpi_write_vars(void)
 {
+	/*
+	 * If more than one physical CPU is installed, northbridge_acpi_write_vars()
+	 * is called more than once and the resultant SSDT table is corrupted
+	 * (duplicated entries).
+	 * This prevents Linux from booting, with log messages like these:
+	 * ACPI Error: [BUSN] Namespace lookup failure, AE_ALREADY_EXISTS (/dswload-353)
+	 * ACPI Exception: AE_ALREADY_EXISTS, During name lookup/catalog (/psobject-222)
+	 * followed by a slew of ACPI method failures and a hang when the invalid PCI
+	 * resource entries are used.
+	 * This routine prevents the SSDT table from being corrupted.
+	 */
+	static uint8_t ssdt_generated = 0;
+	if (ssdt_generated)
+		return;
+	ssdt_generated = 1;
+
 	msr_t msr;
 	char pscope[] = "\\_SB.PCI0";
 	int i;