From d708884d506cfd5a5c99de5bfc1ce48aa8abedbb Mon Sep 17 00:00:00 2001
From: Patrick Rudolph <patrick.rudolph@9elements.com>
Date: Wed, 5 Apr 2023 09:49:11 +0200
Subject: [PATCH] soc/intel/xeon_sp/acpi: Fix _OSC method

Fix a couple of bugs in the _OSC method for handling
"PCI Host Bridge Device" on Xeon-SP.

- Drop the Sleep. The code doesn't write to hardware at all, so
  there's no need to sleep here.
- Make sure that the number of DWORD passed in Arg2 is at least 3.
  The existing check was useless as it would not create the
  DWordField, but then use it anyways.
- Add check for CXL 2 device method calls which provide a 5 DWORD
  long buffer to prevent buffer overflows when invoking the
  "PCI Host Bridge Device" method.

Test:
Boot on Archer City and confirm that no ACPI errors are reported
for _OSC.

Change-Id: Ide598e386c30ced24e4f96c37f2b4a609ac33441
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/74231
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jonathan Zhang <jon.zhixiong.zhang@gmail.com>
---
 src/soc/intel/xeon_sp/acpi/iiostack.asl       |  9 +++---
 .../intel/xeon_sp/spr/acpi/cxl_resource.asl   | 29 ++++++++++++-------
 .../intel/xeon_sp/spr/acpi/pci_resource.asl   | 10 ++++---
 3 files changed, 29 insertions(+), 19 deletions(-)

diff --git a/src/soc/intel/xeon_sp/acpi/iiostack.asl b/src/soc/intel/xeon_sp/acpi/iiostack.asl
index 91a5c6cd4d..e5e6bdc267 100644
--- a/src/soc/intel/xeon_sp/acpi/iiostack.asl
+++ b/src/soc/intel/xeon_sp/acpi/iiostack.asl
@@ -27,17 +27,18 @@
 			CreateDWordField (Arg3, 0x00, CDW1)		\
 			If ((Arg0 == ToUUID ("33db4d5b-1ff7-401c-9657-7441c03dd766") /* PCI Host Bridge Device */))  \
 			{							\
-				CreateDWordField (Arg3, 0x04, CDW2)		\
-				If ((Arg2 > 0x02))				\
+				If (Arg2 < 0x03)				\
 				{						\
-					CreateDWordField (Arg3, 0x08, CDW3)	\
+					CDW1 |= 0x02 /* Unknown failure */	\
+					Return (Arg3)				\
 				}						\
+				CreateDWordField (Arg3, 0x04, CDW2)		\
+				CreateDWordField (Arg3, 0x08, CDW3)		\
 				SUPP = CDW2					\
 				CTRL = CDW3					\
 				If ((AHPE || ((SUPP & 0x16) != 0x16)))		\
 				{						\
 					CTRL &= 0x1E				\
-					Sleep (0x03E8)				\
 				}						\
 				/* Never allow SHPC (no SHPC controller in system) */ \
 				CTRL &= 0x1D					\
diff --git a/src/soc/intel/xeon_sp/spr/acpi/cxl_resource.asl b/src/soc/intel/xeon_sp/spr/acpi/cxl_resource.asl
index 299247f9a1..3644e879c7 100644
--- a/src/soc/intel/xeon_sp/spr/acpi/cxl_resource.asl
+++ b/src/soc/intel/xeon_sp/spr/acpi/cxl_resource.asl
@@ -40,24 +40,28 @@ Device (IIO_DEVICE_NAME(DEVPREFIX, SOCKET, STACK))
 	{
 		CreateDWordField (Arg3, 0x00, CDW1)
 		If (Arg0 == ToUUID ("33db4d5b-1ff7-401c-9657-7441c03dd766") /* PCI Host Bridge Device */
-			|| Arg0 == ToUUID ("68f2d50b-c469-4d8a-bd3d-941a103fd3fc"))
-			/* CXL */
+			|| Arg0 == ToUUID ("68f2d50b-c469-4d8a-bd3d-941a103fd3fc")) /* CXL 2.0 */
 		{
-			CreateDWordField (Arg3, 0x04, CDW2)
-			If (Arg2 > 0x02)
+			If (Arg2 < 0x03) /* Number of DWORDs in Arg3 must be at least 3 */
 			{
-				CreateDWordField (Arg3, 0x08, CDW3)
-				CreateDWordField (Arg3, 0x0C, CDW4)
-				CreateDWordField (Arg3, 0x10, CDW5)
+				CDW1 |= 0x02 /* Unknown failure */
+				Return (Arg3)
 			}
+			CreateDWordField (Arg3, 0x04, CDW2)
+			CreateDWordField (Arg3, 0x08, CDW3)
+
 			SUPP = CDW2
 			CTRL = CDW3
-			SUPC = CDW4
-			CTRC = CDW5
+			If (Arg0 == ToUUID ("68f2d50b-c469-4d8a-bd3d-941a103fd3fc")) /* CXL 2.0 */
+			{
+				CreateDWordField (Arg3, 0x0C, CDW4)
+				CreateDWordField (Arg3, 0x10, CDW5)
+				SUPC = CDW4
+				CTRC = CDW5
+			}
 			If (SUPP & 0x16 != 0x16)
 			{
 				CTRL &= 0x1E
-				Sleep (0x03E8)
 			}
 			/* Never allow SHPC (no SHPC controller in system) */
 			CTRL &= 0x1D
@@ -72,7 +76,10 @@ Device (IIO_DEVICE_NAME(DEVPREFIX, SOCKET, STACK))
 				CDW1 |= 0x10
 			}
 			CDW3 = CTRL
-			CDW5 = CTRC
+			If (Arg0 == ToUUID ("68f2d50b-c469-4d8a-bd3d-941a103fd3fc")) /* CXL 2.0 */
+			{
+				CDW5 = CTRC
+			}
 			Return (Arg3)
 		}
 		Else
diff --git a/src/soc/intel/xeon_sp/spr/acpi/pci_resource.asl b/src/soc/intel/xeon_sp/spr/acpi/pci_resource.asl
index 7988a16242..a369b11862 100644
--- a/src/soc/intel/xeon_sp/spr/acpi/pci_resource.asl
+++ b/src/soc/intel/xeon_sp/spr/acpi/pci_resource.asl
@@ -35,17 +35,19 @@ Device (IIO_DEVICE_NAME(DEVPREFIX, SOCKET, STACK))
 		CreateDWordField (Arg3, 0x00, CDW1)
 		If (Arg0 == ToUUID ("33db4d5b-1ff7-401c-9657-7441c03dd766") /* PCI Host Bridge Device */)
 		{
-			CreateDWordField (Arg3, 0x04, CDW2)
-			If (Arg2 > 0x02)
+			If (Arg2 < 0x03) /* Number of DWORDs in Arg3 must be at least 3 */
 			{
-				CreateDWordField (Arg3, 0x08, CDW3)
+				CDW1 |= 0x02 /* Unknown failure */
+				Return (Arg3)
 			}
+			CreateDWordField (Arg3, 0x04, CDW2)
+			CreateDWordField (Arg3, 0x08, CDW3)
+
 			SUPP = CDW2
 			CTRL = CDW3
 			If (SUPP & 0x16 != 0x16)
 			{
 				CTRL &= 0x1E
-				Sleep (0x03E8)
 			}
 			/* Never allow SHPC (no SHPC controller in system) */
 			CTRL &= 0x1D