PCI: vmd: Fix shadow offsets to reflect spec changes

The shadow offset scratchpad was moved to 0x2000-0x2010. Update the
location to get the correct shadow offset.

Fixes: 6788958 ("PCI: vmd: Assign membar addresses from shadow registers")
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org # v5.2+

drivers/pci/controller/vmd.c

@@ -31,6 +31,9 @@
 #define PCI_REG_VMLOCK		0x70
 #define MB2_SHADOW_EN(vmlock)	(vmlock & 0x2)
 
+#define MB2_SHADOW_OFFSET	0x2000
+#define MB2_SHADOW_SIZE		16
+
 enum vmd_features {
 	/*
 	 * Device may contain registers which hint the physical location of the
@@ -578,7 +581,7 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 		u32 vmlock;
 		int ret;
 
-		membar2_offset = 0x2018;
+		membar2_offset = MB2_SHADOW_OFFSET + MB2_SHADOW_SIZE;
 		ret = pci_read_config_dword(vmd->dev, PCI_REG_VMLOCK, &vmlock);
 		if (ret || vmlock == ~0)
 			return -ENODEV;
@@ -590,9 +593,9 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 			if (!membar2)
 				return -ENOMEM;
 			offset[0] = vmd->dev->resource[VMD_MEMBAR1].start -
-						readq(membar2 + 0x2008);
+					readq(membar2 + MB2_SHADOW_OFFSET);
 			offset[1] = vmd->dev->resource[VMD_MEMBAR2].start -
-						readq(membar2 + 0x2010);
+					readq(membar2 + MB2_SHADOW_OFFSET + 8);
 			pci_iounmap(vmd->dev, membar2);
 		}
 	}