From 88af372fe8b4feb683c9153ab1e79df76cff754b Mon Sep 17 00:00:00 2001 From: Damien Zammit Date: Sat, 27 Aug 2016 00:35:48 +1000 Subject: [PATCH] nb/intel/gm45: Fix DMAR table - IOMMU advertisement for ME interfaces Previously the ME PCI interface (HECI) was being reported as present in the DMAR ACPI table even when ME firmware was missing or the PCI device was hidden and HECI would be unresponsive. Now we check via the PCI config space itself to verify if the HECI is present or not. Note that this test could fail if ME firmware is present but HECI is disabled in devicetree, because it would not advertise that the HECI exists even though there is a running ME. Perhaps this behaviour is desirable because in this case you won't see the HECI in the lspci tree anyway. Change-Id: Ib692d476d85236b4886ecf3d6e6814229f441de0 Signed-off-by: Damien Zammit Reviewed-on: https://review.coreboot.org/16330 Tested-by: build bot (Jenkins) Reviewed-by: Swift Geek Reviewed-by: Nico Huber --- src/northbridge/intel/gm45/acpi.c | 3 ++- src/northbridge/intel/gm45/iommu.c | 2 ++ 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/src/northbridge/intel/gm45/acpi.c b/src/northbridge/intel/gm45/acpi.c index 8990c3b140..b90afca8a2 100644 --- a/src/northbridge/intel/gm45/acpi.c +++ b/src/northbridge/intel/gm45/acpi.c @@ -72,7 +72,8 @@ unsigned long acpi_fill_mcfg(unsigned long current) static unsigned long acpi_fill_dmar(unsigned long current) { - int me_active = (dev_find_slot(0, PCI_DEVFN(3, 0)) != NULL); + int me_active = (dev_find_slot(0, PCI_DEVFN(3, 0)) != NULL) && + (pci_read_config8(dev_find_slot(0, PCI_DEVFN(3, 0)), PCI_CLASS_REVISION) != 0xff); int stepping = pci_read_config8(dev_find_slot(0, PCI_DEVFN(0, 0)), PCI_CLASS_REVISION); unsigned long tmp = current; diff --git a/src/northbridge/intel/gm45/iommu.c b/src/northbridge/intel/gm45/iommu.c index 10548f48a3..0c3c18ef0c 100644 --- a/src/northbridge/intel/gm45/iommu.c +++ b/src/northbridge/intel/gm45/iommu.c @@ -40,6 +40,8 @@ void init_iommu() } if (me_active) { MCHBAR32(0x10) = IOMMU_BASE3 | 1; /* ME @ 0:3.0-3 */ + } else { + MCHBAR32(0x10) = 0; /* disable IOMMU for ME */ } MCHBAR32(0x20) = IOMMU_BASE4 | 1; /* all other DMA sources */