nb/intel/sandybridge: Enable basic IOMMU support

Sandy Bridge and Ivy Bridge processors have two IOMMU units. One for the
integrated graphics controller and one for all other PCI devices. Assign
resources for both IOMMUs and apply some quirks.

Tested with kontron/ktqm77 and a Muen based system that makes use of the
IOMMUs. Not tested on Sandy Bridge, but register dumps show the same
settings that are applied here.

Change-Id: I43b5e20b750e7529f448acac35de173185678fd9
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/12194
Tested-by: build bot (Jenkins)
Reviewed-by: Duncan Laurie <dlaurie@google.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/northbridge/intel/sandybridge/Makefile.inc

@@ -34,6 +34,7 @@ romstage-$(CONFIG_NORTHBRIDGE_INTEL_SANDYBRIDGE) += raminit.c
 romstage-$(CONFIG_NORTHBRIDGE_INTEL_SANDYBRIDGE) += romstage.c
 romstage-$(CONFIG_NORTHBRIDGE_INTEL_SANDYBRIDGE) += ../../../device/dram/ddr3.c
 romstage-y += mrccache.c
+romstage-y += iommu.c
 romstage-y += early_init.c
 romstage-y += report_platform.c
 romstage-y += ../../../arch/x86/walkcbfs.S

src/northbridge/intel/sandybridge/early_init.c

@@ -169,6 +169,9 @@ void sandybridge_early_initialization(int chipset_type)
 	/* Setup all BARs required for early PCIe and raminit */
 	sandybridge_setup_bars();
 
+	/* Setup IOMMU BARs */
+	sandybridge_init_iommu();
+
 	/* Device Enable, don't touch PEG bits */
 	deven = pci_read_config32(PCI_DEV(0, 0, 0), DEVEN) | DEVEN_IGD;
 	pci_write_config32(PCI_DEV(0, 0, 0), DEVEN, deven);

src/northbridge/intel/sandybridge/iommu.c

@@ -0,0 +1,48 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2015 secunet Security Networks AG
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 of
+ * the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <stdint.h>
+
+#include <arch/io.h>
+#include <device/device.h>
+#include <device/pci_def.h>
+
+#include "sandybridge.h"
+
+void sandybridge_init_iommu(void)
+{
+	const u32 capid0_a = pci_read_config32(PCI_DEV(0, 0, 0), 0xe4);
+	if (capid0_a & (1 << 23))
+		return;
+
+	/* setup BARs */
+	MCHBAR32(0x5404) = IOMMU_BASE1 >> 32;
+	MCHBAR32(0x5400) = IOMMU_BASE1 | 1;
+	MCHBAR32(0x5414) = IOMMU_BASE2 >> 32;
+	MCHBAR32(0x5410) = IOMMU_BASE2 | 1;
+
+	/* lock policies */
+	write32((void *)(IOMMU_BASE1 + 0xff0), 0x80000000);
+
+	const struct device *const azalia =
+		dev_find_slot(0x00, PCI_DEVFN(0x1b, 0));
+	if (azalia && azalia->enabled) {
+		write32((void *)(IOMMU_BASE2 + 0xff0), 0x20000000);
+		write32((void *)(IOMMU_BASE2 + 0xff0), 0xa0000000);
+	} else {
+		write32((void *)(IOMMU_BASE2 + 0xff0), 0x80000000);
+	}
+}

src/northbridge/intel/sandybridge/northbridge.c

@@ -127,6 +127,13 @@ static void add_fixed_resources(struct device *dev, int index)
 	/* Required for SandyBridge sighting 3715511 */
 	bad_ram_resource(dev, index++, 0x20000000 >> 10, 0x00200000 >> 10);
 	bad_ram_resource(dev, index++, 0x40000000 >> 10, 0x00200000 >> 10);
+
+	/* Reserve IOMMU BARs */
+	const u32 capid0_a = pci_read_config32(dev, 0xe4);
+	if (!(capid0_a & (1 << 23))) {
+		mmio_resource(dev, index++, IOMMU_BASE1 >> 10, 4);
+		mmio_resource(dev, index++, IOMMU_BASE2 >> 10, 4);
+	}
 }
 
 static void pci_domain_set_resources(device_t dev)

src/northbridge/intel/sandybridge/sandybridge.h

@@ -54,6 +54,9 @@
 #define DEFAULT_EPBAR		0xfed19000	/* 4 KB */
 #define DEFAULT_RCBABASE	((u8 *)0xfed1c000)
 
+#define IOMMU_BASE1		0xfed90000ULL
+#define IOMMU_BASE2		0xfed91000ULL
+
 #include <southbridge/intel/bd82x6x/pch.h>
 
 /* Everything below this line is ignored in the DSDT */
@@ -199,6 +202,7 @@ void intel_sandybridge_finalize_smm(void);
 #else /* !__SMM__ */
 int bridge_silicon_revision(void);
 void sandybridge_early_initialization(int chipset_type);
+void sandybridge_init_iommu(void);
 void sandybridge_late_initialization(void);
 void northbridge_romstage_finalize(int s3resume);