soc/apollolake: Generate DMAR table

Generate DMAR table if VTd feature is enabled.

Test=Booted into Linux on mc_apl2 and verified the DMAR table contents.
In addition turned off Vtd and verified that no DMAR table is generated
at all.

Change-Id: Ie3683a2f3578c141c691b2268e32f27ba2e772fa
Signed-off-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-on: https://review.coreboot.org/c/30990
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

2 files changed, 94 insertions, 1 deletions

diff --git a/src/soc/intel/apollolake/acpi.c b/src/soc/intel/apollolake/acpi.c
index 0c4ff81e82..6780ec4860 100644
--- a/src/soc/intel/apollolake/acpi.c
+++ b/src/soc/intel/apollolake/acpi.c
@@ -2,7 +2,7 @@
  * This file is part of the coreboot project.
  *
  * Copyright (C) 2016 Intel Corp.
- * Copyright (C) 2017 Siemens AG
+ * Copyright (C) 2017-2019 Siemens AG
  * (Written by Lance Zhao <lijian.zhao@intel.com> for Intel Corp.)
  *
  * This program is free software; you can redistribute it and/or modify
@@ -20,16 +20,19 @@
 #include <arch/acpigen.h>
 #include <arch/io.h>
 #include <arch/smp/mpspec.h>
+#include <device/pci_ops.h>
 #include <cbmem.h>
 #include <cpu/x86/smm.h>
 #include <gpio.h>
 #include <intelblocks/acpi.h>
 #include <intelblocks/pmclib.h>
 #include <intelblocks/sgx.h>
+#include <intelblocks/p2sb.h>
 #include <soc/iomap.h>
 #include <soc/pm.h>
 #include <soc/nvs.h>
 #include <soc/pci_devs.h>
+#include <soc/systemagent.h>
 #include <string.h>
 #include "chip.h"
 
@@ -178,6 +181,88 @@ void soc_fill_fadt(acpi_fadt_t *fadt)
 		fadt->flags |= ACPI_FADT_LOW_PWR_IDLE_S0;
 }
 
+static unsigned long soc_fill_dmar(unsigned long current)
+{
+	struct device *const igfx_dev = dev_find_slot(0, SA_DEVFN_IGD);
+	uint64_t gfxvtbar = MCHBAR64(GFXVTBAR) & VTBAR_MASK;
+	uint64_t defvtbar = MCHBAR64(DEFVTBAR) & VTBAR_MASK;
+	bool gfxvten = MCHBAR32(GFXVTBAR) & VTBAR_ENABLED;
+	bool defvten = MCHBAR32(DEFVTBAR) & VTBAR_ENABLED;
+	unsigned long tmp;
+
+	/* IGD has to be enabled, GFXVTBAR set and enabled. */
+	if (igfx_dev && igfx_dev->enabled && gfxvtbar && gfxvten) {
+		tmp = current;
+
+		current += acpi_create_dmar_drhd(current, 0, 0, gfxvtbar);
+		current += acpi_create_dmar_ds_pci(current, 0, 2, 0);
+		acpi_dmar_drhd_fixup(tmp, current);
+
+		/* Add RMRR entry */
+		tmp = current;
+		current += acpi_create_dmar_rmrr(current, 0,
+				sa_get_gsm_base(), sa_get_tolud_base() - 1);
+		current += acpi_create_dmar_ds_pci(current, 0, 2, 0);
+		acpi_dmar_rmrr_fixup(tmp, current);
+	}
+
+	/* DEFVTBAR has to be set and enabled. */
+	if (defvtbar && defvten) {
+		tmp = current;
+		/*
+		 * P2SB may already be hidden. There's no clear rule, when.
+		 * It is needed to get bus, device and function for IOAPIC and
+		 * HPET device which is stored in P2SB device. So unhide it to
+		 * get the info and hide it again when done.
+		 */
+		p2sb_unhide();
+		struct device *p2sb_dev = dev_find_slot(0, PCH_DEVFN_P2SB);
+		uint16_t ibdf = pci_read_config16(p2sb_dev, PCH_P2SB_IBDF);
+		uint16_t hbdf = pci_read_config16(p2sb_dev, PCH_P2SB_HBDF);
+		p2sb_hide();
+
+		current += acpi_create_dmar_drhd(current,
+				DRHD_INCLUDE_PCI_ALL, 0, defvtbar);
+		current += acpi_create_dmar_ds_ioapic(current,
+				2, ibdf >> 8, PCI_SLOT(ibdf), PCI_FUNC(ibdf));
+		current += acpi_create_dmar_ds_msi_hpet(current,
+				0, hbdf >> 8, PCI_SLOT(hbdf), PCI_FUNC(hbdf));
+		acpi_dmar_drhd_fixup(tmp, current);
+	}
+
+	return current;
+}
+
+unsigned long sa_write_acpi_tables(struct device *const dev,
+				     unsigned long current,
+				     struct acpi_rsdp *const rsdp)
+{
+	acpi_dmar_t *const dmar = (acpi_dmar_t *)current;
+
+	/* Create DMAR table only if virtualization is enabled. Due to some
+	 * constraints on Apollo Lake SoC (some stepping affected), VTD could
+	 * not be enabled together with IPU. Doing so will override and disable
+	 * VTD while leaving CAPID0_A still reporting that VTD is available.
+	 * As in this case FSP will lock VTD to disabled state, we need to make
+	 * sure that DMAR table generation only happens when at least DEFVTBAR
+	 * is enabled. Otherwise the DMAR header will be generated while the
+	 * content of the table will be missing.
+	 */
+
+	if ((pci_read_config32(dev, CAPID0_A) & VTD_DISABLE) ||
+	    !(MCHBAR32(DEFVTBAR) & VTBAR_ENABLED))
+		return current;
+
+	printk(BIOS_DEBUG, "ACPI:    * DMAR\n");
+	acpi_create_dmar(dmar, DMAR_INTR_REMAP, soc_fill_dmar);
+	current += dmar->header.length;
+	current = acpi_align_current(current);
+	acpi_add_table(rsdp, dmar);
+	current = acpi_align_current(current);
+
+	return current;
+}
+
 void soc_power_states_generation(int core_id, int cores_per_package)
 {
 	/* Generate P-state tables */
diff --git a/src/soc/intel/apollolake/include/soc/systemagent.h b/src/soc/intel/apollolake/include/soc/systemagent.h
index fe9c15feaa..46c1d7d9c7 100644
--- a/src/soc/intel/apollolake/include/soc/systemagent.h
+++ b/src/soc/intel/apollolake/include/soc/systemagent.h
@@ -3,6 +3,7 @@
  *
  * Copyright (C) 2015 Intel Corp.
  * (Written by Andrey Petrov <andrey.petrov@intel.com> for Intel Corp.)
+ * Copyright (C) 2019 Siemens 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
@@ -28,5 +29,12 @@
 #define   PCODE_INIT_DONE	(1 << 8)
 #define MCHBAR_RAPL_PPL		0x70A8
 #define CORE_DISABLE_MASK	0x7168
+#define CAPID0_A		0xE4
+#define   VTD_DISABLE		(1 << 23)
+#define DEFVTBAR		0x6c80
+#define GFXVTBAR		0x6c88
+#define   VTBAR_ENABLED		0x01
+#define VTBAR_MASK		0xfffffff000ull
+#define VTBAR_SIZE		0x1000
 
 #endif /* SOC_APOLLOLAKE_SYSTEMAGENT_H */