coreboot/haswell: make IOMMU a runtime option

It is now possible to disable the IOMMU on Haswell
boards, by doing this on your ROM image:

./nvramtool -C libreboot.rom -w iommu=Disable

To enable it again, do this:

./nvramtool -C libreboot.rom -w iommu=Enable

If not specified, the default behaviour is *on*.
A follow-up patch will turn IOMMU *off* by default,
on Dell OptiPlex 9020 SFF/MT, by setting it as such
in cmos.default. This is to make graphics cards work
properly to work around a bug when it's turned on.

Leaving the IOMMU enabled is recommended, if it works.
It works in most cases, including on 9020 SFF/MT when
using the Intel GPU without a graphics card inserted.

Signed-off-by: Leah Rowe <leah@libreboot.org>
9020nri
Leah Rowe 2024-03-02 22:55:29 +00:00
parent db074b785c
commit 944cafa230
1 changed files with 292 additions and 0 deletions

View File

@ -0,0 +1,292 @@
From 7c755b4502ea007f2216ea76f2ed734452def883 Mon Sep 17 00:00:00 2001
From: Leah Rowe <info@minifree.org>
Date: Sat, 2 Mar 2024 22:51:09 +0000
Subject: [PATCH 1/2] nb/intel/haswell: make IOMMU a runtime option
When I tested graphics cards on a coreboot port for Dell
OptiPlex 9020 SFF, I could not use a graphics card unless
I set iommu=off on the Linux cmdline.
Coreboot's current behaviour is to check whether the CPU
has vt-d support and, if it does, initialise the IOMMU.
This patch maintains the current behaviour by default, but
allows the user to turn *off* the IOMMU, even if vt-d is
supported by the host CPU.
If iommu=Disable is specified, the check will not be
performed, and the IOMMU will be left disabled. This option
has been added to all current Haswell boards, though it is
recommended to leave the IOMMU turned on in most setups.
Signed-off-by: Leah Rowe <info@minifree.org>
---
src/mainboard/asrock/b85m_pro4/cmos.default | 1 +
src/mainboard/asrock/b85m_pro4/cmos.layout | 3 +++
src/mainboard/asrock/h81m-hds/cmos.default | 1 +
src/mainboard/asrock/h81m-hds/cmos.layout | 6 ++++++
src/mainboard/dell/optiplex_9020/cmos.default | 1 +
src/mainboard/dell/optiplex_9020/cmos.layout | 6 ++++++
src/mainboard/google/beltino/cmos.layout | 5 +++++
src/mainboard/google/slippy/cmos.layout | 5 +++++
src/mainboard/intel/baskingridge/cmos.layout | 4 ++++
src/mainboard/lenovo/haswell/cmos.default | 1 +
src/mainboard/lenovo/haswell/cmos.layout | 3 +++
src/mainboard/supermicro/x10slm-f/cmos.default | 1 +
src/mainboard/supermicro/x10slm-f/cmos.layout | 6 ++++++
src/northbridge/intel/haswell/early_init.c | 5 +++++
14 files changed, 48 insertions(+)
diff --git a/src/mainboard/asrock/b85m_pro4/cmos.default b/src/mainboard/asrock/b85m_pro4/cmos.default
index c51001c03c..1c5c17f841 100644
--- a/src/mainboard/asrock/b85m_pro4/cmos.default
+++ b/src/mainboard/asrock/b85m_pro4/cmos.default
@@ -2,3 +2,4 @@ boot_option=Fallback
debug_level=Debug
nmi=Enable
power_on_after_fail=Disable
+iommu=Enable
diff --git a/src/mainboard/asrock/b85m_pro4/cmos.layout b/src/mainboard/asrock/b85m_pro4/cmos.layout
index efdc333fc2..c9883ea71d 100644
--- a/src/mainboard/asrock/b85m_pro4/cmos.layout
+++ b/src/mainboard/asrock/b85m_pro4/cmos.layout
@@ -11,6 +11,7 @@
395 4 e 4 debug_level
408 1 e 1 nmi
409 2 e 5 power_on_after_fail
+ 412 1 e 6 iommu
984 16 h 0 check_sum
# -----------------------------------------------------------------
@@ -38,6 +39,8 @@
5 0 Disable
5 1 Enable
5 2 Keep
+ 6 0 Disable
+ 6 1 Enable
# -----------------------------------------------------------------
# -----------------------------------------------------------------
diff --git a/src/mainboard/asrock/h81m-hds/cmos.default b/src/mainboard/asrock/h81m-hds/cmos.default
index c51001c03c..1c5c17f841 100644
--- a/src/mainboard/asrock/h81m-hds/cmos.default
+++ b/src/mainboard/asrock/h81m-hds/cmos.default
@@ -2,3 +2,4 @@ boot_option=Fallback
debug_level=Debug
nmi=Enable
power_on_after_fail=Disable
+iommu=Enable
diff --git a/src/mainboard/asrock/h81m-hds/cmos.layout b/src/mainboard/asrock/h81m-hds/cmos.layout
index c9ba76c78f..95ee3d36fb 100644
--- a/src/mainboard/asrock/h81m-hds/cmos.layout
+++ b/src/mainboard/asrock/h81m-hds/cmos.layout
@@ -21,6 +21,9 @@ entries
408 1 e 1 nmi
409 2 e 5 power_on_after_fail
+# enable or disable iommu
+412 1 e 6 iommu
+
# coreboot config options: check sums
984 16 h 0 check_sum
@@ -52,6 +55,9 @@ enumerations
5 1 Enable
5 2 Keep
+6 0 Disable
+6 1 Enable
+
# -----------------------------------------------------------------
checksums
diff --git a/src/mainboard/dell/optiplex_9020/cmos.default b/src/mainboard/dell/optiplex_9020/cmos.default
index b159660aa8..8253570f19 100644
--- a/src/mainboard/dell/optiplex_9020/cmos.default
+++ b/src/mainboard/dell/optiplex_9020/cmos.default
@@ -2,3 +2,4 @@ boot_option=Fallback
debug_level=Debug
nmi=Disable
power_on_after_fail=Disable
+iommu=Enable
diff --git a/src/mainboard/dell/optiplex_9020/cmos.layout b/src/mainboard/dell/optiplex_9020/cmos.layout
index c9ba76c78f..72ff9c4bee 100644
--- a/src/mainboard/dell/optiplex_9020/cmos.layout
+++ b/src/mainboard/dell/optiplex_9020/cmos.layout
@@ -21,6 +21,9 @@ entries
408 1 e 1 nmi
409 2 e 5 power_on_after_fail
+# turn iommu on or off
+412 1 e 6 iommu
+
# coreboot config options: check sums
984 16 h 0 check_sum
@@ -52,6 +55,9 @@ enumerations
5 1 Enable
5 2 Keep
+6 0 Disable
+6 1 Enable
+
# -----------------------------------------------------------------
checksums
diff --git a/src/mainboard/google/beltino/cmos.layout b/src/mainboard/google/beltino/cmos.layout
index 78d44c1415..c143979ae1 100644
--- a/src/mainboard/google/beltino/cmos.layout
+++ b/src/mainboard/google/beltino/cmos.layout
@@ -19,6 +19,9 @@ entries
408 1 e 1 nmi
409 2 e 7 power_on_after_fail
+# enable or disable iommu
+412 1 e 8 iommu
+
# coreboot config options: bootloader
#Used by ChromeOS:
416 128 r 0 vbnv
@@ -47,6 +50,8 @@ enumerations
7 0 Disable
7 1 Enable
7 2 Keep
+8 0 Disable
+8 1 Enable
# -----------------------------------------------------------------
checksums
diff --git a/src/mainboard/google/slippy/cmos.layout b/src/mainboard/google/slippy/cmos.layout
index 78d44c1415..c143979ae1 100644
--- a/src/mainboard/google/slippy/cmos.layout
+++ b/src/mainboard/google/slippy/cmos.layout
@@ -19,6 +19,9 @@ entries
408 1 e 1 nmi
409 2 e 7 power_on_after_fail
+# enable or disable iommu
+412 1 e 8 iommu
+
# coreboot config options: bootloader
#Used by ChromeOS:
416 128 r 0 vbnv
@@ -47,6 +50,8 @@ enumerations
7 0 Disable
7 1 Enable
7 2 Keep
+8 0 Disable
+8 1 Enable
# -----------------------------------------------------------------
checksums
diff --git a/src/mainboard/intel/baskingridge/cmos.layout b/src/mainboard/intel/baskingridge/cmos.layout
index 78d44c1415..f2c602f541 100644
--- a/src/mainboard/intel/baskingridge/cmos.layout
+++ b/src/mainboard/intel/baskingridge/cmos.layout
@@ -19,6 +19,8 @@ entries
408 1 e 1 nmi
409 2 e 7 power_on_after_fail
+412 1 e 8 iommu
+
# coreboot config options: bootloader
#Used by ChromeOS:
416 128 r 0 vbnv
@@ -47,6 +49,8 @@ enumerations
7 0 Disable
7 1 Enable
7 2 Keep
+8 0 Disable
+8 1 Enable
# -----------------------------------------------------------------
checksums
diff --git a/src/mainboard/lenovo/haswell/cmos.default b/src/mainboard/lenovo/haswell/cmos.default
index bb8626d48b..051658d757 100644
--- a/src/mainboard/lenovo/haswell/cmos.default
+++ b/src/mainboard/lenovo/haswell/cmos.default
@@ -12,3 +12,4 @@ trackpoint=Enable
backlight=Keyboard
enable_dual_graphics=Disable
usb_always_on=Disable
+iommu=Enable
diff --git a/src/mainboard/lenovo/haswell/cmos.layout b/src/mainboard/lenovo/haswell/cmos.layout
index 27915d3ab7..59df76b64c 100644
--- a/src/mainboard/lenovo/haswell/cmos.layout
+++ b/src/mainboard/lenovo/haswell/cmos.layout
@@ -23,6 +23,7 @@ entries
# coreboot config options: EC
411 1 e 8 first_battery
+413 1 e 14 iommu
415 1 e 1 wlan
416 1 e 1 trackpoint
417 1 e 1 fn_ctrl_swap
@@ -72,6 +73,8 @@ enumerations
13 0 Disable
13 1 AC and battery
13 2 AC only
+14 0 Disable
+14 1 Enable
# -----------------------------------------------------------------
checksums
diff --git a/src/mainboard/supermicro/x10slm-f/cmos.default b/src/mainboard/supermicro/x10slm-f/cmos.default
index f4047147f7..eea2c36b88 100644
--- a/src/mainboard/supermicro/x10slm-f/cmos.default
+++ b/src/mainboard/supermicro/x10slm-f/cmos.default
@@ -3,3 +3,4 @@ debug_level=Debug
nmi=Enable
power_on_after_fail=Keep
hide_ast2400=Disable
+iommu=Enable
diff --git a/src/mainboard/supermicro/x10slm-f/cmos.layout b/src/mainboard/supermicro/x10slm-f/cmos.layout
index 38ba87aa45..24d39e97ee 100644
--- a/src/mainboard/supermicro/x10slm-f/cmos.layout
+++ b/src/mainboard/supermicro/x10slm-f/cmos.layout
@@ -21,6 +21,9 @@ entries
408 1 e 1 nmi
409 2 e 5 power_on_after_fail
+# enable or disable iommu
+412 1 e 6 iommu
+
# coreboot config options: mainboard
416 1 e 1 hide_ast2400
@@ -55,6 +58,9 @@ enumerations
5 1 Enable
5 2 Keep
+6 0 Disable
+6 1 Enable
+
# -----------------------------------------------------------------
checksums
diff --git a/src/northbridge/intel/haswell/early_init.c b/src/northbridge/intel/haswell/early_init.c
index e47deb5da6..1a7e0b1076 100644
--- a/src/northbridge/intel/haswell/early_init.c
+++ b/src/northbridge/intel/haswell/early_init.c
@@ -5,6 +5,7 @@
#include <device/mmio.h>
#include <device/pci_def.h>
#include <device/pci_ops.h>
+#include <option.h>
#include "haswell.h"
@@ -157,6 +158,10 @@ static void haswell_setup_misc(void)
static void haswell_setup_iommu(void)
{
const u32 capid0_a = pci_read_config32(HOST_BRIDGE, CAPID0_A);
+ u8 enable_iommu = get_uint_option("iommu", 1);
+
+ if (!enable_iommu)
+ return;
if (capid0_a & VTD_DISABLE)
return;
--
2.39.2