Prev: bug when enabling VM DEBUG
Next: [PATCH] CacheFiles: Fix occasional EIO on call to vfs_unlink()
From: Joerg Roedel on 11 May 2010 12:00
This patch adds a command line option to tell the AMD IOMMU
driver to not initialize any IOMMU it finds.

Signed-off-by: Joerg Roedel <joerg.roedel(a)amd.com>
---
Documentation/kernel-parameters.txt | 2 ++
arch/x86/kernel/amd_iommu_init.c | 6 ++++++
2 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 839b21b..0c6c560 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -324,6 +324,8 @@ and is between 256 and 4096 characters. It is defined in the file
they are unmapped. Otherwise they are
flushed before they will be reused, which
is a lot of faster
+ off - do not initialize any AMD IOMMU found in
+ the system

amijoy.map= [HW,JOY] Amiga joystick support
Map of devices attached to JOY0DAT and JOY1DAT
diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 6360abf..3bacb4d 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -120,6 +120,7 @@ struct ivmd_header {
bool amd_iommu_dump;

static int __initdata amd_iommu_detected;
+static bool __initdata amd_iommu_disabled;

u16 amd_iommu_last_bdf; /* largest PCI device id we have
to handle */
@@ -1372,6 +1373,9 @@ void __init amd_iommu_detect(void)
if (no_iommu || (iommu_detected && !gart_iommu_aperture))
return;

+ if (amd_iommu_disabled)
+ return;
+
if (acpi_table_parse("IVRS", early_amd_iommu_detect) == 0) {
iommu_detected = 1;
amd_iommu_detected = 1;
@@ -1401,6 +1405,8 @@ static int __init parse_amd_iommu_options(char *str)
for (; *str; ++str) {
if (strncmp(str, "fullflush", 9) == 0)
amd_iommu_unmap_flush = true;
+ if (strncmp(str, "off", 3) == 0)
+ amd_iommu_disabled = true;
}

return 1;
--
1.7.1


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
 | 
Pages: 1
Prev: bug when enabling VM DEBUG
Next: [PATCH] CacheFiles: Fix occasional EIO on call to vfs_unlink()