[PATCH] intr-remap: allow disabling source id checking

From: Chris Wright
Date: Fri Oct 23 2009 - 21:26:56 EST


Allow users to disable source id checking. This is really a debugging aid
for broken BIOS setups.

Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
---
Documentation/kernel-parameters.txt | 7 +++++++
drivers/pci/intr_remapping.c | 20 ++++++++++++++++++++
2 files changed, 27 insertions(+), 0 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 6fa7292..344256c 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -982,6 +982,12 @@ and is between 256 and 4096 characters. It is defined in the file
result in a hardware IOTLB flush operation as opposed
to batching them for performance.

+ intremap= [X86-64, Intel-IOMMU]
+ Format: { on (default) | off | nosid }
+ on enable Interrupt Remapping (default)
+ off disable Interrupt Remapping
+ nosid disable Source ID checking
+
inttest= [IA64]

iomem= Disable strict checking of access to MMIO memory
@@ -1691,6 +1697,7 @@ and is between 256 and 4096 characters. It is defined in the file

nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
remapping.
+ [Deprecated - use intremap=off]

nointroute [IA-64]

diff --git a/drivers/pci/intr_remapping.c b/drivers/pci/intr_remapping.c
index 0ed78a7..136bb6e 100644
--- a/drivers/pci/intr_remapping.c
+++ b/drivers/pci/intr_remapping.c
@@ -18,6 +18,8 @@ static int ir_ioapic_num;
int intr_remapping_enabled;

static int disable_intremap;
+static int disable_sourceid_checking;
+
static __init int setup_nointremap(char *str)
{
disable_intremap = 1;
@@ -25,6 +27,22 @@ static __init int setup_nointremap(char *str)
}
early_param("nointremap", setup_nointremap);

+static __init int setup_intremap(char *str)
+{
+ if (!str)
+ return -EINVAL;
+
+ if (!strncmp(str, "on", 2))
+ disable_intremap = 0;
+ else if (!strncmp(str, "off", 3))
+ disable_intremap = 1;
+ else if (!strncmp(str, "nosid", 5))
+ disable_sourceid_checking = 1;
+
+ return 0;
+}
+early_param("intremap", setup_intremap);
+
struct irq_2_iommu {
struct intel_iommu *iommu;
u16 irte_index;
@@ -440,6 +458,8 @@ int free_irte(int irq)
static void set_irte_sid(struct irte *irte, unsigned int svt,
unsigned int sq, unsigned int sid)
{
+ if (disable_sourceid_checking)
+ svt = SVT_NO_VERIFY;
irte->svt = svt;
irte->sq = sq;
irte->sid = sid;
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