To support up to 64 sockets with 10 DMAR units each (640), make the
value of DMAR_UNITS_SUPPORTED adjustable by a config variable,
CONFIG_DMAR_UNITS_SUPPORTED, and make it's default 1024 when MAXSMP is
set.
If the available hardware exceeds DMAR_UNITS_SUPPORTED (previously set
to MAX_IO_APICS, or 128), it causes these messages: "DMAR: Failed to
allocate seq_id", "DMAR: Parse DMAR table failure.", and "x2apic: IRQ
remapping doesn't support X2APIC mode x2apic disabled"; and the system
fails to boot properly.
Signed-off-by: Steve Wahl <steve.w...@hpe.com>
Reviewed-by: Kevin Tian <kevin.t...@intel.com>
---
Note that we could not find a reason for connecting
DMAR_UNITS_SUPPORTED to MAX_IO_APICS as was done previously. Perhaps
it seemed like the two would continue to match on earlier processors.
There doesn't appear to be kernel code that assumes that the value of
one is related to the other.
v2: Make this value a config option, rather than a fixed constant. The default
values should match previous configuration except in the MAXSMP case. Keeping
the
value at a power of two was requested by Kevin Tian.
v3: Make the config option dependent upon DMAR_TABLE, as it is not used without
this.
drivers/iommu/intel/Kconfig | 7 +++++++
include/linux/dmar.h | 6 +-----
2 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/intel/Kconfig b/drivers/iommu/intel/Kconfig
index 39a06d245f12..07aaebcb581d 100644
--- a/drivers/iommu/intel/Kconfig
+++ b/drivers/iommu/intel/Kconfig
@@ -9,6 +9,13 @@ config DMAR_PERF
config DMAR_DEBUG
bool
+config DMAR_UNITS_SUPPORTED
+ int "Number of DMA Remapping Units supported"
+ depends on DMAR_TABLE
+ default 1024 if MAXSMP
+ default 128 if X86_64
+ default 64
+
config INTEL_IOMMU
bool "Support for Intel IOMMU using DMA Remapping Devices"
depends on PCI_MSI && ACPI && (X86 || IA64)
diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index 45e903d84733..0c03c1845c23 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -18,11 +18,7 @@
struct acpi_dmar_header;
-#ifdef CONFIG_X86
-# define DMAR_UNITS_SUPPORTED MAX_IO_APICS
-#else
-# define DMAR_UNITS_SUPPORTED 64
-#endif
+#define DMAR_UNITS_SUPPORTED CONFIG_DMAR_UNITS_SUPPORTED
/* DMAR Flags */
#define DMAR_INTR_REMAP 0x1
--
2.26.2
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