can be controlled through /sys/devices/system/cpu/cpu#.
Say N if you want to disable CPU hotplug.
+config ARCH_ENABLE_MEMORY_HOTPLUG
+ def_bool y
config HPET_TIMER
bool
bool "Provide RTC interrupt"
depends on HPET_TIMER && RTC=y
-config GART_IOMMU
- bool "K8 GART IOMMU support"
+# Mark as embedded because too many people got it wrong.
+# The code disables itself when not needed.
+config IOMMU
+ bool "IOMMU support" if EMBEDDED
default y
select SWIOTLB
select AGP
depends on PCI
help
- Support for hardware IOMMU in AMD's Opteron/Athlon64 Processors
- and for the bounce buffering software IOMMU.
- Needed to run systems with more than 3GB of memory properly with
- 32-bit PCI devices that do not support DAC (Double Address Cycle).
- The IOMMU can be turned off at runtime with the iommu=off parameter.
- Normally the kernel will take the right choice by itself.
- This option includes a driver for the AMD Opteron/Athlon64 IOMMU
- northbridge and a software emulation used on other systems without
- hardware IOMMU. If unsure, say Y.
-
-# need this always selected by GART_IOMMU for the VIA workaround
+ Support for full DMA access of devices with 32bit memory access only
+ on systems with more than 3GB. This is usually needed for USB,
+ sound, many IDE/SATA chipsets and some other devices.
+ Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
+ based IOMMU and a software bounce buffer based IOMMU used on Intel
+ systems and as fallback.
+ The code is only active when needed (enough memory and limited
+ device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
+ too.
+
+config CALGARY_IOMMU
+ bool "IBM Calgary IOMMU support"
+ default y
+ select SWIOTLB
+ depends on PCI && EXPERIMENTAL
+ help
+ Support for hardware IOMMUs in IBM's xSeries x366 and x460
+ systems. Needed to run systems with more than 3GB of memory
+ properly with 32-bit PCI devices that do not support DAC
+ (Double Address Cycle). Calgary also supports bus level
+ isolation, where all DMAs pass through the IOMMU. This
+ prevents them from going anywhere except their intended
+ destination. This catches hard-to-find kernel bugs and
+ mis-behaving drivers and devices that do not use the DMA-API
+ properly to set up their DMA buffers. The IOMMU can be
+ turned off at boot time with the iommu=off parameter.
+ Normally the kernel will make the right choice by itself.
+ If unsure, say Y.
+
+# need this always selected by IOMMU for the VIA workaround
config SWIOTLB
bool
help
kexec is a system call that implements the ability to shutdown your
current kernel, and to start another kernel. It is like a reboot
- but it is indepedent of the system firmware. And like a reboot
+ but it is independent of the system firmware. And like a reboot
you can start any kernel with it, not just Linux.
- The name comes from the similiarity to the exec system call.
+ The name comes from the similarity to the exec system call.
It is an ongoing process to be certain the hardware in a machine
is properly shutdown, so do not be surprised if this code does not
optimal TLB usage. If you have pretty much any version of binutils,
this can increase your kernel build time by roughly one minute.
+config K8_NB
+ def_bool y
+ depends on AGP_AMD64 || IOMMU || (PCI && NUMA)
+
endmenu
#