arch/tile: optimize get_user/put_user and friends

[mirror_ubuntu-bionic-kernel.git] / arch / tile / Kconfig

# For a description of the syntax of this configuration file,
# see Documentation/kbuild/kconfig-language.txt.

config TILE
	def_bool y
	select HAVE_KVM if !TILEGX
	select GENERIC_FIND_FIRST_BIT
	select USE_GENERIC_SMP_HELPERS
	select CC_OPTIMIZE_FOR_SIZE
	select HAVE_GENERIC_HARDIRQS
	select GENERIC_IRQ_PROBE
	select GENERIC_PENDING_IRQ if SMP
	select GENERIC_IRQ_SHOW
	select HAVE_SYSCALL_WRAPPERS if TILEGX
	select SYS_HYPERVISOR
	select ARCH_HAVE_NMI_SAFE_CMPXCHG

# FIXME: investigate whether we need/want these options.
#	select HAVE_IOREMAP_PROT
#	select HAVE_OPTPROBES
#	select HAVE_REGS_AND_STACK_ACCESS_API
#	select HAVE_HW_BREAKPOINT
#	select PERF_EVENTS
#	select HAVE_USER_RETURN_NOTIFIER
#	config NO_BOOTMEM
#	config ARCH_SUPPORTS_DEBUG_PAGEALLOC
#	config HUGETLB_PAGE_SIZE_VARIABLE

config MMU
	def_bool y

config GENERIC_CSUM
	def_bool y

config SEMAPHORE_SLEEPERS
	def_bool y

config HAVE_ARCH_ALLOC_REMAP
	def_bool y

config HAVE_SETUP_PER_CPU_AREA
	def_bool y

config NEED_PER_CPU_PAGE_FIRST_CHUNK
	def_bool y

config SYS_SUPPORTS_HUGETLBFS
	def_bool y

config GENERIC_CLOCKEVENTS
	def_bool y

# FIXME: tilegx can implement a more efficient rwsem.
config RWSEM_GENERIC_SPINLOCK
	def_bool y

# We have a very flat architecture from a migration point of view,
# so save boot time by presetting this (particularly useful on tile-sim).
config DEFAULT_MIGRATION_COST
	int
	default "10000000"

# We only support gcc 4.4 and above, so this should work.
config ARCH_SUPPORTS_OPTIMIZED_INLINING
	def_bool y

config ARCH_PHYS_ADDR_T_64BIT
	def_bool y

config ARCH_DMA_ADDR_T_64BIT
	def_bool y

config NEED_DMA_MAP_STATE
	def_bool y

config LOCKDEP_SUPPORT
	def_bool y

config STACKTRACE_SUPPORT
	def_bool y
	select STACKTRACE

# We use discontigmem for now; at some point we may want to switch
# to sparsemem (Tilera bug 7996).
config ARCH_DISCONTIGMEM_ENABLE
	def_bool y

config ARCH_DISCONTIGMEM_DEFAULT
	def_bool y

config TRACE_IRQFLAGS_SUPPORT
	def_bool y

config STRICT_DEVMEM
	def_bool y

# SMP is required for Tilera Linux.
config SMP
	def_bool y

# Allow checking for compile-time determined overflow errors in
# copy_from_user().  There are still unprovable places in the
# generic code as of 2.6.34, so this option is not really compatible
# with -Werror, which is more useful in general.
config DEBUG_COPY_FROM_USER
	def_bool n

config HVC_TILE
	select HVC_DRIVER
	def_bool y

# Please note: TILE-Gx support is not yet finalized; this is
# the preliminary support.  TILE-Gx drivers are only provided
# with the alpha or beta test versions for Tilera customers.
config TILEGX
	depends on EXPERIMENTAL
	bool "Building with TILE-Gx (64-bit) compiler and toolchain"

config 64BIT
	depends on TILEGX
	def_bool y

config ARCH_DEFCONFIG
	string
	default "arch/tile/configs/tilepro_defconfig" if !TILEGX
	default "arch/tile/configs/tilegx_defconfig" if TILEGX

source "init/Kconfig"

menu "Tilera-specific configuration"

config NR_CPUS
	int "Maximum number of tiles (2-255)"
	range 2 255
	depends on SMP
	default "64"
	---help---
	  Building with 64 is the recommended value, but a slightly
	  smaller kernel memory footprint results from using a smaller
	  value on chips with fewer tiles.

source "kernel/time/Kconfig"

source "kernel/Kconfig.hz"

config KEXEC
	bool "kexec system call"
	---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 independent of the system firmware.   It is used
	  to implement the "mboot" Tilera booter.

	  The name comes from the similarity to the exec system call.

config COMPAT
	bool "Support 32-bit TILE-Gx binaries in addition to 64-bit"
	depends on TILEGX
	select COMPAT_BINFMT_ELF
	default y
	---help---
	  If enabled, the kernel will support running TILE-Gx binaries
	  that were built with the -m32 option.

config SYSVIPC_COMPAT
	def_bool y
	depends on COMPAT && SYSVIPC

# We do not currently support disabling HIGHMEM on tile64 and tilepro.
config HIGHMEM
	bool # "Support for more than 512 MB of RAM"
	default !TILEGX
	---help---
	  Linux can use the full amount of RAM in the system by
	  default.  However, the address space of TILE processors is
	  only 4 Gigabytes large. That means that, if you have a large
	  amount of physical memory, not all of it can be "permanently
	  mapped" by the kernel. The physical memory that's not
	  permanently mapped is called "high memory".

	  If you are compiling a kernel which will never run on a
	  machine with more than 512 MB total physical RAM, answer
	  "false" here. This will result in the kernel mapping all of
	  physical memory into the top 1 GB of virtual memory space.

	  If unsure, say "true".

# We do not currently support disabling NUMA.
config NUMA
	bool # "NUMA Memory Allocation and Scheduler Support"
	depends on SMP && DISCONTIGMEM
	default y
	---help---
	  NUMA memory allocation is required for TILE processors
	  unless booting with memory striping enabled in the
	  hypervisor, or with only a single memory controller.
	  It is recommended that this option always be enabled.

config NODES_SHIFT
	int "Log base 2 of the max number of memory controllers"
	default 2
	depends on NEED_MULTIPLE_NODES
	---help---
	  By default, 2, i.e. 2^2 == 4 DDR2 controllers.
	  In a system with more controllers, this value should be raised.

choice
	depends on !TILEGX
	prompt "Memory split" if EXPERT
	default VMSPLIT_3G
	---help---
	  Select the desired split between kernel and user memory.

	  If the address range available to the kernel is less than the
	  physical memory installed, the remaining memory will be available
	  as "high memory". Accessing high memory is a little more costly
	  than low memory, as it needs to be mapped into the kernel first.
	  Note that increasing the kernel address space limits the range
	  available to user programs, making the address space there
	  tighter.  Selecting anything other than the default 3G/1G split
	  will also likely make your kernel incompatible with binary-only
	  kernel modules.

	  If you are not absolutely sure what you are doing, leave this
	  option alone!

	config VMSPLIT_3_75G
		bool "3.75G/0.25G user/kernel split (no kernel networking)"
	config VMSPLIT_3_5G
		bool "3.5G/0.5G user/kernel split"
	config VMSPLIT_3G
		bool "3G/1G user/kernel split"
	config VMSPLIT_2_75G
		bool "2.75G/1.25G user/kernel split (for full 1G low memory)"
	config VMSPLIT_2_5G
		bool "2.5G/1.5G user/kernel split"
	config VMSPLIT_2_25G
		bool "2.25G/1.75G user/kernel split"
	config VMSPLIT_2G
		bool "2G/2G user/kernel split"
	config VMSPLIT_1G
		bool "1G/3G user/kernel split"
endchoice

config PAGE_OFFSET
	hex
	depends on !64BIT
	default 0xF0000000 if VMSPLIT_3_75G
	default 0xE0000000 if VMSPLIT_3_5G
	default 0xB0000000 if VMSPLIT_2_75G
	default 0xA0000000 if VMSPLIT_2_5G
	default 0x90000000 if VMSPLIT_2_25G
	default 0x80000000 if VMSPLIT_2G
	default 0x40000000 if VMSPLIT_1G
	default 0xC0000000

source "mm/Kconfig"

config CMDLINE_BOOL
	bool "Built-in kernel command line"
	default n
	---help---
	  Allow for specifying boot arguments to the kernel at
	  build time.  On some systems (e.g. embedded ones), it is
	  necessary or convenient to provide some or all of the
	  kernel boot arguments with the kernel itself (that is,
	  to not rely on the boot loader to provide them.)

	  To compile command line arguments into the kernel,
	  set this option to 'Y', then fill in the
	  the boot arguments in CONFIG_CMDLINE.

	  Systems with fully functional boot loaders (e.g. mboot, or
	  if booting over PCI) should leave this option set to 'N'.

config CMDLINE
	string "Built-in kernel command string"
	depends on CMDLINE_BOOL
	default ""
	---help---
	  Enter arguments here that should be compiled into the kernel
	  image and used at boot time.  If the boot loader provides a
	  command line at boot time, it is appended to this string to
	  form the full kernel command line, when the system boots.

	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
	  change this behavior.

	  In most cases, the command line (whether built-in or provided
	  by the boot loader) should specify the device for the root
	  file system.

config CMDLINE_OVERRIDE
	bool "Built-in command line overrides boot loader arguments"
	default n
	depends on CMDLINE_BOOL
	---help---
	  Set this option to 'Y' to have the kernel ignore the boot loader
	  command line, and use ONLY the built-in command line.

	  This is used to work around broken boot loaders.  This should
	  be set to 'N' under normal conditions.

config VMALLOC_RESERVE
	hex
	default 0x1000000

config HARDWALL
	bool "Hardwall support to allow access to user dynamic network"
	default y

config KERNEL_PL
	int "Processor protection level for kernel"
	range 1 2
	default "1"
	---help---
	  This setting determines the processor protection level the
	  kernel will be built to run at.  Generally you should use
	  the default value here.

endmenu  # Tilera-specific configuration

menu "Bus options"

config PCI
	bool "PCI support"
	default y
	select PCI_DOMAINS
	select GENERIC_PCI_IOMAP
	---help---
	  Enable PCI root complex support, so PCIe endpoint devices can
	  be attached to the Tile chip.  Many, but not all, PCI devices
	  are supported under Tilera's root complex driver.

config PCI_DOMAINS
	bool

config NO_IOMEM
	def_bool !PCI

config NO_IOPORT
	def_bool !PCI

source "drivers/pci/Kconfig"

config HOTPLUG
	bool "Support for hot-pluggable devices"
	---help---
	  Say Y here if you want to plug devices into your computer while
	  the system is running, and be able to use them quickly.  In many
	  cases, the devices can likewise be unplugged at any time too.
	  One well-known example of this is USB.

source "drivers/pci/hotplug/Kconfig"

endmenu

menu "Executable file formats"

# only elf supported
config KCORE_ELF
	def_bool y
	depends on PROC_FS

source "fs/Kconfig.binfmt"

endmenu

source "net/Kconfig"

source "drivers/Kconfig"

source "fs/Kconfig"

source "arch/tile/Kconfig.debug"

source "security/Kconfig"

source "crypto/Kconfig"

source "lib/Kconfig"

source "arch/tile/kvm/Kconfig"