kernel-ark/arch/xtensa/Kconfig

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config ZONE_DMA
def_bool y
config XTENSA
def_bool y
select ARCH_WANT_FRAME_POINTERS
select HAVE_IDE
select GENERIC_ATOMIC64
select GENERIC_CLOCKEVENTS
select VIRT_TO_BUS
select GENERIC_IRQ_SHOW
select GENERIC_CPU_DEVICES
select GENERIC_SCHED_CLOCK
select MODULES_USE_ELF_RELA
select GENERIC_PCI_IOMAP
select ARCH_WANT_IPC_PARSE_VERSION
select ARCH_WANT_OPTIONAL_GPIOLIB
select CLONE_BACKWARDS
select IRQ_DOMAIN
select HAVE_OPROFILE
select HAVE_FUNCTION_TRACER
help
Xtensa processors are 32-bit RISC machines designed by Tensilica
primarily for embedded systems. These processors are both
configurable and extensible. The Linux port to the Xtensa
architecture supports all processor configurations and extensions,
with reasonable minimum requirements. The Xtensa Linux project has
a home page at <http://www.linux-xtensa.org/>.
config RWSEM_XCHGADD_ALGORITHM
def_bool y
config GENERIC_HWEIGHT
def_bool y
config ARCH_HAS_ILOG2_U32
def_bool n
config ARCH_HAS_ILOG2_U64
def_bool n
config NO_IOPORT
def_bool n
avoid overflows in kernel/time.c When the conversion factor between jiffies and milli- or microseconds is not a single multiply or divide, as for the case of HZ == 300, we currently do a multiply followed by a divide. The intervening result, however, is subject to overflows, especially since the fraction is not simplified (for HZ == 300, we multiply by 300 and divide by 1000). This is exposed to the user when passing a large timeout to poll(), for example. This patch replaces the multiply-divide with a reciprocal multiplication on 32-bit platforms. When the input is an unsigned long, there is no portable way to do this on 64-bit platforms there is no portable way to do this since it requires a 128-bit intermediate result (which gcc does support on 64-bit platforms but may generate libgcc calls, e.g. on 64-bit s390), but since the output is a 32-bit integer in the cases affected, just simplify the multiply-divide (*3/10 instead of *300/1000). The reciprocal multiply used can have off-by-one errors in the upper half of the valid output range. This could be avoided at the expense of having to deal with a potential 65-bit intermediate result. Since the intent is to avoid overflow problems and most of the other time conversions are only semiexact, the off-by-one errors were considered an acceptable tradeoff. At Ralf Baechle's suggestion, this version uses a Perl script to compute the necessary constants. We already have dependencies on Perl for kernel compiles. This does, however, require the Perl module Math::BigInt, which is included in the standard Perl distribution starting with version 5.8.0. In order to support older versions of Perl, include a table of canned constants in the script itself, and structure the script so that Math::BigInt isn't required if pulling values from said table. Running the script requires that the HZ value is available from the Makefile. Thus, this patch also adds the Kconfig variable CONFIG_HZ to the architectures which didn't already have it (alpha, cris, frv, h8300, m32r, m68k, m68knommu, sparc, v850, and xtensa.) It does *not* touch the sh or sh64 architectures, since Paul Mundt has dealt with those separately in the sh tree. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Ralf Baechle <ralf@linux-mips.org>, Cc: Sam Ravnborg <sam@ravnborg.org>, Cc: Paul Mundt <lethal@linux-sh.org>, Cc: Richard Henderson <rth@twiddle.net>, Cc: Michael Starvik <starvik@axis.com>, Cc: David Howells <dhowells@redhat.com>, Cc: Yoshinori Sato <ysato@users.sourceforge.jp>, Cc: Hirokazu Takata <takata@linux-m32r.org>, Cc: Geert Uytterhoeven <geert@linux-m68k.org>, Cc: Roman Zippel <zippel@linux-m68k.org>, Cc: William L. Irwin <sparclinux@vger.kernel.org>, Cc: Chris Zankel <chris@zankel.net>, Cc: H. Peter Anvin <hpa@zytor.com>, Cc: Jan Engelhardt <jengelh@computergmbh.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 12:21:26 +00:00
config HZ
int
default 100
source "init/Kconfig"
container freezer: implement freezer cgroup subsystem This patch implements a new freezer subsystem in the control groups framework. It provides a way to stop and resume execution of all tasks in a cgroup by writing in the cgroup filesystem. The freezer subsystem in the container filesystem defines a file named freezer.state. Writing "FROZEN" to the state file will freeze all tasks in the cgroup. Subsequently writing "RUNNING" will unfreeze the tasks in the cgroup. Reading will return the current state. * Examples of usage : # mkdir /containers/freezer # mount -t cgroup -ofreezer freezer /containers # mkdir /containers/0 # echo $some_pid > /containers/0/tasks to get status of the freezer subsystem : # cat /containers/0/freezer.state RUNNING to freeze all tasks in the container : # echo FROZEN > /containers/0/freezer.state # cat /containers/0/freezer.state FREEZING # cat /containers/0/freezer.state FROZEN to unfreeze all tasks in the container : # echo RUNNING > /containers/0/freezer.state # cat /containers/0/freezer.state RUNNING This is the basic mechanism which should do the right thing for user space task in a simple scenario. It's important to note that freezing can be incomplete. In that case we return EBUSY. This means that some tasks in the cgroup are busy doing something that prevents us from completely freezing the cgroup at this time. After EBUSY, the cgroup will remain partially frozen -- reflected by freezer.state reporting "FREEZING" when read. The state will remain "FREEZING" until one of these things happens: 1) Userspace cancels the freezing operation by writing "RUNNING" to the freezer.state file 2) Userspace retries the freezing operation by writing "FROZEN" to the freezer.state file (writing "FREEZING" is not legal and returns EIO) 3) The tasks that blocked the cgroup from entering the "FROZEN" state disappear from the cgroup's set of tasks. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: export thaw_process] Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Tested-by: Matt Helsley <matthltc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-19 03:27:21 +00:00
source "kernel/Kconfig.freezer"
config LOCKDEP_SUPPORT
def_bool y
config STACKTRACE_SUPPORT
def_bool y
config TRACE_IRQFLAGS_SUPPORT
def_bool y
config MMU
def_bool n
config VARIANT_IRQ_SWITCH
def_bool n
menu "Processor type and features"
choice
prompt "Xtensa Processor Configuration"
default XTENSA_VARIANT_FSF
config XTENSA_VARIANT_FSF
bool "fsf - default (not generic) configuration"
select MMU
config XTENSA_VARIANT_DC232B
bool "dc232b - Diamond 232L Standard Core Rev.B (LE)"
select MMU
help
This variant refers to Tensilica's Diamond 232L Standard core Rev.B (LE).
config XTENSA_VARIANT_DC233C
bool "dc233c - Diamond 233L Standard Core Rev.C (LE)"
select MMU
help
This variant refers to Tensilica's Diamond 233L Standard core Rev.C (LE).
config XTENSA_VARIANT_S6000
bool "s6000 - Stretch software configurable processor"
select VARIANT_IRQ_SWITCH
select ARCH_REQUIRE_GPIOLIB
select XTENSA_CALIBRATE_CCOUNT
endchoice
config XTENSA_UNALIGNED_USER
bool "Unaligned memory access in use space"
help
The Xtensa architecture currently does not handle unaligned
memory accesses in hardware but through an exception handler.
Per default, unaligned memory accesses are disabled in user space.
Say Y here to enable unaligned memory access in user space.
source "kernel/Kconfig.preempt"
config MATH_EMULATION
bool "Math emulation"
help
Can we use information of configuration file?
config INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
bool "Initialize Xtensa MMU inside the Linux kernel code"
default y
help
Earlier version initialized the MMU in the exception vector
before jumping to _startup in head.S and had an advantage that
it was possible to place a software breakpoint at 'reset' and
then enter your normal kernel breakpoints once the MMU was mapped
to the kernel mappings (0XC0000000).
This unfortunately doesn't work for U-Boot and likley also wont
work for using KEXEC to have a hot kernel ready for doing a
KDUMP.
So now the MMU is initialized in head.S but it's necessary to
use hardware breakpoints (gdb 'hbreak' cmd) to break at _startup.
xt-gdb can't place a Software Breakpoint in the 0XD region prior
to mapping the MMU and after mapping even if the area of low memory
was mapped gdb wouldn't remove the breakpoint on hitting it as the
PC wouldn't match. Since Hardware Breakpoints are recommended for
Linux configurations it seems reasonable to just assume they exist
and leave this older mechanism for unfortunate souls that choose
not to follow Tensilica's recommendation.
Selecting this will cause U-Boot to set the KERNEL Load and Entry
address at 0x00003000 instead of the mapped std of 0xD0003000.
If in doubt, say Y.
endmenu
config XTENSA_CALIBRATE_CCOUNT
def_bool n
help
On some platforms (XT2000, for example), the CPU clock rate can
vary. The frequency can be determined, however, by measuring
against a well known, fixed frequency, such as an UART oscillator.
config SERIAL_CONSOLE
def_bool n
config XTENSA_ISS_NETWORK
def_bool n
menu "Bus options"
config PCI
bool "PCI support"
default y
help
Find out whether you have a PCI motherboard. PCI is the name of a
bus system, i.e. the way the CPU talks to the other stuff inside
your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
VESA. If you have PCI, say Y, otherwise N.
source "drivers/pci/Kconfig"
endmenu
menu "Platform options"
choice
prompt "Xtensa System Type"
default XTENSA_PLATFORM_ISS
config XTENSA_PLATFORM_ISS
bool "ISS"
depends on TTY
select XTENSA_CALIBRATE_CCOUNT
select SERIAL_CONSOLE
select XTENSA_ISS_NETWORK
help
ISS is an acronym for Tensilica's Instruction Set Simulator.
config XTENSA_PLATFORM_XT2000
bool "XT2000"
help
XT2000 is the name of Tensilica's feature-rich emulation platform.
This hardware is capable of running a full Linux distribution.
config XTENSA_PLATFORM_S6105
bool "S6105"
select SERIAL_CONSOLE
select NO_IOPORT
config XTENSA_PLATFORM_XTFPGA
bool "XTFPGA"
select SERIAL_CONSOLE
select ETHOC
select XTENSA_CALIBRATE_CCOUNT
help
XTFPGA is the name of Tensilica board family (LX60, LX110, LX200, ML605).
This hardware is capable of running a full Linux distribution.
endchoice
config XTENSA_CPU_CLOCK
int "CPU clock rate [MHz]"
depends on !XTENSA_CALIBRATE_CCOUNT
default 16
config GENERIC_CALIBRATE_DELAY
bool "Auto calibration of the BogoMIPS value"
help
The BogoMIPS value can easily be derived from the CPU frequency.
config CMDLINE_BOOL
bool "Default bootloader kernel arguments"
config CMDLINE
string "Initial kernel command string"
depends on CMDLINE_BOOL
default "console=ttyS0,38400 root=/dev/ram"
help
On some architectures (EBSA110 and CATS), there is currently no way
for the boot loader to pass arguments to the kernel. For these
architectures, you should supply some command-line options at build
time by entering them here. As a minimum, you should specify the
memory size and the root device (e.g., mem=64M root=/dev/nfs).
config USE_OF
bool "Flattened Device Tree support"
select OF
select OF_EARLY_FLATTREE
help
Include support for flattened device tree machine descriptions.
config BUILTIN_DTB
string "DTB to build into the kernel image"
depends on OF
config BLK_DEV_SIMDISK
tristate "Host file-based simulated block device support"
default n
depends on XTENSA_PLATFORM_ISS
help
Create block devices that map to files in the host file system.
Device binding to host file may be changed at runtime via proc
interface provided the device is not in use.
config BLK_DEV_SIMDISK_COUNT
int "Number of host file-based simulated block devices"
range 1 10
depends on BLK_DEV_SIMDISK
default 2
help
This is the default minimal number of created block devices.
Kernel/module parameter 'simdisk_count' may be used to change this
value at runtime. More file names (but no more than 10) may be
specified as parameters, simdisk_count grows accordingly.
config SIMDISK0_FILENAME
string "Host filename for the first simulated device"
depends on BLK_DEV_SIMDISK = y
default ""
help
Attach a first simdisk to a host file. Conventionally, this file
contains a root file system.
config SIMDISK1_FILENAME
string "Host filename for the second simulated device"
depends on BLK_DEV_SIMDISK = y && BLK_DEV_SIMDISK_COUNT != 1
default ""
help
Another simulated disk in a host file for a buildroot-independent
storage.
source "mm/Kconfig"
source "drivers/pcmcia/Kconfig"
source "drivers/pci/hotplug/Kconfig"
endmenu
menu "Executable file formats"
source "fs/Kconfig.binfmt"
endmenu
source "net/Kconfig"
source "drivers/Kconfig"
source "fs/Kconfig"
source "arch/xtensa/Kconfig.debug"
source "security/Kconfig"
source "crypto/Kconfig"
source "lib/Kconfig"