[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / Kconfig

#
# General architecture dependent options
#

config OPROFILE
	tristate "OProfile system profiling"
	depends on PROFILING
	depends on HAVE_OPROFILE
	select RING_BUFFER
	select RING_BUFFER_ALLOW_SWAP
	help
	  OProfile is a profiling system capable of profiling the
	  whole system, include the kernel, kernel modules, libraries,
	  and applications.

	  If unsure, say N.

config OPROFILE_EVENT_MULTIPLEX
	bool "OProfile multiplexing support (EXPERIMENTAL)"
	default n
	depends on OPROFILE && X86
	help
	  The number of hardware counters is limited. The multiplexing
	  feature enables OProfile to gather more events than counters
	  are provided by the hardware. This is realized by switching
	  between events at an user specified time interval.

	  If unsure, say N.

config HAVE_OPROFILE
	bool

config OPROFILE_NMI_TIMER
	def_bool y
	depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI

config KPROBES
	bool "Kprobes"
	depends on MODULES
	depends on HAVE_KPROBES
	select KALLSYMS
	help
	  Kprobes allows you to trap at almost any kernel address and
	  execute a callback function.  register_kprobe() establishes
	  a probepoint and specifies the callback.  Kprobes is useful
	  for kernel debugging, non-intrusive instrumentation and testing.
	  If in doubt, say "N".

config JUMP_LABEL
       bool "Optimize very unlikely/likely branches"
       depends on HAVE_ARCH_JUMP_LABEL
       help
         This option enables a transparent branch optimization that
	 makes certain almost-always-true or almost-always-false branch
	 conditions even cheaper to execute within the kernel.

	 Certain performance-sensitive kernel code, such as trace points,
	 scheduler functionality, networking code and KVM have such
	 branches and include support for this optimization technique.

         If it is detected that the compiler has support for "asm goto",
	 the kernel will compile such branches with just a nop
	 instruction. When the condition flag is toggled to true, the
	 nop will be converted to a jump instruction to execute the
	 conditional block of instructions.

	 This technique lowers overhead and stress on the branch prediction
	 of the processor and generally makes the kernel faster. The update
	 of the condition is slower, but those are always very rare.

	 ( On 32-bit x86, the necessary options added to the compiler
	   flags may increase the size of the kernel slightly. )

config OPTPROBES
	def_bool y
	depends on KPROBES && HAVE_OPTPROBES
	depends on !PREEMPT

config KPROBES_ON_FTRACE
	def_bool y
	depends on KPROBES && HAVE_KPROBES_ON_FTRACE
	depends on DYNAMIC_FTRACE_WITH_REGS
	help
	 If function tracer is enabled and the arch supports full
	 passing of pt_regs to function tracing, then kprobes can
	 optimize on top of function tracing.

config UPROBES
	bool "Transparent user-space probes (EXPERIMENTAL)"
	depends on UPROBE_EVENT && PERF_EVENTS
	default n
	select PERCPU_RWSEM
	help
	  Uprobes is the user-space counterpart to kprobes: they
	  enable instrumentation applications (such as 'perf probe')
	  to establish unintrusive probes in user-space binaries and
	  libraries, by executing handler functions when the probes
	  are hit by user-space applications.

	  ( These probes come in the form of single-byte breakpoints,
	    managed by the kernel and kept transparent to the probed
	    application. )

	  If in doubt, say "N".

config HAVE_64BIT_ALIGNED_ACCESS
	def_bool 64BIT && !HAVE_EFFICIENT_UNALIGNED_ACCESS
	help
	  Some architectures require 64 bit accesses to be 64 bit
	  aligned, which also requires structs containing 64 bit values
	  to be 64 bit aligned too. This includes some 32 bit
	  architectures which can do 64 bit accesses, as well as 64 bit
	  architectures without unaligned access.

	  This symbol should be selected by an architecture if 64 bit
	  accesses are required to be 64 bit aligned in this way even
	  though it is not a 64 bit architecture.

	  See Documentation/unaligned-memory-access.txt for more
	  information on the topic of unaligned memory accesses.

config HAVE_EFFICIENT_UNALIGNED_ACCESS
	bool
	help
	  Some architectures are unable to perform unaligned accesses
	  without the use of get_unaligned/put_unaligned. Others are
	  unable to perform such accesses efficiently (e.g. trap on
	  unaligned access and require fixing it up in the exception
	  handler.)

	  This symbol should be selected by an architecture if it can
	  perform unaligned accesses efficiently to allow different
	  code paths to be selected for these cases. Some network
	  drivers, for example, could opt to not fix up alignment
	  problems with received packets if doing so would not help
	  much.

	  See Documentation/unaligned-memory-access.txt for more
	  information on the topic of unaligned memory accesses.

config ARCH_USE_BUILTIN_BSWAP
       bool
       help
	 Modern versions of GCC (since 4.4) have builtin functions
	 for handling byte-swapping. Using these, instead of the old
	 inline assembler that the architecture code provides in the
	 __arch_bswapXX() macros, allows the compiler to see what's
	 happening and offers more opportunity for optimisation. In
	 particular, the compiler will be able to combine the byteswap
	 with a nearby load or store and use load-and-swap or
	 store-and-swap instructions if the architecture has them. It
	 should almost *never* result in code which is worse than the
	 hand-coded assembler in <asm/swab.h>.  But just in case it
	 does, the use of the builtins is optional.

	 Any architecture with load-and-swap or store-and-swap
	 instructions should set this. And it shouldn't hurt to set it
	 on architectures that don't have such instructions.

config KRETPROBES
	def_bool y
	depends on KPROBES && HAVE_KRETPROBES

config USER_RETURN_NOTIFIER
	bool
	depends on HAVE_USER_RETURN_NOTIFIER
	help
	  Provide a kernel-internal notification when a cpu is about to
	  switch to user mode.

config HAVE_IOREMAP_PROT
	bool

config HAVE_KPROBES
	bool

config HAVE_KRETPROBES
	bool

config HAVE_OPTPROBES
	bool

config HAVE_KPROBES_ON_FTRACE
	bool

config HAVE_NMI_WATCHDOG
	bool
#
# An arch should select this if it provides all these things:
#
#	task_pt_regs()		in asm/processor.h or asm/ptrace.h
#	arch_has_single_step()	if there is hardware single-step support
#	arch_has_block_step()	if there is hardware block-step support
#	asm/syscall.h		supplying asm-generic/syscall.h interface
#	linux/regset.h		user_regset interfaces
#	CORE_DUMP_USE_REGSET	#define'd in linux/elf.h
#	TIF_SYSCALL_TRACE	calls tracehook_report_syscall_{entry,exit}
#	TIF_NOTIFY_RESUME	calls tracehook_notify_resume()
#	signal delivery		calls tracehook_signal_handler()
#
config HAVE_ARCH_TRACEHOOK
	bool

config HAVE_DMA_ATTRS
	bool

config HAVE_DMA_CONTIGUOUS
	bool

config USE_GENERIC_SMP_HELPERS
	bool

config GENERIC_SMP_IDLE_THREAD
       bool

config GENERIC_IDLE_POLL_SETUP
       bool

# Select if arch init_task initializer is different to init/init_task.c
config ARCH_INIT_TASK
       bool

# Select if arch has its private alloc_task_struct() function
config ARCH_TASK_STRUCT_ALLOCATOR
	bool

# Select if arch has its private alloc_thread_info() function
config ARCH_THREAD_INFO_ALLOCATOR
	bool

config HAVE_REGS_AND_STACK_ACCESS_API
	bool
	help
	  This symbol should be selected by an architecure if it supports
	  the API needed to access registers and stack entries from pt_regs,
	  declared in asm/ptrace.h
	  For example the kprobes-based event tracer needs this API.

config HAVE_CLK
	bool
	help
	  The <linux/clk.h> calls support software clock gating and
	  thus are a key power management tool on many systems.

config HAVE_DMA_API_DEBUG
	bool

config HAVE_HW_BREAKPOINT
	bool
	depends on PERF_EVENTS

config HAVE_MIXED_BREAKPOINTS_REGS
	bool
	depends on HAVE_HW_BREAKPOINT
	help
	  Depending on the arch implementation of hardware breakpoints,
	  some of them have separate registers for data and instruction
	  breakpoints addresses, others have mixed registers to store
	  them but define the access type in a control register.
	  Select this option if your arch implements breakpoints under the
	  latter fashion.

config HAVE_USER_RETURN_NOTIFIER
	bool

config HAVE_PERF_EVENTS_NMI
	bool
	help
	  System hardware can generate an NMI using the perf event
	  subsystem.  Also has support for calculating CPU cycle events
	  to determine how many clock cycles in a given period.

config HAVE_PERF_REGS
	bool
	help
	  Support selective register dumps for perf events. This includes
	  bit-mapping of each registers and a unique architecture id.

config HAVE_PERF_USER_STACK_DUMP
	bool
	help
	  Support user stack dumps for perf event samples. This needs
	  access to the user stack pointer which is not unified across
	  architectures.

config HAVE_ARCH_JUMP_LABEL
	bool

config HAVE_ARCH_MUTEX_CPU_RELAX
	bool

config HAVE_RCU_TABLE_FREE
	bool

config ARCH_HAVE_NMI_SAFE_CMPXCHG
	bool

config HAVE_ALIGNED_STRUCT_PAGE
	bool
	help
	  This makes sure that struct pages are double word aligned and that
	  e.g. the SLUB allocator can perform double word atomic operations
	  on a struct page for better performance. However selecting this
	  might increase the size of a struct page by a word.

config HAVE_CMPXCHG_LOCAL
	bool

config HAVE_CMPXCHG_DOUBLE
	bool

config ARCH_WANT_IPC_PARSE_VERSION
	bool

config ARCH_WANT_COMPAT_IPC_PARSE_VERSION
	bool

config ARCH_WANT_OLD_COMPAT_IPC
	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
	bool

config HAVE_ARCH_SECCOMP_FILTER
	bool
	help
	  An arch should select this symbol if it provides all of these things:
	  - syscall_get_arch()
	  - syscall_get_arguments()
	  - syscall_rollback()
	  - syscall_set_return_value()
	  - SIGSYS siginfo_t support
	  - secure_computing is called from a ptrace_event()-safe context
	  - secure_computing return value is checked and a return value of -1
	    results in the system call being skipped immediately.

config SECCOMP_FILTER
	def_bool y
	depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET
	help
	  Enable tasks to build secure computing environments defined
	  in terms of Berkeley Packet Filter programs which implement
	  task-defined system call filtering polices.

	  See Documentation/prctl/seccomp_filter.txt for details.

config HAVE_CONTEXT_TRACKING
	bool
	help
	  Provide kernel/user boundaries probes necessary for subsystems
	  that need it, such as userspace RCU extended quiescent state.
	  Syscalls need to be wrapped inside user_exit()-user_enter() through
	  the slow path using TIF_NOHZ flag. Exceptions handlers must be
	  wrapped as well. Irqs are already protected inside
	  rcu_irq_enter/rcu_irq_exit() but preemption or signal handling on
	  irq exit still need to be protected.

config HAVE_VIRT_CPU_ACCOUNTING
	bool

config HAVE_IRQ_TIME_ACCOUNTING
	bool
	help
	  Archs need to ensure they use a high enough resolution clock to
	  support irq time accounting and then call enable_sched_clock_irqtime().

config HAVE_ARCH_TRANSPARENT_HUGEPAGE
	bool

config HAVE_MOD_ARCH_SPECIFIC
	bool
	help
	  The arch uses struct mod_arch_specific to store data.  Many arches
	  just need a simple module loader without arch specific data - those
	  should not enable this.

config MODULES_USE_ELF_RELA
	bool
	help
	  Modules only use ELF RELA relocations.  Modules with ELF REL
	  relocations will give an error.

config MODULES_USE_ELF_REL
	bool
	help
	  Modules only use ELF REL relocations.  Modules with ELF RELA
	  relocations will give an error.

config HAVE_UNDERSCORE_SYMBOL_PREFIX
	bool
	help
	  Some architectures generate an _ in front of C symbols; things like
	  module loading and assembly files need to know about this.

#
# ABI hall of shame
#
config CLONE_BACKWARDS
	bool
	help
	  Architecture has tls passed as the 4th argument of clone(2),
	  not the 5th one.

config CLONE_BACKWARDS2
	bool
	help
	  Architecture has the first two arguments of clone(2) swapped.

config CLONE_BACKWARDS3
	bool
	help
	  Architecture has tls passed as the 3rd argument of clone(2),
	  not the 5th one.

config ODD_RT_SIGACTION
	bool
	help
	  Architecture has unusual rt_sigaction(2) arguments

config OLD_SIGSUSPEND
	bool
	help
	  Architecture has old sigsuspend(2) syscall, of one-argument variety

config OLD_SIGSUSPEND3
	bool
	help
	  Even weirder antique ABI - three-argument sigsuspend(2)

config OLD_SIGACTION
	bool
	help
	  Architecture has old sigaction(2) syscall.  Nope, not the same
	  as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2),
	  but fairly different variant of sigaction(2), thanks to OSF/1
	  compatibility...

config COMPAT_OLD_SIGACTION
	bool

source "kernel/gcov/Kconfig"
Commit	Line	Data
fb32e03f MD	1	#
	2	# General architecture dependent options
	3	#
125e5645 MD	4
125e5645 MD	5	config OPROFILE
b309a294	6	tristate "OProfile system profiling"
125e5645 MD	7	depends on PROFILING
125e5645 MD	8	depends on HAVE_OPROFILE
d69d59f4	9	select RING_BUFFER
9a5963eb	10	select RING_BUFFER_ALLOW_SWAP
125e5645 MD	11	help
	12	OProfile is a profiling system capable of profiling the
	13	whole system, include the kernel, kernel modules, libraries,
	14	and applications.
	15
	16	If unsure, say N.
	17
4d4036e0 JY	18	config OPROFILE_EVENT_MULTIPLEX
	19	bool "OProfile multiplexing support (EXPERIMENTAL)"
	20	default n
	21	depends on OPROFILE && X86
	22	help
	23	The number of hardware counters is limited. The multiplexing
	24	feature enables OProfile to gather more events than counters
	25	are provided by the hardware. This is realized by switching
	26	between events at an user specified time interval.
	27
	28	If unsure, say N.
	29
125e5645	30	config HAVE_OPROFILE
9ba16087	31	bool
125e5645	32
dcfce4a0 RR	33	config OPROFILE_NMI_TIMER
	34	def_bool y
	35	depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI
	36
125e5645 MD	37	config KPROBES
125e5645 MD	38	bool "Kprobes"
05ed160e	39	depends on MODULES
125e5645	40	depends on HAVE_KPROBES
05ed160e	41	select KALLSYMS
125e5645 MD	42	help
	43	Kprobes allows you to trap at almost any kernel address and
	44	execute a callback function. register_kprobe() establishes
	45	a probepoint and specifies the callback. Kprobes is useful
	46	for kernel debugging, non-intrusive instrumentation and testing.
	47	If in doubt, say "N".
	48
45f81b1c	49	config JUMP_LABEL
c5905afb	50	bool "Optimize very unlikely/likely branches"
45f81b1c SR	51	depends on HAVE_ARCH_JUMP_LABEL
45f81b1c SR	52	help
c5905afb IM	53	This option enables a transparent branch optimization that
	54	makes certain almost-always-true or almost-always-false branch
	55	conditions even cheaper to execute within the kernel.
	56
	57	Certain performance-sensitive kernel code, such as trace points,
	58	scheduler functionality, networking code and KVM have such
	59	branches and include support for this optimization technique.
	60
45f81b1c	61	If it is detected that the compiler has support for "asm goto",
c5905afb IM	62	the kernel will compile such branches with just a nop
	63	instruction. When the condition flag is toggled to true, the
	64	nop will be converted to a jump instruction to execute the
	65	conditional block of instructions.
	66
	67	This technique lowers overhead and stress on the branch prediction
	68	of the processor and generally makes the kernel faster. The update
	69	of the condition is slower, but those are always very rare.
45f81b1c	70
c5905afb IM	71	( On 32-bit x86, the necessary options added to the compiler
c5905afb IM	72	flags may increase the size of the kernel slightly. )
45f81b1c	73
afd66255	74	config OPTPROBES
5cc718b9 MH	75	def_bool y
5cc718b9 MH	76	depends on KPROBES && HAVE_OPTPROBES
afd66255	77	depends on !PREEMPT
afd66255	78
e7dbfe34 MH	79	config KPROBES_ON_FTRACE
	80	def_bool y
	81	depends on KPROBES && HAVE_KPROBES_ON_FTRACE
	82	depends on DYNAMIC_FTRACE_WITH_REGS
	83	help
	84	If function tracer is enabled and the arch supports full
	85	passing of pt_regs to function tracing, then kprobes can
	86	optimize on top of function tracing.
	87
2b144498	88	config UPROBES
7b2d81d4	89	bool "Transparent user-space probes (EXPERIMENTAL)"
ec83db0f	90	depends on UPROBE_EVENT && PERF_EVENTS
2b144498	91	default n
22b361d1	92	select PERCPU_RWSEM
2b144498	93	help
7b2d81d4 IM	94	Uprobes is the user-space counterpart to kprobes: they
	95	enable instrumentation applications (such as 'perf probe')
	96	to establish unintrusive probes in user-space binaries and
	97	libraries, by executing handler functions when the probes
	98	are hit by user-space applications.
	99
	100	( These probes come in the form of single-byte breakpoints,
	101	managed by the kernel and kept transparent to the probed
	102	application. )
2b144498 SD	103
	104	If in doubt, say "N".
	105
c19fa94a JH	106	config HAVE_64BIT_ALIGNED_ACCESS
	107	def_bool 64BIT && !HAVE_EFFICIENT_UNALIGNED_ACCESS
	108	help
	109	Some architectures require 64 bit accesses to be 64 bit
	110	aligned, which also requires structs containing 64 bit values
	111	to be 64 bit aligned too. This includes some 32 bit
	112	architectures which can do 64 bit accesses, as well as 64 bit
	113	architectures without unaligned access.
	114
	115	This symbol should be selected by an architecture if 64 bit
	116	accesses are required to be 64 bit aligned in this way even
	117	though it is not a 64 bit architecture.
	118
	119	See Documentation/unaligned-memory-access.txt for more
	120	information on the topic of unaligned memory accesses.
	121
58340a07	122	config HAVE_EFFICIENT_UNALIGNED_ACCESS
9ba16087	123	bool
58340a07 JB	124	help
	125	Some architectures are unable to perform unaligned accesses
	126	without the use of get_unaligned/put_unaligned. Others are
	127	unable to perform such accesses efficiently (e.g. trap on
	128	unaligned access and require fixing it up in the exception
	129	handler.)
	130
	131	This symbol should be selected by an architecture if it can
	132	perform unaligned accesses efficiently to allow different
	133	code paths to be selected for these cases. Some network
	134	drivers, for example, could opt to not fix up alignment
	135	problems with received packets if doing so would not help
	136	much.
	137
	138	See Documentation/unaligned-memory-access.txt for more
	139	information on the topic of unaligned memory accesses.
	140
cf66bb93 DW	141	config ARCH_USE_BUILTIN_BSWAP
	142	bool
	143	help
	144	Modern versions of GCC (since 4.4) have builtin functions
	145	for handling byte-swapping. Using these, instead of the old
	146	inline assembler that the architecture code provides in the
	147	__arch_bswapXX() macros, allows the compiler to see what's
	148	happening and offers more opportunity for optimisation. In
	149	particular, the compiler will be able to combine the byteswap
	150	with a nearby load or store and use load-and-swap or
	151	store-and-swap instructions if the architecture has them. It
	152	should almost never result in code which is worse than the
	153	hand-coded assembler in <asm/swab.h>. But just in case it
	154	does, the use of the builtins is optional.
	155
	156	Any architecture with load-and-swap or store-and-swap
	157	instructions should set this. And it shouldn't hurt to set it
	158	on architectures that don't have such instructions.
	159
9edddaa2 AM	160	config KRETPROBES
	161	def_bool y
	162	depends on KPROBES && HAVE_KRETPROBES
	163
7c68af6e AK	164	config USER_RETURN_NOTIFIER
	165	bool
	166	depends on HAVE_USER_RETURN_NOTIFIER
	167	help
	168	Provide a kernel-internal notification when a cpu is about to
	169	switch to user mode.
	170
28b2ee20	171	config HAVE_IOREMAP_PROT
9ba16087	172	bool
28b2ee20	173
125e5645	174	config HAVE_KPROBES
9ba16087	175	bool
9edddaa2 AM	176
9edddaa2 AM	177	config HAVE_KRETPROBES
9ba16087	178	bool
74bc7cee	179
afd66255 MH	180	config HAVE_OPTPROBES
afd66255 MH	181	bool
d314d74c	182
e7dbfe34 MH	183	config HAVE_KPROBES_ON_FTRACE
	184	bool
	185
d314d74c CW	186	config HAVE_NMI_WATCHDOG
d314d74c CW	187	bool
1f5a4ad9 RM	188	#
	189	# An arch should select this if it provides all these things:
	190	#
	191	# task_pt_regs() in asm/processor.h or asm/ptrace.h
	192	# arch_has_single_step() if there is hardware single-step support
	193	# arch_has_block_step() if there is hardware block-step support
1f5a4ad9 RM	194	# asm/syscall.h supplying asm-generic/syscall.h interface
	195	# linux/regset.h user_regset interfaces
	196	# CORE_DUMP_USE_REGSET #define'd in linux/elf.h
	197	# TIF_SYSCALL_TRACE calls tracehook_report_syscall_{entry,exit}
	198	# TIF_NOTIFY_RESUME calls tracehook_notify_resume()
	199	# signal delivery calls tracehook_signal_handler()
	200	#
	201	config HAVE_ARCH_TRACEHOOK
9ba16087	202	bool
1f5a4ad9	203
74bc7cee	204	config HAVE_DMA_ATTRS
9ba16087	205	bool
3d442233	206
c64be2bb MS	207	config HAVE_DMA_CONTIGUOUS
	208	bool
	209
3d442233	210	config USE_GENERIC_SMP_HELPERS
9ba16087	211	bool
9483a578	212
29d5e047 TG	213	config GENERIC_SMP_IDLE_THREAD
	214	bool
	215
485cf5da KH	216	config GENERIC_IDLE_POLL_SETUP
	217	bool
	218
a6359d1e TG	219	# Select if arch init_task initializer is different to init/init_task.c
a6359d1e TG	220	config ARCH_INIT_TASK
a4a2eb49 TG	221	bool
a4a2eb49 TG	222
f5e10287 TG	223	# Select if arch has its private alloc_task_struct() function
	224	config ARCH_TASK_STRUCT_ALLOCATOR
	225	bool
	226
	227	# Select if arch has its private alloc_thread_info() function
	228	config ARCH_THREAD_INFO_ALLOCATOR
	229	bool
	230
f850c30c HC	231	config HAVE_REGS_AND_STACK_ACCESS_API
f850c30c HC	232	bool
e01292b1 HC	233	help
	234	This symbol should be selected by an architecure if it supports
	235	the API needed to access registers and stack entries from pt_regs,
	236	declared in asm/ptrace.h
	237	For example the kprobes-based event tracer needs this API.
f850c30c	238
9483a578	239	config HAVE_CLK
9ba16087	240	bool
9483a578 DB	241	help
	242	The <linux/clk.h> calls support software clock gating and
	243	thus are a key power management tool on many systems.
	244
5ee00bd4 JR	245	config HAVE_DMA_API_DEBUG
5ee00bd4 JR	246	bool
36cd3c9f	247
62a038d3 P	248	config HAVE_HW_BREAKPOINT
62a038d3 P	249	bool
99e8c5a3	250	depends on PERF_EVENTS
62a038d3	251
0102752e FW	252	config HAVE_MIXED_BREAKPOINTS_REGS
	253	bool
	254	depends on HAVE_HW_BREAKPOINT
	255	help
	256	Depending on the arch implementation of hardware breakpoints,
	257	some of them have separate registers for data and instruction
	258	breakpoints addresses, others have mixed registers to store
	259	them but define the access type in a control register.
	260	Select this option if your arch implements breakpoints under the
	261	latter fashion.
	262
7c68af6e AK	263	config HAVE_USER_RETURN_NOTIFIER
7c68af6e AK	264	bool
a1922ed6	265
c01d4323 FW	266	config HAVE_PERF_EVENTS_NMI
c01d4323 FW	267	bool
23637d47 FW	268	help
	269	System hardware can generate an NMI using the perf event
	270	subsystem. Also has support for calculating CPU cycle events
	271	to determine how many clock cycles in a given period.
c01d4323	272
c5e63197 JO	273	config HAVE_PERF_REGS
	274	bool
	275	help
	276	Support selective register dumps for perf events. This includes
	277	bit-mapping of each registers and a unique architecture id.
	278
c5ebcedb JO	279	config HAVE_PERF_USER_STACK_DUMP
	280	bool
	281	help
	282	Support user stack dumps for perf event samples. This needs
	283	access to the user stack pointer which is not unified across
	284	architectures.
	285
bf5438fc JB	286	config HAVE_ARCH_JUMP_LABEL
	287	bool
	288
335d7afb GS	289	config HAVE_ARCH_MUTEX_CPU_RELAX
	290	bool
	291
26723911 PZ	292	config HAVE_RCU_TABLE_FREE
	293	bool
	294
df013ffb HY	295	config ARCH_HAVE_NMI_SAFE_CMPXCHG
	296	bool
	297
43570fd2 HC	298	config HAVE_ALIGNED_STRUCT_PAGE
	299	bool
	300	help
	301	This makes sure that struct pages are double word aligned and that
	302	e.g. the SLUB allocator can perform double word atomic operations
	303	on a struct page for better performance. However selecting this
	304	might increase the size of a struct page by a word.
	305
4156153c HC	306	config HAVE_CMPXCHG_LOCAL
	307	bool
	308
2565409f HC	309	config HAVE_CMPXCHG_DOUBLE
	310	bool
	311
c1d7e01d WD	312	config ARCH_WANT_IPC_PARSE_VERSION
	313	bool
	314
	315	config ARCH_WANT_COMPAT_IPC_PARSE_VERSION
	316	bool
	317
48b25c43	318	config ARCH_WANT_OLD_COMPAT_IPC
c1d7e01d	319	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
48b25c43 CM	320	bool
48b25c43 CM	321
e2cfabdf WD	322	config HAVE_ARCH_SECCOMP_FILTER
	323	bool
	324	help
fb0fadf9	325	An arch should select this symbol if it provides all of these things:
bb6ea430 WD	326	- syscall_get_arch()
	327	- syscall_get_arguments()
	328	- syscall_rollback()
	329	- syscall_set_return_value()
fb0fadf9 WD	330	- SIGSYS siginfo_t support
	331	- secure_computing is called from a ptrace_event()-safe context
	332	- secure_computing return value is checked and a return value of -1
	333	results in the system call being skipped immediately.
e2cfabdf WD	334
	335	config SECCOMP_FILTER
	336	def_bool y
	337	depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET
	338	help
	339	Enable tasks to build secure computing environments defined
	340	in terms of Berkeley Packet Filter programs which implement
	341	task-defined system call filtering polices.
	342
	343	See Documentation/prctl/seccomp_filter.txt for details.
	344
91d1aa43	345	config HAVE_CONTEXT_TRACKING
2b1d5024 FW	346	bool
2b1d5024 FW	347	help
91d1aa43 FW	348	Provide kernel/user boundaries probes necessary for subsystems
	349	that need it, such as userspace RCU extended quiescent state.
	350	Syscalls need to be wrapped inside user_exit()-user_enter() through
	351	the slow path using TIF_NOHZ flag. Exceptions handlers must be
	352	wrapped as well. Irqs are already protected inside
	353	rcu_irq_enter/rcu_irq_exit() but preemption or signal handling on
	354	irq exit still need to be protected.
2b1d5024	355
b952741c FW	356	config HAVE_VIRT_CPU_ACCOUNTING
	357	bool
	358
fdf9c356 FW	359	config HAVE_IRQ_TIME_ACCOUNTING
	360	bool
	361	help
	362	Archs need to ensure they use a high enough resolution clock to
	363	support irq time accounting and then call enable_sched_clock_irqtime().
	364
15626062 GS	365	config HAVE_ARCH_TRANSPARENT_HUGEPAGE
	366	bool
	367
786d35d4 DH	368	config HAVE_MOD_ARCH_SPECIFIC
	369	bool
	370	help
	371	The arch uses struct mod_arch_specific to store data. Many arches
	372	just need a simple module loader without arch specific data - those
	373	should not enable this.
	374
	375	config MODULES_USE_ELF_RELA
	376	bool
	377	help
	378	Modules only use ELF RELA relocations. Modules with ELF REL
	379	relocations will give an error.
	380
	381	config MODULES_USE_ELF_REL
	382	bool
	383	help
	384	Modules only use ELF REL relocations. Modules with ELF RELA
	385	relocations will give an error.
	386
b92021b0 RR	387	config HAVE_UNDERSCORE_SYMBOL_PREFIX
	388	bool
	389	help
	390	Some architectures generate an _ in front of C symbols; things like
	391	module loading and assembly files need to know about this.
	392
d2125043 AV	393	#
	394	# ABI hall of shame
	395	#
	396	config CLONE_BACKWARDS
	397	bool
	398	help
	399	Architecture has tls passed as the 4th argument of clone(2),
	400	not the 5th one.
	401
	402	config CLONE_BACKWARDS2
	403	bool
	404	help
	405	Architecture has the first two arguments of clone(2) swapped.
	406
4f01c72e MS	407	config CLONE_BACKWARDS3
	408	bool
	409	help
	410	Architecture has tls passed as the 3rd argument of clone(2),
	411	not the 5th one.
	412
eaca6eae AV	413	config ODD_RT_SIGACTION
	414	bool
	415	help
	416	Architecture has unusual rt_sigaction(2) arguments
	417
0a0e8cdf AV	418	config OLD_SIGSUSPEND
	419	bool
	420	help
	421	Architecture has old sigsuspend(2) syscall, of one-argument variety
	422
	423	config OLD_SIGSUSPEND3
	424	bool
	425	help
	426	Even weirder antique ABI - three-argument sigsuspend(2)
	427
495dfbf7 AV	428	config OLD_SIGACTION
	429	bool
	430	help
	431	Architecture has old sigaction(2) syscall. Nope, not the same
	432	as OLD_SIGSUSPEND \| OLD_SIGSUSPEND3 - alpha has sigsuspend(2),
	433	but fairly different variant of sigaction(2), thanks to OSF/1
	434	compatibility...
	435
	436	config COMPAT_OLD_SIGACTION
	437	bool
	438
2521f2c2	439	source "kernel/gcov/Kconfig"