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Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001#
2# General architecture dependent options
3#
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05004
5config OPROFILE
Robert Richterb309a292010-02-26 15:01:23 +01006 tristate "OProfile system profiling"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05007 depends on PROFILING
8 depends on HAVE_OPROFILE
Ingo Molnard69d59f2008-12-12 09:38:57 +01009 select RING_BUFFER
Christian Borntraeger9a5963e2009-09-16 21:56:49 +020010 select RING_BUFFER_ALLOW_SWAP
Mathieu Desnoyers125e5642008-02-02 15:10:36 -050011 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
Jason Yeh4d4036e2009-07-08 13:49:38 +020018config 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
Mathieu Desnoyers125e5642008-02-02 15:10:36 -050030config HAVE_OPROFILE
Jan Beulich9ba16082008-10-15 22:01:38 -070031 bool
Mathieu Desnoyers125e5642008-02-02 15:10:36 -050032
Robert Richterdcfce4a2011-10-11 17:11:08 +020033config OPROFILE_NMI_TIMER
34 def_bool y
35 depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI
36
Mathieu Desnoyers125e5642008-02-02 15:10:36 -050037config KPROBES
38 bool "Kprobes"
Masami Hiramatsu05ed1602010-09-13 19:25:41 +090039 depends on MODULES
Mathieu Desnoyers125e5642008-02-02 15:10:36 -050040 depends on HAVE_KPROBES
Masami Hiramatsu05ed1602010-09-13 19:25:41 +090041 select KALLSYMS
Mathieu Desnoyers125e5642008-02-02 15:10:36 -050042 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
Steven Rostedt45f81b12010-10-29 12:33:43 -040049config JUMP_LABEL
Ingo Molnarc5905af2012-02-24 08:31:31 +010050 bool "Optimize very unlikely/likely branches"
Steven Rostedt45f81b12010-10-29 12:33:43 -040051 depends on HAVE_ARCH_JUMP_LABEL
52 help
Ingo Molnarc5905af2012-02-24 08:31:31 +010053 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.
Steven Rostedt45f81b12010-10-29 12:33:43 -040056
Ingo Molnarc5905af2012-02-24 08:31:31 +010057 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
61 If it is detected that the compiler has support for "asm goto",
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.
70
71 ( On 32-bit x86, the necessary options added to the compiler
72 flags may increase the size of the kernel slightly. )
Steven Rostedt45f81b12010-10-29 12:33:43 -040073
Masami Hiramatsuafd66252010-02-25 08:34:07 -050074config OPTPROBES
Masami Hiramatsu5cc718b2010-03-15 13:00:54 -040075 def_bool y
76 depends on KPROBES && HAVE_OPTPROBES
Masami Hiramatsuafd66252010-02-25 08:34:07 -050077 depends on !PREEMPT
Masami Hiramatsuafd66252010-02-25 08:34:07 -050078
Masami Hiramatsue7dbfe32012-09-28 17:15:20 +090079config 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
Srikar Dronamraju2b144492012-02-09 14:56:42 +053088config UPROBES
Ingo Molnar7b2d81d2012-02-17 09:27:41 +010089 bool "Transparent user-space probes (EXPERIMENTAL)"
Srikar Dronamrajuec83db02012-05-08 16:41:26 +053090 depends on UPROBE_EVENT && PERF_EVENTS
Srikar Dronamraju2b144492012-02-09 14:56:42 +053091 default n
Oleg Nesterov22b361d2012-12-17 16:01:39 -080092 select PERCPU_RWSEM
Srikar Dronamraju2b144492012-02-09 14:56:42 +053093 help
Ingo Molnar7b2d81d2012-02-17 09:27:41 +010094 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. )
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530103
104 If in doubt, say "N".
105
James Hoganc19fa942012-05-30 11:23:23 +0100106config 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
Johannes Berg58340a02008-07-25 01:45:33 -0700122config HAVE_EFFICIENT_UNALIGNED_ACCESS
Jan Beulich9ba16082008-10-15 22:01:38 -0700123 bool
Johannes Berg58340a02008-07-25 01:45:33 -0700124 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
David Woodhousecf66bb92012-12-03 16:25:40 +0000141config 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
Ananth N Mavinakayanahalli9edddaa2008-03-04 14:28:37 -0800160config KRETPROBES
161 def_bool y
162 depends on KPROBES && HAVE_KRETPROBES
163
Avi Kivity7c68af62009-09-19 09:40:22 +0300164config 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
Rik van Riel28b2ee22008-07-23 21:27:05 -0700171config HAVE_IOREMAP_PROT
Jan Beulich9ba16082008-10-15 22:01:38 -0700172 bool
Rik van Riel28b2ee22008-07-23 21:27:05 -0700173
Mathieu Desnoyers125e5642008-02-02 15:10:36 -0500174config HAVE_KPROBES
Jan Beulich9ba16082008-10-15 22:01:38 -0700175 bool
Ananth N Mavinakayanahalli9edddaa2008-03-04 14:28:37 -0800176
177config HAVE_KRETPROBES
Jan Beulich9ba16082008-10-15 22:01:38 -0700178 bool
Arthur Kepner74bc7ce2008-04-29 01:00:30 -0700179
Masami Hiramatsuafd66252010-02-25 08:34:07 -0500180config HAVE_OPTPROBES
181 bool
Cong Wangd314d742012-03-23 15:01:51 -0700182
Masami Hiramatsue7dbfe32012-09-28 17:15:20 +0900183config HAVE_KPROBES_ON_FTRACE
184 bool
185
Cong Wangd314d742012-03-23 15:01:51 -0700186config HAVE_NMI_WATCHDOG
187 bool
Roland McGrath1f5a4ad2008-07-25 19:45:57 -0700188#
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
Roland McGrath1f5a4ad2008-07-25 19:45:57 -0700194# 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#
201config HAVE_ARCH_TRACEHOOK
Jan Beulich9ba16082008-10-15 22:01:38 -0700202 bool
Roland McGrath1f5a4ad2008-07-25 19:45:57 -0700203
Arthur Kepner74bc7ce2008-04-29 01:00:30 -0700204config HAVE_DMA_ATTRS
Jan Beulich9ba16082008-10-15 22:01:38 -0700205 bool
Jens Axboe3d442232008-06-26 11:21:34 +0200206
Marek Szyprowskic64be2b2011-12-29 13:09:51 +0100207config HAVE_DMA_CONTIGUOUS
208 bool
209
Jens Axboe3d442232008-06-26 11:21:34 +0200210config USE_GENERIC_SMP_HELPERS
Jan Beulich9ba16082008-10-15 22:01:38 -0700211 bool
David Brownell9483a572008-07-23 21:26:48 -0700212
Thomas Gleixner29d5e042012-04-20 13:05:45 +0000213config GENERIC_SMP_IDLE_THREAD
214 bool
215
Thomas Gleixnera6359d12012-05-03 09:03:02 +0000216# Select if arch init_task initializer is different to init/init_task.c
217config ARCH_INIT_TASK
Thomas Gleixnera4a2eb42012-05-03 09:02:48 +0000218 bool
219
Thomas Gleixnerf5e10282012-05-05 15:05:48 +0000220# Select if arch has its private alloc_task_struct() function
221config ARCH_TASK_STRUCT_ALLOCATOR
222 bool
223
224# Select if arch has its private alloc_thread_info() function
225config ARCH_THREAD_INFO_ALLOCATOR
226 bool
227
Heiko Carstensf850c30c2010-02-10 17:25:17 +0100228config HAVE_REGS_AND_STACK_ACCESS_API
229 bool
Heiko Carstense01292b2010-02-18 14:25:21 +0100230 help
231 This symbol should be selected by an architecure if it supports
232 the API needed to access registers and stack entries from pt_regs,
233 declared in asm/ptrace.h
234 For example the kprobes-based event tracer needs this API.
Heiko Carstensf850c30c2010-02-10 17:25:17 +0100235
David Brownell9483a572008-07-23 21:26:48 -0700236config HAVE_CLK
Jan Beulich9ba16082008-10-15 22:01:38 -0700237 bool
David Brownell9483a572008-07-23 21:26:48 -0700238 help
239 The <linux/clk.h> calls support software clock gating and
240 thus are a key power management tool on many systems.
241
Joerg Roedel5ee00bd2009-01-09 12:14:24 +0100242config HAVE_DMA_API_DEBUG
243 bool
Heiko Carstens36cd3c92009-04-09 18:48:34 +0200244
K.Prasad62a038d2009-06-01 23:43:33 +0530245config HAVE_HW_BREAKPOINT
246 bool
Frederic Weisbecker99e8c5a2009-12-17 01:33:54 +0100247 depends on PERF_EVENTS
K.Prasad62a038d2009-06-01 23:43:33 +0530248
Frederic Weisbecker01027522010-04-11 18:55:56 +0200249config HAVE_MIXED_BREAKPOINTS_REGS
250 bool
251 depends on HAVE_HW_BREAKPOINT
252 help
253 Depending on the arch implementation of hardware breakpoints,
254 some of them have separate registers for data and instruction
255 breakpoints addresses, others have mixed registers to store
256 them but define the access type in a control register.
257 Select this option if your arch implements breakpoints under the
258 latter fashion.
259
Avi Kivity7c68af62009-09-19 09:40:22 +0300260config HAVE_USER_RETURN_NOTIFIER
261 bool
Ingo Molnara1922ed2009-09-07 08:19:51 +0200262
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200263config HAVE_PERF_EVENTS_NMI
264 bool
Frederic Weisbecker23637d42010-05-15 23:15:20 +0200265 help
266 System hardware can generate an NMI using the perf event
267 subsystem. Also has support for calculating CPU cycle events
268 to determine how many clock cycles in a given period.
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200269
Jiri Olsac5e63192012-08-07 15:20:36 +0200270config HAVE_PERF_REGS
271 bool
272 help
273 Support selective register dumps for perf events. This includes
274 bit-mapping of each registers and a unique architecture id.
275
Jiri Olsac5ebced2012-08-07 15:20:40 +0200276config HAVE_PERF_USER_STACK_DUMP
277 bool
278 help
279 Support user stack dumps for perf event samples. This needs
280 access to the user stack pointer which is not unified across
281 architectures.
282
Jason Baronbf5438fc2010-09-17 11:09:00 -0400283config HAVE_ARCH_JUMP_LABEL
284 bool
285
Gerald Schaefer335d7af2010-11-22 15:47:36 +0100286config HAVE_ARCH_MUTEX_CPU_RELAX
287 bool
288
Peter Zijlstra26723912011-05-24 17:12:00 -0700289config HAVE_RCU_TABLE_FREE
290 bool
291
Huang Yingdf013ff2011-07-13 13:14:22 +0800292config ARCH_HAVE_NMI_SAFE_CMPXCHG
293 bool
294
Heiko Carstens43570fd2012-01-12 17:17:27 -0800295config HAVE_ALIGNED_STRUCT_PAGE
296 bool
297 help
298 This makes sure that struct pages are double word aligned and that
299 e.g. the SLUB allocator can perform double word atomic operations
300 on a struct page for better performance. However selecting this
301 might increase the size of a struct page by a word.
302
Heiko Carstens41561532012-01-12 17:17:30 -0800303config HAVE_CMPXCHG_LOCAL
304 bool
305
Heiko Carstens25654092012-01-12 17:17:33 -0800306config HAVE_CMPXCHG_DOUBLE
307 bool
308
Will Deaconc1d7e012012-07-30 14:42:46 -0700309config ARCH_WANT_IPC_PARSE_VERSION
310 bool
311
312config ARCH_WANT_COMPAT_IPC_PARSE_VERSION
313 bool
314
Chris Metcalf48b25c42012-03-15 13:13:38 -0400315config ARCH_WANT_OLD_COMPAT_IPC
Will Deaconc1d7e012012-07-30 14:42:46 -0700316 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
Chris Metcalf48b25c42012-03-15 13:13:38 -0400317 bool
318
Will Drewrye2cfabdf2012-04-12 16:47:57 -0500319config HAVE_ARCH_SECCOMP_FILTER
320 bool
321 help
Will Drewryfb0fadf2012-04-12 16:48:02 -0500322 An arch should select this symbol if it provides all of these things:
Will Drewrybb6ea432012-04-12 16:48:01 -0500323 - syscall_get_arch()
324 - syscall_get_arguments()
325 - syscall_rollback()
326 - syscall_set_return_value()
Will Drewryfb0fadf2012-04-12 16:48:02 -0500327 - SIGSYS siginfo_t support
328 - secure_computing is called from a ptrace_event()-safe context
329 - secure_computing return value is checked and a return value of -1
330 results in the system call being skipped immediately.
Will Drewrye2cfabdf2012-04-12 16:47:57 -0500331
332config SECCOMP_FILTER
333 def_bool y
334 depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET
335 help
336 Enable tasks to build secure computing environments defined
337 in terms of Berkeley Packet Filter programs which implement
338 task-defined system call filtering polices.
339
340 See Documentation/prctl/seccomp_filter.txt for details.
341
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100342config HAVE_CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200343 bool
344 help
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100345 Provide kernel/user boundaries probes necessary for subsystems
346 that need it, such as userspace RCU extended quiescent state.
347 Syscalls need to be wrapped inside user_exit()-user_enter() through
348 the slow path using TIF_NOHZ flag. Exceptions handlers must be
349 wrapped as well. Irqs are already protected inside
350 rcu_irq_enter/rcu_irq_exit() but preemption or signal handling on
351 irq exit still need to be protected.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200352
Frederic Weisbeckerb9527412012-06-16 15:39:34 +0200353config HAVE_VIRT_CPU_ACCOUNTING
354 bool
355
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200356config HAVE_IRQ_TIME_ACCOUNTING
357 bool
358 help
359 Archs need to ensure they use a high enough resolution clock to
360 support irq time accounting and then call enable_sched_clock_irqtime().
361
Gerald Schaefer15626062012-10-08 16:30:04 -0700362config HAVE_ARCH_TRANSPARENT_HUGEPAGE
363 bool
364
David Howells786d35d2012-09-28 14:31:03 +0930365config HAVE_MOD_ARCH_SPECIFIC
366 bool
367 help
368 The arch uses struct mod_arch_specific to store data. Many arches
369 just need a simple module loader without arch specific data - those
370 should not enable this.
371
372config MODULES_USE_ELF_RELA
373 bool
374 help
375 Modules only use ELF RELA relocations. Modules with ELF REL
376 relocations will give an error.
377
378config MODULES_USE_ELF_REL
379 bool
380 help
381 Modules only use ELF REL relocations. Modules with ELF RELA
382 relocations will give an error.
383
Rusty Russellb92021b2013-03-15 15:04:17 +1030384config HAVE_UNDERSCORE_SYMBOL_PREFIX
385 bool
386 help
387 Some architectures generate an _ in front of C symbols; things like
388 module loading and assembly files need to know about this.
389
Al Virod2125042012-10-23 13:17:59 -0400390#
391# ABI hall of shame
392#
393config CLONE_BACKWARDS
394 bool
395 help
396 Architecture has tls passed as the 4th argument of clone(2),
397 not the 5th one.
398
399config CLONE_BACKWARDS2
400 bool
401 help
402 Architecture has the first two arguments of clone(2) swapped.
403
Al Viroeaca6ea2012-11-25 23:12:10 -0500404config ODD_RT_SIGACTION
405 bool
406 help
407 Architecture has unusual rt_sigaction(2) arguments
408
Al Viro0a0e8cd2012-12-25 16:04:12 -0500409config OLD_SIGSUSPEND
410 bool
411 help
412 Architecture has old sigsuspend(2) syscall, of one-argument variety
413
414config OLD_SIGSUSPEND3
415 bool
416 help
417 Even weirder antique ABI - three-argument sigsuspend(2)
418
Al Viro495dfbf2012-12-25 19:09:45 -0500419config OLD_SIGACTION
420 bool
421 help
422 Architecture has old sigaction(2) syscall. Nope, not the same
423 as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2),
424 but fairly different variant of sigaction(2), thanks to OSF/1
425 compatibility...
426
427config COMPAT_OLD_SIGACTION
428 bool
429
Peter Oberparleiter2521f2c2009-06-17 16:28:08 -0700430source "kernel/gcov/Kconfig"