drivers: power: report battery voltage in AOSP compatible format
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / Kconfig
CommitLineData
fb32e03f
MD
1#
2# General architecture dependent options
3#
125e5645
MD
4
5config OPROFILE
b309a294 6 tristate "OProfile system profiling"
125e5645
MD
7 depends on PROFILING
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
18config 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 30config HAVE_OPROFILE
9ba16087 31 bool
125e5645 32
dcfce4a0
RR
33config OPROFILE_NMI_TIMER
34 def_bool y
35 depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI
36
125e5645
MD
37config KPROBES
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 49config JUMP_LABEL
c5905afb 50 bool "Optimize very unlikely/likely branches"
45f81b1c
SR
51 depends on HAVE_ARCH_JUMP_LABEL
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
72 flags may increase the size of the kernel slightly. )
45f81b1c 73
afd66255 74config OPTPROBES
5cc718b9
MH
75 def_bool y
76 depends on KPROBES && HAVE_OPTPROBES
afd66255 77 depends on !PREEMPT
afd66255 78
e7dbfe34
MH
79config 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 88config 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
106config 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 122config 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
141config 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
160config KRETPROBES
161 def_bool y
162 depends on KPROBES && HAVE_KRETPROBES
163
7c68af6e
AK
164config 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 171config HAVE_IOREMAP_PROT
9ba16087 172 bool
28b2ee20 173
125e5645 174config HAVE_KPROBES
9ba16087 175 bool
9edddaa2
AM
176
177config HAVE_KRETPROBES
9ba16087 178 bool
74bc7cee 179
afd66255
MH
180config HAVE_OPTPROBES
181 bool
d314d74c 182
e7dbfe34
MH
183config HAVE_KPROBES_ON_FTRACE
184 bool
185
d314d74c
CW
186config HAVE_NMI_WATCHDOG
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#
201config HAVE_ARCH_TRACEHOOK
9ba16087 202 bool
1f5a4ad9 203
74bc7cee 204config HAVE_DMA_ATTRS
9ba16087 205 bool
3d442233 206
c64be2bb
MS
207config HAVE_DMA_CONTIGUOUS
208 bool
209
3d442233 210config USE_GENERIC_SMP_HELPERS
9ba16087 211 bool
9483a578 212
29d5e047
TG
213config GENERIC_SMP_IDLE_THREAD
214 bool
215
485cf5da
KH
216config GENERIC_IDLE_POLL_SETUP
217 bool
218
a6359d1e
TG
219# Select if arch init_task initializer is different to init/init_task.c
220config ARCH_INIT_TASK
a4a2eb49
TG
221 bool
222
f5e10287
TG
223# Select if arch has its private alloc_task_struct() function
224config ARCH_TASK_STRUCT_ALLOCATOR
225 bool
226
227# Select if arch has its private alloc_thread_info() function
228config ARCH_THREAD_INFO_ALLOCATOR
229 bool
230
f850c30c
HC
231config HAVE_REGS_AND_STACK_ACCESS_API
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 239config 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
245config HAVE_DMA_API_DEBUG
246 bool
36cd3c9f 247
62a038d3
P
248config HAVE_HW_BREAKPOINT
249 bool
99e8c5a3 250 depends on PERF_EVENTS
62a038d3 251
0102752e
FW
252config 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
263config HAVE_USER_RETURN_NOTIFIER
264 bool
a1922ed6 265
c01d4323
FW
266config HAVE_PERF_EVENTS_NMI
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
273config 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
279config 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
286config HAVE_ARCH_JUMP_LABEL
287 bool
288
335d7afb
GS
289config HAVE_ARCH_MUTEX_CPU_RELAX
290 bool
291
26723911
PZ
292config HAVE_RCU_TABLE_FREE
293 bool
294
df013ffb
HY
295config ARCH_HAVE_NMI_SAFE_CMPXCHG
296 bool
297
43570fd2
HC
298config 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
306config HAVE_CMPXCHG_LOCAL
307 bool
308
2565409f
HC
309config HAVE_CMPXCHG_DOUBLE
310 bool
311
c1d7e01d
WD
312config ARCH_WANT_IPC_PARSE_VERSION
313 bool
314
315config ARCH_WANT_COMPAT_IPC_PARSE_VERSION
316 bool
317
48b25c43 318config ARCH_WANT_OLD_COMPAT_IPC
c1d7e01d 319 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
48b25c43
CM
320 bool
321
e2cfabdf
WD
322config 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.
6fa3eb70 334 - seccomp syscall wired up
e2cfabdf
WD
335
336config SECCOMP_FILTER
337 def_bool y
338 depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET
339 help
340 Enable tasks to build secure computing environments defined
341 in terms of Berkeley Packet Filter programs which implement
342 task-defined system call filtering polices.
343
344 See Documentation/prctl/seccomp_filter.txt for details.
345
91d1aa43 346config HAVE_CONTEXT_TRACKING
2b1d5024
FW
347 bool
348 help
91d1aa43
FW
349 Provide kernel/user boundaries probes necessary for subsystems
350 that need it, such as userspace RCU extended quiescent state.
351 Syscalls need to be wrapped inside user_exit()-user_enter() through
352 the slow path using TIF_NOHZ flag. Exceptions handlers must be
353 wrapped as well. Irqs are already protected inside
354 rcu_irq_enter/rcu_irq_exit() but preemption or signal handling on
355 irq exit still need to be protected.
2b1d5024 356
b952741c
FW
357config HAVE_VIRT_CPU_ACCOUNTING
358 bool
359
fdf9c356
FW
360config HAVE_IRQ_TIME_ACCOUNTING
361 bool
362 help
363 Archs need to ensure they use a high enough resolution clock to
364 support irq time accounting and then call enable_sched_clock_irqtime().
365
15626062
GS
366config HAVE_ARCH_TRANSPARENT_HUGEPAGE
367 bool
368
786d35d4
DH
369config HAVE_MOD_ARCH_SPECIFIC
370 bool
371 help
372 The arch uses struct mod_arch_specific to store data. Many arches
373 just need a simple module loader without arch specific data - those
374 should not enable this.
375
376config MODULES_USE_ELF_RELA
377 bool
378 help
379 Modules only use ELF RELA relocations. Modules with ELF REL
380 relocations will give an error.
381
382config MODULES_USE_ELF_REL
383 bool
384 help
385 Modules only use ELF REL relocations. Modules with ELF RELA
386 relocations will give an error.
387
b92021b0
RR
388config HAVE_UNDERSCORE_SYMBOL_PREFIX
389 bool
390 help
391 Some architectures generate an _ in front of C symbols; things like
392 module loading and assembly files need to know about this.
393
d2125043
AV
394#
395# ABI hall of shame
396#
397config CLONE_BACKWARDS
398 bool
399 help
400 Architecture has tls passed as the 4th argument of clone(2),
401 not the 5th one.
402
403config CLONE_BACKWARDS2
404 bool
405 help
406 Architecture has the first two arguments of clone(2) swapped.
407
4f01c72e
MS
408config CLONE_BACKWARDS3
409 bool
410 help
411 Architecture has tls passed as the 3rd argument of clone(2),
412 not the 5th one.
413
eaca6eae
AV
414config ODD_RT_SIGACTION
415 bool
416 help
417 Architecture has unusual rt_sigaction(2) arguments
418
0a0e8cdf
AV
419config OLD_SIGSUSPEND
420 bool
421 help
422 Architecture has old sigsuspend(2) syscall, of one-argument variety
423
424config OLD_SIGSUSPEND3
425 bool
426 help
427 Even weirder antique ABI - three-argument sigsuspend(2)
428
495dfbf7
AV
429config OLD_SIGACTION
430 bool
431 help
432 Architecture has old sigaction(2) syscall. Nope, not the same
433 as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2),
434 but fairly different variant of sigaction(2), thanks to OSF/1
435 compatibility...
436
437config COMPAT_OLD_SIGACTION
438 bool
439
2521f2c2 440source "kernel/gcov/Kconfig"