[deliverable/linux.git] / include / linux / compiler.h

#ifndef __LINUX_COMPILER_H
#define __LINUX_COMPILER_H

#ifndef __ASSEMBLY__

#ifdef __CHECKER__
# define __user		__attribute__((noderef, address_space(1)))
# define __kernel	__attribute__((address_space(0)))
# define __safe		__attribute__((safe))
# define __force	__attribute__((force))
# define __nocast	__attribute__((nocast))
# define __iomem	__attribute__((noderef, address_space(2)))
# define __must_hold(x)	__attribute__((context(x,1,1)))
# define __acquires(x)	__attribute__((context(x,0,1)))
# define __releases(x)	__attribute__((context(x,1,0)))
# define __acquire(x)	__context__(x,1)
# define __release(x)	__context__(x,-1)
# define __cond_lock(x,c)	((c) ? ({ __acquire(x); 1; }) : 0)
# define __percpu	__attribute__((noderef, address_space(3)))
# define __pmem		__attribute__((noderef, address_space(5)))
#ifdef CONFIG_SPARSE_RCU_POINTER
# define __rcu		__attribute__((noderef, address_space(4)))
#else /* CONFIG_SPARSE_RCU_POINTER */
# define __rcu
#endif /* CONFIG_SPARSE_RCU_POINTER */
# define __private	__attribute__((noderef))
extern void __chk_user_ptr(const volatile void __user *);
extern void __chk_io_ptr(const volatile void __iomem *);
# define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member))
#else /* __CHECKER__ */
# define __user
# define __kernel
# define __safe
# define __force
# define __nocast
# define __iomem
# define __chk_user_ptr(x) (void)0
# define __chk_io_ptr(x) (void)0
# define __builtin_warning(x, y...) (1)
# define __must_hold(x)
# define __acquires(x)
# define __releases(x)
# define __acquire(x) (void)0
# define __release(x) (void)0
# define __cond_lock(x,c) (c)
# define __percpu
# define __rcu
# define __pmem
# define __private
# define ACCESS_PRIVATE(p, member) ((p)->member)
#endif /* __CHECKER__ */

/* Indirect macros required for expanded argument pasting, eg. __LINE__. */
#define ___PASTE(a,b) a##b
#define __PASTE(a,b) ___PASTE(a,b)

#ifdef __KERNEL__

#ifdef __GNUC__
#include <linux/compiler-gcc.h>
#endif

#if defined(CC_USING_HOTPATCH) && !defined(__CHECKER__)
#define notrace __attribute__((hotpatch(0,0)))
#else
#define notrace __attribute__((no_instrument_function))
#endif

/* Intel compiler defines __GNUC__. So we will overwrite implementations
 * coming from above header files here
 */
#ifdef __INTEL_COMPILER
# include <linux/compiler-intel.h>
#endif

/* Clang compiler defines __GNUC__. So we will overwrite implementations
 * coming from above header files here
 */
#ifdef __clang__
#include <linux/compiler-clang.h>
#endif

/*
 * Generic compiler-dependent macros required for kernel
 * build go below this comment. Actual compiler/compiler version
 * specific implementations come from the above header files
 */

struct ftrace_branch_data {
	const char *func;
	const char *file;
	unsigned line;
	union {
		struct {
			unsigned long correct;
			unsigned long incorrect;
		};
		struct {
			unsigned long miss;
			unsigned long hit;
		};
		unsigned long miss_hit[2];
	};
};

/*
 * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
 * to disable branch tracing on a per file basis.
 */
#if defined(CONFIG_TRACE_BRANCH_PROFILING) \
    && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);

#define likely_notrace(x)	__builtin_expect(!!(x), 1)
#define unlikely_notrace(x)	__builtin_expect(!!(x), 0)

#define __branch_check__(x, expect) ({					\
			int ______r;					\
			static struct ftrace_branch_data		\
				__attribute__((__aligned__(4)))		\
				__attribute__((section("_ftrace_annotated_branch"))) \
				______f = {				\
				.func = __func__,			\
				.file = __FILE__,			\
				.line = __LINE__,			\
			};						\
			______r = likely_notrace(x);			\
			ftrace_likely_update(&______f, ______r, expect); \
			______r;					\
		})

/*
 * Using __builtin_constant_p(x) to ignore cases where the return
 * value is always the same.  This idea is taken from a similar patch
 * written by Daniel Walker.
 */
# ifndef likely
#  define likely(x)	(__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
# endif
# ifndef unlikely
#  define unlikely(x)	(__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
# endif

#ifdef CONFIG_PROFILE_ALL_BRANCHES
/*
 * "Define 'is'", Bill Clinton
 * "Define 'if'", Steven Rostedt
 */
#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
#define __trace_if(cond) \
	if (__builtin_constant_p(!!(cond)) ? !!(cond) :			\
	({								\
		int ______r;						\
		static struct ftrace_branch_data			\
			__attribute__((__aligned__(4)))			\
			__attribute__((section("_ftrace_branch")))	\
			______f = {					\
				.func = __func__,			\
				.file = __FILE__,			\
				.line = __LINE__,			\
			};						\
		______r = !!(cond);					\
		______f.miss_hit[______r]++;					\
		______r;						\
	}))
#endif /* CONFIG_PROFILE_ALL_BRANCHES */

#else
# define likely(x)	__builtin_expect(!!(x), 1)
# define unlikely(x)	__builtin_expect(!!(x), 0)
#endif

/* Optimization barrier */
#ifndef barrier
# define barrier() __memory_barrier()
#endif

#ifndef barrier_data
# define barrier_data(ptr) barrier()
#endif

/* Unreachable code */
#ifndef unreachable
# define unreachable() do { } while (1)
#endif

#ifndef RELOC_HIDE
# define RELOC_HIDE(ptr, off)					\
  ({ unsigned long __ptr;					\
     __ptr = (unsigned long) (ptr);				\
    (typeof(ptr)) (__ptr + (off)); })
#endif

#ifndef OPTIMIZER_HIDE_VAR
#define OPTIMIZER_HIDE_VAR(var) barrier()
#endif

/* Not-quite-unique ID. */
#ifndef __UNIQUE_ID
# define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
#endif

#include <uapi/linux/types.h>

#define __READ_ONCE_SIZE						\
({									\
	switch (size) {							\
	case 1: *(__u8 *)res = *(volatile __u8 *)p; break;		\
	case 2: *(__u16 *)res = *(volatile __u16 *)p; break;		\
	case 4: *(__u32 *)res = *(volatile __u32 *)p; break;		\
	case 8: *(__u64 *)res = *(volatile __u64 *)p; break;		\
	default:							\
		barrier();						\
		__builtin_memcpy((void *)res, (const void *)p, size);	\
		barrier();						\
	}								\
})

static __always_inline
void __read_once_size(const volatile void *p, void *res, int size)
{
	__READ_ONCE_SIZE;
}

#ifdef CONFIG_KASAN
/*
 * This function is not 'inline' because __no_sanitize_address confilcts
 * with inlining. Attempt to inline it may cause a build failure.
 * 	https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
 * '__maybe_unused' allows us to avoid defined-but-not-used warnings.
 */
static __no_sanitize_address __maybe_unused
void __read_once_size_nocheck(const volatile void *p, void *res, int size)
{
	__READ_ONCE_SIZE;
}
#else
static __always_inline
void __read_once_size_nocheck(const volatile void *p, void *res, int size)
{
	__READ_ONCE_SIZE;
}
#endif

static __always_inline void __write_once_size(volatile void *p, void *res, int size)
{
	switch (size) {
	case 1: *(volatile __u8 *)p = *(__u8 *)res; break;
	case 2: *(volatile __u16 *)p = *(__u16 *)res; break;
	case 4: *(volatile __u32 *)p = *(__u32 *)res; break;
	case 8: *(volatile __u64 *)p = *(__u64 *)res; break;
	default:
		barrier();
		__builtin_memcpy((void *)p, (const void *)res, size);
		barrier();
	}
}

/*
 * Prevent the compiler from merging or refetching reads or writes. The
 * compiler is also forbidden from reordering successive instances of
 * READ_ONCE, WRITE_ONCE and ACCESS_ONCE (see below), but only when the
 * compiler is aware of some particular ordering.  One way to make the
 * compiler aware of ordering is to put the two invocations of READ_ONCE,
 * WRITE_ONCE or ACCESS_ONCE() in different C statements.
 *
 * In contrast to ACCESS_ONCE these two macros will also work on aggregate
 * data types like structs or unions. If the size of the accessed data
 * type exceeds the word size of the machine (e.g., 32 bits or 64 bits)
 * READ_ONCE() and WRITE_ONCE() will fall back to memcpy(). There's at
 * least two memcpy()s: one for the __builtin_memcpy() and then one for
 * the macro doing the copy of variable - '__u' allocated on the stack.
 *
 * Their two major use cases are: (1) Mediating communication between
 * process-level code and irq/NMI handlers, all running on the same CPU,
 * and (2) Ensuring that the compiler does not  fold, spindle, or otherwise
 * mutilate accesses that either do not require ordering or that interact
 * with an explicit memory barrier or atomic instruction that provides the
 * required ordering.
 */

#define __READ_ONCE(x, check)						\
({									\
	union { typeof(x) __val; char __c[1]; } __u;			\
	if (check)							\
		__read_once_size(&(x), __u.__c, sizeof(x));		\
	else								\
		__read_once_size_nocheck(&(x), __u.__c, sizeof(x));	\
	__u.__val;							\
})
#define READ_ONCE(x) __READ_ONCE(x, 1)

/*
 * Use READ_ONCE_NOCHECK() instead of READ_ONCE() if you need
 * to hide memory access from KASAN.
 */
#define READ_ONCE_NOCHECK(x) __READ_ONCE(x, 0)

#define WRITE_ONCE(x, val) \
({							\
	union { typeof(x) __val; char __c[1]; } __u =	\
		{ .__val = (__force typeof(x)) (val) }; \
	__write_once_size(&(x), __u.__c, sizeof(x));	\
	__u.__val;					\
})

/**
 * smp_cond_acquire() - Spin wait for cond with ACQUIRE ordering
 * @cond: boolean expression to wait for
 *
 * Equivalent to using smp_load_acquire() on the condition variable but employs
 * the control dependency of the wait to reduce the barrier on many platforms.
 *
 * The control dependency provides a LOAD->STORE order, the additional RMB
 * provides LOAD->LOAD order, together they provide LOAD->{LOAD,STORE} order,
 * aka. ACQUIRE.
 */
#define smp_cond_acquire(cond)	do {		\
	while (!(cond))				\
		cpu_relax();			\
	smp_rmb(); /* ctrl + rmb := acquire */	\
} while (0)

#endif /* __KERNEL__ */

#endif /* __ASSEMBLY__ */

#ifdef __KERNEL__
/*
 * Allow us to mark functions as 'deprecated' and have gcc emit a nice
 * warning for each use, in hopes of speeding the functions removal.
 * Usage is:
 * 		int __deprecated foo(void)
 */
#ifndef __deprecated
# define __deprecated		/* unimplemented */
#endif

#ifdef MODULE
#define __deprecated_for_modules __deprecated
#else
#define __deprecated_for_modules
#endif

#ifndef __must_check
#define __must_check
#endif

#ifndef CONFIG_ENABLE_MUST_CHECK
#undef __must_check
#define __must_check
#endif
#ifndef CONFIG_ENABLE_WARN_DEPRECATED
#undef __deprecated
#undef __deprecated_for_modules
#define __deprecated
#define __deprecated_for_modules
#endif

#ifndef __malloc
#define __malloc
#endif

/*
 * Allow us to avoid 'defined but not used' warnings on functions and data,
 * as well as force them to be emitted to the assembly file.
 *
 * As of gcc 3.4, static functions that are not marked with attribute((used))
 * may be elided from the assembly file.  As of gcc 3.4, static data not so
 * marked will not be elided, but this may change in a future gcc version.
 *
 * NOTE: Because distributions shipped with a backported unit-at-a-time
 * compiler in gcc 3.3, we must define __used to be __attribute__((used))
 * for gcc >=3.3 instead of 3.4.
 *
 * In prior versions of gcc, such functions and data would be emitted, but
 * would be warned about except with attribute((unused)).
 *
 * Mark functions that are referenced only in inline assembly as __used so
 * the code is emitted even though it appears to be unreferenced.
 */
#ifndef __used
# define __used			/* unimplemented */
#endif

#ifndef __maybe_unused
# define __maybe_unused		/* unimplemented */
#endif

#ifndef __always_unused
# define __always_unused	/* unimplemented */
#endif

#ifndef noinline
#define noinline
#endif

/*
 * Rather then using noinline to prevent stack consumption, use
 * noinline_for_stack instead.  For documentation reasons.
 */
#define noinline_for_stack noinline

#ifndef __always_inline
#define __always_inline inline
#endif

#endif /* __KERNEL__ */

/*
 * From the GCC manual:
 *
 * Many functions do not examine any values except their arguments,
 * and have no effects except the return value.  Basically this is
 * just slightly more strict class than the `pure' attribute above,
 * since function is not allowed to read global memory.
 *
 * Note that a function that has pointer arguments and examines the
 * data pointed to must _not_ be declared `const'.  Likewise, a
 * function that calls a non-`const' function usually must not be
 * `const'.  It does not make sense for a `const' function to return
 * `void'.
 */
#ifndef __attribute_const__
# define __attribute_const__	/* unimplemented */
#endif

/*
 * Tell gcc if a function is cold. The compiler will assume any path
 * directly leading to the call is unlikely.
 */

#ifndef __cold
#define __cold
#endif

/* Simple shorthand for a section definition */
#ifndef __section
# define __section(S) __attribute__ ((__section__(#S)))
#endif

#ifndef __visible
#define __visible
#endif

/*
 * Assume alignment of return value.
 */
#ifndef __assume_aligned
#define __assume_aligned(a, ...)
#endif


/* Are two types/vars the same type (ignoring qualifiers)? */
#ifndef __same_type
# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
#endif

/* Is this type a native word size -- useful for atomic operations */
#ifndef __native_word
# define __native_word(t) (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
#endif

/* Compile time object size, -1 for unknown */
#ifndef __compiletime_object_size
# define __compiletime_object_size(obj) -1
#endif
#ifndef __compiletime_warning
# define __compiletime_warning(message)
#endif
#ifndef __compiletime_error
# define __compiletime_error(message)
/*
 * Sparse complains of variable sized arrays due to the temporary variable in
 * __compiletime_assert. Unfortunately we can't just expand it out to make
 * sparse see a constant array size without breaking compiletime_assert on old
 * versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether.
 */
# ifndef __CHECKER__
#  define __compiletime_error_fallback(condition) \
	do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
# endif
#endif
#ifndef __compiletime_error_fallback
# define __compiletime_error_fallback(condition) do { } while (0)
#endif

#define __compiletime_assert(condition, msg, prefix, suffix)		\
	do {								\
		bool __cond = !(condition);				\
		extern void prefix ## suffix(void) __compiletime_error(msg); \
		if (__cond)						\
			prefix ## suffix();				\
		__compiletime_error_fallback(__cond);			\
	} while (0)

#define _compiletime_assert(condition, msg, prefix, suffix) \
	__compiletime_assert(condition, msg, prefix, suffix)

/**
 * compiletime_assert - break build and emit msg if condition is false
 * @condition: a compile-time constant condition to check
 * @msg:       a message to emit if condition is false
 *
 * In tradition of POSIX assert, this macro will break the build if the
 * supplied condition is *false*, emitting the supplied error message if the
 * compiler has support to do so.
 */
#define compiletime_assert(condition, msg) \
	_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)

#define compiletime_assert_atomic_type(t)				\
	compiletime_assert(__native_word(t),				\
		"Need native word sized stores/loads for atomicity.")

/*
 * Prevent the compiler from merging or refetching accesses.  The compiler
 * is also forbidden from reordering successive instances of ACCESS_ONCE(),
 * but only when the compiler is aware of some particular ordering.  One way
 * to make the compiler aware of ordering is to put the two invocations of
 * ACCESS_ONCE() in different C statements.
 *
 * ACCESS_ONCE will only work on scalar types. For union types, ACCESS_ONCE
 * on a union member will work as long as the size of the member matches the
 * size of the union and the size is smaller than word size.
 *
 * The major use cases of ACCESS_ONCE used to be (1) Mediating communication
 * between process-level code and irq/NMI handlers, all running on the same CPU,
 * and (2) Ensuring that the compiler does not  fold, spindle, or otherwise
 * mutilate accesses that either do not require ordering or that interact
 * with an explicit memory barrier or atomic instruction that provides the
 * required ordering.
 *
 * If possible use READ_ONCE()/WRITE_ONCE() instead.
 */
#define __ACCESS_ONCE(x) ({ \
	 __maybe_unused typeof(x) __var = (__force typeof(x)) 0; \
	(volatile typeof(x) *)&(x); })
#define ACCESS_ONCE(x) (*__ACCESS_ONCE(x))

/**
 * lockless_dereference() - safely load a pointer for later dereference
 * @p: The pointer to load
 *
 * Similar to rcu_dereference(), but for situations where the pointed-to
 * object's lifetime is managed by something other than RCU.  That
 * "something other" might be reference counting or simple immortality.
 */
#define lockless_dereference(p) \
({ \
	typeof(p) _________p1 = READ_ONCE(p); \
	smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
	(_________p1); \
})

/* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */
#ifdef CONFIG_KPROBES
# define __kprobes	__attribute__((__section__(".kprobes.text")))
# define nokprobe_inline	__always_inline
#else
# define __kprobes
# define nokprobe_inline	inline
#endif
#endif /* __LINUX_COMPILER_H */
Commit	Line	Data
	1	#ifndef __LINUX_COMPILER_H
	2	#define __LINUX_COMPILER_H
	3
	4	#ifndef __ASSEMBLY__
	5
	6	#ifdef __CHECKER__
	7	# define __user __attribute__((noderef, address_space(1)))
	8	# define __kernel __attribute__((address_space(0)))
	9	# define __safe __attribute__((safe))
	10	# define __force __attribute__((force))
	11	# define __nocast __attribute__((nocast))
	12	# define __iomem __attribute__((noderef, address_space(2)))
	13	# define __must_hold(x) __attribute__((context(x,1,1)))
	14	# define __acquires(x) __attribute__((context(x,0,1)))
	15	# define __releases(x) __attribute__((context(x,1,0)))
	16	# define __acquire(x) __context__(x,1)
	17	# define __release(x) __context__(x,-1)
	18	# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
	19	# define __percpu __attribute__((noderef, address_space(3)))
	20	# define __pmem __attribute__((noderef, address_space(5)))
	21	#ifdef CONFIG_SPARSE_RCU_POINTER
	22	# define __rcu __attribute__((noderef, address_space(4)))
	23	#else /* CONFIG_SPARSE_RCU_POINTER */
	24	# define __rcu
	25	#endif /* CONFIG_SPARSE_RCU_POINTER */
	26	# define __private __attribute__((noderef))
	27	extern void __chk_user_ptr(const volatile void __user *);
	28	extern void __chk_io_ptr(const volatile void __iomem *);
	29	# define ACCESS_PRIVATE(p, member) (((typeof((p)->member) __force ) &(p)->member))
	30	#else /* __CHECKER__ */
	31	# define __user
	32	# define __kernel
	33	# define __safe
	34	# define __force
	35	# define __nocast
	36	# define __iomem
	37	# define __chk_user_ptr(x) (void)0
	38	# define __chk_io_ptr(x) (void)0
	39	# define __builtin_warning(x, y...) (1)
	40	# define __must_hold(x)
	41	# define __acquires(x)
	42	# define __releases(x)
	43	# define __acquire(x) (void)0
	44	# define __release(x) (void)0
	45	# define __cond_lock(x,c) (c)
	46	# define __percpu
	47	# define __rcu
	48	# define __pmem
	49	# define __private
	50	# define ACCESS_PRIVATE(p, member) ((p)->member)
	51	#endif /* __CHECKER__ */
	52
	53	/* Indirect macros required for expanded argument pasting, eg. __LINE__. */
	54	#define ___PASTE(a,b) a##b
	55	#define __PASTE(a,b) ___PASTE(a,b)
	56
	57	#ifdef __KERNEL__
	58
	59	#ifdef __GNUC__
	60	#include <linux/compiler-gcc.h>
	61	#endif
	62
	63	#if defined(CC_USING_HOTPATCH) && !defined(__CHECKER__)
	64	#define notrace __attribute__((hotpatch(0,0)))
	65	#else
	66	#define notrace __attribute__((no_instrument_function))
	67	#endif
	68
	69	/* Intel compiler defines __GNUC__. So we will overwrite implementations
	70	* coming from above header files here
	71	*/
	72	#ifdef __INTEL_COMPILER
	73	# include <linux/compiler-intel.h>
	74	#endif
	75
	76	/* Clang compiler defines __GNUC__. So we will overwrite implementations
	77	* coming from above header files here
	78	*/
	79	#ifdef __clang__
	80	#include <linux/compiler-clang.h>
	81	#endif
	82
	83	/*
	84	* Generic compiler-dependent macros required for kernel
	85	* build go below this comment. Actual compiler/compiler version
	86	* specific implementations come from the above header files
	87	*/
	88
	89	struct ftrace_branch_data {
	90	const char *func;
	91	const char *file;
	92	unsigned line;
	93	union {
	94	struct {
	95	unsigned long correct;
	96	unsigned long incorrect;
	97	};
	98	struct {
	99	unsigned long miss;
	100	unsigned long hit;
	101	};
	102	unsigned long miss_hit[2];
	103	};
	104	};
	105
	106	/*
	107	* Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
	108	* to disable branch tracing on a per file basis.
	109	*/
	110	#if defined(CONFIG_TRACE_BRANCH_PROFILING) \
	111	&& !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
	112	void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
	113
	114	#define likely_notrace(x) __builtin_expect(!!(x), 1)
	115	#define unlikely_notrace(x) __builtin_expect(!!(x), 0)
	116
	117	#define __branch_check__(x, expect) ({ \
	118	int ______r; \
	119	static struct ftrace_branch_data \
	120	__attribute__((__aligned__(4))) \
	121	__attribute__((section("_ftrace_annotated_branch"))) \
	122	______f = { \
	123	.func = __func__, \
	124	.file = __FILE__, \
	125	.line = __LINE__, \
	126	}; \
	127	______r = likely_notrace(x); \
	128	ftrace_likely_update(&______f, ______r, expect); \
	129	______r; \
	130	})
	131
	132	/*
	133	* Using __builtin_constant_p(x) to ignore cases where the return
	134	* value is always the same. This idea is taken from a similar patch
	135	* written by Daniel Walker.
	136	*/
	137	# ifndef likely
	138	# define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
	139	# endif
	140	# ifndef unlikely
	141	# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
	142	# endif
	143
	144	#ifdef CONFIG_PROFILE_ALL_BRANCHES
	145	/*
	146	* "Define 'is'", Bill Clinton
	147	* "Define 'if'", Steven Rostedt
	148	*/
	149	#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
	150	#define __trace_if(cond) \
	151	if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
	152	({ \
	153	int ______r; \
	154	static struct ftrace_branch_data \
	155	__attribute__((__aligned__(4))) \
	156	__attribute__((section("_ftrace_branch"))) \
	157	______f = { \
	158	.func = __func__, \
	159	.file = __FILE__, \
	160	.line = __LINE__, \
	161	}; \
	162	______r = !!(cond); \
	163	______f.miss_hit[______r]++; \
	164	______r; \
	165	}))
	166	#endif /* CONFIG_PROFILE_ALL_BRANCHES */
	167
	168	#else
	169	# define likely(x) __builtin_expect(!!(x), 1)
	170	# define unlikely(x) __builtin_expect(!!(x), 0)
	171	#endif
	172
	173	/* Optimization barrier */
	174	#ifndef barrier
	175	# define barrier() __memory_barrier()
	176	#endif
	177
	178	#ifndef barrier_data
	179	# define barrier_data(ptr) barrier()
	180	#endif
	181
	182	/* Unreachable code */
	183	#ifndef unreachable
	184	# define unreachable() do { } while (1)
	185	#endif
	186
	187	#ifndef RELOC_HIDE
	188	# define RELOC_HIDE(ptr, off) \
	189	({ unsigned long __ptr; \
	190	__ptr = (unsigned long) (ptr); \
	191	(typeof(ptr)) (__ptr + (off)); })
	192	#endif
	193
	194	#ifndef OPTIMIZER_HIDE_VAR
	195	#define OPTIMIZER_HIDE_VAR(var) barrier()
	196	#endif
	197
	198	/* Not-quite-unique ID. */
	199	#ifndef __UNIQUE_ID
	200	# define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
	201	#endif
	202
	203	#include <uapi/linux/types.h>
	204
	205	#define __READ_ONCE_SIZE \
	206	({ \
	207	switch (size) { \
	208	case 1: (__u8 )res = (volatile __u8 )p; break; \
	209	case 2: (__u16 )res = (volatile __u16 )p; break; \
	210	case 4: (__u32 )res = (volatile __u32 )p; break; \
	211	case 8: (__u64 )res = (volatile __u64 )p; break; \
	212	default: \
	213	barrier(); \
	214	__builtin_memcpy((void )res, (const void )p, size); \
	215	barrier(); \
	216	} \
	217	})
	218
	219	static __always_inline
	220	void __read_once_size(const volatile void p, void res, int size)
	221	{
	222	__READ_ONCE_SIZE;
	223	}
	224
	225	#ifdef CONFIG_KASAN
	226	/*
	227	* This function is not 'inline' because __no_sanitize_address confilcts
	228	* with inlining. Attempt to inline it may cause a build failure.
	229	* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
	230	* '__maybe_unused' allows us to avoid defined-but-not-used warnings.
	231	*/
	232	static __no_sanitize_address __maybe_unused
	233	void __read_once_size_nocheck(const volatile void p, void res, int size)
	234	{
	235	__READ_ONCE_SIZE;
	236	}
	237	#else
	238	static __always_inline
	239	void __read_once_size_nocheck(const volatile void p, void res, int size)
	240	{
	241	__READ_ONCE_SIZE;
	242	}
	243	#endif
	244
	245	static __always_inline void __write_once_size(volatile void p, void res, int size)
	246	{
	247	switch (size) {
	248	case 1: (volatile __u8 )p = (__u8 )res; break;
	249	case 2: (volatile __u16 )p = (__u16 )res; break;
	250	case 4: (volatile __u32 )p = (__u32 )res; break;
	251	case 8: (volatile __u64 )p = (__u64 )res; break;
	252	default:
	253	barrier();
	254	__builtin_memcpy((void )p, (const void )res, size);
	255	barrier();
	256	}
	257	}
	258
	259	/*
	260	* Prevent the compiler from merging or refetching reads or writes. The
	261	* compiler is also forbidden from reordering successive instances of
	262	* READ_ONCE, WRITE_ONCE and ACCESS_ONCE (see below), but only when the
	263	* compiler is aware of some particular ordering. One way to make the
	264	* compiler aware of ordering is to put the two invocations of READ_ONCE,
	265	* WRITE_ONCE or ACCESS_ONCE() in different C statements.
	266	*
	267	* In contrast to ACCESS_ONCE these two macros will also work on aggregate
	268	* data types like structs or unions. If the size of the accessed data
	269	* type exceeds the word size of the machine (e.g., 32 bits or 64 bits)
	270	* READ_ONCE() and WRITE_ONCE() will fall back to memcpy(). There's at
	271	* least two memcpy()s: one for the __builtin_memcpy() and then one for
	272	* the macro doing the copy of variable - '__u' allocated on the stack.
	273	*
	274	* Their two major use cases are: (1) Mediating communication between
	275	* process-level code and irq/NMI handlers, all running on the same CPU,
	276	* and (2) Ensuring that the compiler does not fold, spindle, or otherwise
	277	* mutilate accesses that either do not require ordering or that interact
	278	* with an explicit memory barrier or atomic instruction that provides the
	279	* required ordering.
	280	*/
	281
	282	#define __READ_ONCE(x, check) \
	283	({ \
	284	union { typeof(x) __val; char __c[1]; } __u; \
	285	if (check) \
	286	__read_once_size(&(x), __u.__c, sizeof(x)); \
	287	else \
	288	__read_once_size_nocheck(&(x), __u.__c, sizeof(x)); \
	289	__u.__val; \
	290	})
	291	#define READ_ONCE(x) __READ_ONCE(x, 1)
	292
	293	/*
	294	* Use READ_ONCE_NOCHECK() instead of READ_ONCE() if you need
	295	* to hide memory access from KASAN.
	296	*/
	297	#define READ_ONCE_NOCHECK(x) __READ_ONCE(x, 0)
	298
	299	#define WRITE_ONCE(x, val) \
	300	({ \
	301	union { typeof(x) __val; char __c[1]; } __u = \
	302	{ .__val = (__force typeof(x)) (val) }; \
	303	__write_once_size(&(x), __u.__c, sizeof(x)); \
	304	__u.__val; \
	305	})
	306
	307	/**
	308	* smp_cond_acquire() - Spin wait for cond with ACQUIRE ordering
	309	* @cond: boolean expression to wait for
	310	*
	311	* Equivalent to using smp_load_acquire() on the condition variable but employs
	312	* the control dependency of the wait to reduce the barrier on many platforms.
	313	*
	314	* The control dependency provides a LOAD->STORE order, the additional RMB
	315	* provides LOAD->LOAD order, together they provide LOAD->{LOAD,STORE} order,
	316	* aka. ACQUIRE.
	317	*/
	318	#define smp_cond_acquire(cond) do { \
	319	while (!(cond)) \
	320	cpu_relax(); \
	321	smp_rmb(); /* ctrl + rmb := acquire */ \
	322	} while (0)
	323
	324	#endif /* __KERNEL__ */
	325
	326	#endif /* __ASSEMBLY__ */
	327
	328	#ifdef __KERNEL__
	329	/*
	330	* Allow us to mark functions as 'deprecated' and have gcc emit a nice
	331	* warning for each use, in hopes of speeding the functions removal.
	332	* Usage is:
	333	* int __deprecated foo(void)
	334	*/
	335	#ifndef __deprecated
	336	# define __deprecated /* unimplemented */
	337	#endif
	338
	339	#ifdef MODULE
	340	#define __deprecated_for_modules __deprecated
	341	#else
	342	#define __deprecated_for_modules
	343	#endif
	344
	345	#ifndef __must_check
	346	#define __must_check
	347	#endif
	348
	349	#ifndef CONFIG_ENABLE_MUST_CHECK
	350	#undef __must_check
	351	#define __must_check
	352	#endif
	353	#ifndef CONFIG_ENABLE_WARN_DEPRECATED
	354	#undef __deprecated
	355	#undef __deprecated_for_modules
	356	#define __deprecated
	357	#define __deprecated_for_modules
	358	#endif
	359
	360	#ifndef __malloc
	361	#define __malloc
	362	#endif
	363
	364	/*
	365	* Allow us to avoid 'defined but not used' warnings on functions and data,
	366	* as well as force them to be emitted to the assembly file.
	367	*
	368	* As of gcc 3.4, static functions that are not marked with attribute((used))
	369	* may be elided from the assembly file. As of gcc 3.4, static data not so
	370	* marked will not be elided, but this may change in a future gcc version.
	371	*
	372	* NOTE: Because distributions shipped with a backported unit-at-a-time
	373	* compiler in gcc 3.3, we must define __used to be __attribute__((used))
	374	* for gcc >=3.3 instead of 3.4.
	375	*
	376	* In prior versions of gcc, such functions and data would be emitted, but
	377	* would be warned about except with attribute((unused)).
	378	*
	379	* Mark functions that are referenced only in inline assembly as __used so
	380	* the code is emitted even though it appears to be unreferenced.
	381	*/
	382	#ifndef __used
	383	# define __used /* unimplemented */
	384	#endif
	385
	386	#ifndef __maybe_unused
	387	# define __maybe_unused /* unimplemented */
	388	#endif
	389
	390	#ifndef __always_unused
	391	# define __always_unused /* unimplemented */
	392	#endif
	393
	394	#ifndef noinline
	395	#define noinline
	396	#endif
	397
	398	/*
	399	* Rather then using noinline to prevent stack consumption, use
	400	* noinline_for_stack instead. For documentation reasons.
	401	*/
	402	#define noinline_for_stack noinline
	403
	404	#ifndef __always_inline
	405	#define __always_inline inline
	406	#endif
	407
	408	#endif /* __KERNEL__ */
	409
	410	/*
	411	* From the GCC manual:
	412	*
	413	* Many functions do not examine any values except their arguments,
	414	* and have no effects except the return value. Basically this is
	415	* just slightly more strict class than the `pure' attribute above,
	416	* since function is not allowed to read global memory.
	417	*
	418	* Note that a function that has pointer arguments and examines the
	419	* data pointed to must _not_ be declared `const'. Likewise, a
	420	* function that calls a non-`const' function usually must not be
	421	* `const'. It does not make sense for a `const' function to return
	422	* `void'.
	423	*/
	424	#ifndef __attribute_const__
	425	# define __attribute_const__ /* unimplemented */
	426	#endif
	427
	428	/*
	429	* Tell gcc if a function is cold. The compiler will assume any path
	430	* directly leading to the call is unlikely.
	431	*/
	432
	433	#ifndef __cold
	434	#define __cold
	435	#endif
	436
	437	/* Simple shorthand for a section definition */
	438	#ifndef __section
	439	# define __section(S) __attribute__ ((__section__(#S)))
	440	#endif
	441
	442	#ifndef __visible
	443	#define __visible
	444	#endif
	445
	446	/*
	447	* Assume alignment of return value.
	448	*/
	449	#ifndef __assume_aligned
	450	#define __assume_aligned(a, ...)
	451	#endif
	452
	453
	454	/* Are two types/vars the same type (ignoring qualifiers)? */
	455	#ifndef __same_type
	456	# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
	457	#endif
	458
	459	/* Is this type a native word size -- useful for atomic operations */
	460	#ifndef __native_word
	461	# define __native_word(t) (sizeof(t) == sizeof(char) \|\| sizeof(t) == sizeof(short) \|\| sizeof(t) == sizeof(int) \|\| sizeof(t) == sizeof(long))
	462	#endif
	463
	464	/* Compile time object size, -1 for unknown */
	465	#ifndef __compiletime_object_size
	466	# define __compiletime_object_size(obj) -1
	467	#endif
	468	#ifndef __compiletime_warning
	469	# define __compiletime_warning(message)
	470	#endif
	471	#ifndef __compiletime_error
	472	# define __compiletime_error(message)
	473	/*
	474	* Sparse complains of variable sized arrays due to the temporary variable in
	475	* __compiletime_assert. Unfortunately we can't just expand it out to make
	476	* sparse see a constant array size without breaking compiletime_assert on old
	477	* versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether.
	478	*/
	479	# ifndef __CHECKER__
	480	# define __compiletime_error_fallback(condition) \
	481	do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
	482	# endif
	483	#endif
	484	#ifndef __compiletime_error_fallback
	485	# define __compiletime_error_fallback(condition) do { } while (0)
	486	#endif
	487
	488	#define __compiletime_assert(condition, msg, prefix, suffix) \
	489	do { \
	490	bool __cond = !(condition); \
	491	extern void prefix ## suffix(void) __compiletime_error(msg); \
	492	if (__cond) \
	493	prefix ## suffix(); \
	494	__compiletime_error_fallback(__cond); \
	495	} while (0)
	496
	497	#define _compiletime_assert(condition, msg, prefix, suffix) \
	498	__compiletime_assert(condition, msg, prefix, suffix)
	499
	500	/**
	501	* compiletime_assert - break build and emit msg if condition is false
	502	* @condition: a compile-time constant condition to check
	503	* @msg: a message to emit if condition is false
	504	*
	505	* In tradition of POSIX assert, this macro will break the build if the
	506	* supplied condition is false, emitting the supplied error message if the
	507	* compiler has support to do so.
	508	*/
	509	#define compiletime_assert(condition, msg) \
	510	_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
	511
	512	#define compiletime_assert_atomic_type(t) \
	513	compiletime_assert(__native_word(t), \
	514	"Need native word sized stores/loads for atomicity.")
	515
	516	/*
	517	* Prevent the compiler from merging or refetching accesses. The compiler
	518	* is also forbidden from reordering successive instances of ACCESS_ONCE(),
	519	* but only when the compiler is aware of some particular ordering. One way
	520	* to make the compiler aware of ordering is to put the two invocations of
	521	* ACCESS_ONCE() in different C statements.
	522	*
	523	* ACCESS_ONCE will only work on scalar types. For union types, ACCESS_ONCE
	524	* on a union member will work as long as the size of the member matches the
	525	* size of the union and the size is smaller than word size.
	526	*
	527	* The major use cases of ACCESS_ONCE used to be (1) Mediating communication
	528	* between process-level code and irq/NMI handlers, all running on the same CPU,
	529	* and (2) Ensuring that the compiler does not fold, spindle, or otherwise
	530	* mutilate accesses that either do not require ordering or that interact
	531	* with an explicit memory barrier or atomic instruction that provides the
	532	* required ordering.
	533	*
	534	* If possible use READ_ONCE()/WRITE_ONCE() instead.
	535	*/
	536	#define __ACCESS_ONCE(x) ({ \
	537	__maybe_unused typeof(x) __var = (__force typeof(x)) 0; \
	538	(volatile typeof(x) *)&(x); })
	539	#define ACCESS_ONCE(x) (*__ACCESS_ONCE(x))
	540
	541	/**
	542	* lockless_dereference() - safely load a pointer for later dereference
	543	* @p: The pointer to load
	544	*
	545	* Similar to rcu_dereference(), but for situations where the pointed-to
	546	* object's lifetime is managed by something other than RCU. That
	547	* "something other" might be reference counting or simple immortality.
	548	*/
	549	#define lockless_dereference(p) \
	550	({ \
	551	typeof(p) _________p1 = READ_ONCE(p); \
	552	smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
	553	(_________p1); \
	554	})
	555
	556	/* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */
	557	#ifdef CONFIG_KPROBES
	558	# define __kprobes __attribute__((__section__(".kprobes.text")))
	559	# define nokprobe_inline __always_inline
	560	#else
	561	# define __kprobes
	562	# define nokprobe_inline inline
	563	#endif
	564	#endif /* __LINUX_COMPILER_H */