#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# define __rcu#endifextern void __chk_user_ptr(const volatile void __user *);extern void __chk_io_ptr(const volatile void __iomem *);#else# 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#endif /* 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 #ifdef CC_USING_HOTPATCH#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> static __always_inline void __read_once_size(const volatile void *p, void *res, int 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 __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 and print a * compile-time warning. * * 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) \	({ union { typeof(x) __val; char __c[1]; } __u; __read_once_size(&(x), __u.__c, sizeof(x)); __u.__val; }) #define WRITE_ONCE(x, val) \	({ union { typeof(x) __val; char __c[1]; } __u = { .__val = (val) }; __write_once_size(&(x), __u.__c, sizeof(x)); __u.__val; }) /** * READ_ONCE_CTRL - Read a value heading a control dependency * @x: The value to be read, heading the control dependency * * Control dependencies are tricky.  See Documentation/memory-barriers.txt * for important information on how to use them.  Note that in many cases, * use of smp_load_acquire() will be much simpler.  Control dependencies * should be avoided except on the hottest of hotpaths. */#define READ_ONCE_CTRL(x) \({ \	typeof(x) __val = READ_ONCE(x); \	smp_read_barrier_depends(); /* Enforce control dependency. */ \	__val; \}) #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 /* * 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 /* 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

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