/* SPDX-License-Identifier: GPL-2.0 */#ifndef __LINUX_COMPILER_H#define __LINUX_COMPILER_H #include <linux/compiler_types.h> #ifndef __ASSEMBLY__ #ifdef __KERNEL__ /* * 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_likely_data *f, int val,			  int expect, int is_constant); #define likely_notrace(x)	__builtin_expect(!!(x), 1)#define unlikely_notrace(x)	__builtin_expect(!!(x), 0) #define __branch_check__(x, expect, is_constant) ({			\			int ______r;					\			static struct ftrace_likely_data		\				__attribute__((__aligned__(4)))		\				__attribute__((section("_ftrace_annotated_branch"))) \				______f = {				\				.data.func = __func__,			\				.data.file = __FILE__,			\				.data.line = __LINE__,			\			};						\			______r = __builtin_expect(!!(x), expect);	\			ftrace_likely_update(&______f, ______r,		\					     expect, is_constant);	\			______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)	(__branch_check__(x, 1, __builtin_constant_p(x)))# endif# ifndef unlikely#  define unlikely(x)	(__branch_check__(x, 0, __builtin_constant_p(x)))# 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 */#ifdef CONFIG_STACK_VALIDATION/* * These macros help objtool understand GCC code flow for unreachable code. * The __COUNTER__ based labels are a hack to make each instance of the macros * unique, to convince GCC not to merge duplicate inline asm statements. */#define annotate_reachable() ({						\	asm volatile("%c0:\n\t"						\		     ".pushsection .discard.reachable\n\t"		\		     ".long %c0b - .\n\t"				\		     ".popsection\n\t" : : "i" (__COUNTER__));		\})#define annotate_unreachable() ({					\	asm volatile("%c0:\n\t"						\		     ".pushsection .discard.unreachable\n\t"		\		     ".long %c0b - .\n\t"				\		     ".popsection\n\t" : : "i" (__COUNTER__));		\})#define ASM_UNREACHABLE							\	"999:\n\t"							\	".pushsection .discard.unreachable\n\t"				\	".long 999b - .\n\t"						\	".popsection\n\t"#else#define annotate_reachable()#define annotate_unreachable()#endif #ifndef ASM_UNREACHABLE# define ASM_UNREACHABLE#endif#ifndef unreachable# define unreachable() do { annotate_reachable(); do { } while (1); } while (0)#endif /* * KENTRY - kernel entry point * This can be used to annotate symbols (functions or data) that are used * without their linker symbol being referenced explicitly. For example, * interrupt vector handlers, or functions in the kernel image that are found * programatically. * * Not required for symbols exported with EXPORT_SYMBOL, or initcalls. Those * are handled in their own way (with KEEP() in linker scripts). * * KENTRY can be avoided if the symbols in question are marked as KEEP() in the * linker script. For example an architecture could KEEP() its entire * boot/exception vector code rather than annotate each function and data. */#ifndef KENTRY# define KENTRY(sym)						\	extern typeof(sym) sym;					\	static const unsigned long __kentry_##sym		\	__used							\	__attribute__((section("___kentry" "+" #sym ), used))	\	= (unsigned long)&sym;#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_inlinevoid __read_once_size(const volatile void *p, void *res, int size){	__READ_ONCE_SIZE;} #ifdef CONFIG_KASAN/* * We can't declare function '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. */# define __no_kasan_or_inline __no_sanitize_address __maybe_unused#else# define __no_kasan_or_inline __always_inline#endif static __no_kasan_or_inlinevoid __read_once_size_nocheck(const volatile void *p, void *res, int size){	__READ_ONCE_SIZE;} 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 and WRITE_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 READ_ONCE or WRITE_ONCE in different C * statements. * * 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. */#include <asm/barrier.h>#include <linux/kasan-checks.h> #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));	\	smp_read_barrier_depends(); /* Enforce dependency ordering from 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) static __no_kasan_or_inlineunsigned long read_word_at_a_time(const void *addr){	kasan_check_read(addr, 1);	return *(unsigned long *)addr;} #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;					\}) #endif /* __KERNEL__ */ #endif /* __ASSEMBLY__ */ #ifndef __optimize# define __optimize(level)#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 #ifdef __OPTIMIZE__# 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)#else# define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0)#endif #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.") #endif /* __LINUX_COMPILER_H */