diff options
Diffstat (limited to 'include/linux/compiler.h')
| -rw-r--r-- | include/linux/compiler.h | 226 |
1 files changed, 216 insertions, 10 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index dcae0c8d97e..d5ad7b1118f 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -5,16 +5,23 @@ #ifdef __CHECKER__ # define __user __attribute__((noderef, address_space(1))) -# define __kernel /* default address space */ +# 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))) +#ifdef CONFIG_SPARSE_RCU_POINTER +# define __rcu __attribute__((noderef, address_space(4))) +#else +# define __rcu +#endif extern void __chk_user_ptr(const volatile void __user *); extern void __chk_io_ptr(const volatile void __iomem *); #else @@ -27,23 +34,28 @@ extern void __chk_io_ptr(const volatile void __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 #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__ -#if __GNUC__ >= 4 -# include <linux/compiler-gcc4.h> -#elif __GNUC__ == 3 && __GNUC_MINOR__ >= 2 -# include <linux/compiler-gcc3.h> -#else -# error Sorry, your compiler is too old/not recognized. +#ifdef __GNUC__ +#include <linux/compiler-gcc.h> #endif +#define notrace __attribute__((no_instrument_function)) + /* Intel compiler defines __GNUC__. So we will overwrite implementations * coming from above header files here */ @@ -51,20 +63,113 @@ extern void __chk_io_ptr(const volatile void __iomem *); # 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 */ -#define likely(x) __builtin_expect(!!(x), 1) -#define unlikely(x) __builtin_expect(!!(x), 0) +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 +/* Unreachable code */ +#ifndef unreachable +# define unreachable() do { } while (1) +#endif + #ifndef RELOC_HIDE # define RELOC_HIDE(ptr, off) \ ({ unsigned long __ptr; \ @@ -72,6 +177,15 @@ extern void __chk_io_ptr(const volatile void __iomem *); (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 + #endif /* __KERNEL__ */ #endif /* __ASSEMBLY__ */ @@ -134,13 +248,17 @@ extern void __chk_io_ptr(const volatile void __iomem *); # 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 documentaiton reasons. + * noinline_for_stack instead. For documentation reasons. */ #define noinline_for_stack noinline @@ -182,4 +300,92 @@ extern void __chk_io_ptr(const volatile void __iomem *); # 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(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. + * + * This macro does absolutely -nothing- to prevent the CPU from reordering, + * merging, or refetching absolutely anything at any time. Its main intended + * use is to mediate communication between process-level code and irq/NMI + * handlers, all running on the same CPU. + */ +#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) + +/* 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 */ |