561 lines
17 KiB
C
561 lines
17 KiB
C
#ifndef __LINUX_COMPILER_H
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#define __LINUX_COMPILER_H
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#ifndef __ASSEMBLY__
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#ifdef __CHECKER__
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# define __user __attribute__((noderef, address_space(1)))
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# define __kernel __attribute__((address_space(0)))
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# define __safe __attribute__((safe))
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# define __force __attribute__((force))
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# define __nocast __attribute__((nocast))
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# define __iomem __attribute__((noderef, address_space(2)))
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# define __must_hold(x) __attribute__((context(x,1,1)))
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# define __acquires(x) __attribute__((context(x,0,1)))
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# define __releases(x) __attribute__((context(x,1,0)))
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# define __acquire(x) __context__(x,1)
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# define __release(x) __context__(x,-1)
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# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
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# define __percpu __attribute__((noderef, address_space(3)))
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# define __pmem __attribute__((noderef, address_space(5)))
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#ifdef CONFIG_SPARSE_RCU_POINTER
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# define __rcu __attribute__((noderef, address_space(4)))
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#else /* CONFIG_SPARSE_RCU_POINTER */
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# define __rcu
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#endif /* CONFIG_SPARSE_RCU_POINTER */
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# define __private __attribute__((noderef))
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extern void __chk_user_ptr(const volatile void __user *);
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extern void __chk_io_ptr(const volatile void __iomem *);
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# define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member))
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#else /* __CHECKER__ */
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# define __user
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# define __kernel
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# define __safe
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# define __force
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# define __nocast
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# define __iomem
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# define __chk_user_ptr(x) (void)0
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# define __chk_io_ptr(x) (void)0
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# define __builtin_warning(x, y...) (1)
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# define __must_hold(x)
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# define __acquires(x)
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# define __releases(x)
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# define __acquire(x) (void)0
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# define __release(x) (void)0
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# define __cond_lock(x,c) (c)
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# define __percpu
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# define __rcu
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# define __pmem
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# define __private
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# define ACCESS_PRIVATE(p, member) ((p)->member)
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#endif /* __CHECKER__ */
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/* Indirect macros required for expanded argument pasting, eg. __LINE__. */
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#define ___PASTE(a,b) a##b
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#define __PASTE(a,b) ___PASTE(a,b)
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#ifdef __KERNEL__
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#ifdef __GNUC__
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#include <linux/compiler-gcc.h>
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#endif
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#if defined(CC_USING_HOTPATCH) && !defined(__CHECKER__)
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#define notrace __attribute__((hotpatch(0,0)))
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#else
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#define notrace __attribute__((no_instrument_function))
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#endif
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/* Intel compiler defines __GNUC__. So we will overwrite implementations
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* coming from above header files here
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*/
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#ifdef __INTEL_COMPILER
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# include <linux/compiler-intel.h>
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#endif
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/* Clang compiler defines __GNUC__. So we will overwrite implementations
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* coming from above header files here
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*/
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#ifdef __clang__
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#include <linux/compiler-clang.h>
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#endif
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/*
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* Generic compiler-dependent macros required for kernel
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* build go below this comment. Actual compiler/compiler version
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* specific implementations come from the above header files
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*/
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struct ftrace_branch_data {
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const char *func;
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const char *file;
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unsigned line;
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union {
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struct {
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unsigned long correct;
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unsigned long incorrect;
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};
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struct {
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unsigned long miss;
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unsigned long hit;
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};
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unsigned long miss_hit[2];
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};
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};
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/*
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* Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
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* to disable branch tracing on a per file basis.
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*/
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#if defined(CONFIG_TRACE_BRANCH_PROFILING) \
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&& !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
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void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
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#define likely_notrace(x) __builtin_expect(!!(x), 1)
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#define unlikely_notrace(x) __builtin_expect(!!(x), 0)
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#define __branch_check__(x, expect) ({ \
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int ______r; \
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static struct ftrace_branch_data \
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__attribute__((__aligned__(4))) \
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__attribute__((section("_ftrace_annotated_branch"))) \
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______f = { \
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.func = __func__, \
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.file = __FILE__, \
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.line = __LINE__, \
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}; \
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______r = likely_notrace(x); \
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ftrace_likely_update(&______f, ______r, expect); \
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______r; \
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})
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/*
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* Using __builtin_constant_p(x) to ignore cases where the return
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* value is always the same. This idea is taken from a similar patch
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* written by Daniel Walker.
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*/
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# ifndef likely
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# define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
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# endif
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# ifndef unlikely
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# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
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# endif
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#ifdef CONFIG_PROFILE_ALL_BRANCHES
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/*
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* "Define 'is'", Bill Clinton
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* "Define 'if'", Steven Rostedt
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*/
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#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
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#define __trace_if(cond) \
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if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
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({ \
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int ______r; \
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static struct ftrace_branch_data \
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__attribute__((__aligned__(4))) \
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__attribute__((section("_ftrace_branch"))) \
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______f = { \
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.func = __func__, \
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.file = __FILE__, \
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.line = __LINE__, \
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}; \
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______r = !!(cond); \
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______f.miss_hit[______r]++; \
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______r; \
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}))
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#endif /* CONFIG_PROFILE_ALL_BRANCHES */
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#else
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# define likely(x) __builtin_expect(!!(x), 1)
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# define unlikely(x) __builtin_expect(!!(x), 0)
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#endif
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/* Optimization barrier */
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#ifndef barrier
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# define barrier() __memory_barrier()
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#endif
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#ifndef barrier_data
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# define barrier_data(ptr) barrier()
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#endif
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/* Unreachable code */
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#ifndef unreachable
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# define unreachable() do { } while (1)
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#endif
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#ifndef RELOC_HIDE
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# define RELOC_HIDE(ptr, off) \
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({ unsigned long __ptr; \
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__ptr = (unsigned long) (ptr); \
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(typeof(ptr)) (__ptr + (off)); })
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#endif
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#ifndef OPTIMIZER_HIDE_VAR
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#define OPTIMIZER_HIDE_VAR(var) barrier()
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#endif
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/* Not-quite-unique ID. */
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#ifndef __UNIQUE_ID
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# define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
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#endif
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#include <uapi/linux/types.h>
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#define __READ_ONCE_SIZE \
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({ \
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switch (size) { \
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case 1: *(__u8 *)res = *(volatile __u8 *)p; break; \
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case 2: *(__u16 *)res = *(volatile __u16 *)p; break; \
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case 4: *(__u32 *)res = *(volatile __u32 *)p; break; \
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case 8: *(__u64 *)res = *(volatile __u64 *)p; break; \
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default: \
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barrier(); \
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__builtin_memcpy((void *)res, (const void *)p, size); \
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barrier(); \
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} \
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})
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static __always_inline
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void __read_once_size(const volatile void *p, void *res, int size)
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{
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__READ_ONCE_SIZE;
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}
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#ifdef CONFIG_KASAN
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/*
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* This function is not 'inline' because __no_sanitize_address confilcts
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* with inlining. Attempt to inline it may cause a build failure.
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* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
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* '__maybe_unused' allows us to avoid defined-but-not-used warnings.
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*/
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static __no_sanitize_address __maybe_unused
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void __read_once_size_nocheck(const volatile void *p, void *res, int size)
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{
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__READ_ONCE_SIZE;
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}
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#else
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static __always_inline
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void __read_once_size_nocheck(const volatile void *p, void *res, int size)
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{
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__READ_ONCE_SIZE;
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}
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#endif
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static __always_inline void __write_once_size(volatile void *p, void *res, int size)
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{
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switch (size) {
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case 1: *(volatile __u8 *)p = *(__u8 *)res; break;
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case 2: *(volatile __u16 *)p = *(__u16 *)res; break;
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case 4: *(volatile __u32 *)p = *(__u32 *)res; break;
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case 8: *(volatile __u64 *)p = *(__u64 *)res; break;
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default:
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barrier();
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__builtin_memcpy((void *)p, (const void *)res, size);
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barrier();
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}
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}
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/*
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* Prevent the compiler from merging or refetching reads or writes. The
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* compiler is also forbidden from reordering successive instances of
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* READ_ONCE, WRITE_ONCE and ACCESS_ONCE (see below), but only when the
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* compiler is aware of some particular ordering. One way to make the
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* compiler aware of ordering is to put the two invocations of READ_ONCE,
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* WRITE_ONCE or ACCESS_ONCE() in different C statements.
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*
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* In contrast to ACCESS_ONCE these two macros will also work on aggregate
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* data types like structs or unions. If the size of the accessed data
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* type exceeds the word size of the machine (e.g., 32 bits or 64 bits)
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* READ_ONCE() and WRITE_ONCE() will fall back to memcpy(). There's at
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* least two memcpy()s: one for the __builtin_memcpy() and then one for
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* the macro doing the copy of variable - '__u' allocated on the stack.
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*
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* Their two major use cases are: (1) Mediating communication between
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* process-level code and irq/NMI handlers, all running on the same CPU,
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* and (2) Ensuring that the compiler does not fold, spindle, or otherwise
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* mutilate accesses that either do not require ordering or that interact
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* with an explicit memory barrier or atomic instruction that provides the
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* required ordering.
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*/
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#define __READ_ONCE(x, check) \
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({ \
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union { typeof(x) __val; char __c[1]; } __u; \
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if (check) \
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__read_once_size(&(x), __u.__c, sizeof(x)); \
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else \
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__read_once_size_nocheck(&(x), __u.__c, sizeof(x)); \
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__u.__val; \
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})
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#define READ_ONCE(x) __READ_ONCE(x, 1)
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/*
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* Use READ_ONCE_NOCHECK() instead of READ_ONCE() if you need
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* to hide memory access from KASAN.
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*/
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#define READ_ONCE_NOCHECK(x) __READ_ONCE(x, 0)
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#define WRITE_ONCE(x, val) \
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({ \
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union { typeof(x) __val; char __c[1]; } __u = \
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{ .__val = (__force typeof(x)) (val) }; \
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__write_once_size(&(x), __u.__c, sizeof(x)); \
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__u.__val; \
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})
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/**
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* smp_cond_acquire() - Spin wait for cond with ACQUIRE ordering
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* @cond: boolean expression to wait for
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*
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* Equivalent to using smp_load_acquire() on the condition variable but employs
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* the control dependency of the wait to reduce the barrier on many platforms.
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*
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* The control dependency provides a LOAD->STORE order, the additional RMB
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* provides LOAD->LOAD order, together they provide LOAD->{LOAD,STORE} order,
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* aka. ACQUIRE.
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*/
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#define smp_cond_acquire(cond) do { \
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while (!(cond)) \
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cpu_relax(); \
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smp_rmb(); /* ctrl + rmb := acquire */ \
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} while (0)
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#endif /* __KERNEL__ */
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#endif /* __ASSEMBLY__ */
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#ifdef __KERNEL__
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/*
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* Allow us to mark functions as 'deprecated' and have gcc emit a nice
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* warning for each use, in hopes of speeding the functions removal.
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* Usage is:
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* int __deprecated foo(void)
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*/
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#ifndef __deprecated
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# define __deprecated /* unimplemented */
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#endif
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#ifdef MODULE
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#define __deprecated_for_modules __deprecated
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#else
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#define __deprecated_for_modules
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#endif
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#ifndef __must_check
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#define __must_check
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#endif
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#ifndef CONFIG_ENABLE_MUST_CHECK
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#undef __must_check
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#define __must_check
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#endif
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#ifndef CONFIG_ENABLE_WARN_DEPRECATED
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#undef __deprecated
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#undef __deprecated_for_modules
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#define __deprecated
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#define __deprecated_for_modules
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#endif
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/*
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* Allow us to avoid 'defined but not used' warnings on functions and data,
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* as well as force them to be emitted to the assembly file.
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*
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* As of gcc 3.4, static functions that are not marked with attribute((used))
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* may be elided from the assembly file. As of gcc 3.4, static data not so
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* marked will not be elided, but this may change in a future gcc version.
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*
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* NOTE: Because distributions shipped with a backported unit-at-a-time
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* compiler in gcc 3.3, we must define __used to be __attribute__((used))
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* for gcc >=3.3 instead of 3.4.
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*
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* In prior versions of gcc, such functions and data would be emitted, but
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* would be warned about except with attribute((unused)).
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*
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* Mark functions that are referenced only in inline assembly as __used so
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* the code is emitted even though it appears to be unreferenced.
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*/
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#ifndef __used
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# define __used /* unimplemented */
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#endif
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#ifndef __maybe_unused
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# define __maybe_unused /* unimplemented */
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#endif
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#ifndef __always_unused
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# define __always_unused /* unimplemented */
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#endif
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#ifndef noinline
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#define noinline
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#endif
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/*
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* Rather then using noinline to prevent stack consumption, use
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* noinline_for_stack instead. For documentation reasons.
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*/
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#define noinline_for_stack noinline
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#ifndef __always_inline
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#define __always_inline inline
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#endif
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#endif /* __KERNEL__ */
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/*
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* From the GCC manual:
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*
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* Many functions do not examine any values except their arguments,
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* and have no effects except the return value. Basically this is
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* just slightly more strict class than the `pure' attribute above,
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* since function is not allowed to read global memory.
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*
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* Note that a function that has pointer arguments and examines the
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* data pointed to must _not_ be declared `const'. Likewise, a
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* function that calls a non-`const' function usually must not be
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* `const'. It does not make sense for a `const' function to return
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* `void'.
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*/
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#ifndef __attribute_const__
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# define __attribute_const__ /* unimplemented */
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#endif
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/*
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* Tell gcc if a function is cold. The compiler will assume any path
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* directly leading to the call is unlikely.
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*/
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#ifndef __cold
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#define __cold
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#endif
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/* Simple shorthand for a section definition */
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#ifndef __section
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# define __section(S) __attribute__ ((__section__(#S)))
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#endif
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#ifndef __visible
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#define __visible
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#endif
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/*
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* Assume alignment of return value.
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*/
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#ifndef __assume_aligned
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#define __assume_aligned(a, ...)
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#endif
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/* Are two types/vars the same type (ignoring qualifiers)? */
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#ifndef __same_type
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# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
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#endif
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/* Is this type a native word size -- useful for atomic operations */
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#ifndef __native_word
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# define __native_word(t) (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
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#endif
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/* Compile time object size, -1 for unknown */
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#ifndef __compiletime_object_size
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# define __compiletime_object_size(obj) -1
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#endif
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#ifndef __compiletime_warning
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# define __compiletime_warning(message)
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#endif
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#ifndef __compiletime_error
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# define __compiletime_error(message)
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/*
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* Sparse complains of variable sized arrays due to the temporary variable in
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* __compiletime_assert. Unfortunately we can't just expand it out to make
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* sparse see a constant array size without breaking compiletime_assert on old
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* versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether.
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*/
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# ifndef __CHECKER__
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# define __compiletime_error_fallback(condition) \
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do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
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# endif
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#endif
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#ifndef __compiletime_error_fallback
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# define __compiletime_error_fallback(condition) do { } while (0)
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#endif
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#define __compiletime_assert(condition, msg, prefix, suffix) \
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do { \
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bool __cond = !(condition); \
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extern void prefix ## suffix(void) __compiletime_error(msg); \
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if (__cond) \
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prefix ## suffix(); \
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__compiletime_error_fallback(__cond); \
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} while (0)
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#define _compiletime_assert(condition, msg, prefix, suffix) \
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__compiletime_assert(condition, msg, prefix, suffix)
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/**
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* compiletime_assert - break build and emit msg if condition is false
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* @condition: a compile-time constant condition to check
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* @msg: a message to emit if condition is false
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*
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* In tradition of POSIX assert, this macro will break the build if the
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* supplied condition is *false*, emitting the supplied error message if the
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* compiler has support to do so.
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*/
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#define compiletime_assert(condition, msg) \
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_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 */
|