1 #ifndef _TOOLS_LINUX_COMPILER_H_
2 #define _TOOLS_LINUX_COMPILER_H_
4 /* Optimization barrier */
5 /* The "volatile" is due to gcc bugs */
6 #define barrier() __asm__ __volatile__("": : :"memory")
7 #define barrier_data(ptr) __asm__ __volatile__("": :"r"(ptr) :"memory")
9 #ifndef __always_inline
10 # define __always_inline inline __attribute__((always_inline))
13 #ifndef __attribute_const__
14 #define __attribute_const__ __attribute__((__const__))
19 * FIXME: Big hammer to get rid of tons of:
20 * "warning: always_inline function might not be inlinable"
22 * At least on android-ndk-r12/platforms/android-24/arch-arm
24 #undef __always_inline
25 #define __always_inline inline
29 #define noinline_for_stack noinline
34 #define __pure __attribute__((pure))
35 #define __aligned(x) __attribute__((aligned(x)))
36 #define __printf(a, b) __attribute__((format(printf, a, b)))
37 #define __used __attribute__((__used__))
38 #define __maybe_unused __attribute__((unused))
39 #define __always_unused __attribute__((unused))
40 #define __packed __attribute__((__packed__))
41 #define __flatten __attribute__((flatten))
45 #define __chk_user_ptr(x) (void)0
46 #define __chk_io_ptr(x) (void)0
47 #define __builtin_warning(x, y...) (1)
48 #define __must_hold(x)
51 #define __acquire(x) (void)0
52 #define __release(x) (void)0
53 #define __cond_lock(x,c) (c)
62 #define __weak __attribute__((weak))
63 #define likely(x) __builtin_expect(!!(x), 1)
64 #define unlikely(x) __builtin_expect(!!(x), 0)
65 #define unreachable() __builtin_unreachable()
66 #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
67 #define fallthrough __attribute__((__fallthrough__))
68 #define __noreturn __attribute__((__noreturn__))
71 #define __counted_by(nr)
74 #define ___PASTE(a,b) a##b
75 #define __PASTE(a,b) ___PASTE(a,b)
76 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
78 #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
80 #define __initcall(x) /* unimplemented */
81 #define __exitcall(x) /* unimplemented */
83 #include <linux/types.h>
86 * Following functions are taken from kernel sources and
87 * break aliasing rules in their original form.
89 * While kernel is compiled with -fno-strict-aliasing,
90 * perf uses -Wstrict-aliasing=3 which makes build fail
93 * Using extra __may_alias__ type to allow aliasing
96 typedef __u8 __attribute__((__may_alias__)) __u8_alias_t;
97 typedef __u16 __attribute__((__may_alias__)) __u16_alias_t;
98 typedef __u32 __attribute__((__may_alias__)) __u32_alias_t;
99 typedef __u64 __attribute__((__may_alias__)) __u64_alias_t;
101 static __always_inline void __read_once_size(const volatile void *p, void *res, int size)
104 case 1: *(__u8_alias_t *) res = *(volatile __u8_alias_t *) p; break;
105 case 2: *(__u16_alias_t *) res = *(volatile __u16_alias_t *) p; break;
106 case 4: *(__u32_alias_t *) res = *(volatile __u32_alias_t *) p; break;
107 case 8: *(__u64_alias_t *) res = *(volatile __u64_alias_t *) p; break;
110 __builtin_memcpy((void *)res, (const void *)p, size);
115 static __always_inline void __write_once_size(volatile void *p, void *res, int size)
118 case 1: *(volatile __u8_alias_t *) p = *(__u8_alias_t *) res; break;
119 case 2: *(volatile __u16_alias_t *) p = *(__u16_alias_t *) res; break;
120 case 4: *(volatile __u32_alias_t *) p = *(__u32_alias_t *) res; break;
121 case 8: *(volatile __u64_alias_t *) p = *(__u64_alias_t *) res; break;
124 __builtin_memcpy((void *)p, (const void *)res, size);
130 * Prevent the compiler from merging or refetching reads or writes. The
131 * compiler is also forbidden from reordering successive instances of
132 * READ_ONCE, WRITE_ONCE and ACCESS_ONCE (see below), but only when the
133 * compiler is aware of some particular ordering. One way to make the
134 * compiler aware of ordering is to put the two invocations of READ_ONCE,
135 * WRITE_ONCE or ACCESS_ONCE() in different C statements.
137 * In contrast to ACCESS_ONCE these two macros will also work on aggregate
138 * data types like structs or unions. If the size of the accessed data
139 * type exceeds the word size of the machine (e.g., 32 bits or 64 bits)
140 * READ_ONCE() and WRITE_ONCE() will fall back to memcpy and print a
141 * compile-time warning.
143 * Their two major use cases are: (1) Mediating communication between
144 * process-level code and irq/NMI handlers, all running on the same CPU,
145 * and (2) Ensuring that the compiler does not fold, spindle, or otherwise
146 * mutilate accesses that either do not require ordering or that interact
147 * with an explicit memory barrier or atomic instruction that provides the
151 #define READ_ONCE(x) \
152 ({ union { typeof(x) __val; char __c[1]; } __u; __read_once_size(&(x), __u.__c, sizeof(x)); __u.__val; })
154 #define WRITE_ONCE(x, val) \
155 ({ union { typeof(x) __val; char __c[1]; } __u = { .__val = (val) }; __write_once_size(&(x), __u.__c, sizeof(x)); __u.__val; })
157 #define lockless_dereference(p) \
159 typeof(p) _________p1 = READ_ONCE(p); \
160 typeof(*(p)) *___typecheck_p __maybe_unused; \
161 smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
165 #define flush_cache_all() do { } while (0)
166 #define flush_cache_mm(mm) do { } while (0)
167 #define flush_cache_dup_mm(mm) do { } while (0)
168 #define flush_cache_range(vma, start, end) do { } while (0)
169 #define flush_cache_page(vma, vmaddr, pfn) do { } while (0)
170 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
171 #define flush_dcache_page(page) do { } while (0)
172 #define flush_dcache_mmap_lock(mapping) do { } while (0)
173 #define flush_dcache_mmap_unlock(mapping) do { } while (0)
174 #define flush_icache_range(start, end) do { } while (0)
175 #define flush_icache_page(vma,pg) do { } while (0)
176 #define flush_icache_user_range(vma,pg,adr,len) do { } while (0)
177 #define flush_cache_vmap(start, end) do { } while (0)
178 #define flush_cache_vunmap(start, end) do { } while (0)
181 #define CONFIG_X86_64 y
184 #endif /* _TOOLS_LINUX_COMPILER_H */