1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Based on arch/arm/include/asm/cmpxchg.h 4 * 5 * Copyright (C) 2012 ARM Ltd. 6 */ 7 #ifndef __ASM_CMPXCHG_H 8 #define __ASM_CMPXCHG_H 9 10 #include <linux/build_bug.h> 11 #include <linux/compiler.h> 12 13 #include <asm/barrier.h> 14 #include <asm/lse.h> 15 16 /* 17 * We need separate acquire parameters for ll/sc and lse, since the full 18 * barrier case is generated as release+dmb for the former and 19 * acquire+release for the latter. 20 */ 21 #define __XCHG_CASE(w, sfx, name, sz, mb, nop_lse, acq, acq_lse, rel, cl) \ 22 static inline u##sz __xchg_case_##name##sz(u##sz x, volatile void *ptr) \ 23 { \ 24 u##sz ret; \ 25 unsigned long tmp; \ 26 \ 27 asm volatile(ARM64_LSE_ATOMIC_INSN( \ 28 /* LL/SC */ \ 29 " prfm pstl1strm, %2\n" \ 30 "1: ld" #acq "xr" #sfx "\t%" #w "0, %2\n" \ 31 " st" #rel "xr" #sfx "\t%w1, %" #w "3, %2\n" \ 32 " cbnz %w1, 1b\n" \ 33 " " #mb, \ 34 /* LSE atomics */ \ 35 " swp" #acq_lse #rel #sfx "\t%" #w "3, %" #w "0, %2\n" \ 36 __nops(3) \ 37 " " #nop_lse) \ 38 : "=&r" (ret), "=&r" (tmp), "+Q" (*(u##sz *)ptr) \ 39 : "r" (x) \ 40 : cl); \ 41 \ 42 return ret; \ 43 } 44 45 __XCHG_CASE(w, b, , 8, , , , , , ) 46 __XCHG_CASE(w, h, , 16, , , , , , ) 47 __XCHG_CASE(w, , , 32, , , , , , ) 48 __XCHG_CASE( , , , 64, , , , , , ) 49 __XCHG_CASE(w, b, acq_, 8, , , a, a, , "memory") 50 __XCHG_CASE(w, h, acq_, 16, , , a, a, , "memory") 51 __XCHG_CASE(w, , acq_, 32, , , a, a, , "memory") 52 __XCHG_CASE( , , acq_, 64, , , a, a, , "memory") 53 __XCHG_CASE(w, b, rel_, 8, , , , , l, "memory") 54 __XCHG_CASE(w, h, rel_, 16, , , , , l, "memory") 55 __XCHG_CASE(w, , rel_, 32, , , , , l, "memory") 56 __XCHG_CASE( , , rel_, 64, , , , , l, "memory") 57 __XCHG_CASE(w, b, mb_, 8, dmb ish, nop, , a, l, "memory") 58 __XCHG_CASE(w, h, mb_, 16, dmb ish, nop, , a, l, "memory") 59 __XCHG_CASE(w, , mb_, 32, dmb ish, nop, , a, l, "memory") 60 __XCHG_CASE( , , mb_, 64, dmb ish, nop, , a, l, "memory") 61 62 #undef __XCHG_CASE 63 64 #define __XCHG_GEN(sfx) \ 65 static __always_inline unsigned long \ 66 __arch_xchg##sfx(unsigned long x, volatile void *ptr, int size) \ 67 { \ 68 switch (size) { \ 69 case 1: \ 70 return __xchg_case##sfx##_8(x, ptr); \ 71 case 2: \ 72 return __xchg_case##sfx##_16(x, ptr); \ 73 case 4: \ 74 return __xchg_case##sfx##_32(x, ptr); \ 75 case 8: \ 76 return __xchg_case##sfx##_64(x, ptr); \ 77 default: \ 78 BUILD_BUG(); \ 79 } \ 80 \ 81 unreachable(); \ 82 } 83 84 __XCHG_GEN() 85 __XCHG_GEN(_acq) 86 __XCHG_GEN(_rel) 87 __XCHG_GEN(_mb) 88 89 #undef __XCHG_GEN 90 91 #define __xchg_wrapper(sfx, ptr, x) \ 92 ({ \ 93 __typeof__(*(ptr)) __ret; \ 94 __ret = (__force __typeof__(*(ptr))) \ 95 __arch_xchg##sfx((__force unsigned long)(x), (ptr), \ 96 sizeof(*(ptr))); \ 97 __ret; \ 98 }) 99 100 /* xchg */ 101 #define arch_xchg_relaxed(...) __xchg_wrapper( , __VA_ARGS__) 102 #define arch_xchg_acquire(...) __xchg_wrapper(_acq, __VA_ARGS__) 103 #define arch_xchg_release(...) __xchg_wrapper(_rel, __VA_ARGS__) 104 #define arch_xchg(...) __xchg_wrapper( _mb, __VA_ARGS__) 105 106 #define __CMPXCHG_CASE(name, sz) \ 107 static inline u##sz __cmpxchg_case_##name##sz(volatile void *ptr, \ 108 u##sz old, \ 109 u##sz new) \ 110 { \ 111 return __lse_ll_sc_body(_cmpxchg_case_##name##sz, \ 112 ptr, old, new); \ 113 } 114 115 __CMPXCHG_CASE( , 8) 116 __CMPXCHG_CASE( , 16) 117 __CMPXCHG_CASE( , 32) 118 __CMPXCHG_CASE( , 64) 119 __CMPXCHG_CASE(acq_, 8) 120 __CMPXCHG_CASE(acq_, 16) 121 __CMPXCHG_CASE(acq_, 32) 122 __CMPXCHG_CASE(acq_, 64) 123 __CMPXCHG_CASE(rel_, 8) 124 __CMPXCHG_CASE(rel_, 16) 125 __CMPXCHG_CASE(rel_, 32) 126 __CMPXCHG_CASE(rel_, 64) 127 __CMPXCHG_CASE(mb_, 8) 128 __CMPXCHG_CASE(mb_, 16) 129 __CMPXCHG_CASE(mb_, 32) 130 __CMPXCHG_CASE(mb_, 64) 131 132 #undef __CMPXCHG_CASE 133 134 #define __CMPXCHG128(name) \ 135 static inline u128 __cmpxchg128##name(volatile u128 *ptr, \ 136 u128 old, u128 new) \ 137 { \ 138 return __lse_ll_sc_body(_cmpxchg128##name, \ 139 ptr, old, new); \ 140 } 141 142 __CMPXCHG128( ) 143 __CMPXCHG128(_mb) 144 145 #undef __CMPXCHG128 146 147 #define __CMPXCHG_GEN(sfx) \ 148 static __always_inline unsigned long __cmpxchg##sfx(volatile void *ptr, \ 149 unsigned long old, \ 150 unsigned long new, \ 151 int size) \ 152 { \ 153 switch (size) { \ 154 case 1: \ 155 return __cmpxchg_case##sfx##_8(ptr, old, new); \ 156 case 2: \ 157 return __cmpxchg_case##sfx##_16(ptr, old, new); \ 158 case 4: \ 159 return __cmpxchg_case##sfx##_32(ptr, old, new); \ 160 case 8: \ 161 return __cmpxchg_case##sfx##_64(ptr, old, new); \ 162 default: \ 163 BUILD_BUG(); \ 164 } \ 165 \ 166 unreachable(); \ 167 } 168 169 __CMPXCHG_GEN() 170 __CMPXCHG_GEN(_acq) 171 __CMPXCHG_GEN(_rel) 172 __CMPXCHG_GEN(_mb) 173 174 #undef __CMPXCHG_GEN 175 176 #define __cmpxchg_wrapper(sfx, ptr, o, n) \ 177 ({ \ 178 __typeof__(*(ptr)) __ret; \ 179 __ret = (__force __typeof__(*(ptr))) \ 180 __cmpxchg##sfx((ptr), (__force unsigned long)(o), \ 181 (__force unsigned long)(n), \ 182 sizeof(*(ptr))); \ 183 __ret; \ 184 }) 185 186 /* cmpxchg */ 187 #define arch_cmpxchg_relaxed(...) __cmpxchg_wrapper( , __VA_ARGS__) 188 #define arch_cmpxchg_acquire(...) __cmpxchg_wrapper(_acq, __VA_ARGS__) 189 #define arch_cmpxchg_release(...) __cmpxchg_wrapper(_rel, __VA_ARGS__) 190 #define arch_cmpxchg(...) __cmpxchg_wrapper( _mb, __VA_ARGS__) 191 #define arch_cmpxchg_local arch_cmpxchg_relaxed 192 193 /* cmpxchg64 */ 194 #define arch_cmpxchg64_relaxed arch_cmpxchg_relaxed 195 #define arch_cmpxchg64_acquire arch_cmpxchg_acquire 196 #define arch_cmpxchg64_release arch_cmpxchg_release 197 #define arch_cmpxchg64 arch_cmpxchg 198 #define arch_cmpxchg64_local arch_cmpxchg_local 199 200 /* cmpxchg128 */ 201 #define system_has_cmpxchg128() 1 202 203 #define arch_cmpxchg128(ptr, o, n) \ 204 ({ \ 205 __cmpxchg128_mb((ptr), (o), (n)); \ 206 }) 207 208 #define arch_cmpxchg128_local(ptr, o, n) \ 209 ({ \ 210 __cmpxchg128((ptr), (o), (n)); \ 211 }) 212 213 #define __CMPWAIT_CASE(w, sfx, sz) \ 214 static inline void __cmpwait_case_##sz(volatile void *ptr, \ 215 unsigned long val) \ 216 { \ 217 unsigned long tmp; \ 218 \ 219 asm volatile( \ 220 " sevl\n" \ 221 " wfe\n" \ 222 " ldxr" #sfx "\t%" #w "[tmp], %[v]\n" \ 223 " eor %" #w "[tmp], %" #w "[tmp], %" #w "[val]\n" \ 224 " cbnz %" #w "[tmp], 1f\n" \ 225 " wfe\n" \ 226 "1:" \ 227 : [tmp] "=&r" (tmp), [v] "+Q" (*(u##sz *)ptr) \ 228 : [val] "r" (val)); \ 229 } 230 231 __CMPWAIT_CASE(w, b, 8); 232 __CMPWAIT_CASE(w, h, 16); 233 __CMPWAIT_CASE(w, , 32); 234 __CMPWAIT_CASE( , , 64); 235 236 #undef __CMPWAIT_CASE 237 238 #define __CMPWAIT_GEN(sfx) \ 239 static __always_inline void __cmpwait##sfx(volatile void *ptr, \ 240 unsigned long val, \ 241 int size) \ 242 { \ 243 switch (size) { \ 244 case 1: \ 245 return __cmpwait_case##sfx##_8(ptr, (u8)val); \ 246 case 2: \ 247 return __cmpwait_case##sfx##_16(ptr, (u16)val); \ 248 case 4: \ 249 return __cmpwait_case##sfx##_32(ptr, val); \ 250 case 8: \ 251 return __cmpwait_case##sfx##_64(ptr, val); \ 252 default: \ 253 BUILD_BUG(); \ 254 } \ 255 \ 256 unreachable(); \ 257 } 258 259 __CMPWAIT_GEN() 260 261 #undef __CMPWAIT_GEN 262 263 #define __cmpwait_relaxed(ptr, val) \ 264 __cmpwait((ptr), (unsigned long)(val), sizeof(*(ptr))) 265 266 #endif /* __ASM_CMPXCHG_H */ 267