1 #ifndef _ASM_X86_PERCPU_H 2 #define _ASM_X86_PERCPU_H 3 4 #ifdef CONFIG_X86_64 5 #define __percpu_seg gs 6 #define __percpu_mov_op movq 7 #else 8 #define __percpu_seg fs 9 #define __percpu_mov_op movl 10 #endif 11 12 #ifdef __ASSEMBLY__ 13 14 /* 15 * PER_CPU finds an address of a per-cpu variable. 16 * 17 * Args: 18 * var - variable name 19 * reg - 32bit register 20 * 21 * The resulting address is stored in the "reg" argument. 22 * 23 * Example: 24 * PER_CPU(cpu_gdt_descr, %ebx) 25 */ 26 #ifdef CONFIG_SMP 27 #define PER_CPU(var, reg) \ 28 __percpu_mov_op %__percpu_seg:this_cpu_off, reg; \ 29 lea var(reg), reg 30 #define PER_CPU_VAR(var) %__percpu_seg:var 31 #else /* ! SMP */ 32 #define PER_CPU(var, reg) __percpu_mov_op $var, reg 33 #define PER_CPU_VAR(var) var 34 #endif /* SMP */ 35 36 #ifdef CONFIG_X86_64_SMP 37 #define INIT_PER_CPU_VAR(var) init_per_cpu__##var 38 #else 39 #define INIT_PER_CPU_VAR(var) var 40 #endif 41 42 #else /* ...!ASSEMBLY */ 43 44 #include <linux/kernel.h> 45 #include <linux/stringify.h> 46 47 #ifdef CONFIG_SMP 48 #define __percpu_arg(x) "%%"__stringify(__percpu_seg)":%P" #x 49 #define __my_cpu_offset percpu_read(this_cpu_off) 50 51 /* 52 * Compared to the generic __my_cpu_offset version, the following 53 * saves one instruction and avoids clobbering a temp register. 54 */ 55 #define __this_cpu_ptr(ptr) \ 56 ({ \ 57 unsigned long tcp_ptr__; \ 58 __verify_pcpu_ptr(ptr); \ 59 asm volatile("add " __percpu_arg(1) ", %0" \ 60 : "=r" (tcp_ptr__) \ 61 : "m" (this_cpu_off), "0" (ptr)); \ 62 (typeof(*(ptr)) __kernel __force *)tcp_ptr__; \ 63 }) 64 #else 65 #define __percpu_arg(x) "%P" #x 66 #endif 67 68 /* 69 * Initialized pointers to per-cpu variables needed for the boot 70 * processor need to use these macros to get the proper address 71 * offset from __per_cpu_load on SMP. 72 * 73 * There also must be an entry in vmlinux_64.lds.S 74 */ 75 #define DECLARE_INIT_PER_CPU(var) \ 76 extern typeof(var) init_per_cpu_var(var) 77 78 #ifdef CONFIG_X86_64_SMP 79 #define init_per_cpu_var(var) init_per_cpu__##var 80 #else 81 #define init_per_cpu_var(var) var 82 #endif 83 84 /* For arch-specific code, we can use direct single-insn ops (they 85 * don't give an lvalue though). */ 86 extern void __bad_percpu_size(void); 87 88 #define percpu_to_op(op, var, val) \ 89 do { \ 90 typedef typeof(var) pto_T__; \ 91 if (0) { \ 92 pto_T__ pto_tmp__; \ 93 pto_tmp__ = (val); \ 94 (void)pto_tmp__; \ 95 } \ 96 switch (sizeof(var)) { \ 97 case 1: \ 98 asm(op "b %1,"__percpu_arg(0) \ 99 : "+m" (var) \ 100 : "qi" ((pto_T__)(val))); \ 101 break; \ 102 case 2: \ 103 asm(op "w %1,"__percpu_arg(0) \ 104 : "+m" (var) \ 105 : "ri" ((pto_T__)(val))); \ 106 break; \ 107 case 4: \ 108 asm(op "l %1,"__percpu_arg(0) \ 109 : "+m" (var) \ 110 : "ri" ((pto_T__)(val))); \ 111 break; \ 112 case 8: \ 113 asm(op "q %1,"__percpu_arg(0) \ 114 : "+m" (var) \ 115 : "re" ((pto_T__)(val))); \ 116 break; \ 117 default: __bad_percpu_size(); \ 118 } \ 119 } while (0) 120 121 /* 122 * Generate a percpu add to memory instruction and optimize code 123 * if one is added or subtracted. 124 */ 125 #define percpu_add_op(var, val) \ 126 do { \ 127 typedef typeof(var) pao_T__; \ 128 const int pao_ID__ = (__builtin_constant_p(val) && \ 129 ((val) == 1 || (val) == -1)) ? (val) : 0; \ 130 if (0) { \ 131 pao_T__ pao_tmp__; \ 132 pao_tmp__ = (val); \ 133 (void)pao_tmp__; \ 134 } \ 135 switch (sizeof(var)) { \ 136 case 1: \ 137 if (pao_ID__ == 1) \ 138 asm("incb "__percpu_arg(0) : "+m" (var)); \ 139 else if (pao_ID__ == -1) \ 140 asm("decb "__percpu_arg(0) : "+m" (var)); \ 141 else \ 142 asm("addb %1, "__percpu_arg(0) \ 143 : "+m" (var) \ 144 : "qi" ((pao_T__)(val))); \ 145 break; \ 146 case 2: \ 147 if (pao_ID__ == 1) \ 148 asm("incw "__percpu_arg(0) : "+m" (var)); \ 149 else if (pao_ID__ == -1) \ 150 asm("decw "__percpu_arg(0) : "+m" (var)); \ 151 else \ 152 asm("addw %1, "__percpu_arg(0) \ 153 : "+m" (var) \ 154 : "ri" ((pao_T__)(val))); \ 155 break; \ 156 case 4: \ 157 if (pao_ID__ == 1) \ 158 asm("incl "__percpu_arg(0) : "+m" (var)); \ 159 else if (pao_ID__ == -1) \ 160 asm("decl "__percpu_arg(0) : "+m" (var)); \ 161 else \ 162 asm("addl %1, "__percpu_arg(0) \ 163 : "+m" (var) \ 164 : "ri" ((pao_T__)(val))); \ 165 break; \ 166 case 8: \ 167 if (pao_ID__ == 1) \ 168 asm("incq "__percpu_arg(0) : "+m" (var)); \ 169 else if (pao_ID__ == -1) \ 170 asm("decq "__percpu_arg(0) : "+m" (var)); \ 171 else \ 172 asm("addq %1, "__percpu_arg(0) \ 173 : "+m" (var) \ 174 : "re" ((pao_T__)(val))); \ 175 break; \ 176 default: __bad_percpu_size(); \ 177 } \ 178 } while (0) 179 180 #define percpu_from_op(op, var, constraint) \ 181 ({ \ 182 typeof(var) pfo_ret__; \ 183 switch (sizeof(var)) { \ 184 case 1: \ 185 asm(op "b "__percpu_arg(1)",%0" \ 186 : "=q" (pfo_ret__) \ 187 : constraint); \ 188 break; \ 189 case 2: \ 190 asm(op "w "__percpu_arg(1)",%0" \ 191 : "=r" (pfo_ret__) \ 192 : constraint); \ 193 break; \ 194 case 4: \ 195 asm(op "l "__percpu_arg(1)",%0" \ 196 : "=r" (pfo_ret__) \ 197 : constraint); \ 198 break; \ 199 case 8: \ 200 asm(op "q "__percpu_arg(1)",%0" \ 201 : "=r" (pfo_ret__) \ 202 : constraint); \ 203 break; \ 204 default: __bad_percpu_size(); \ 205 } \ 206 pfo_ret__; \ 207 }) 208 209 #define percpu_unary_op(op, var) \ 210 ({ \ 211 switch (sizeof(var)) { \ 212 case 1: \ 213 asm(op "b "__percpu_arg(0) \ 214 : "+m" (var)); \ 215 break; \ 216 case 2: \ 217 asm(op "w "__percpu_arg(0) \ 218 : "+m" (var)); \ 219 break; \ 220 case 4: \ 221 asm(op "l "__percpu_arg(0) \ 222 : "+m" (var)); \ 223 break; \ 224 case 8: \ 225 asm(op "q "__percpu_arg(0) \ 226 : "+m" (var)); \ 227 break; \ 228 default: __bad_percpu_size(); \ 229 } \ 230 }) 231 232 /* 233 * percpu_read() makes gcc load the percpu variable every time it is 234 * accessed while percpu_read_stable() allows the value to be cached. 235 * percpu_read_stable() is more efficient and can be used if its value 236 * is guaranteed to be valid across cpus. The current users include 237 * get_current() and get_thread_info() both of which are actually 238 * per-thread variables implemented as per-cpu variables and thus 239 * stable for the duration of the respective task. 240 */ 241 #define percpu_read(var) percpu_from_op("mov", var, "m" (var)) 242 #define percpu_read_stable(var) percpu_from_op("mov", var, "p" (&(var))) 243 #define percpu_write(var, val) percpu_to_op("mov", var, val) 244 #define percpu_add(var, val) percpu_add_op(var, val) 245 #define percpu_sub(var, val) percpu_add_op(var, -(val)) 246 #define percpu_and(var, val) percpu_to_op("and", var, val) 247 #define percpu_or(var, val) percpu_to_op("or", var, val) 248 #define percpu_xor(var, val) percpu_to_op("xor", var, val) 249 #define percpu_inc(var) percpu_unary_op("inc", var) 250 251 #define __this_cpu_read_1(pcp) percpu_from_op("mov", (pcp), "m"(pcp)) 252 #define __this_cpu_read_2(pcp) percpu_from_op("mov", (pcp), "m"(pcp)) 253 #define __this_cpu_read_4(pcp) percpu_from_op("mov", (pcp), "m"(pcp)) 254 255 #define __this_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val) 256 #define __this_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val) 257 #define __this_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val) 258 #define __this_cpu_add_1(pcp, val) percpu_add_op((pcp), val) 259 #define __this_cpu_add_2(pcp, val) percpu_add_op((pcp), val) 260 #define __this_cpu_add_4(pcp, val) percpu_add_op((pcp), val) 261 #define __this_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val) 262 #define __this_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val) 263 #define __this_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val) 264 #define __this_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val) 265 #define __this_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val) 266 #define __this_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val) 267 #define __this_cpu_xor_1(pcp, val) percpu_to_op("xor", (pcp), val) 268 #define __this_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val) 269 #define __this_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val) 270 271 #define this_cpu_read_1(pcp) percpu_from_op("mov", (pcp), "m"(pcp)) 272 #define this_cpu_read_2(pcp) percpu_from_op("mov", (pcp), "m"(pcp)) 273 #define this_cpu_read_4(pcp) percpu_from_op("mov", (pcp), "m"(pcp)) 274 #define this_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val) 275 #define this_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val) 276 #define this_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val) 277 #define this_cpu_add_1(pcp, val) percpu_add_op((pcp), val) 278 #define this_cpu_add_2(pcp, val) percpu_add_op((pcp), val) 279 #define this_cpu_add_4(pcp, val) percpu_add_op((pcp), val) 280 #define this_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val) 281 #define this_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val) 282 #define this_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val) 283 #define this_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val) 284 #define this_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val) 285 #define this_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val) 286 #define this_cpu_xor_1(pcp, val) percpu_to_op("xor", (pcp), val) 287 #define this_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val) 288 #define this_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val) 289 290 #define irqsafe_cpu_add_1(pcp, val) percpu_add_op((pcp), val) 291 #define irqsafe_cpu_add_2(pcp, val) percpu_add_op((pcp), val) 292 #define irqsafe_cpu_add_4(pcp, val) percpu_add_op((pcp), val) 293 #define irqsafe_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val) 294 #define irqsafe_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val) 295 #define irqsafe_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val) 296 #define irqsafe_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val) 297 #define irqsafe_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val) 298 #define irqsafe_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val) 299 #define irqsafe_cpu_xor_1(pcp, val) percpu_to_op("xor", (pcp), val) 300 #define irqsafe_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val) 301 #define irqsafe_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val) 302 303 /* 304 * Per cpu atomic 64 bit operations are only available under 64 bit. 305 * 32 bit must fall back to generic operations. 306 */ 307 #ifdef CONFIG_X86_64 308 #define __this_cpu_read_8(pcp) percpu_from_op("mov", (pcp), "m"(pcp)) 309 #define __this_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val) 310 #define __this_cpu_add_8(pcp, val) percpu_add_op((pcp), val) 311 #define __this_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val) 312 #define __this_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val) 313 #define __this_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val) 314 315 #define this_cpu_read_8(pcp) percpu_from_op("mov", (pcp), "m"(pcp)) 316 #define this_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val) 317 #define this_cpu_add_8(pcp, val) percpu_add_op((pcp), val) 318 #define this_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val) 319 #define this_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val) 320 #define this_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val) 321 322 #define irqsafe_cpu_add_8(pcp, val) percpu_add_op((pcp), val) 323 #define irqsafe_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val) 324 #define irqsafe_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val) 325 #define irqsafe_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val) 326 327 #endif 328 329 /* This is not atomic against other CPUs -- CPU preemption needs to be off */ 330 #define x86_test_and_clear_bit_percpu(bit, var) \ 331 ({ \ 332 int old__; \ 333 asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0" \ 334 : "=r" (old__), "+m" (var) \ 335 : "dIr" (bit)); \ 336 old__; \ 337 }) 338 339 #include <asm-generic/percpu.h> 340 341 /* We can use this directly for local CPU (faster). */ 342 DECLARE_PER_CPU(unsigned long, this_cpu_off); 343 344 #endif /* !__ASSEMBLY__ */ 345 346 #ifdef CONFIG_SMP 347 348 /* 349 * Define the "EARLY_PER_CPU" macros. These are used for some per_cpu 350 * variables that are initialized and accessed before there are per_cpu 351 * areas allocated. 352 */ 353 354 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \ 355 DEFINE_PER_CPU(_type, _name) = _initvalue; \ 356 __typeof__(_type) _name##_early_map[NR_CPUS] __initdata = \ 357 { [0 ... NR_CPUS-1] = _initvalue }; \ 358 __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map 359 360 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \ 361 EXPORT_PER_CPU_SYMBOL(_name) 362 363 #define DECLARE_EARLY_PER_CPU(_type, _name) \ 364 DECLARE_PER_CPU(_type, _name); \ 365 extern __typeof__(_type) *_name##_early_ptr; \ 366 extern __typeof__(_type) _name##_early_map[] 367 368 #define early_per_cpu_ptr(_name) (_name##_early_ptr) 369 #define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx]) 370 #define early_per_cpu(_name, _cpu) \ 371 *(early_per_cpu_ptr(_name) ? \ 372 &early_per_cpu_ptr(_name)[_cpu] : \ 373 &per_cpu(_name, _cpu)) 374 375 #else /* !CONFIG_SMP */ 376 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \ 377 DEFINE_PER_CPU(_type, _name) = _initvalue 378 379 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \ 380 EXPORT_PER_CPU_SYMBOL(_name) 381 382 #define DECLARE_EARLY_PER_CPU(_type, _name) \ 383 DECLARE_PER_CPU(_type, _name) 384 385 #define early_per_cpu(_name, _cpu) per_cpu(_name, _cpu) 386 #define early_per_cpu_ptr(_name) NULL 387 /* no early_per_cpu_map() */ 388 389 #endif /* !CONFIG_SMP */ 390 391 #endif /* _ASM_X86_PERCPU_H */ 392