percpu.h revision db7829c6cc32f3c0c9a324118d743acb1abff081
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). */ 86extern void __bad_percpu_size(void); 87 88#define percpu_to_op(op, var, val) \ 89do { \ 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) \ 126do { \ 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). */ 342DECLARE_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