percpu.h 12 KB

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