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