percpu.h 7.3 KB

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  1. /*
  2. * Copyright (C) 2013 ARM Ltd.
  3. *
  4. * This program is free software; you can redistribute it and/or modify
  5. * it under the terms of the GNU General Public License version 2 as
  6. * published by the Free Software Foundation.
  7. *
  8. * This program is distributed in the hope that it will be useful,
  9. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11. * GNU General Public License for more details.
  12. *
  13. * You should have received a copy of the GNU General Public License
  14. * along with this program. If not, see <http://www.gnu.org/licenses/>.
  15. */
  16. #ifndef __ASM_PERCPU_H
  17. #define __ASM_PERCPU_H
  18. #include <asm/stack_pointer.h>
  19. static inline void set_my_cpu_offset(unsigned long off)
  20. {
  21. asm volatile("msr tpidr_el1, %0" :: "r" (off) : "memory");
  22. }
  23. static inline unsigned long __my_cpu_offset(void)
  24. {
  25. unsigned long off;
  26. /*
  27. * We want to allow caching the value, so avoid using volatile and
  28. * instead use a fake stack read to hazard against barrier().
  29. */
  30. asm("mrs %0, tpidr_el1" : "=r" (off) :
  31. "Q" (*(const unsigned long *)current_stack_pointer));
  32. return off;
  33. }
  34. #define __my_cpu_offset __my_cpu_offset()
  35. #define PERCPU_OP(op, asm_op) \
  36. static inline unsigned long __percpu_##op(void *ptr, \
  37. unsigned long val, int size) \
  38. { \
  39. unsigned long loop, ret; \
  40. \
  41. switch (size) { \
  42. case 1: \
  43. asm ("//__per_cpu_" #op "_1\n" \
  44. "1: ldxrb %w[ret], %[ptr]\n" \
  45. #asm_op " %w[ret], %w[ret], %w[val]\n" \
  46. " stxrb %w[loop], %w[ret], %[ptr]\n" \
  47. " cbnz %w[loop], 1b" \
  48. : [loop] "=&r" (loop), [ret] "=&r" (ret), \
  49. [ptr] "+Q"(*(u8 *)ptr) \
  50. : [val] "Ir" (val)); \
  51. break; \
  52. case 2: \
  53. asm ("//__per_cpu_" #op "_2\n" \
  54. "1: ldxrh %w[ret], %[ptr]\n" \
  55. #asm_op " %w[ret], %w[ret], %w[val]\n" \
  56. " stxrh %w[loop], %w[ret], %[ptr]\n" \
  57. " cbnz %w[loop], 1b" \
  58. : [loop] "=&r" (loop), [ret] "=&r" (ret), \
  59. [ptr] "+Q"(*(u16 *)ptr) \
  60. : [val] "Ir" (val)); \
  61. break; \
  62. case 4: \
  63. asm ("//__per_cpu_" #op "_4\n" \
  64. "1: ldxr %w[ret], %[ptr]\n" \
  65. #asm_op " %w[ret], %w[ret], %w[val]\n" \
  66. " stxr %w[loop], %w[ret], %[ptr]\n" \
  67. " cbnz %w[loop], 1b" \
  68. : [loop] "=&r" (loop), [ret] "=&r" (ret), \
  69. [ptr] "+Q"(*(u32 *)ptr) \
  70. : [val] "Ir" (val)); \
  71. break; \
  72. case 8: \
  73. asm ("//__per_cpu_" #op "_8\n" \
  74. "1: ldxr %[ret], %[ptr]\n" \
  75. #asm_op " %[ret], %[ret], %[val]\n" \
  76. " stxr %w[loop], %[ret], %[ptr]\n" \
  77. " cbnz %w[loop], 1b" \
  78. : [loop] "=&r" (loop), [ret] "=&r" (ret), \
  79. [ptr] "+Q"(*(u64 *)ptr) \
  80. : [val] "Ir" (val)); \
  81. break; \
  82. default: \
  83. BUILD_BUG(); \
  84. } \
  85. \
  86. return ret; \
  87. }
  88. PERCPU_OP(add, add)
  89. PERCPU_OP(and, and)
  90. PERCPU_OP(or, orr)
  91. #undef PERCPU_OP
  92. static inline unsigned long __percpu_read(void *ptr, int size)
  93. {
  94. unsigned long ret;
  95. switch (size) {
  96. case 1:
  97. ret = READ_ONCE(*(u8 *)ptr);
  98. break;
  99. case 2:
  100. ret = READ_ONCE(*(u16 *)ptr);
  101. break;
  102. case 4:
  103. ret = READ_ONCE(*(u32 *)ptr);
  104. break;
  105. case 8:
  106. ret = READ_ONCE(*(u64 *)ptr);
  107. break;
  108. default:
  109. BUILD_BUG();
  110. }
  111. return ret;
  112. }
  113. static inline void __percpu_write(void *ptr, unsigned long val, int size)
  114. {
  115. switch (size) {
  116. case 1:
  117. WRITE_ONCE(*(u8 *)ptr, (u8)val);
  118. break;
  119. case 2:
  120. WRITE_ONCE(*(u16 *)ptr, (u16)val);
  121. break;
  122. case 4:
  123. WRITE_ONCE(*(u32 *)ptr, (u32)val);
  124. break;
  125. case 8:
  126. WRITE_ONCE(*(u64 *)ptr, (u64)val);
  127. break;
  128. default:
  129. BUILD_BUG();
  130. }
  131. }
  132. static inline unsigned long __percpu_xchg(void *ptr, unsigned long val,
  133. int size)
  134. {
  135. unsigned long ret, loop;
  136. switch (size) {
  137. case 1:
  138. asm ("//__percpu_xchg_1\n"
  139. "1: ldxrb %w[ret], %[ptr]\n"
  140. " stxrb %w[loop], %w[val], %[ptr]\n"
  141. " cbnz %w[loop], 1b"
  142. : [loop] "=&r"(loop), [ret] "=&r"(ret),
  143. [ptr] "+Q"(*(u8 *)ptr)
  144. : [val] "r" (val));
  145. break;
  146. case 2:
  147. asm ("//__percpu_xchg_2\n"
  148. "1: ldxrh %w[ret], %[ptr]\n"
  149. " stxrh %w[loop], %w[val], %[ptr]\n"
  150. " cbnz %w[loop], 1b"
  151. : [loop] "=&r"(loop), [ret] "=&r"(ret),
  152. [ptr] "+Q"(*(u16 *)ptr)
  153. : [val] "r" (val));
  154. break;
  155. case 4:
  156. asm ("//__percpu_xchg_4\n"
  157. "1: ldxr %w[ret], %[ptr]\n"
  158. " stxr %w[loop], %w[val], %[ptr]\n"
  159. " cbnz %w[loop], 1b"
  160. : [loop] "=&r"(loop), [ret] "=&r"(ret),
  161. [ptr] "+Q"(*(u32 *)ptr)
  162. : [val] "r" (val));
  163. break;
  164. case 8:
  165. asm ("//__percpu_xchg_8\n"
  166. "1: ldxr %[ret], %[ptr]\n"
  167. " stxr %w[loop], %[val], %[ptr]\n"
  168. " cbnz %w[loop], 1b"
  169. : [loop] "=&r"(loop), [ret] "=&r"(ret),
  170. [ptr] "+Q"(*(u64 *)ptr)
  171. : [val] "r" (val));
  172. break;
  173. default:
  174. BUILD_BUG();
  175. }
  176. return ret;
  177. }
  178. #define _percpu_read(pcp) \
  179. ({ \
  180. typeof(pcp) __retval; \
  181. preempt_disable_notrace(); \
  182. __retval = (typeof(pcp))__percpu_read(raw_cpu_ptr(&(pcp)), \
  183. sizeof(pcp)); \
  184. preempt_enable_notrace(); \
  185. __retval; \
  186. })
  187. #define _percpu_write(pcp, val) \
  188. do { \
  189. preempt_disable_notrace(); \
  190. __percpu_write(raw_cpu_ptr(&(pcp)), (unsigned long)(val), \
  191. sizeof(pcp)); \
  192. preempt_enable_notrace(); \
  193. } while(0) \
  194. #define _pcp_protect(operation, pcp, val) \
  195. ({ \
  196. typeof(pcp) __retval; \
  197. preempt_disable(); \
  198. __retval = (typeof(pcp))operation(raw_cpu_ptr(&(pcp)), \
  199. (val), sizeof(pcp)); \
  200. preempt_enable(); \
  201. __retval; \
  202. })
  203. #define _percpu_add(pcp, val) \
  204. _pcp_protect(__percpu_add, pcp, val)
  205. #define _percpu_add_return(pcp, val) _percpu_add(pcp, val)
  206. #define _percpu_and(pcp, val) \
  207. _pcp_protect(__percpu_and, pcp, val)
  208. #define _percpu_or(pcp, val) \
  209. _pcp_protect(__percpu_or, pcp, val)
  210. #define _percpu_xchg(pcp, val) (typeof(pcp)) \
  211. _pcp_protect(__percpu_xchg, pcp, (unsigned long)(val))
  212. #define this_cpu_add_1(pcp, val) _percpu_add(pcp, val)
  213. #define this_cpu_add_2(pcp, val) _percpu_add(pcp, val)
  214. #define this_cpu_add_4(pcp, val) _percpu_add(pcp, val)
  215. #define this_cpu_add_8(pcp, val) _percpu_add(pcp, val)
  216. #define this_cpu_add_return_1(pcp, val) _percpu_add_return(pcp, val)
  217. #define this_cpu_add_return_2(pcp, val) _percpu_add_return(pcp, val)
  218. #define this_cpu_add_return_4(pcp, val) _percpu_add_return(pcp, val)
  219. #define this_cpu_add_return_8(pcp, val) _percpu_add_return(pcp, val)
  220. #define this_cpu_and_1(pcp, val) _percpu_and(pcp, val)
  221. #define this_cpu_and_2(pcp, val) _percpu_and(pcp, val)
  222. #define this_cpu_and_4(pcp, val) _percpu_and(pcp, val)
  223. #define this_cpu_and_8(pcp, val) _percpu_and(pcp, val)
  224. #define this_cpu_or_1(pcp, val) _percpu_or(pcp, val)
  225. #define this_cpu_or_2(pcp, val) _percpu_or(pcp, val)
  226. #define this_cpu_or_4(pcp, val) _percpu_or(pcp, val)
  227. #define this_cpu_or_8(pcp, val) _percpu_or(pcp, val)
  228. #define this_cpu_read_1(pcp) _percpu_read(pcp)
  229. #define this_cpu_read_2(pcp) _percpu_read(pcp)
  230. #define this_cpu_read_4(pcp) _percpu_read(pcp)
  231. #define this_cpu_read_8(pcp) _percpu_read(pcp)
  232. #define this_cpu_write_1(pcp, val) _percpu_write(pcp, val)
  233. #define this_cpu_write_2(pcp, val) _percpu_write(pcp, val)
  234. #define this_cpu_write_4(pcp, val) _percpu_write(pcp, val)
  235. #define this_cpu_write_8(pcp, val) _percpu_write(pcp, val)
  236. #define this_cpu_xchg_1(pcp, val) _percpu_xchg(pcp, val)
  237. #define this_cpu_xchg_2(pcp, val) _percpu_xchg(pcp, val)
  238. #define this_cpu_xchg_4(pcp, val) _percpu_xchg(pcp, val)
  239. #define this_cpu_xchg_8(pcp, val) _percpu_xchg(pcp, val)
  240. #include <asm-generic/percpu.h>
  241. #endif /* __ASM_PERCPU_H */