system.h 6.4 KB

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  1. #ifndef __ASM_SYSTEM_H
  2. #define __ASM_SYSTEM_H
  3. #include <linux/kernel.h>
  4. #include <asm/segment.h>
  5. #include <asm/alternative.h>
  6. #ifdef __KERNEL__
  7. #define __STR(x) #x
  8. #define STR(x) __STR(x)
  9. #define __SAVE(reg,offset) "movq %%" #reg ",(14-" #offset ")*8(%%rsp)\n\t"
  10. #define __RESTORE(reg,offset) "movq (14-" #offset ")*8(%%rsp),%%" #reg "\n\t"
  11. /* frame pointer must be last for get_wchan */
  12. #define SAVE_CONTEXT "pushq %%rbp ; movq %%rsi,%%rbp\n\t"
  13. #define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp\n\t"
  14. #define __EXTRA_CLOBBER \
  15. ,"rcx","rbx","rdx","r8","r9","r10","r11","r12","r13","r14","r15"
  16. #define switch_to(prev,next,last) \
  17. asm volatile(SAVE_CONTEXT \
  18. "movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */ \
  19. "movq %P[threadrsp](%[next]),%%rsp\n\t" /* restore RSP */ \
  20. "call __switch_to\n\t" \
  21. ".globl thread_return\n" \
  22. "thread_return:\n\t" \
  23. "movq %%gs:%P[pda_pcurrent],%%rsi\n\t" \
  24. "movq %P[thread_info](%%rsi),%%r8\n\t" \
  25. LOCK_PREFIX "btr %[tif_fork],%P[ti_flags](%%r8)\n\t" \
  26. "movq %%rax,%%rdi\n\t" \
  27. "jc ret_from_fork\n\t" \
  28. RESTORE_CONTEXT \
  29. : "=a" (last) \
  30. : [next] "S" (next), [prev] "D" (prev), \
  31. [threadrsp] "i" (offsetof(struct task_struct, thread.rsp)), \
  32. [ti_flags] "i" (offsetof(struct thread_info, flags)),\
  33. [tif_fork] "i" (TIF_FORK), \
  34. [thread_info] "i" (offsetof(struct task_struct, thread_info)), \
  35. [pda_pcurrent] "i" (offsetof(struct x8664_pda, pcurrent)) \
  36. : "memory", "cc" __EXTRA_CLOBBER)
  37. extern void load_gs_index(unsigned);
  38. /*
  39. * Load a segment. Fall back on loading the zero
  40. * segment if something goes wrong..
  41. */
  42. #define loadsegment(seg,value) \
  43. asm volatile("\n" \
  44. "1:\t" \
  45. "movl %k0,%%" #seg "\n" \
  46. "2:\n" \
  47. ".section .fixup,\"ax\"\n" \
  48. "3:\t" \
  49. "movl %1,%%" #seg "\n\t" \
  50. "jmp 2b\n" \
  51. ".previous\n" \
  52. ".section __ex_table,\"a\"\n\t" \
  53. ".align 8\n\t" \
  54. ".quad 1b,3b\n" \
  55. ".previous" \
  56. : :"r" (value), "r" (0))
  57. /*
  58. * Clear and set 'TS' bit respectively
  59. */
  60. #define clts() __asm__ __volatile__ ("clts")
  61. static inline unsigned long read_cr0(void)
  62. {
  63. unsigned long cr0;
  64. asm volatile("movq %%cr0,%0" : "=r" (cr0));
  65. return cr0;
  66. }
  67. static inline void write_cr0(unsigned long val)
  68. {
  69. asm volatile("movq %0,%%cr0" :: "r" (val));
  70. }
  71. static inline unsigned long read_cr3(void)
  72. {
  73. unsigned long cr3;
  74. asm("movq %%cr3,%0" : "=r" (cr3));
  75. return cr3;
  76. }
  77. static inline unsigned long read_cr4(void)
  78. {
  79. unsigned long cr4;
  80. asm("movq %%cr4,%0" : "=r" (cr4));
  81. return cr4;
  82. }
  83. static inline void write_cr4(unsigned long val)
  84. {
  85. asm volatile("movq %0,%%cr4" :: "r" (val));
  86. }
  87. #define stts() write_cr0(8 | read_cr0())
  88. #define wbinvd() \
  89. __asm__ __volatile__ ("wbinvd": : :"memory");
  90. /*
  91. * On SMP systems, when the scheduler does migration-cost autodetection,
  92. * it needs a way to flush as much of the CPU's caches as possible.
  93. */
  94. static inline void sched_cacheflush(void)
  95. {
  96. wbinvd();
  97. }
  98. #endif /* __KERNEL__ */
  99. #define nop() __asm__ __volatile__ ("nop")
  100. #define xchg(ptr,v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v),(ptr),sizeof(*(ptr))))
  101. #define tas(ptr) (xchg((ptr),1))
  102. #define __xg(x) ((volatile long *)(x))
  103. static inline void set_64bit(volatile unsigned long *ptr, unsigned long val)
  104. {
  105. *ptr = val;
  106. }
  107. #define _set_64bit set_64bit
  108. /*
  109. * Note: no "lock" prefix even on SMP: xchg always implies lock anyway
  110. * Note 2: xchg has side effect, so that attribute volatile is necessary,
  111. * but generally the primitive is invalid, *ptr is output argument. --ANK
  112. */
  113. static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
  114. {
  115. switch (size) {
  116. case 1:
  117. __asm__ __volatile__("xchgb %b0,%1"
  118. :"=q" (x)
  119. :"m" (*__xg(ptr)), "0" (x)
  120. :"memory");
  121. break;
  122. case 2:
  123. __asm__ __volatile__("xchgw %w0,%1"
  124. :"=r" (x)
  125. :"m" (*__xg(ptr)), "0" (x)
  126. :"memory");
  127. break;
  128. case 4:
  129. __asm__ __volatile__("xchgl %k0,%1"
  130. :"=r" (x)
  131. :"m" (*__xg(ptr)), "0" (x)
  132. :"memory");
  133. break;
  134. case 8:
  135. __asm__ __volatile__("xchgq %0,%1"
  136. :"=r" (x)
  137. :"m" (*__xg(ptr)), "0" (x)
  138. :"memory");
  139. break;
  140. }
  141. return x;
  142. }
  143. /*
  144. * Atomic compare and exchange. Compare OLD with MEM, if identical,
  145. * store NEW in MEM. Return the initial value in MEM. Success is
  146. * indicated by comparing RETURN with OLD.
  147. */
  148. #define __HAVE_ARCH_CMPXCHG 1
  149. static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
  150. unsigned long new, int size)
  151. {
  152. unsigned long prev;
  153. switch (size) {
  154. case 1:
  155. __asm__ __volatile__(LOCK_PREFIX "cmpxchgb %b1,%2"
  156. : "=a"(prev)
  157. : "q"(new), "m"(*__xg(ptr)), "0"(old)
  158. : "memory");
  159. return prev;
  160. case 2:
  161. __asm__ __volatile__(LOCK_PREFIX "cmpxchgw %w1,%2"
  162. : "=a"(prev)
  163. : "r"(new), "m"(*__xg(ptr)), "0"(old)
  164. : "memory");
  165. return prev;
  166. case 4:
  167. __asm__ __volatile__(LOCK_PREFIX "cmpxchgl %k1,%2"
  168. : "=a"(prev)
  169. : "r"(new), "m"(*__xg(ptr)), "0"(old)
  170. : "memory");
  171. return prev;
  172. case 8:
  173. __asm__ __volatile__(LOCK_PREFIX "cmpxchgq %1,%2"
  174. : "=a"(prev)
  175. : "r"(new), "m"(*__xg(ptr)), "0"(old)
  176. : "memory");
  177. return prev;
  178. }
  179. return old;
  180. }
  181. #define cmpxchg(ptr,o,n)\
  182. ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
  183. (unsigned long)(n),sizeof(*(ptr))))
  184. #ifdef CONFIG_SMP
  185. #define smp_mb() mb()
  186. #define smp_rmb() rmb()
  187. #define smp_wmb() wmb()
  188. #define smp_read_barrier_depends() do {} while(0)
  189. #else
  190. #define smp_mb() barrier()
  191. #define smp_rmb() barrier()
  192. #define smp_wmb() barrier()
  193. #define smp_read_barrier_depends() do {} while(0)
  194. #endif
  195. /*
  196. * Force strict CPU ordering.
  197. * And yes, this is required on UP too when we're talking
  198. * to devices.
  199. */
  200. #define mb() asm volatile("mfence":::"memory")
  201. #define rmb() asm volatile("lfence":::"memory")
  202. #ifdef CONFIG_UNORDERED_IO
  203. #define wmb() asm volatile("sfence" ::: "memory")
  204. #else
  205. #define wmb() asm volatile("" ::: "memory")
  206. #endif
  207. #define read_barrier_depends() do {} while(0)
  208. #define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
  209. #define set_wmb(var, value) do { var = value; wmb(); } while (0)
  210. #define warn_if_not_ulong(x) do { unsigned long foo; (void) (&(x) == &foo); } while (0)
  211. #include <linux/irqflags.h>
  212. void cpu_idle_wait(void);
  213. extern unsigned long arch_align_stack(unsigned long sp);
  214. extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
  215. #endif