system.h 6.6 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 "pushf ; pushq %%rbp ; movq %%rsi,%%rbp\n\t"
  13. #define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp ; popf\t"
  14. #define __EXTRA_CLOBBER \
  15. ,"rcx","rbx","rdx","r8","r9","r10","r11","r12","r13","r14","r15"
  16. /* Save restore flags to clear handle leaking NT */
  17. #define switch_to(prev,next,last) \
  18. asm volatile(SAVE_CONTEXT \
  19. "movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */ \
  20. "movq %P[threadrsp](%[next]),%%rsp\n\t" /* restore RSP */ \
  21. "call __switch_to\n\t" \
  22. ".globl thread_return\n" \
  23. "thread_return:\n\t" \
  24. "movq %%gs:%P[pda_pcurrent],%%rsi\n\t" \
  25. "movq %P[thread_info](%%rsi),%%r8\n\t" \
  26. LOCK_PREFIX "btr %[tif_fork],%P[ti_flags](%%r8)\n\t" \
  27. "movq %%rax,%%rdi\n\t" \
  28. "jc ret_from_fork\n\t" \
  29. RESTORE_CONTEXT \
  30. : "=a" (last) \
  31. : [next] "S" (next), [prev] "D" (prev), \
  32. [threadrsp] "i" (offsetof(struct task_struct, thread.rsp)), \
  33. [ti_flags] "i" (offsetof(struct thread_info, flags)),\
  34. [tif_fork] "i" (TIF_FORK), \
  35. [thread_info] "i" (offsetof(struct task_struct, thread_info)), \
  36. [pda_pcurrent] "i" (offsetof(struct x8664_pda, pcurrent)) \
  37. : "memory", "cc" __EXTRA_CLOBBER)
  38. extern void load_gs_index(unsigned);
  39. /*
  40. * Load a segment. Fall back on loading the zero
  41. * segment if something goes wrong..
  42. */
  43. #define loadsegment(seg,value) \
  44. asm volatile("\n" \
  45. "1:\t" \
  46. "movl %k0,%%" #seg "\n" \
  47. "2:\n" \
  48. ".section .fixup,\"ax\"\n" \
  49. "3:\t" \
  50. "movl %1,%%" #seg "\n\t" \
  51. "jmp 2b\n" \
  52. ".previous\n" \
  53. ".section __ex_table,\"a\"\n\t" \
  54. ".align 8\n\t" \
  55. ".quad 1b,3b\n" \
  56. ".previous" \
  57. : :"r" (value), "r" (0))
  58. /*
  59. * Clear and set 'TS' bit respectively
  60. */
  61. #define clts() __asm__ __volatile__ ("clts")
  62. static inline unsigned long read_cr0(void)
  63. {
  64. unsigned long cr0;
  65. asm volatile("movq %%cr0,%0" : "=r" (cr0));
  66. return cr0;
  67. }
  68. static inline void write_cr0(unsigned long val)
  69. {
  70. asm volatile("movq %0,%%cr0" :: "r" (val));
  71. }
  72. static inline unsigned long read_cr3(void)
  73. {
  74. unsigned long cr3;
  75. asm("movq %%cr3,%0" : "=r" (cr3));
  76. return cr3;
  77. }
  78. static inline void write_cr3(unsigned long val)
  79. {
  80. asm volatile("movq %0,%%cr3" :: "r" (val) : "memory");
  81. }
  82. static inline unsigned long read_cr4(void)
  83. {
  84. unsigned long cr4;
  85. asm("movq %%cr4,%0" : "=r" (cr4));
  86. return cr4;
  87. }
  88. static inline void write_cr4(unsigned long val)
  89. {
  90. asm volatile("movq %0,%%cr4" :: "r" (val) : "memory");
  91. }
  92. #define stts() write_cr0(8 | read_cr0())
  93. #define wbinvd() \
  94. __asm__ __volatile__ ("wbinvd": : :"memory");
  95. /*
  96. * On SMP systems, when the scheduler does migration-cost autodetection,
  97. * it needs a way to flush as much of the CPU's caches as possible.
  98. */
  99. static inline void sched_cacheflush(void)
  100. {
  101. wbinvd();
  102. }
  103. #endif /* __KERNEL__ */
  104. #define nop() __asm__ __volatile__ ("nop")
  105. #define xchg(ptr,v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v),(ptr),sizeof(*(ptr))))
  106. #define tas(ptr) (xchg((ptr),1))
  107. #define __xg(x) ((volatile long *)(x))
  108. static inline void set_64bit(volatile unsigned long *ptr, unsigned long val)
  109. {
  110. *ptr = val;
  111. }
  112. #define _set_64bit set_64bit
  113. /*
  114. * Note: no "lock" prefix even on SMP: xchg always implies lock anyway
  115. * Note 2: xchg has side effect, so that attribute volatile is necessary,
  116. * but generally the primitive is invalid, *ptr is output argument. --ANK
  117. */
  118. static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
  119. {
  120. switch (size) {
  121. case 1:
  122. __asm__ __volatile__("xchgb %b0,%1"
  123. :"=q" (x)
  124. :"m" (*__xg(ptr)), "0" (x)
  125. :"memory");
  126. break;
  127. case 2:
  128. __asm__ __volatile__("xchgw %w0,%1"
  129. :"=r" (x)
  130. :"m" (*__xg(ptr)), "0" (x)
  131. :"memory");
  132. break;
  133. case 4:
  134. __asm__ __volatile__("xchgl %k0,%1"
  135. :"=r" (x)
  136. :"m" (*__xg(ptr)), "0" (x)
  137. :"memory");
  138. break;
  139. case 8:
  140. __asm__ __volatile__("xchgq %0,%1"
  141. :"=r" (x)
  142. :"m" (*__xg(ptr)), "0" (x)
  143. :"memory");
  144. break;
  145. }
  146. return x;
  147. }
  148. /*
  149. * Atomic compare and exchange. Compare OLD with MEM, if identical,
  150. * store NEW in MEM. Return the initial value in MEM. Success is
  151. * indicated by comparing RETURN with OLD.
  152. */
  153. #define __HAVE_ARCH_CMPXCHG 1
  154. static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
  155. unsigned long new, int size)
  156. {
  157. unsigned long prev;
  158. switch (size) {
  159. case 1:
  160. __asm__ __volatile__(LOCK_PREFIX "cmpxchgb %b1,%2"
  161. : "=a"(prev)
  162. : "q"(new), "m"(*__xg(ptr)), "0"(old)
  163. : "memory");
  164. return prev;
  165. case 2:
  166. __asm__ __volatile__(LOCK_PREFIX "cmpxchgw %w1,%2"
  167. : "=a"(prev)
  168. : "r"(new), "m"(*__xg(ptr)), "0"(old)
  169. : "memory");
  170. return prev;
  171. case 4:
  172. __asm__ __volatile__(LOCK_PREFIX "cmpxchgl %k1,%2"
  173. : "=a"(prev)
  174. : "r"(new), "m"(*__xg(ptr)), "0"(old)
  175. : "memory");
  176. return prev;
  177. case 8:
  178. __asm__ __volatile__(LOCK_PREFIX "cmpxchgq %1,%2"
  179. : "=a"(prev)
  180. : "r"(new), "m"(*__xg(ptr)), "0"(old)
  181. : "memory");
  182. return prev;
  183. }
  184. return old;
  185. }
  186. #define cmpxchg(ptr,o,n)\
  187. ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
  188. (unsigned long)(n),sizeof(*(ptr))))
  189. #ifdef CONFIG_SMP
  190. #define smp_mb() mb()
  191. #define smp_rmb() rmb()
  192. #define smp_wmb() wmb()
  193. #define smp_read_barrier_depends() do {} while(0)
  194. #else
  195. #define smp_mb() barrier()
  196. #define smp_rmb() barrier()
  197. #define smp_wmb() barrier()
  198. #define smp_read_barrier_depends() do {} while(0)
  199. #endif
  200. /*
  201. * Force strict CPU ordering.
  202. * And yes, this is required on UP too when we're talking
  203. * to devices.
  204. */
  205. #define mb() asm volatile("mfence":::"memory")
  206. #define rmb() asm volatile("lfence":::"memory")
  207. #ifdef CONFIG_UNORDERED_IO
  208. #define wmb() asm volatile("sfence" ::: "memory")
  209. #else
  210. #define wmb() asm volatile("" ::: "memory")
  211. #endif
  212. #define read_barrier_depends() do {} while(0)
  213. #define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
  214. #define warn_if_not_ulong(x) do { unsigned long foo; (void) (&(x) == &foo); } while (0)
  215. #include <linux/irqflags.h>
  216. void cpu_idle_wait(void);
  217. extern unsigned long arch_align_stack(unsigned long sp);
  218. extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
  219. #endif