include/asm-x86_64/system.h

   1 #ifndef __ASM_SYSTEM_H
   2 #define __ASM_SYSTEM_H
   3
   4 #include <linux/kernel.h>
   5 #include <asm/segment.h>
   6 #include <asm/cmpxchg.h>
   7
   8 #ifdef __KERNEL__
   9
  10 #define __STR(x) #x
  11 #define STR(x) __STR(x)
  12
  13 #define __SAVE(reg,offset) "movq %%" #reg ",(14-" #offset ")*8(%%rsp)\n\t"
  14 #define __RESTORE(reg,offset) "movq (14-" #offset ")*8(%%rsp),%%" #reg "\n\t"
  15
  16 /* frame pointer must be last for get_wchan */
  17 #define SAVE_CONTEXT    "pushf ; pushq %%rbp ; movq %%rsi,%%rbp\n\t"
  18 #define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp ; popf\t"
  19
  20 #define __EXTRA_CLOBBER  \
  21         ,"rcx","rbx","rdx","r8","r9","r10","r11","r12","r13","r14","r15"
  22
  23 /* Save restore flags to clear handle leaking NT */
  24 #define switch_to(prev,next,last) \
  25         asm volatile(SAVE_CONTEXT                                                   \
  26                      "movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */       \
  27                      "movq %P[threadrsp](%[next]),%%rsp\n\t" /* restore RSP */    \
  28                      "call __switch_to\n\t"                                       \
  29                      ".globl thread_return\n"                                   \
  30                      "thread_return:\n\t"                                           \
  31                      "movq %%gs:%P[pda_pcurrent],%%rsi\n\t"                       \
  32                      "movq %P[thread_info](%%rsi),%%r8\n\t"                       \
  33                      LOCK_PREFIX "btr  %[tif_fork],%P[ti_flags](%%r8)\n\t"        \
  34                      "movq %%rax,%%rdi\n\t"                                       \
  35                      "jc   ret_from_fork\n\t"                                     \
  36                      RESTORE_CONTEXT                                                \
  37                      : "=a" (last)                                                \
  38                      : [next] "S" (next), [prev] "D" (prev),                      \
  39                        [threadrsp] "i" (offsetof(struct task_struct, thread.rsp)), \
  40                        [ti_flags] "i" (offsetof(struct thread_info, flags)),\
  41                        [tif_fork] "i" (TIF_FORK),                         \
  42                        [thread_info] "i" (offsetof(struct task_struct, stack)), \
  43                        [pda_pcurrent] "i" (offsetof(struct x8664_pda, pcurrent))   \
  44                      : "memory", "cc" __EXTRA_CLOBBER)
  45
  46 extern void load_gs_index(unsigned);
  47
  48 /*
  49  * Load a segment. Fall back on loading the zero
  50  * segment if something goes wrong..
  51  */
  52 #define loadsegment(seg,value)  \
  53         asm volatile("\n"                       \
  54                 "1:\t"                          \
  55                 "movl %k0,%%" #seg "\n"         \
  56                 "2:\n"                          \
  57                 ".section .fixup,\"ax\"\n"      \
  58                 "3:\t"                          \
  59                 "movl %1,%%" #seg "\n\t"        \
  60                 "jmp 2b\n"                      \
  61                 ".previous\n"                   \
  62                 ".section __ex_table,\"a\"\n\t" \
  63                 ".align 8\n\t"                  \
  64                 ".quad 1b,3b\n"                 \
  65                 ".previous"                     \
  66                 : :"r" (value), "r" (0))
  67
  68 /*
  69  * Clear and set 'TS' bit respectively
  70  */
  71 #define clts() __asm__ __volatile__ ("clts")
  72
  73 static inline unsigned long read_cr0(void)
  74 {
  75         unsigned long cr0;
  76         asm volatile("movq %%cr0,%0" : "=r" (cr0));
  77         return cr0;
  78 }
  79
  80 static inline void write_cr0(unsigned long val)
  81 {
  82         asm volatile("movq %0,%%cr0" :: "r" (val));
  83 }
  84
  85 static inline unsigned long read_cr3(void)
  86 {
  87         unsigned long cr3;
  88         asm("movq %%cr3,%0" : "=r" (cr3));
  89         return cr3;
  90 }
  91
  92 static inline void write_cr3(unsigned long val)
  93 {
  94         asm volatile("movq %0,%%cr3" :: "r" (val) : "memory");
  95 }
  96
  97 static inline unsigned long read_cr4(void)
  98 {
  99         unsigned long cr4;
 100         asm("movq %%cr4,%0" : "=r" (cr4));
 101         return cr4;
 102 }
 103
 104 static inline void write_cr4(unsigned long val)
 105 {
 106         asm volatile("movq %0,%%cr4" :: "r" (val) : "memory");
 107 }
 108
 109 #define stts() write_cr0(8 | read_cr0())
 110
 111 #define wbinvd() \
 112         __asm__ __volatile__ ("wbinvd": : :"memory");
 113
 114 /*
 115  * On SMP systems, when the scheduler does migration-cost autodetection,
 116  * it needs a way to flush as much of the CPU's caches as possible.
 117  */
 118 static inline void sched_cacheflush(void)
 119 {
 120         wbinvd();
 121 }
 122
 123 #endif  /* __KERNEL__ */
 124
 125 #define nop() __asm__ __volatile__ ("nop")
 126
 127 #ifdef CONFIG_SMP
 128 #define smp_mb()        mb()
 129 #define smp_rmb()       rmb()
 130 #define smp_wmb()       wmb()
 131 #define smp_read_barrier_depends()      do {} while(0)
 132 #else
 133 #define smp_mb()        barrier()
 134 #define smp_rmb()       barrier()
 135 #define smp_wmb()       barrier()
 136 #define smp_read_barrier_depends()      do {} while(0)
 137 #endif
 138
 139
 140 /*
 141  * Force strict CPU ordering.
 142  * And yes, this is required on UP too when we're talking
 143  * to devices.
 144  */
 145 #define mb()    asm volatile("mfence":::"memory")
 146 #define rmb()   asm volatile("lfence":::"memory")
 147
 148 #ifdef CONFIG_UNORDERED_IO
 149 #define wmb()   asm volatile("sfence" ::: "memory")
 150 #else
 151 #define wmb()   asm volatile("" ::: "memory")
 152 #endif
 153 #define read_barrier_depends()  do {} while(0)
 154 #define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
 155
 156 #define warn_if_not_ulong(x) do { unsigned long foo; (void) (&(x) == &foo); } while (0)
 157
 158 #include <linux/irqflags.h>
 159
 160 void cpu_idle_wait(void);
 161
 162 extern unsigned long arch_align_stack(unsigned long sp);
 163 extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
 164
 165 #endif