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/alternative.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, thread_info)), \
  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 #define xchg(ptr,v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v),(ptr),sizeof(*(ptr))))
 128
 129 #define tas(ptr) (xchg((ptr),1))
 130
 131 #define __xg(x) ((volatile long *)(x))
 132
 133 static inline void set_64bit(volatile unsigned long *ptr, unsigned long val)
 134 {
 135         *ptr = val;
 136 }
 137
 138 #define _set_64bit set_64bit
 139
 140 /*
 141  * Note: no "lock" prefix even on SMP: xchg always implies lock anyway
 142  * Note 2: xchg has side effect, so that attribute volatile is necessary,
 143  *        but generally the primitive is invalid, *ptr is output argument. --ANK
 144  */
 145 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
 146 {
 147         switch (size) {
 148                 case 1:
 149                         __asm__ __volatile__("xchgb %b0,%1"
 150                                 :"=q" (x)
 151                                 :"m" (*__xg(ptr)), "0" (x)
 152                                 :"memory");
 153                         break;
 154                 case 2:
 155                         __asm__ __volatile__("xchgw %w0,%1"
 156                                 :"=r" (x)
 157                                 :"m" (*__xg(ptr)), "0" (x)
 158                                 :"memory");
 159                         break;
 160                 case 4:
 161                         __asm__ __volatile__("xchgl %k0,%1"
 162                                 :"=r" (x)
 163                                 :"m" (*__xg(ptr)), "0" (x)
 164                                 :"memory");
 165                         break;
 166                 case 8:
 167                         __asm__ __volatile__("xchgq %0,%1"
 168                                 :"=r" (x)
 169                                 :"m" (*__xg(ptr)), "0" (x)
 170                                 :"memory");
 171                         break;
 172         }
 173         return x;
 174 }
 175
 176 /*
 177  * Atomic compare and exchange.  Compare OLD with MEM, if identical,
 178  * store NEW in MEM.  Return the initial value in MEM.  Success is
 179  * indicated by comparing RETURN with OLD.
 180  */
 181
 182 #define __HAVE_ARCH_CMPXCHG 1
 183
 184 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
 185                                       unsigned long new, int size)
 186 {
 187         unsigned long prev;
 188         switch (size) {
 189         case 1:
 190                 __asm__ __volatile__(LOCK_PREFIX "cmpxchgb %b1,%2"
 191                                      : "=a"(prev)
 192                                      : "q"(new), "m"(*__xg(ptr)), "0"(old)
 193                                      : "memory");
 194                 return prev;
 195         case 2:
 196                 __asm__ __volatile__(LOCK_PREFIX "cmpxchgw %w1,%2"
 197                                      : "=a"(prev)
 198                                      : "r"(new), "m"(*__xg(ptr)), "0"(old)
 199                                      : "memory");
 200                 return prev;
 201         case 4:
 202                 __asm__ __volatile__(LOCK_PREFIX "cmpxchgl %k1,%2"
 203                                      : "=a"(prev)
 204                                      : "r"(new), "m"(*__xg(ptr)), "0"(old)
 205                                      : "memory");
 206                 return prev;
 207         case 8:
 208                 __asm__ __volatile__(LOCK_PREFIX "cmpxchgq %1,%2"
 209                                      : "=a"(prev)
 210                                      : "r"(new), "m"(*__xg(ptr)), "0"(old)
 211                                      : "memory");
 212                 return prev;
 213         }
 214         return old;
 215 }
 216
 217 #define cmpxchg(ptr,o,n)\
 218         ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
 219                                         (unsigned long)(n),sizeof(*(ptr))))
 220
 221 #ifdef CONFIG_SMP
 222 #define smp_mb()        mb()
 223 #define smp_rmb()       rmb()
 224 #define smp_wmb()       wmb()
 225 #define smp_read_barrier_depends()      do {} while(0)
 226 #else
 227 #define smp_mb()        barrier()
 228 #define smp_rmb()       barrier()
 229 #define smp_wmb()       barrier()
 230 #define smp_read_barrier_depends()      do {} while(0)
 231 #endif
 232
 233
 234 /*
 235  * Force strict CPU ordering.
 236  * And yes, this is required on UP too when we're talking
 237  * to devices.
 238  */
 239 #define mb()    asm volatile("mfence":::"memory")
 240 #define rmb()   asm volatile("lfence":::"memory")
 241
 242 #ifdef CONFIG_UNORDERED_IO
 243 #define wmb()   asm volatile("sfence" ::: "memory")
 244 #else
 245 #define wmb()   asm volatile("" ::: "memory")
 246 #endif
 247 #define read_barrier_depends()  do {} while(0)
 248 #define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
 249
 250 #define warn_if_not_ulong(x) do { unsigned long foo; (void) (&(x) == &foo); } while (0)
 251
 252 #include <linux/irqflags.h>
 253
 254 void cpu_idle_wait(void);
 255
 256 extern unsigned long arch_align_stack(unsigned long sp);
 257 extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
 258
 259 #endif