include/asm-x86/system_32.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/cpufeature.h>
   7 #include <asm/cmpxchg.h>
   8
   9 #ifdef __KERNEL__
  10 #define AT_VECTOR_SIZE_ARCH 2 /* entries in ARCH_DLINFO */
  11
  12 struct task_struct;     /* one of the stranger aspects of C forward declarations.. */
  13 extern struct task_struct * FASTCALL(__switch_to(struct task_struct *prev, struct task_struct *next));
  14
  15 /*
  16  * Saving eflags is important. It switches not only IOPL between tasks,
  17  * it also protects other tasks from NT leaking through sysenter etc.
  18  */
  19 #define switch_to(prev,next,last) do {                                  \
  20         unsigned long esi,edi;                                          \
  21         asm volatile("pushfl\n\t"               /* Save flags */        \
  22                      "pushl %%ebp\n\t"                                  \
  23                      "movl %%esp,%0\n\t"        /* save ESP */          \
  24                      "movl %5,%%esp\n\t"        /* restore ESP */       \
  25                      "movl $1f,%1\n\t"          /* save EIP */          \
  26                      "pushl %6\n\t"             /* restore EIP */       \
  27                      "jmp __switch_to\n"                                \
  28                      "1:\t"                                             \
  29                      "popl %%ebp\n\t"                                   \
  30                      "popfl"                                            \
  31                      :"=m" (prev->thread.esp),"=m" (prev->thread.eip),  \
  32                       "=a" (last),"=S" (esi),"=D" (edi)                 \
  33                      :"m" (next->thread.esp),"m" (next->thread.eip),    \
  34                       "2" (prev), "d" (next));                          \
  35 } while (0)
  36
  37 #define _set_base(addr,base) do { unsigned long __pr; \
  38 __asm__ __volatile__ ("movw %%dx,%1\n\t" \
  39         "rorl $16,%%edx\n\t" \
  40         "movb %%dl,%2\n\t" \
  41         "movb %%dh,%3" \
  42         :"=&d" (__pr) \
  43         :"m" (*((addr)+2)), \
  44          "m" (*((addr)+4)), \
  45          "m" (*((addr)+7)), \
  46          "0" (base) \
  47         ); } while(0)
  48
  49 #define _set_limit(addr,limit) do { unsigned long __lr; \
  50 __asm__ __volatile__ ("movw %%dx,%1\n\t" \
  51         "rorl $16,%%edx\n\t" \
  52         "movb %2,%%dh\n\t" \
  53         "andb $0xf0,%%dh\n\t" \
  54         "orb %%dh,%%dl\n\t" \
  55         "movb %%dl,%2" \
  56         :"=&d" (__lr) \
  57         :"m" (*(addr)), \
  58          "m" (*((addr)+6)), \
  59          "0" (limit) \
  60         ); } while(0)
  61
  62 #define set_base(ldt,base) _set_base( ((char *)&(ldt)) , (base) )
  63 #define set_limit(ldt,limit) _set_limit( ((char *)&(ldt)) , ((limit)-1) )
  64
  65 /*
  66  * Load a segment. Fall back on loading the zero
  67  * segment if something goes wrong..
  68  */
  69 #define loadsegment(seg,value)                  \
  70         asm volatile("\n"                       \
  71                 "1:\t"                          \
  72                 "mov %0,%%" #seg "\n"           \
  73                 "2:\n"                          \
  74                 ".section .fixup,\"ax\"\n"      \
  75                 "3:\t"                          \
  76                 "pushl $0\n\t"                  \
  77                 "popl %%" #seg "\n\t"           \
  78                 "jmp 2b\n"                      \
  79                 ".previous\n"                   \
  80                 ".section __ex_table,\"a\"\n\t" \
  81                 ".align 4\n\t"                  \
  82                 ".long 1b,3b\n"                 \
  83                 ".previous"                     \
  84                 : :"rm" (value))
  85
  86 /*
  87  * Save a segment register away
  88  */
  89 #define savesegment(seg, value) \
  90         asm volatile("mov %%" #seg ",%0":"=rm" (value))
  91
  92
  93 static inline void native_clts(void)
  94 {
  95         asm volatile ("clts");
  96 }
  97
  98 static inline unsigned long native_read_cr0(void)
  99 {
 100         unsigned long val;
 101         asm volatile("movl %%cr0,%0\n\t" :"=r" (val));
 102         return val;
 103 }
 104
 105 static inline void native_write_cr0(unsigned long val)
 106 {
 107         asm volatile("movl %0,%%cr0": :"r" (val));
 108 }
 109
 110 static inline unsigned long native_read_cr2(void)
 111 {
 112         unsigned long val;
 113         asm volatile("movl %%cr2,%0\n\t" :"=r" (val));
 114         return val;
 115 }
 116
 117 static inline void native_write_cr2(unsigned long val)
 118 {
 119         asm volatile("movl %0,%%cr2": :"r" (val));
 120 }
 121
 122 static inline unsigned long native_read_cr3(void)
 123 {
 124         unsigned long val;
 125         asm volatile("movl %%cr3,%0\n\t" :"=r" (val));
 126         return val;
 127 }
 128
 129 static inline void native_write_cr3(unsigned long val)
 130 {
 131         asm volatile("movl %0,%%cr3": :"r" (val));
 132 }
 133
 134 static inline unsigned long native_read_cr4(void)
 135 {
 136         unsigned long val;
 137         asm volatile("movl %%cr4,%0\n\t" :"=r" (val));
 138         return val;
 139 }
 140
 141 static inline unsigned long native_read_cr4_safe(void)
 142 {
 143         unsigned long val;
 144         /* This could fault if %cr4 does not exist */
 145         asm("1: movl %%cr4, %0          \n"
 146                 "2:                             \n"
 147                 ".section __ex_table,\"a\"      \n"
 148                 ".long 1b,2b                    \n"
 149                 ".previous                      \n"
 150                 : "=r" (val): "0" (0));
 151         return val;
 152 }
 153
 154 static inline void native_write_cr4(unsigned long val)
 155 {
 156         asm volatile("movl %0,%%cr4": :"r" (val));
 157 }
 158
 159 static inline void native_wbinvd(void)
 160 {
 161         asm volatile("wbinvd": : :"memory");
 162 }
 163
 164
 165 #ifdef CONFIG_PARAVIRT
 166 #include <asm/paravirt.h>
 167 #else
 168 #define read_cr0()      (native_read_cr0())
 169 #define write_cr0(x)    (native_write_cr0(x))
 170 #define read_cr2()      (native_read_cr2())
 171 #define write_cr2(x)    (native_write_cr2(x))
 172 #define read_cr3()      (native_read_cr3())
 173 #define write_cr3(x)    (native_write_cr3(x))
 174 #define read_cr4()      (native_read_cr4())
 175 #define read_cr4_safe() (native_read_cr4_safe())
 176 #define write_cr4(x)    (native_write_cr4(x))
 177 #define wbinvd()        (native_wbinvd())
 178
 179 /* Clear the 'TS' bit */
 180 #define clts()          (native_clts())
 181
 182 #endif/* CONFIG_PARAVIRT */
 183
 184 /* Set the 'TS' bit */
 185 #define stts() write_cr0(8 | read_cr0())
 186
 187 #endif  /* __KERNEL__ */
 188
 189 static inline unsigned long get_limit(unsigned long segment)
 190 {
 191         unsigned long __limit;
 192         __asm__("lsll %1,%0"
 193                 :"=r" (__limit):"r" (segment));
 194         return __limit+1;
 195 }
 196
 197 #define nop() __asm__ __volatile__ ("nop")
 198
 199 /*
 200  * Force strict CPU ordering.
 201  * And yes, this is required on UP too when we're talking
 202  * to devices.
 203  *
 204  * For now, "wmb()" doesn't actually do anything, as all
 205  * Intel CPU's follow what Intel calls a *Processor Order*,
 206  * in which all writes are seen in the program order even
 207  * outside the CPU.
 208  *
 209  * I expect future Intel CPU's to have a weaker ordering,
 210  * but I'd also expect them to finally get their act together
 211  * and add some real memory barriers if so.
 212  *
 213  * Some non intel clones support out of order store. wmb() ceases to be a
 214  * nop for these.
 215  */
 216
 217
 218 #define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2)
 219 #define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2)
 220 #define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM)
 221
 222 /**
 223  * read_barrier_depends - Flush all pending reads that subsequents reads
 224  * depend on.
 225  *
 226  * No data-dependent reads from memory-like regions are ever reordered
 227  * over this barrier.  All reads preceding this primitive are guaranteed
 228  * to access memory (but not necessarily other CPUs' caches) before any
 229  * reads following this primitive that depend on the data return by
 230  * any of the preceding reads.  This primitive is much lighter weight than
 231  * rmb() on most CPUs, and is never heavier weight than is
 232  * rmb().
 233  *
 234  * These ordering constraints are respected by both the local CPU
 235  * and the compiler.
 236  *
 237  * Ordering is not guaranteed by anything other than these primitives,
 238  * not even by data dependencies.  See the documentation for
 239  * memory_barrier() for examples and URLs to more information.
 240  *
 241  * For example, the following code would force ordering (the initial
 242  * value of "a" is zero, "b" is one, and "p" is "&a"):
 243  *
 244  * <programlisting>
 245  *      CPU 0                           CPU 1
 246  *
 247  *      b = 2;
 248  *      memory_barrier();
 249  *      p = &b;                         q = p;
 250  *                                      read_barrier_depends();
 251  *                                      d = *q;
 252  * </programlisting>
 253  *
 254  * because the read of "*q" depends on the read of "p" and these
 255  * two reads are separated by a read_barrier_depends().  However,
 256  * the following code, with the same initial values for "a" and "b":
 257  *
 258  * <programlisting>
 259  *      CPU 0                           CPU 1
 260  *
 261  *      a = 2;
 262  *      memory_barrier();
 263  *      b = 3;                          y = b;
 264  *                                      read_barrier_depends();
 265  *                                      x = a;
 266  * </programlisting>
 267  *
 268  * does not enforce ordering, since there is no data dependency between
 269  * the read of "a" and the read of "b".  Therefore, on some CPUs, such
 270  * as Alpha, "y" could be set to 3 and "x" to 0.  Use rmb()
 271  * in cases like this where there are no data dependencies.
 272  **/
 273
 274 #define read_barrier_depends()  do { } while(0)
 275
 276 #ifdef CONFIG_SMP
 277 #define smp_mb()        mb()
 278 #ifdef CONFIG_X86_PPRO_FENCE
 279 # define smp_rmb()      rmb()
 280 #else
 281 # define smp_rmb()      barrier()
 282 #endif
 283 #ifdef CONFIG_X86_OOSTORE
 284 # define smp_wmb()      wmb()
 285 #else
 286 # define smp_wmb()      barrier()
 287 #endif
 288 #define smp_read_barrier_depends()      read_barrier_depends()
 289 #define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
 290 #else
 291 #define smp_mb()        barrier()
 292 #define smp_rmb()       barrier()
 293 #define smp_wmb()       barrier()
 294 #define smp_read_barrier_depends()      do { } while(0)
 295 #define set_mb(var, value) do { var = value; barrier(); } while (0)
 296 #endif
 297
 298 #include <linux/irqflags.h>
 299
 300 /*
 301  * disable hlt during certain critical i/o operations
 302  */
 303 #define HAVE_DISABLE_HLT
 304 void disable_hlt(void);
 305 void enable_hlt(void);
 306
 307 extern int es7000_plat;
 308 void cpu_idle_wait(void);
 309
 310 extern unsigned long arch_align_stack(unsigned long sp);
 311 extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
 312
 313 void default_idle(void);
 314
 315 #endif