xen-vtx-unstable
annotate linux-2.6-xen-sparse/include/asm-xen/asm-i386/system.h @ 6552:8af8ddf91078
Fix non-SMP build, broken by the previous changeset.
Signed-off-by: Keir Fraser <keir@xensource.com>
Signed-off-by: Keir Fraser <keir@xensource.com>
author | kaf24@firebug.cl.cam.ac.uk |
---|---|
date | Wed Aug 31 14:53:43 2005 +0000 (2005-08-31) |
parents | 6fdbb0e35083 |
children | f0dc15fd3c1b |
rev | line source |
---|---|
cl349@4087 | 1 #ifndef __ASM_SYSTEM_H |
cl349@4087 | 2 #define __ASM_SYSTEM_H |
cl349@4087 | 3 |
cl349@4087 | 4 #include <linux/config.h> |
cl349@4087 | 5 #include <linux/kernel.h> |
cl349@4087 | 6 #include <linux/bitops.h> |
kaf24@5402 | 7 #include <asm-xen/synch_bitops.h> |
cl349@4087 | 8 #include <asm/segment.h> |
cl349@4087 | 9 #include <asm/cpufeature.h> |
cl349@4087 | 10 #include <asm-xen/hypervisor.h> |
sos22@5466 | 11 #include <asm/smp_alt.h> |
cl349@4087 | 12 |
cl349@4087 | 13 #ifdef __KERNEL__ |
cl349@4087 | 14 |
cl349@4087 | 15 struct task_struct; /* one of the stranger aspects of C forward declarations.. */ |
cl349@4087 | 16 extern struct task_struct * FASTCALL(__switch_to(struct task_struct *prev, struct task_struct *next)); |
cl349@4087 | 17 |
cl349@4087 | 18 #define switch_to(prev,next,last) do { \ |
cl349@4087 | 19 unsigned long esi,edi; \ |
cl349@4087 | 20 asm volatile("pushfl\n\t" \ |
cl349@4087 | 21 "pushl %%ebp\n\t" \ |
cl349@4087 | 22 "movl %%esp,%0\n\t" /* save ESP */ \ |
cl349@4087 | 23 "movl %5,%%esp\n\t" /* restore ESP */ \ |
cl349@4087 | 24 "movl $1f,%1\n\t" /* save EIP */ \ |
cl349@4087 | 25 "pushl %6\n\t" /* restore EIP */ \ |
cl349@4087 | 26 "jmp __switch_to\n" \ |
cl349@4087 | 27 "1:\t" \ |
cl349@4087 | 28 "popl %%ebp\n\t" \ |
cl349@4087 | 29 "popfl" \ |
cl349@4087 | 30 :"=m" (prev->thread.esp),"=m" (prev->thread.eip), \ |
cl349@4087 | 31 "=a" (last),"=S" (esi),"=D" (edi) \ |
cl349@4087 | 32 :"m" (next->thread.esp),"m" (next->thread.eip), \ |
cl349@4087 | 33 "2" (prev), "d" (next)); \ |
cl349@4087 | 34 } while (0) |
cl349@4087 | 35 |
cl349@4087 | 36 #define _set_base(addr,base) do { unsigned long __pr; \ |
cl349@4087 | 37 __asm__ __volatile__ ("movw %%dx,%1\n\t" \ |
cl349@4087 | 38 "rorl $16,%%edx\n\t" \ |
cl349@4087 | 39 "movb %%dl,%2\n\t" \ |
cl349@4087 | 40 "movb %%dh,%3" \ |
cl349@4087 | 41 :"=&d" (__pr) \ |
cl349@4087 | 42 :"m" (*((addr)+2)), \ |
cl349@4087 | 43 "m" (*((addr)+4)), \ |
cl349@4087 | 44 "m" (*((addr)+7)), \ |
cl349@4087 | 45 "0" (base) \ |
cl349@4087 | 46 ); } while(0) |
cl349@4087 | 47 |
cl349@4087 | 48 #define _set_limit(addr,limit) do { unsigned long __lr; \ |
cl349@4087 | 49 __asm__ __volatile__ ("movw %%dx,%1\n\t" \ |
cl349@4087 | 50 "rorl $16,%%edx\n\t" \ |
cl349@4087 | 51 "movb %2,%%dh\n\t" \ |
cl349@4087 | 52 "andb $0xf0,%%dh\n\t" \ |
cl349@4087 | 53 "orb %%dh,%%dl\n\t" \ |
cl349@4087 | 54 "movb %%dl,%2" \ |
cl349@4087 | 55 :"=&d" (__lr) \ |
cl349@4087 | 56 :"m" (*(addr)), \ |
cl349@4087 | 57 "m" (*((addr)+6)), \ |
cl349@4087 | 58 "0" (limit) \ |
cl349@4087 | 59 ); } while(0) |
cl349@4087 | 60 |
cl349@4087 | 61 #define set_base(ldt,base) _set_base( ((char *)&(ldt)) , (base) ) |
cl349@4087 | 62 #define set_limit(ldt,limit) _set_limit( ((char *)&(ldt)) , ((limit)-1)>>12 ) |
cl349@4087 | 63 |
cl349@4087 | 64 static inline unsigned long _get_base(char * addr) |
cl349@4087 | 65 { |
cl349@4087 | 66 unsigned long __base; |
cl349@4087 | 67 __asm__("movb %3,%%dh\n\t" |
cl349@4087 | 68 "movb %2,%%dl\n\t" |
cl349@4087 | 69 "shll $16,%%edx\n\t" |
cl349@4087 | 70 "movw %1,%%dx" |
cl349@4087 | 71 :"=&d" (__base) |
cl349@4087 | 72 :"m" (*((addr)+2)), |
cl349@4087 | 73 "m" (*((addr)+4)), |
cl349@4087 | 74 "m" (*((addr)+7))); |
cl349@4087 | 75 return __base; |
cl349@4087 | 76 } |
cl349@4087 | 77 |
cl349@4087 | 78 #define get_base(ldt) _get_base( ((char *)&(ldt)) ) |
cl349@4087 | 79 |
cl349@4087 | 80 /* |
cl349@4087 | 81 * Load a segment. Fall back on loading the zero |
cl349@4087 | 82 * segment if something goes wrong.. |
cl349@4087 | 83 */ |
cl349@4087 | 84 #define loadsegment(seg,value) \ |
cl349@4087 | 85 asm volatile("\n" \ |
cl349@4087 | 86 "1:\t" \ |
vh249@5730 | 87 "mov %0,%%" #seg "\n" \ |
cl349@4087 | 88 "2:\n" \ |
cl349@4087 | 89 ".section .fixup,\"ax\"\n" \ |
cl349@4087 | 90 "3:\t" \ |
cl349@4087 | 91 "pushl $0\n\t" \ |
cl349@4087 | 92 "popl %%" #seg "\n\t" \ |
cl349@4087 | 93 "jmp 2b\n" \ |
cl349@4087 | 94 ".previous\n" \ |
cl349@4087 | 95 ".section __ex_table,\"a\"\n\t" \ |
cl349@4087 | 96 ".align 4\n\t" \ |
cl349@4087 | 97 ".long 1b,3b\n" \ |
cl349@4087 | 98 ".previous" \ |
vh249@5730 | 99 : :"m" (value)) |
cl349@4087 | 100 |
cl349@4087 | 101 /* |
cl349@4087 | 102 * Save a segment register away |
cl349@4087 | 103 */ |
cl349@4087 | 104 #define savesegment(seg, value) \ |
vh249@5730 | 105 asm volatile("mov %%" #seg ",%0":"=m" (value)) |
cl349@4087 | 106 |
cl349@4087 | 107 /* |
cl349@4087 | 108 * Clear and set 'TS' bit respectively |
cl349@4087 | 109 */ |
cl349@4112 | 110 #define clts() (HYPERVISOR_fpu_taskswitch(0)) |
kaf24@5367 | 111 #define read_cr0() ({ \ |
kaf24@5367 | 112 unsigned int __dummy; \ |
kaf24@5367 | 113 __asm__( \ |
kaf24@5367 | 114 "movl %%cr0,%0\n\t" \ |
kaf24@5367 | 115 :"=r" (__dummy)); \ |
kaf24@5367 | 116 __dummy; \ |
kaf24@5367 | 117 }) |
cl349@4087 | 118 #define write_cr0(x) \ |
kaf24@5367 | 119 __asm__("movl %0,%%cr0": :"r" (x)); |
kaf24@5367 | 120 |
kaf24@5367 | 121 #define read_cr4() ({ \ |
kaf24@5367 | 122 unsigned int __dummy; \ |
kaf24@5367 | 123 __asm__( \ |
kaf24@5367 | 124 "movl %%cr4,%0\n\t" \ |
kaf24@5367 | 125 :"=r" (__dummy)); \ |
kaf24@5367 | 126 __dummy; \ |
kaf24@5367 | 127 }) |
cl349@4087 | 128 #define write_cr4(x) \ |
kaf24@5367 | 129 __asm__("movl %0,%%cr4": :"r" (x)); |
cl349@4112 | 130 #define stts() (HYPERVISOR_fpu_taskswitch(1)) |
cl349@4087 | 131 |
cl349@4087 | 132 #endif /* __KERNEL__ */ |
cl349@4087 | 133 |
cl349@4112 | 134 #define wbinvd() \ |
cl349@4112 | 135 __asm__ __volatile__ ("wbinvd": : :"memory"); |
cl349@4087 | 136 |
cl349@4087 | 137 static inline unsigned long get_limit(unsigned long segment) |
cl349@4087 | 138 { |
cl349@4087 | 139 unsigned long __limit; |
cl349@4087 | 140 __asm__("lsll %1,%0" |
cl349@4087 | 141 :"=r" (__limit):"r" (segment)); |
cl349@4087 | 142 return __limit+1; |
cl349@4087 | 143 } |
cl349@4087 | 144 |
cl349@4087 | 145 #define nop() __asm__ __volatile__ ("nop") |
cl349@4087 | 146 |
cl349@4087 | 147 #define xchg(ptr,v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v),(ptr),sizeof(*(ptr)))) |
cl349@4087 | 148 |
cl349@4087 | 149 #define tas(ptr) (xchg((ptr),1)) |
cl349@4087 | 150 |
cl349@4087 | 151 struct __xchg_dummy { unsigned long a[100]; }; |
cl349@4087 | 152 #define __xg(x) ((struct __xchg_dummy *)(x)) |
cl349@4087 | 153 |
cl349@4087 | 154 |
cl349@4087 | 155 /* |
cl349@4087 | 156 * The semantics of XCHGCMP8B are a bit strange, this is why |
cl349@4087 | 157 * there is a loop and the loading of %%eax and %%edx has to |
cl349@4087 | 158 * be inside. This inlines well in most cases, the cached |
cl349@4087 | 159 * cost is around ~38 cycles. (in the future we might want |
cl349@4087 | 160 * to do an SIMD/3DNOW!/MMX/FPU 64-bit store here, but that |
cl349@4087 | 161 * might have an implicit FPU-save as a cost, so it's not |
cl349@4087 | 162 * clear which path to go.) |
cl349@4087 | 163 * |
cl349@4087 | 164 * cmpxchg8b must be used with the lock prefix here to allow |
cl349@4087 | 165 * the instruction to be executed atomically, see page 3-102 |
cl349@4087 | 166 * of the instruction set reference 24319102.pdf. We need |
cl349@4087 | 167 * the reader side to see the coherent 64bit value. |
cl349@4087 | 168 */ |
cl349@4087 | 169 static inline void __set_64bit (unsigned long long * ptr, |
cl349@4087 | 170 unsigned int low, unsigned int high) |
cl349@4087 | 171 { |
cl349@4087 | 172 __asm__ __volatile__ ( |
cl349@4087 | 173 "\n1:\t" |
cl349@4087 | 174 "movl (%0), %%eax\n\t" |
cl349@4087 | 175 "movl 4(%0), %%edx\n\t" |
cl349@4087 | 176 "lock cmpxchg8b (%0)\n\t" |
cl349@4087 | 177 "jnz 1b" |
cl349@4087 | 178 : /* no outputs */ |
cl349@4087 | 179 : "D"(ptr), |
cl349@4087 | 180 "b"(low), |
cl349@4087 | 181 "c"(high) |
cl349@4087 | 182 : "ax","dx","memory"); |
cl349@4087 | 183 } |
cl349@4087 | 184 |
cl349@4087 | 185 static inline void __set_64bit_constant (unsigned long long *ptr, |
cl349@4087 | 186 unsigned long long value) |
cl349@4087 | 187 { |
cl349@4087 | 188 __set_64bit(ptr,(unsigned int)(value), (unsigned int)((value)>>32ULL)); |
cl349@4087 | 189 } |
cl349@4087 | 190 #define ll_low(x) *(((unsigned int*)&(x))+0) |
cl349@4087 | 191 #define ll_high(x) *(((unsigned int*)&(x))+1) |
cl349@4087 | 192 |
cl349@4087 | 193 static inline void __set_64bit_var (unsigned long long *ptr, |
cl349@4087 | 194 unsigned long long value) |
cl349@4087 | 195 { |
cl349@4087 | 196 __set_64bit(ptr,ll_low(value), ll_high(value)); |
cl349@4087 | 197 } |
cl349@4087 | 198 |
cl349@4087 | 199 #define set_64bit(ptr,value) \ |
cl349@4087 | 200 (__builtin_constant_p(value) ? \ |
cl349@4087 | 201 __set_64bit_constant(ptr, value) : \ |
cl349@4087 | 202 __set_64bit_var(ptr, value) ) |
cl349@4087 | 203 |
cl349@4087 | 204 #define _set_64bit(ptr,value) \ |
cl349@4087 | 205 (__builtin_constant_p(value) ? \ |
cl349@4087 | 206 __set_64bit(ptr, (unsigned int)(value), (unsigned int)((value)>>32ULL) ) : \ |
cl349@4087 | 207 __set_64bit(ptr, ll_low(value), ll_high(value)) ) |
cl349@4087 | 208 |
cl349@4087 | 209 /* |
cl349@4087 | 210 * Note: no "lock" prefix even on SMP: xchg always implies lock anyway |
cl349@4087 | 211 * Note 2: xchg has side effect, so that attribute volatile is necessary, |
cl349@4087 | 212 * but generally the primitive is invalid, *ptr is output argument. --ANK |
cl349@4087 | 213 */ |
cl349@4087 | 214 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size) |
cl349@4087 | 215 { |
cl349@4087 | 216 switch (size) { |
cl349@4087 | 217 case 1: |
cl349@4087 | 218 __asm__ __volatile__("xchgb %b0,%1" |
cl349@4087 | 219 :"=q" (x) |
cl349@4087 | 220 :"m" (*__xg(ptr)), "0" (x) |
cl349@4087 | 221 :"memory"); |
cl349@4087 | 222 break; |
cl349@4087 | 223 case 2: |
cl349@4087 | 224 __asm__ __volatile__("xchgw %w0,%1" |
cl349@4087 | 225 :"=r" (x) |
cl349@4087 | 226 :"m" (*__xg(ptr)), "0" (x) |
cl349@4087 | 227 :"memory"); |
cl349@4087 | 228 break; |
cl349@4087 | 229 case 4: |
cl349@4087 | 230 __asm__ __volatile__("xchgl %0,%1" |
cl349@4087 | 231 :"=r" (x) |
cl349@4087 | 232 :"m" (*__xg(ptr)), "0" (x) |
cl349@4087 | 233 :"memory"); |
cl349@4087 | 234 break; |
cl349@4087 | 235 } |
cl349@4087 | 236 return x; |
cl349@4087 | 237 } |
cl349@4087 | 238 |
cl349@4087 | 239 /* |
cl349@4087 | 240 * Atomic compare and exchange. Compare OLD with MEM, if identical, |
cl349@4087 | 241 * store NEW in MEM. Return the initial value in MEM. Success is |
cl349@4087 | 242 * indicated by comparing RETURN with OLD. |
cl349@4087 | 243 */ |
cl349@4087 | 244 |
cl349@4087 | 245 #ifdef CONFIG_X86_CMPXCHG |
cl349@4087 | 246 #define __HAVE_ARCH_CMPXCHG 1 |
cl349@4087 | 247 #endif |
cl349@4087 | 248 |
cl349@4087 | 249 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, |
cl349@4087 | 250 unsigned long new, int size) |
cl349@4087 | 251 { |
cl349@4087 | 252 unsigned long prev; |
cl349@4087 | 253 switch (size) { |
cl349@4087 | 254 case 1: |
sos22@5466 | 255 __asm__ __volatile__(LOCK "cmpxchgb %b1,%2" |
cl349@4087 | 256 : "=a"(prev) |
cl349@4087 | 257 : "q"(new), "m"(*__xg(ptr)), "0"(old) |
cl349@4087 | 258 : "memory"); |
cl349@4087 | 259 return prev; |
cl349@4087 | 260 case 2: |
sos22@5466 | 261 __asm__ __volatile__(LOCK "cmpxchgw %w1,%2" |
cl349@4087 | 262 : "=a"(prev) |
cl349@4087 | 263 : "q"(new), "m"(*__xg(ptr)), "0"(old) |
cl349@4087 | 264 : "memory"); |
cl349@4087 | 265 return prev; |
cl349@4087 | 266 case 4: |
sos22@5466 | 267 __asm__ __volatile__(LOCK "cmpxchgl %1,%2" |
cl349@4087 | 268 : "=a"(prev) |
cl349@4087 | 269 : "q"(new), "m"(*__xg(ptr)), "0"(old) |
cl349@4087 | 270 : "memory"); |
cl349@4087 | 271 return prev; |
cl349@4087 | 272 } |
cl349@4087 | 273 return old; |
cl349@4087 | 274 } |
cl349@4087 | 275 |
cl349@4087 | 276 #define cmpxchg(ptr,o,n)\ |
cl349@4087 | 277 ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\ |
cl349@4087 | 278 (unsigned long)(n),sizeof(*(ptr)))) |
cl349@4087 | 279 |
cl349@4087 | 280 #ifdef __KERNEL__ |
cl349@4087 | 281 struct alt_instr { |
cl349@4087 | 282 __u8 *instr; /* original instruction */ |
cl349@4087 | 283 __u8 *replacement; |
cl349@4087 | 284 __u8 cpuid; /* cpuid bit set for replacement */ |
cl349@4087 | 285 __u8 instrlen; /* length of original instruction */ |
cl349@4087 | 286 __u8 replacementlen; /* length of new instruction, <= instrlen */ |
cl349@4087 | 287 __u8 pad; |
cl349@4087 | 288 }; |
cl349@4087 | 289 #endif |
cl349@4087 | 290 |
cl349@4087 | 291 /* |
cl349@4087 | 292 * Alternative instructions for different CPU types or capabilities. |
cl349@4087 | 293 * |
cl349@4087 | 294 * This allows to use optimized instructions even on generic binary |
cl349@4087 | 295 * kernels. |
cl349@4087 | 296 * |
cl349@4087 | 297 * length of oldinstr must be longer or equal the length of newinstr |
cl349@4087 | 298 * It can be padded with nops as needed. |
cl349@4087 | 299 * |
cl349@4087 | 300 * For non barrier like inlines please define new variants |
cl349@4087 | 301 * without volatile and memory clobber. |
cl349@4087 | 302 */ |
cl349@4087 | 303 #define alternative(oldinstr, newinstr, feature) \ |
cl349@4087 | 304 asm volatile ("661:\n\t" oldinstr "\n662:\n" \ |
cl349@4087 | 305 ".section .altinstructions,\"a\"\n" \ |
cl349@4087 | 306 " .align 4\n" \ |
cl349@4087 | 307 " .long 661b\n" /* label */ \ |
cl349@4087 | 308 " .long 663f\n" /* new instruction */ \ |
cl349@4087 | 309 " .byte %c0\n" /* feature bit */ \ |
cl349@4087 | 310 " .byte 662b-661b\n" /* sourcelen */ \ |
cl349@4087 | 311 " .byte 664f-663f\n" /* replacementlen */ \ |
cl349@4087 | 312 ".previous\n" \ |
cl349@4087 | 313 ".section .altinstr_replacement,\"ax\"\n" \ |
cl349@4087 | 314 "663:\n\t" newinstr "\n664:\n" /* replacement */ \ |
cl349@4087 | 315 ".previous" :: "i" (feature) : "memory") |
cl349@4087 | 316 |
cl349@4087 | 317 /* |
cl349@4087 | 318 * Alternative inline assembly with input. |
cl349@4087 | 319 * |
cl349@4087 | 320 * Pecularities: |
cl349@4087 | 321 * No memory clobber here. |
cl349@4087 | 322 * Argument numbers start with 1. |
cl349@4087 | 323 * Best is to use constraints that are fixed size (like (%1) ... "r") |
cl349@4087 | 324 * If you use variable sized constraints like "m" or "g" in the |
cl349@4087 | 325 * replacement maake sure to pad to the worst case length. |
cl349@4087 | 326 */ |
cl349@4087 | 327 #define alternative_input(oldinstr, newinstr, feature, input...) \ |
cl349@4087 | 328 asm volatile ("661:\n\t" oldinstr "\n662:\n" \ |
cl349@4087 | 329 ".section .altinstructions,\"a\"\n" \ |
cl349@4087 | 330 " .align 4\n" \ |
cl349@4087 | 331 " .long 661b\n" /* label */ \ |
cl349@4087 | 332 " .long 663f\n" /* new instruction */ \ |
cl349@4087 | 333 " .byte %c0\n" /* feature bit */ \ |
cl349@4087 | 334 " .byte 662b-661b\n" /* sourcelen */ \ |
cl349@4087 | 335 " .byte 664f-663f\n" /* replacementlen */ \ |
cl349@4087 | 336 ".previous\n" \ |
cl349@4087 | 337 ".section .altinstr_replacement,\"ax\"\n" \ |
cl349@4087 | 338 "663:\n\t" newinstr "\n664:\n" /* replacement */ \ |
cl349@4087 | 339 ".previous" :: "i" (feature), ##input) |
cl349@4087 | 340 |
cl349@4087 | 341 /* |
cl349@4087 | 342 * Force strict CPU ordering. |
cl349@4087 | 343 * And yes, this is required on UP too when we're talking |
cl349@4087 | 344 * to devices. |
cl349@4087 | 345 * |
cl349@4087 | 346 * For now, "wmb()" doesn't actually do anything, as all |
cl349@4087 | 347 * Intel CPU's follow what Intel calls a *Processor Order*, |
cl349@4087 | 348 * in which all writes are seen in the program order even |
cl349@4087 | 349 * outside the CPU. |
cl349@4087 | 350 * |
cl349@4087 | 351 * I expect future Intel CPU's to have a weaker ordering, |
cl349@4087 | 352 * but I'd also expect them to finally get their act together |
cl349@4087 | 353 * and add some real memory barriers if so. |
cl349@4087 | 354 * |
cl349@4087 | 355 * Some non intel clones support out of order store. wmb() ceases to be a |
cl349@4087 | 356 * nop for these. |
cl349@4087 | 357 */ |
cl349@4087 | 358 |
cl349@4087 | 359 |
cl349@4087 | 360 /* |
cl349@4087 | 361 * Actually only lfence would be needed for mb() because all stores done |
cl349@4087 | 362 * by the kernel should be already ordered. But keep a full barrier for now. |
cl349@4087 | 363 */ |
cl349@4087 | 364 |
cl349@4087 | 365 #define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2) |
cl349@4087 | 366 #define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2) |
cl349@4087 | 367 |
cl349@4087 | 368 /** |
cl349@4087 | 369 * read_barrier_depends - Flush all pending reads that subsequents reads |
cl349@4087 | 370 * depend on. |
cl349@4087 | 371 * |
cl349@4087 | 372 * No data-dependent reads from memory-like regions are ever reordered |
cl349@4087 | 373 * over this barrier. All reads preceding this primitive are guaranteed |
cl349@4087 | 374 * to access memory (but not necessarily other CPUs' caches) before any |
cl349@4087 | 375 * reads following this primitive that depend on the data return by |
cl349@4087 | 376 * any of the preceding reads. This primitive is much lighter weight than |
cl349@4087 | 377 * rmb() on most CPUs, and is never heavier weight than is |
cl349@4087 | 378 * rmb(). |
cl349@4087 | 379 * |
cl349@4087 | 380 * These ordering constraints are respected by both the local CPU |
cl349@4087 | 381 * and the compiler. |
cl349@4087 | 382 * |
cl349@4087 | 383 * Ordering is not guaranteed by anything other than these primitives, |
cl349@4087 | 384 * not even by data dependencies. See the documentation for |
cl349@4087 | 385 * memory_barrier() for examples and URLs to more information. |
cl349@4087 | 386 * |
cl349@4087 | 387 * For example, the following code would force ordering (the initial |
cl349@4087 | 388 * value of "a" is zero, "b" is one, and "p" is "&a"): |
cl349@4087 | 389 * |
cl349@4087 | 390 * <programlisting> |
cl349@4087 | 391 * CPU 0 CPU 1 |
cl349@4087 | 392 * |
cl349@4087 | 393 * b = 2; |
cl349@4087 | 394 * memory_barrier(); |
cl349@4087 | 395 * p = &b; q = p; |
cl349@4087 | 396 * read_barrier_depends(); |
cl349@4087 | 397 * d = *q; |
cl349@4087 | 398 * </programlisting> |
cl349@4087 | 399 * |
cl349@4087 | 400 * because the read of "*q" depends on the read of "p" and these |
cl349@4087 | 401 * two reads are separated by a read_barrier_depends(). However, |
cl349@4087 | 402 * the following code, with the same initial values for "a" and "b": |
cl349@4087 | 403 * |
cl349@4087 | 404 * <programlisting> |
cl349@4087 | 405 * CPU 0 CPU 1 |
cl349@4087 | 406 * |
cl349@4087 | 407 * a = 2; |
cl349@4087 | 408 * memory_barrier(); |
cl349@4087 | 409 * b = 3; y = b; |
cl349@4087 | 410 * read_barrier_depends(); |
cl349@4087 | 411 * x = a; |
cl349@4087 | 412 * </programlisting> |
cl349@4087 | 413 * |
cl349@4087 | 414 * does not enforce ordering, since there is no data dependency between |
cl349@4087 | 415 * the read of "a" and the read of "b". Therefore, on some CPUs, such |
cl349@4087 | 416 * as Alpha, "y" could be set to 3 and "x" to 0. Use rmb() |
cl349@4087 | 417 * in cases like thiswhere there are no data dependencies. |
cl349@4087 | 418 **/ |
cl349@4087 | 419 |
cl349@4087 | 420 #define read_barrier_depends() do { } while(0) |
cl349@4087 | 421 |
cl349@4087 | 422 #ifdef CONFIG_X86_OOSTORE |
cl349@4087 | 423 /* Actually there are no OOO store capable CPUs for now that do SSE, |
cl349@4087 | 424 but make it already an possibility. */ |
cl349@4087 | 425 #define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM) |
cl349@4087 | 426 #else |
cl349@4087 | 427 #define wmb() __asm__ __volatile__ ("": : :"memory") |
cl349@4087 | 428 #endif |
cl349@4087 | 429 |
cl349@4087 | 430 #ifdef CONFIG_SMP |
sos22@5466 | 431 #define smp_wmb() wmb() |
sos22@5466 | 432 #if defined(CONFIG_SMP_ALTERNATIVES) && !defined(MODULE) |
sos22@5466 | 433 #define smp_alt_mb(instr) \ |
sos22@5466 | 434 __asm__ __volatile__("6667:\nnop\nnop\nnop\nnop\nnop\nnop\n6668:\n" \ |
sos22@5466 | 435 ".section __smp_alternatives,\"a\"\n" \ |
sos22@5466 | 436 ".long 6667b\n" \ |
sos22@5466 | 437 ".long 6673f\n" \ |
sos22@5466 | 438 ".previous\n" \ |
sos22@5466 | 439 ".section __smp_replacements,\"a\"\n" \ |
sos22@5466 | 440 "6673:.byte 6668b-6667b\n" \ |
sos22@5466 | 441 ".byte 6670f-6669f\n" \ |
sos22@5466 | 442 ".byte 6671f-6670f\n" \ |
sos22@5466 | 443 ".byte 0\n" \ |
sos22@5466 | 444 ".byte %c0\n" \ |
sos22@5466 | 445 "6669:lock;addl $0,0(%%esp)\n" \ |
sos22@5466 | 446 "6670:" instr "\n" \ |
sos22@5466 | 447 "6671:\n" \ |
sos22@5466 | 448 ".previous\n" \ |
sos22@5466 | 449 : \ |
sos22@5466 | 450 : "i" (X86_FEATURE_XMM2) \ |
sos22@5466 | 451 : "memory") |
sos22@5466 | 452 #define smp_rmb() smp_alt_mb("lfence") |
sos22@5466 | 453 #define smp_mb() smp_alt_mb("mfence") |
sos22@5466 | 454 #define set_mb(var, value) do { \ |
sos22@5466 | 455 unsigned long __set_mb_temp; \ |
sos22@5466 | 456 __asm__ __volatile__("6667:movl %1, %0\n6668:\n" \ |
sos22@5466 | 457 ".section __smp_alternatives,\"a\"\n" \ |
sos22@5466 | 458 ".long 6667b\n" \ |
sos22@5466 | 459 ".long 6673f\n" \ |
sos22@5466 | 460 ".previous\n" \ |
sos22@5466 | 461 ".section __smp_replacements,\"a\"\n" \ |
sos22@5466 | 462 "6673: .byte 6668b-6667b\n" \ |
sos22@5466 | 463 ".byte 6670f-6669f\n" \ |
sos22@5466 | 464 ".byte 0\n" \ |
sos22@5466 | 465 ".byte 6671f-6670f\n" \ |
sos22@5466 | 466 ".byte -1\n" \ |
sos22@5466 | 467 "6669: xchg %1, %0\n" \ |
sos22@5466 | 468 "6670:movl %1, %0\n" \ |
sos22@5466 | 469 "6671:\n" \ |
sos22@5466 | 470 ".previous\n" \ |
sos22@5466 | 471 : "=m" (var), "=r" (__set_mb_temp) \ |
sos22@5466 | 472 : "1" (value) \ |
sos22@5466 | 473 : "memory"); } while (0) |
sos22@5466 | 474 #else |
cl349@4087 | 475 #define smp_rmb() rmb() |
sos22@5466 | 476 #define smp_mb() mb() |
sos22@5466 | 477 #define set_mb(var, value) do { xchg(&var, value); } while (0) |
sos22@5466 | 478 #endif |
cl349@4087 | 479 #define smp_read_barrier_depends() read_barrier_depends() |
cl349@4087 | 480 #else |
cl349@4087 | 481 #define smp_mb() barrier() |
cl349@4087 | 482 #define smp_rmb() barrier() |
cl349@4087 | 483 #define smp_wmb() barrier() |
cl349@4087 | 484 #define smp_read_barrier_depends() do { } while(0) |
cl349@4087 | 485 #define set_mb(var, value) do { var = value; barrier(); } while (0) |
cl349@4087 | 486 #endif |
cl349@4087 | 487 |
cl349@4087 | 488 #define set_wmb(var, value) do { var = value; wmb(); } while (0) |
cl349@4087 | 489 |
cl349@4087 | 490 /* interrupt control.. */ |
cl349@4087 | 491 |
cl349@4087 | 492 /* |
cl349@4087 | 493 * The use of 'barrier' in the following reflects their use as local-lock |
cl349@4087 | 494 * operations. Reentrancy must be prevented (e.g., __cli()) /before/ following |
cl349@4684 | 495 * critical operations are executed. All critical operations must complete |
cl349@4087 | 496 * /before/ reentrancy is permitted (e.g., __sti()). Alpha architecture also |
cl349@4087 | 497 * includes these barriers, for example. |
cl349@4087 | 498 */ |
cl349@4087 | 499 |
cl349@4087 | 500 #define __cli() \ |
cl349@4087 | 501 do { \ |
cl349@4112 | 502 vcpu_info_t *_vcpu; \ |
cl349@4112 | 503 preempt_disable(); \ |
cl349@4112 | 504 _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \ |
cl349@4112 | 505 _vcpu->evtchn_upcall_mask = 1; \ |
cl349@4112 | 506 preempt_enable_no_resched(); \ |
cl349@4087 | 507 barrier(); \ |
cl349@4087 | 508 } while (0) |
cl349@4087 | 509 |
cl349@4087 | 510 #define __sti() \ |
cl349@4087 | 511 do { \ |
cl349@4112 | 512 vcpu_info_t *_vcpu; \ |
cl349@4087 | 513 barrier(); \ |
cl349@4112 | 514 preempt_disable(); \ |
cl349@4112 | 515 _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \ |
cl349@4112 | 516 _vcpu->evtchn_upcall_mask = 0; \ |
cl349@4087 | 517 barrier(); /* unmask then check (avoid races) */ \ |
cl349@4112 | 518 if ( unlikely(_vcpu->evtchn_upcall_pending) ) \ |
cl349@4112 | 519 force_evtchn_callback(); \ |
cl349@4112 | 520 preempt_enable(); \ |
cl349@4087 | 521 } while (0) |
cl349@4087 | 522 |
cl349@4087 | 523 #define __save_flags(x) \ |
cl349@4087 | 524 do { \ |
cl349@4112 | 525 vcpu_info_t *_vcpu; \ |
cl349@4112 | 526 _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \ |
cl349@4112 | 527 (x) = _vcpu->evtchn_upcall_mask; \ |
cl349@4087 | 528 } while (0) |
cl349@4087 | 529 |
cl349@4087 | 530 #define __restore_flags(x) \ |
cl349@4087 | 531 do { \ |
cl349@4112 | 532 vcpu_info_t *_vcpu; \ |
cl349@4087 | 533 barrier(); \ |
cl349@4112 | 534 preempt_disable(); \ |
cl349@4112 | 535 _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \ |
cl349@4112 | 536 if ((_vcpu->evtchn_upcall_mask = (x)) == 0) { \ |
cl349@4112 | 537 barrier(); /* unmask then check (avoid races) */ \ |
cl349@4112 | 538 if ( unlikely(_vcpu->evtchn_upcall_pending) ) \ |
cl349@4112 | 539 force_evtchn_callback(); \ |
cl349@4112 | 540 preempt_enable(); \ |
cl349@4112 | 541 } else \ |
cl349@4112 | 542 preempt_enable_no_resched(); \ |
cl349@4087 | 543 } while (0) |
cl349@4087 | 544 |
cl349@4112 | 545 #define safe_halt() ((void)0) |
cl349@4087 | 546 |
cl349@4087 | 547 #define __save_and_cli(x) \ |
cl349@4087 | 548 do { \ |
cl349@4112 | 549 vcpu_info_t *_vcpu; \ |
cl349@4112 | 550 preempt_disable(); \ |
cl349@4112 | 551 _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \ |
cl349@4112 | 552 (x) = _vcpu->evtchn_upcall_mask; \ |
cl349@4112 | 553 _vcpu->evtchn_upcall_mask = 1; \ |
cl349@4112 | 554 preempt_enable_no_resched(); \ |
cl349@4087 | 555 barrier(); \ |
cl349@4087 | 556 } while (0) |
cl349@4087 | 557 |
cl349@4087 | 558 #define local_irq_save(x) __save_and_cli(x) |
cl349@4087 | 559 #define local_irq_restore(x) __restore_flags(x) |
cl349@4087 | 560 #define local_save_flags(x) __save_flags(x) |
cl349@4087 | 561 #define local_irq_disable() __cli() |
cl349@4087 | 562 #define local_irq_enable() __sti() |
cl349@4087 | 563 |
kaf24@6551 | 564 /* Don't use smp_processor_id: this is called in debug versions of that fn. */ |
kaf24@6552 | 565 #ifdef CONFIG_SMP |
cl349@4112 | 566 #define irqs_disabled() \ |
kaf24@6551 | 567 HYPERVISOR_shared_info->vcpu_data[__smp_processor_id()].evtchn_upcall_mask |
kaf24@6552 | 568 #else |
kaf24@6552 | 569 #define irqs_disabled() \ |
kaf24@6552 | 570 HYPERVISOR_shared_info->vcpu_data[0].evtchn_upcall_mask |
kaf24@6552 | 571 #endif |
cl349@4087 | 572 |
cl349@4087 | 573 /* |
cl349@4087 | 574 * disable hlt during certain critical i/o operations |
cl349@4087 | 575 */ |
cl349@4087 | 576 #define HAVE_DISABLE_HLT |
cl349@4087 | 577 void disable_hlt(void); |
cl349@4087 | 578 void enable_hlt(void); |
cl349@4087 | 579 |
cl349@4087 | 580 extern int es7000_plat; |
cl349@4087 | 581 void cpu_idle_wait(void); |
cl349@4087 | 582 |
vh249@5730 | 583 extern unsigned long arch_align_stack(unsigned long sp); |
vh249@5730 | 584 |
cl349@4087 | 585 #endif |