include/asm-mips/system.h

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1994, 95, 96, 97, 98, 99, 2003, 06 by Ralf Baechle
   7  * Copyright (C) 1996 by Paul M. Antoine
   8  * Copyright (C) 1999 Silicon Graphics
   9  * Kevin D. Kissell, kevink@mips.org and Carsten Langgaard, carstenl@mips.com
  10  * Copyright (C) 2000 MIPS Technologies, Inc.
  11  */
  12 #ifndef _ASM_SYSTEM_H
  13 #define _ASM_SYSTEM_H
  14
  15 #include <linux/types.h>
  16 #include <linux/irqflags.h>
  17
  18 #include <asm/addrspace.h>
  19 #include <asm/barrier.h>
  20 #include <asm/cpu-features.h>
  21 #include <asm/dsp.h>
  22 #include <asm/war.h>
  23
  24
  25 /*
  26  * switch_to(n) should switch tasks to task nr n, first
  27  * checking that n isn't the current task, in which case it does nothing.
  28  */
  29 extern asmlinkage void *resume(void *last, void *next, void *next_ti);
  30
  31 struct task_struct;
  32
  33 #ifdef CONFIG_MIPS_MT_FPAFF
  34
  35 /*
  36  * Handle the scheduler resume end of FPU affinity management.  We do this
  37  * inline to try to keep the overhead down. If we have been forced to run on
  38  * a "CPU" with an FPU because of a previous high level of FP computation,
  39  * but did not actually use the FPU during the most recent time-slice (CU1
  40  * isn't set), we undo the restriction on cpus_allowed.
  41  *
  42  * We're not calling set_cpus_allowed() here, because we have no need to
  43  * force prompt migration - we're already switching the current CPU to a
  44  * different thread.
  45  */
  46
  47 #define switch_to(prev,next,last)                                       \
  48 do {                                                                    \
  49         if (cpu_has_fpu &&                                              \
  50             (prev->thread.mflags & MF_FPUBOUND) &&                      \
  51              (!(KSTK_STATUS(prev) & ST0_CU1))) {                        \
  52                 prev->thread.mflags &= ~MF_FPUBOUND;                    \
  53                 prev->cpus_allowed = prev->thread.user_cpus_allowed;    \
  54         }                                                               \
  55         if (cpu_has_dsp)                                                \
  56                 __save_dsp(prev);                                       \
  57         next->thread.emulated_fp = 0;                                   \
  58         (last) = resume(prev, next, next->thread_info);                 \
  59         if (cpu_has_dsp)                                                \
  60                 __restore_dsp(current);                                 \
  61 } while(0)
  62
  63 #else
  64 #define switch_to(prev,next,last)                                       \
  65 do {                                                                    \
  66         if (cpu_has_dsp)                                                \
  67                 __save_dsp(prev);                                       \
  68         (last) = resume(prev, next, task_thread_info(next));            \
  69         if (cpu_has_dsp)                                                \
  70                 __restore_dsp(current);                                 \
  71 } while(0)
  72 #endif
  73
  74 /*
  75  * On SMP systems, when the scheduler does migration-cost autodetection,
  76  * it needs a way to flush as much of the CPU's caches as possible.
  77  *
  78  * TODO: fill this in!
  79  */
  80 static inline void sched_cacheflush(void)
  81 {
  82 }
  83
  84 static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
  85 {
  86         __u32 retval;
  87
  88         if (cpu_has_llsc && R10000_LLSC_WAR) {
  89                 unsigned long dummy;
  90
  91                 __asm__ __volatile__(
  92                 "       .set    mips3                                   \n"
  93                 "1:     ll      %0, %3                  # xchg_u32      \n"
  94                 "       .set    mips0                                   \n"
  95                 "       move    %2, %z4                                 \n"
  96                 "       .set    mips3                                   \n"
  97                 "       sc      %2, %1                                  \n"
  98                 "       beqzl   %2, 1b                                  \n"
  99                 "       .set    mips0                                   \n"
 100                 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
 101                 : "R" (*m), "Jr" (val)
 102                 : "memory");
 103         } else if (cpu_has_llsc) {
 104                 unsigned long dummy;
 105
 106                 __asm__ __volatile__(
 107                 "       .set    mips3                                   \n"
 108                 "1:     ll      %0, %3                  # xchg_u32      \n"
 109                 "       .set    mips0                                   \n"
 110                 "       move    %2, %z4                                 \n"
 111                 "       .set    mips3                                   \n"
 112                 "       sc      %2, %1                                  \n"
 113                 "       beqz    %2, 2f                                  \n"
 114                 "       .subsection 2                                   \n"
 115                 "2:     b       1b                                      \n"
 116                 "       .previous                                       \n"
 117                 "       .set    mips0                                   \n"
 118                 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
 119                 : "R" (*m), "Jr" (val)
 120                 : "memory");
 121         } else {
 122                 unsigned long flags;
 123
 124                 raw_local_irq_save(flags);
 125                 retval = *m;
 126                 *m = val;
 127                 raw_local_irq_restore(flags);   /* implies memory barrier  */
 128         }
 129
 130         smp_mb();
 131
 132         return retval;
 133 }
 134
 135 #ifdef CONFIG_64BIT
 136 static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val)
 137 {
 138         __u64 retval;
 139
 140         if (cpu_has_llsc && R10000_LLSC_WAR) {
 141                 unsigned long dummy;
 142
 143                 __asm__ __volatile__(
 144                 "       .set    mips3                                   \n"
 145                 "1:     lld     %0, %3                  # xchg_u64      \n"
 146                 "       move    %2, %z4                                 \n"
 147                 "       scd     %2, %1                                  \n"
 148                 "       beqzl   %2, 1b                                  \n"
 149                 "       .set    mips0                                   \n"
 150                 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
 151                 : "R" (*m), "Jr" (val)
 152                 : "memory");
 153         } else if (cpu_has_llsc) {
 154                 unsigned long dummy;
 155
 156                 __asm__ __volatile__(
 157                 "       .set    mips3                                   \n"
 158                 "1:     lld     %0, %3                  # xchg_u64      \n"
 159                 "       move    %2, %z4                                 \n"
 160                 "       scd     %2, %1                                  \n"
 161                 "       beqz    %2, 2f                                  \n"
 162                 "       .subsection 2                                   \n"
 163                 "2:     b       1b                                      \n"
 164                 "       .previous                                       \n"
 165                 "       .set    mips0                                   \n"
 166                 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
 167                 : "R" (*m), "Jr" (val)
 168                 : "memory");
 169         } else {
 170                 unsigned long flags;
 171
 172                 raw_local_irq_save(flags);
 173                 retval = *m;
 174                 *m = val;
 175                 raw_local_irq_restore(flags);   /* implies memory barrier  */
 176         }
 177
 178         smp_mb();
 179
 180         return retval;
 181 }
 182 #else
 183 extern __u64 __xchg_u64_unsupported_on_32bit_kernels(volatile __u64 * m, __u64 val);
 184 #define __xchg_u64 __xchg_u64_unsupported_on_32bit_kernels
 185 #endif
 186
 187 /* This function doesn't exist, so you'll get a linker error
 188    if something tries to do an invalid xchg().  */
 189 extern void __xchg_called_with_bad_pointer(void);
 190
 191 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
 192 {
 193         switch (size) {
 194         case 4:
 195                 return __xchg_u32(ptr, x);
 196         case 8:
 197                 return __xchg_u64(ptr, x);
 198         }
 199         __xchg_called_with_bad_pointer();
 200         return x;
 201 }
 202
 203 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 204 #define tas(ptr) (xchg((ptr),1))
 205
 206 #define __HAVE_ARCH_CMPXCHG 1
 207
 208 static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old,
 209         unsigned long new)
 210 {
 211         __u32 retval;
 212
 213         if (cpu_has_llsc && R10000_LLSC_WAR) {
 214                 __asm__ __volatile__(
 215                 "       .set    push                                    \n"
 216                 "       .set    noat                                    \n"
 217                 "       .set    mips3                                   \n"
 218                 "1:     ll      %0, %2                  # __cmpxchg_u32 \n"
 219                 "       bne     %0, %z3, 2f                             \n"
 220                 "       .set    mips0                                   \n"
 221                 "       move    $1, %z4                                 \n"
 222                 "       .set    mips3                                   \n"
 223                 "       sc      $1, %1                                  \n"
 224                 "       beqzl   $1, 1b                                  \n"
 225                 "2:                                                     \n"
 226                 "       .set    pop                                     \n"
 227                 : "=&r" (retval), "=R" (*m)
 228                 : "R" (*m), "Jr" (old), "Jr" (new)
 229                 : "memory");
 230         } else if (cpu_has_llsc) {
 231                 __asm__ __volatile__(
 232                 "       .set    push                                    \n"
 233                 "       .set    noat                                    \n"
 234                 "       .set    mips3                                   \n"
 235                 "1:     ll      %0, %2                  # __cmpxchg_u32 \n"
 236                 "       bne     %0, %z3, 2f                             \n"
 237                 "       .set    mips0                                   \n"
 238                 "       move    $1, %z4                                 \n"
 239                 "       .set    mips3                                   \n"
 240                 "       sc      $1, %1                                  \n"
 241                 "       beqz    $1, 3f                                  \n"
 242                 "2:                                                     \n"
 243                 "       .subsection 2                                   \n"
 244                 "3:     b       1b                                      \n"
 245                 "       .previous                                       \n"
 246                 "       .set    pop                                     \n"
 247                 : "=&r" (retval), "=R" (*m)
 248                 : "R" (*m), "Jr" (old), "Jr" (new)
 249                 : "memory");
 250         } else {
 251                 unsigned long flags;
 252
 253                 raw_local_irq_save(flags);
 254                 retval = *m;
 255                 if (retval == old)
 256                         *m = new;
 257                 raw_local_irq_restore(flags);   /* implies memory barrier  */
 258         }
 259
 260         smp_mb();
 261
 262         return retval;
 263 }
 264
 265 #ifdef CONFIG_64BIT
 266 static inline unsigned long __cmpxchg_u64(volatile int * m, unsigned long old,
 267         unsigned long new)
 268 {
 269         __u64 retval;
 270
 271         if (cpu_has_llsc && R10000_LLSC_WAR) {
 272                 __asm__ __volatile__(
 273                 "       .set    push                                    \n"
 274                 "       .set    noat                                    \n"
 275                 "       .set    mips3                                   \n"
 276                 "1:     lld     %0, %2                  # __cmpxchg_u64 \n"
 277                 "       bne     %0, %z3, 2f                             \n"
 278                 "       move    $1, %z4                                 \n"
 279                 "       scd     $1, %1                                  \n"
 280                 "       beqzl   $1, 1b                                  \n"
 281                 "2:                                                     \n"
 282                 "       .set    pop                                     \n"
 283                 : "=&r" (retval), "=R" (*m)
 284                 : "R" (*m), "Jr" (old), "Jr" (new)
 285                 : "memory");
 286         } else if (cpu_has_llsc) {
 287                 __asm__ __volatile__(
 288                 "       .set    push                                    \n"
 289                 "       .set    noat                                    \n"
 290                 "       .set    mips3                                   \n"
 291                 "1:     lld     %0, %2                  # __cmpxchg_u64 \n"
 292                 "       bne     %0, %z3, 2f                             \n"
 293                 "       move    $1, %z4                                 \n"
 294                 "       scd     $1, %1                                  \n"
 295                 "       beqz    $1, 3f                                  \n"
 296                 "2:                                                     \n"
 297                 "       .subsection 2                                   \n"
 298                 "3:     b       1b                                      \n"
 299                 "       .previous                                       \n"
 300                 "       .set    pop                                     \n"
 301                 : "=&r" (retval), "=R" (*m)
 302                 : "R" (*m), "Jr" (old), "Jr" (new)
 303                 : "memory");
 304         } else {
 305                 unsigned long flags;
 306
 307                 raw_local_irq_save(flags);
 308                 retval = *m;
 309                 if (retval == old)
 310                         *m = new;
 311                 raw_local_irq_restore(flags);   /* implies memory barrier  */
 312         }
 313
 314         smp_mb();
 315
 316         return retval;
 317 }
 318 #else
 319 extern unsigned long __cmpxchg_u64_unsupported_on_32bit_kernels(
 320         volatile int * m, unsigned long old, unsigned long new);
 321 #define __cmpxchg_u64 __cmpxchg_u64_unsupported_on_32bit_kernels
 322 #endif
 323
 324 /* This function doesn't exist, so you'll get a linker error
 325    if something tries to do an invalid cmpxchg().  */
 326 extern void __cmpxchg_called_with_bad_pointer(void);
 327
 328 static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
 329         unsigned long new, int size)
 330 {
 331         switch (size) {
 332         case 4:
 333                 return __cmpxchg_u32(ptr, old, new);
 334         case 8:
 335                 return __cmpxchg_u64(ptr, old, new);
 336         }
 337         __cmpxchg_called_with_bad_pointer();
 338         return old;
 339 }
 340
 341 #define cmpxchg(ptr,old,new) ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(old), (unsigned long)(new),sizeof(*(ptr))))
 342
 343 extern void set_handler (unsigned long offset, void *addr, unsigned long len);
 344 extern void set_uncached_handler (unsigned long offset, void *addr, unsigned long len);
 345 extern void *set_vi_handler (int n, void *addr);
 346 extern void *set_except_vector(int n, void *addr);
 347 extern unsigned long ebase;
 348 extern void per_cpu_trap_init(void);
 349
 350 extern int stop_a_enabled;
 351
 352 /*
 353  * See include/asm-ia64/system.h; prevents deadlock on SMP
 354  * systems.
 355  */
 356 #define __ARCH_WANT_UNLOCKED_CTXSW
 357
 358 #define arch_align_stack(x) (x)
 359
 360 #endif /* _ASM_SYSTEM_H */