git.oblomov.eu Git - linux-2.6/blob - arch/ia64/kernel/fsys.S

   1 /*
   2  * This file contains the light-weight system call handlers (fsyscall-handlers).
   3  *
   4  * Copyright (C) 2003 Hewlett-Packard Co
   5  *      David Mosberger-Tang <davidm@hpl.hp.com>
   6  *
   7  * 25-Sep-03 davidm     Implement fsys_rt_sigprocmask().
   8  * 18-Feb-03 louisk     Implement fsys_gettimeofday().
   9  * 28-Feb-03 davidm     Fixed several bugs in fsys_gettimeofday().  Tuned it some more,
  10  *                      probably broke it along the way... ;-)
  11  * 13-Jul-04 clameter   Implement fsys_clock_gettime and revise fsys_gettimeofday to make
  12  *                      it capable of using memory based clocks without falling back to C code.
  13  * 08-Feb-07 Fenghua Yu Implement fsys_getcpu.
  14  *
  15  */
  16
  17 #include <asm/asmmacro.h>
  18 #include <asm/errno.h>
  19 #include <asm/asm-offsets.h>
  20 #include <asm/percpu.h>
  21 #include <asm/thread_info.h>
  22 #include <asm/sal.h>
  23 #include <asm/signal.h>
  24 #include <asm/system.h>
  25 #include <asm/unistd.h>
  26
  27 #include "entry.h"
  28
  29 /*
  30  * See Documentation/ia64/fsys.txt for details on fsyscalls.
  31  *
  32  * On entry to an fsyscall handler:
  33  *   r10        = 0 (i.e., defaults to "successful syscall return")
  34  *   r11        = saved ar.pfs (a user-level value)
  35  *   r15        = system call number
  36  *   r16        = "current" task pointer (in normal kernel-mode, this is in r13)
  37  *   r32-r39    = system call arguments
  38  *   b6         = return address (a user-level value)
  39  *   ar.pfs     = previous frame-state (a user-level value)
  40  *   PSR.be     = cleared to zero (i.e., little-endian byte order is in effect)
  41  *   all other registers may contain values passed in from user-mode
  42  *
  43  * On return from an fsyscall handler:
  44  *   r11        = saved ar.pfs (as passed into the fsyscall handler)
  45  *   r15        = system call number (as passed into the fsyscall handler)
  46  *   r32-r39    = system call arguments (as passed into the fsyscall handler)
  47  *   b6         = return address (as passed into the fsyscall handler)
  48  *   ar.pfs     = previous frame-state (as passed into the fsyscall handler)
  49  */
  50
  51 ENTRY(fsys_ni_syscall)
  52         .prologue
  53         .altrp b6
  54         .body
  55         mov r8=ENOSYS
  56         mov r10=-1
  57         FSYS_RETURN
  58 END(fsys_ni_syscall)
  59
  60 ENTRY(fsys_getpid)
  61         .prologue
  62         .altrp b6
  63         .body
  64         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
  65         ;;
  66         ld4 r9=[r9]
  67         add r8=IA64_TASK_TGID_OFFSET,r16
  68         ;;
  69         and r9=TIF_ALLWORK_MASK,r9
  70         ld4 r8=[r8]                             // r8 = current->tgid
  71         ;;
  72         cmp.ne p8,p0=0,r9
  73 (p8)    br.spnt.many fsys_fallback_syscall
  74         FSYS_RETURN
  75 END(fsys_getpid)
  76
  77 ENTRY(fsys_getppid)
  78         .prologue
  79         .altrp b6
  80         .body
  81         add r17=IA64_TASK_GROUP_LEADER_OFFSET,r16
  82         ;;
  83         ld8 r17=[r17]                           // r17 = current->group_leader
  84         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
  85         ;;
  86
  87         ld4 r9=[r9]
  88         add r17=IA64_TASK_REAL_PARENT_OFFSET,r17 // r17 = &current->group_leader->real_parent
  89         ;;
  90         and r9=TIF_ALLWORK_MASK,r9
  91
  92 1:      ld8 r18=[r17]                           // r18 = current->group_leader->real_parent
  93         ;;
  94         cmp.ne p8,p0=0,r9
  95         add r8=IA64_TASK_TGID_OFFSET,r18        // r8 = &current->group_leader->real_parent->tgid
  96         ;;
  97
  98         /*
  99          * The .acq is needed to ensure that the read of tgid has returned its data before
 100          * we re-check "real_parent".
 101          */
 102         ld4.acq r8=[r8]                         // r8 = current->group_leader->real_parent->tgid
 103 #ifdef CONFIG_SMP
 104         /*
 105          * Re-read current->group_leader->real_parent.
 106          */
 107         ld8 r19=[r17]                           // r19 = current->group_leader->real_parent
 108 (p8)    br.spnt.many fsys_fallback_syscall
 109         ;;
 110         cmp.ne p6,p0=r18,r19                    // did real_parent change?
 111         mov r19=0                       // i must not leak kernel bits...
 112 (p6)    br.cond.spnt.few 1b                     // yes -> redo the read of tgid and the check
 113         ;;
 114         mov r17=0                       // i must not leak kernel bits...
 115         mov r18=0                       // i must not leak kernel bits...
 116 #else
 117         mov r17=0                       // i must not leak kernel bits...
 118         mov r18=0                       // i must not leak kernel bits...
 119         mov r19=0                       // i must not leak kernel bits...
 120 #endif
 121         FSYS_RETURN
 122 END(fsys_getppid)
 123
 124 ENTRY(fsys_set_tid_address)
 125         .prologue
 126         .altrp b6
 127         .body
 128         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
 129         ;;
 130         ld4 r9=[r9]
 131         tnat.z p6,p7=r32                // check argument register for being NaT
 132         ;;
 133         and r9=TIF_ALLWORK_MASK,r9
 134         add r8=IA64_TASK_PID_OFFSET,r16
 135         add r18=IA64_TASK_CLEAR_CHILD_TID_OFFSET,r16
 136         ;;
 137         ld4 r8=[r8]
 138         cmp.ne p8,p0=0,r9
 139         mov r17=-1
 140         ;;
 141 (p6)    st8 [r18]=r32
 142 (p7)    st8 [r18]=r17
 143 (p8)    br.spnt.many fsys_fallback_syscall
 144         ;;
 145         mov r17=0                       // i must not leak kernel bits...
 146         mov r18=0                       // i must not leak kernel bits...
 147         FSYS_RETURN
 148 END(fsys_set_tid_address)
 149
 150 #if IA64_GTOD_LOCK_OFFSET !=0
 151 #error fsys_gettimeofday incompatible with changes to struct fsyscall_gtod_data_t
 152 #endif
 153 #if IA64_ITC_JITTER_OFFSET !=0
 154 #error fsys_gettimeofday incompatible with changes to struct itc_jitter_data_t
 155 #endif
 156 #define CLOCK_REALTIME 0
 157 #define CLOCK_MONOTONIC 1
 158 #define CLOCK_DIVIDE_BY_1000 0x4000
 159 #define CLOCK_ADD_MONOTONIC 0x8000
 160
 161 ENTRY(fsys_gettimeofday)
 162         .prologue
 163         .altrp b6
 164         .body
 165         mov r31 = r32
 166         tnat.nz p6,p0 = r33             // guard against NaT argument
 167 (p6)    br.cond.spnt.few .fail_einval
 168         mov r30 = CLOCK_DIVIDE_BY_1000
 169         ;;
 170 .gettime:
 171         // Register map
 172         // Incoming r31 = pointer to address where to place result
 173         //          r30 = flags determining how time is processed
 174         // r2,r3 = temp r4-r7 preserved
 175         // r8 = result nanoseconds
 176         // r9 = result seconds
 177         // r10 = temporary storage for clock difference
 178         // r11 = preserved: saved ar.pfs
 179         // r12 = preserved: memory stack
 180         // r13 = preserved: thread pointer
 181         // r14 = address of mask / mask value
 182         // r15 = preserved: system call number
 183         // r16 = preserved: current task pointer
 184         // r17 = (not used)
 185         // r18 = (not used)
 186         // r19 = address of itc_lastcycle
 187         // r20 = struct fsyscall_gtod_data (= address of gtod_lock.sequence)
 188         // r21 = address of mmio_ptr
 189         // r22 = address of wall_time or monotonic_time
 190         // r23 = address of shift / value
 191         // r24 = address mult factor / cycle_last value
 192         // r25 = itc_lastcycle value
 193         // r26 = address clocksource cycle_last
 194         // r27 = (not used)
 195         // r28 = sequence number at the beginning of critcal section
 196         // r29 = address of itc_jitter
 197         // r30 = time processing flags / memory address
 198         // r31 = pointer to result
 199         // Predicates
 200         // p6,p7 short term use
 201         // p8 = timesource ar.itc
 202         // p9 = timesource mmio64
 203         // p10 = timesource mmio32 - not used
 204         // p11 = timesource not to be handled by asm code
 205         // p12 = memory time source ( = p9 | p10) - not used
 206         // p13 = do cmpxchg with itc_lastcycle
 207         // p14 = Divide by 1000
 208         // p15 = Add monotonic
 209         //
 210         // Note that instructions are optimized for McKinley. McKinley can
 211         // process two bundles simultaneously and therefore we continuously
 212         // try to feed the CPU two bundles and then a stop.
 213
 214         add r2 = TI_FLAGS+IA64_TASK_SIZE,r16
 215         tnat.nz p6,p0 = r31             // guard against Nat argument
 216 (p6)    br.cond.spnt.few .fail_einval
 217         movl r20 = fsyscall_gtod_data // load fsyscall gettimeofday data address
 218         ;;
 219         ld4 r2 = [r2]                   // process work pending flags
 220         movl r29 = itc_jitter_data      // itc_jitter
 221         add r22 = IA64_GTOD_WALL_TIME_OFFSET,r20        // wall_time
 222         add r21 = IA64_CLKSRC_MMIO_OFFSET,r20
 223         mov pr = r30,0xc000     // Set predicates according to function
 224         ;;
 225         and r2 = TIF_ALLWORK_MASK,r2
 226         add r19 = IA64_ITC_LASTCYCLE_OFFSET,r29
 227 (p15)   add r22 = IA64_GTOD_MONO_TIME_OFFSET,r20        // monotonic_time
 228         ;;
 229         add r26 = IA64_CLKSRC_CYCLE_LAST_OFFSET,r20     // clksrc_cycle_last
 230         cmp.ne p6, p0 = 0, r2   // Fallback if work is scheduled
 231 (p6)    br.cond.spnt.many fsys_fallback_syscall
 232         ;;
 233         // Begin critical section
 234 .time_redo:
 235         ld4.acq r28 = [r20]     // gtod_lock.sequence, Must take first
 236         ;;
 237         and r28 = ~1,r28        // And make sequence even to force retry if odd
 238         ;;
 239         ld8 r30 = [r21]         // clocksource->mmio_ptr
 240         add r24 = IA64_CLKSRC_MULT_OFFSET,r20
 241         ld4 r2 = [r29]          // itc_jitter value
 242         add r23 = IA64_CLKSRC_SHIFT_OFFSET,r20
 243         add r14 = IA64_CLKSRC_MASK_OFFSET,r20
 244         ;;
 245         ld4 r3 = [r24]          // clocksource mult value
 246         ld8 r14 = [r14]         // clocksource mask value
 247         cmp.eq p8,p9 = 0,r30    // use cpu timer if no mmio_ptr
 248         ;;
 249         setf.sig f7 = r3        // Setup for mult scaling of counter
 250 (p8)    cmp.ne p13,p0 = r2,r0   // need itc_jitter compensation, set p13
 251         ld4 r23 = [r23]         // clocksource shift value
 252         ld8 r24 = [r26]         // get clksrc_cycle_last value
 253 (p9)    cmp.eq p13,p0 = 0,r30   // if mmio_ptr, clear p13 jitter control
 254         ;;
 255         .pred.rel.mutex p8,p9
 256 (p8)    mov r2 = ar.itc         // CPU_TIMER. 36 clocks latency!!!
 257 (p9)    ld8 r2 = [r30]          // MMIO_TIMER. Could also have latency issues..
 258 (p13)   ld8 r25 = [r19]         // get itc_lastcycle value
 259         ld8 r9 = [r22],IA64_TIMESPEC_TV_NSEC_OFFSET     // tv_sec
 260         ;;
 261         ld8 r8 = [r22],-IA64_TIMESPEC_TV_NSEC_OFFSET    // tv_nsec
 262 (p13)   sub r3 = r25,r2         // Diff needed before comparison (thanks davidm)
 263         ;;
 264 (p13)   cmp.gt.unc p6,p7 = r3,r0 // check if it is less than last. p6,p7 cleared
 265         sub r10 = r2,r24        // current_cycle - last_cycle
 266         ;;
 267 (p6)    sub r10 = r25,r24       // time we got was less than last_cycle
 268 (p7)    mov ar.ccv = r25        // more than last_cycle. Prep for cmpxchg
 269         ;;
 270 (p7)    cmpxchg8.rel r3 = [r19],r2,ar.ccv
 271         ;;
 272 (p7)    cmp.ne p7,p0 = r25,r3   // if cmpxchg not successful
 273         ;;
 274 (p7)    sub r10 = r3,r24        // then use new last_cycle instead
 275         ;;
 276         and r10 = r10,r14       // Apply mask
 277         ;;
 278         setf.sig f8 = r10
 279         nop.i 123
 280         ;;
 281         // fault check takes 5 cycles and we have spare time
 282 EX(.fail_efault, probe.w.fault r31, 3)
 283         xmpy.l f8 = f8,f7       // nsec_per_cyc*(counter-last_counter)
 284         ;;
 285         getf.sig r2 = f8
 286         mf
 287         ;;
 288         ld4 r10 = [r20]         // gtod_lock.sequence
 289         shr.u r2 = r2,r23       // shift by factor
 290         ;;
 291         add r8 = r8,r2          // Add xtime.nsecs
 292         cmp4.ne p7,p0 = r28,r10
 293 (p7)    br.cond.dpnt.few .time_redo     // sequence number changed, redo
 294         // End critical section.
 295         // Now r8=tv->tv_nsec and r9=tv->tv_sec
 296         mov r10 = r0
 297         movl r2 = 1000000000
 298         add r23 = IA64_TIMESPEC_TV_NSEC_OFFSET, r31
 299 (p14)   movl r3 = 2361183241434822607   // Prep for / 1000 hack
 300         ;;
 301 .time_normalize:
 302         mov r21 = r8
 303         cmp.ge p6,p0 = r8,r2
 304 (p14)   shr.u r20 = r8, 3 // We can repeat this if necessary just wasting time
 305         ;;
 306 (p14)   setf.sig f8 = r20
 307 (p6)    sub r8 = r8,r2
 308 (p6)    add r9 = 1,r9           // two nops before the branch.
 309 (p14)   setf.sig f7 = r3        // Chances for repeats are 1 in 10000 for gettod
 310 (p6)    br.cond.dpnt.few .time_normalize
 311         ;;
 312         // Divided by 8 though shift. Now divide by 125
 313         // The compiler was able to do that with a multiply
 314         // and a shift and we do the same
 315 EX(.fail_efault, probe.w.fault r23, 3)  // This also costs 5 cycles
 316 (p14)   xmpy.hu f8 = f8, f7             // xmpy has 5 cycles latency so use it
 317         ;;
 318 (p14)   getf.sig r2 = f8
 319         ;;
 320         mov r8 = r0
 321 (p14)   shr.u r21 = r2, 4
 322         ;;
 323 EX(.fail_efault, st8 [r31] = r9)
 324 EX(.fail_efault, st8 [r23] = r21)
 325         FSYS_RETURN
 326 .fail_einval:
 327         mov r8 = EINVAL
 328         mov r10 = -1
 329         FSYS_RETURN
 330 .fail_efault:
 331         mov r8 = EFAULT
 332         mov r10 = -1
 333         FSYS_RETURN
 334 END(fsys_gettimeofday)
 335
 336 ENTRY(fsys_clock_gettime)
 337         .prologue
 338         .altrp b6
 339         .body
 340         cmp4.ltu p6, p0 = CLOCK_MONOTONIC, r32
 341         // Fallback if this is not CLOCK_REALTIME or CLOCK_MONOTONIC
 342 (p6)    br.spnt.few fsys_fallback_syscall
 343         mov r31 = r33
 344         shl r30 = r32,15
 345         br.many .gettime
 346 END(fsys_clock_gettime)
 347
 348 /*
 349  * long fsys_rt_sigprocmask (int how, sigset_t *set, sigset_t *oset, size_t sigsetsize).
 350  */
 351 #if _NSIG_WORDS != 1
 352 # error Sorry, fsys_rt_sigprocmask() needs to be updated for _NSIG_WORDS != 1.
 353 #endif
 354 ENTRY(fsys_rt_sigprocmask)
 355         .prologue
 356         .altrp b6
 357         .body
 358
 359         add r2=IA64_TASK_BLOCKED_OFFSET,r16
 360         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
 361         cmp4.ltu p6,p0=SIG_SETMASK,r32
 362
 363         cmp.ne p15,p0=r0,r34                    // oset != NULL?
 364         tnat.nz p8,p0=r34
 365         add r31=IA64_TASK_SIGHAND_OFFSET,r16
 366         ;;
 367         ld8 r3=[r2]                             // read/prefetch current->blocked
 368         ld4 r9=[r9]
 369         tnat.nz.or p6,p0=r35
 370
 371         cmp.ne.or p6,p0=_NSIG_WORDS*8,r35
 372         tnat.nz.or p6,p0=r32
 373 (p6)    br.spnt.few .fail_einval                // fail with EINVAL
 374         ;;
 375 #ifdef CONFIG_SMP
 376         ld8 r31=[r31]                           // r31 <- current->sighand
 377 #endif
 378         and r9=TIF_ALLWORK_MASK,r9
 379         tnat.nz.or p8,p0=r33
 380         ;;
 381         cmp.ne p7,p0=0,r9
 382         cmp.eq p6,p0=r0,r33                     // set == NULL?
 383         add r31=IA64_SIGHAND_SIGLOCK_OFFSET,r31 // r31 <- current->sighand->siglock
 384 (p8)    br.spnt.few .fail_efault                // fail with EFAULT
 385 (p7)    br.spnt.many fsys_fallback_syscall      // got pending kernel work...
 386 (p6)    br.dpnt.many .store_mask                // -> short-circuit to just reading the signal mask
 387
 388         /* Argh, we actually have to do some work and _update_ the signal mask: */
 389
 390 EX(.fail_efault, probe.r.fault r33, 3)          // verify user has read-access to *set
 391 EX(.fail_efault, ld8 r14=[r33])                 // r14 <- *set
 392         mov r17=(1 << (SIGKILL - 1)) | (1 << (SIGSTOP - 1))
 393         ;;
 394
 395         rsm psr.i                               // mask interrupt delivery
 396         mov ar.ccv=0
 397         andcm r14=r14,r17                       // filter out SIGKILL & SIGSTOP
 398
 399 #ifdef CONFIG_SMP
 400         mov r17=1
 401         ;;
 402         cmpxchg4.acq r18=[r31],r17,ar.ccv       // try to acquire the lock
 403         mov r8=EINVAL                   // default to EINVAL
 404         ;;
 405         ld8 r3=[r2]                     // re-read current->blocked now that we hold the lock
 406         cmp4.ne p6,p0=r18,r0
 407 (p6)    br.cond.spnt.many .lock_contention
 408         ;;
 409 #else
 410         ld8 r3=[r2]                     // re-read current->blocked now that we hold the lock
 411         mov r8=EINVAL                   // default to EINVAL
 412 #endif
 413         add r18=IA64_TASK_PENDING_OFFSET+IA64_SIGPENDING_SIGNAL_OFFSET,r16
 414         add r19=IA64_TASK_SIGNAL_OFFSET,r16
 415         cmp4.eq p6,p0=SIG_BLOCK,r32
 416         ;;
 417         ld8 r19=[r19]                   // r19 <- current->signal
 418         cmp4.eq p7,p0=SIG_UNBLOCK,r32
 419         cmp4.eq p8,p0=SIG_SETMASK,r32
 420         ;;
 421         ld8 r18=[r18]                   // r18 <- current->pending.signal
 422         .pred.rel.mutex p6,p7,p8
 423 (p6)    or r14=r3,r14                   // SIG_BLOCK
 424 (p7)    andcm r14=r3,r14                // SIG_UNBLOCK
 425
 426 (p8)    mov r14=r14                     // SIG_SETMASK
 427 (p6)    mov r8=0                        // clear error code
 428         // recalc_sigpending()
 429         add r17=IA64_SIGNAL_GROUP_STOP_COUNT_OFFSET,r19
 430
 431         add r19=IA64_SIGNAL_SHARED_PENDING_OFFSET+IA64_SIGPENDING_SIGNAL_OFFSET,r19
 432         ;;
 433         ld4 r17=[r17]           // r17 <- current->signal->group_stop_count
 434 (p7)    mov r8=0                // clear error code
 435
 436         ld8 r19=[r19]           // r19 <- current->signal->shared_pending
 437         ;;
 438         cmp4.gt p6,p7=r17,r0    // p6/p7 <- (current->signal->group_stop_count > 0)?
 439 (p8)    mov r8=0                // clear error code
 440
 441         or r18=r18,r19          // r18 <- current->pending | current->signal->shared_pending
 442         ;;
 443         // r18 <- (current->pending | current->signal->shared_pending) & ~current->blocked:
 444         andcm r18=r18,r14
 445         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
 446         ;;
 447
 448 (p7)    cmp.ne.or.andcm p6,p7=r18,r0            // p6/p7 <- signal pending
 449         mov r19=0                                       // i must not leak kernel bits...
 450 (p6)    br.cond.dpnt.many .sig_pending
 451         ;;
 452
 453 1:      ld4 r17=[r9]                            // r17 <- current->thread_info->flags
 454         ;;
 455         mov ar.ccv=r17
 456         and r18=~_TIF_SIGPENDING,r17            // r18 <- r17 & ~(1 << TIF_SIGPENDING)
 457         ;;
 458
 459         st8 [r2]=r14                            // update current->blocked with new mask
 460         cmpxchg4.acq r8=[r9],r18,ar.ccv         // current->thread_info->flags <- r18
 461         ;;
 462         cmp.ne p6,p0=r17,r8                     // update failed?
 463 (p6)    br.cond.spnt.few 1b                     // yes -> retry
 464
 465 #ifdef CONFIG_SMP
 466         st4.rel [r31]=r0                        // release the lock
 467 #endif
 468         ssm psr.i
 469         ;;
 470
 471         srlz.d                                  // ensure psr.i is set again
 472         mov r18=0                                       // i must not leak kernel bits...
 473
 474 .store_mask:
 475 EX(.fail_efault, (p15) probe.w.fault r34, 3)    // verify user has write-access to *oset
 476 EX(.fail_efault, (p15) st8 [r34]=r3)
 477         mov r2=0                                        // i must not leak kernel bits...
 478         mov r3=0                                        // i must not leak kernel bits...
 479         mov r8=0                                // return 0
 480         mov r9=0                                        // i must not leak kernel bits...
 481         mov r14=0                                       // i must not leak kernel bits...
 482         mov r17=0                                       // i must not leak kernel bits...
 483         mov r31=0                                       // i must not leak kernel bits...
 484         FSYS_RETURN
 485
 486 .sig_pending:
 487 #ifdef CONFIG_SMP
 488         st4.rel [r31]=r0                        // release the lock
 489 #endif
 490         ssm psr.i
 491         ;;
 492         srlz.d
 493         br.sptk.many fsys_fallback_syscall      // with signal pending, do the heavy-weight syscall
 494
 495 #ifdef CONFIG_SMP
 496 .lock_contention:
 497         /* Rather than spinning here, fall back on doing a heavy-weight syscall.  */
 498         ssm psr.i
 499         ;;
 500         srlz.d
 501         br.sptk.many fsys_fallback_syscall
 502 #endif
 503 END(fsys_rt_sigprocmask)
 504
 505 /*
 506  * fsys_getcpu doesn't use the third parameter in this implementation. It reads
 507  * current_thread_info()->cpu and corresponding node in cpu_to_node_map.
 508  */
 509 ENTRY(fsys_getcpu)
 510         .prologue
 511         .altrp b6
 512         .body
 513         ;;
 514         add r2=TI_FLAGS+IA64_TASK_SIZE,r16
 515         tnat.nz p6,p0 = r32                     // guard against NaT argument
 516         add r3=TI_CPU+IA64_TASK_SIZE,r16
 517         ;;
 518         ld4 r3=[r3]                             // M r3 = thread_info->cpu
 519         ld4 r2=[r2]                             // M r2 = thread_info->flags
 520 (p6)    br.cond.spnt.few .fail_einval           // B
 521         ;;
 522         tnat.nz p7,p0 = r33                     // I guard against NaT argument
 523 (p7)    br.cond.spnt.few .fail_einval           // B
 524 #ifdef CONFIG_NUMA
 525         movl r17=cpu_to_node_map
 526         ;;
 527 EX(.fail_efault, probe.w.fault r32, 3)          // M This takes 5 cycles
 528 EX(.fail_efault, probe.w.fault r33, 3)          // M This takes 5 cycles
 529         shladd r18=r3,1,r17
 530         ;;
 531         ld2 r20=[r18]                           // r20 = cpu_to_node_map[cpu]
 532         and r2 = TIF_ALLWORK_MASK,r2
 533         ;;
 534         cmp.ne p8,p0=0,r2
 535 (p8)    br.spnt.many fsys_fallback_syscall
 536         ;;
 537         ;;
 538 EX(.fail_efault, st4 [r32] = r3)
 539 EX(.fail_efault, st2 [r33] = r20)
 540         mov r8=0
 541         ;;
 542 #else
 543 EX(.fail_efault, probe.w.fault r32, 3)          // M This takes 5 cycles
 544 EX(.fail_efault, probe.w.fault r33, 3)          // M This takes 5 cycles
 545         and r2 = TIF_ALLWORK_MASK,r2
 546         ;;
 547         cmp.ne p8,p0=0,r2
 548 (p8)    br.spnt.many fsys_fallback_syscall
 549         ;;
 550 EX(.fail_efault, st4 [r32] = r3)
 551 EX(.fail_efault, st2 [r33] = r0)
 552         mov r8=0
 553         ;;
 554 #endif
 555         FSYS_RETURN
 556 END(fsys_getcpu)
 557
 558 ENTRY(fsys_fallback_syscall)
 559         .prologue
 560         .altrp b6
 561         .body
 562         /*
 563          * We only get here from light-weight syscall handlers.  Thus, we already
 564          * know that r15 contains a valid syscall number.  No need to re-check.
 565          */
 566         adds r17=-1024,r15
 567         movl r14=sys_call_table
 568         ;;
 569         rsm psr.i
 570         shladd r18=r17,3,r14
 571         ;;
 572         ld8 r18=[r18]                           // load normal (heavy-weight) syscall entry-point
 573         mov r29=psr                             // read psr (12 cyc load latency)
 574         mov r27=ar.rsc
 575         mov r21=ar.fpsr
 576         mov r26=ar.pfs
 577 END(fsys_fallback_syscall)
 578         /* FALL THROUGH */
 579 GLOBAL_ENTRY(fsys_bubble_down)
 580         .prologue
 581         .altrp b6
 582         .body
 583         /*
 584          * We get here for syscalls that don't have a lightweight
 585          * handler.  For those, we need to bubble down into the kernel
 586          * and that requires setting up a minimal pt_regs structure,
 587          * and initializing the CPU state more or less as if an
 588          * interruption had occurred.  To make syscall-restarts work,
 589          * we setup pt_regs such that cr_iip points to the second
 590          * instruction in syscall_via_break.  Decrementing the IP
 591          * hence will restart the syscall via break and not
 592          * decrementing IP will return us to the caller, as usual.
 593          * Note that we preserve the value of psr.pp rather than
 594          * initializing it from dcr.pp.  This makes it possible to
 595          * distinguish fsyscall execution from other privileged
 596          * execution.
 597          *
 598          * On entry:
 599          *      - normal fsyscall handler register usage, except
 600          *        that we also have:
 601          *      - r18: address of syscall entry point
 602          *      - r21: ar.fpsr
 603          *      - r26: ar.pfs
 604          *      - r27: ar.rsc
 605          *      - r29: psr
 606          *
 607          * We used to clear some PSR bits here but that requires slow
 608          * serialization.  Fortuntely, that isn't really necessary.
 609          * The rationale is as follows: we used to clear bits
 610          * ~PSR_PRESERVED_BITS in PSR.L.  Since
 611          * PSR_PRESERVED_BITS==PSR.{UP,MFL,MFH,PK,DT,PP,SP,RT,IC}, we
 612          * ended up clearing PSR.{BE,AC,I,DFL,DFH,DI,DB,SI,TB}.
 613          * However,
 614          *
 615          * PSR.BE : already is turned off in __kernel_syscall_via_epc()
 616          * PSR.AC : don't care (kernel normally turns PSR.AC on)
 617          * PSR.I  : already turned off by the time fsys_bubble_down gets
 618          *          invoked
 619          * PSR.DFL: always 0 (kernel never turns it on)
 620          * PSR.DFH: don't care --- kernel never touches f32-f127 on its own
 621          *          initiative
 622          * PSR.DI : always 0 (kernel never turns it on)
 623          * PSR.SI : always 0 (kernel never turns it on)
 624          * PSR.DB : don't care --- kernel never enables kernel-level
 625          *          breakpoints
 626          * PSR.TB : must be 0 already; if it wasn't zero on entry to
 627          *          __kernel_syscall_via_epc, the branch to fsys_bubble_down
 628          *          will trigger a taken branch; the taken-trap-handler then
 629          *          converts the syscall into a break-based system-call.
 630          */
 631         /*
 632          * Reading psr.l gives us only bits 0-31, psr.it, and psr.mc.
 633          * The rest we have to synthesize.
 634          */
 635 #       define PSR_ONE_BITS             ((3 << IA64_PSR_CPL0_BIT)       \
 636                                          | (0x1 << IA64_PSR_RI_BIT)     \
 637                                          | IA64_PSR_BN | IA64_PSR_I)
 638
 639         invala                                  // M0|1
 640         movl r14=ia64_ret_from_syscall          // X
 641
 642         nop.m 0
 643         movl r28=__kernel_syscall_via_break     // X    create cr.iip
 644         ;;
 645
 646         mov r2=r16                              // A    get task addr to addl-addressable register
 647         adds r16=IA64_TASK_THREAD_ON_USTACK_OFFSET,r16 // A
 648         mov r31=pr                              // I0   save pr (2 cyc)
 649         ;;
 650         st1 [r16]=r0                            // M2|3 clear current->thread.on_ustack flag
 651         addl r22=IA64_RBS_OFFSET,r2             // A    compute base of RBS
 652         add r3=TI_FLAGS+IA64_TASK_SIZE,r2       // A
 653         ;;
 654         ld4 r3=[r3]                             // M0|1 r3 = current_thread_info()->flags
 655         lfetch.fault.excl.nt1 [r22]             // M0|1 prefetch register backing-store
 656         nop.i 0
 657         ;;
 658         mov ar.rsc=0                            // M2   set enforced lazy mode, pl 0, LE, loadrs=0
 659         nop.m 0
 660         nop.i 0
 661         ;;
 662         mov r23=ar.bspstore                     // M2 (12 cyc) save ar.bspstore
 663         mov.m r24=ar.rnat                       // M2 (5 cyc) read ar.rnat (dual-issues!)
 664         nop.i 0
 665         ;;
 666         mov ar.bspstore=r22                     // M2 (6 cyc) switch to kernel RBS
 667         movl r8=PSR_ONE_BITS                    // X
 668         ;;
 669         mov r25=ar.unat                         // M2 (5 cyc) save ar.unat
 670         mov r19=b6                              // I0   save b6 (2 cyc)
 671         mov r20=r1                              // A    save caller's gp in r20
 672         ;;
 673         or r29=r8,r29                           // A    construct cr.ipsr value to save
 674         mov b6=r18                              // I0   copy syscall entry-point to b6 (7 cyc)
 675         addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r2 // A compute base of memory stack
 676
 677         mov r18=ar.bsp                          // M2   save (kernel) ar.bsp (12 cyc)
 678         cmp.ne pKStk,pUStk=r0,r0                // A    set pKStk <- 0, pUStk <- 1
 679         br.call.sptk.many b7=ia64_syscall_setup // B
 680         ;;
 681         mov ar.rsc=0x3                          // M2   set eager mode, pl 0, LE, loadrs=0
 682         mov rp=r14                              // I0   set the real return addr
 683         and r3=_TIF_SYSCALL_TRACEAUDIT,r3       // A
 684         ;;
 685         ssm psr.i                               // M2   we're on kernel stacks now, reenable irqs
 686         cmp.eq p8,p0=r3,r0                      // A
 687 (p10)   br.cond.spnt.many ia64_ret_from_syscall // B    return if bad call-frame or r15 is a NaT
 688
 689         nop.m 0
 690 (p8)    br.call.sptk.many b6=b6                 // B    (ignore return address)
 691         br.cond.spnt ia64_trace_syscall         // B
 692 END(fsys_bubble_down)
 693
 694         .rodata
 695         .align 8
 696         .globl fsyscall_table
 697
 698         data8 fsys_bubble_down
 699 fsyscall_table:
 700         data8 fsys_ni_syscall
 701         data8 0                         // exit                 // 1025
 702         data8 0                         // read
 703         data8 0                         // write
 704         data8 0                         // open
 705         data8 0                         // close
 706         data8 0                         // creat                // 1030
 707         data8 0                         // link
 708         data8 0                         // unlink
 709         data8 0                         // execve
 710         data8 0                         // chdir
 711         data8 0                         // fchdir               // 1035
 712         data8 0                         // utimes
 713         data8 0                         // mknod
 714         data8 0                         // chmod
 715         data8 0                         // chown
 716         data8 0                         // lseek                // 1040
 717         data8 fsys_getpid               // getpid
 718         data8 fsys_getppid              // getppid
 719         data8 0                         // mount
 720         data8 0                         // umount
 721         data8 0                         // setuid               // 1045
 722         data8 0                         // getuid
 723         data8 0                         // geteuid
 724         data8 0                         // ptrace
 725         data8 0                         // access
 726         data8 0                         // sync                 // 1050
 727         data8 0                         // fsync
 728         data8 0                         // fdatasync
 729         data8 0                         // kill
 730         data8 0                         // rename
 731         data8 0                         // mkdir                // 1055
 732         data8 0                         // rmdir
 733         data8 0                         // dup
 734         data8 0                         // pipe
 735         data8 0                         // times
 736         data8 0                         // brk                  // 1060
 737         data8 0                         // setgid
 738         data8 0                         // getgid
 739         data8 0                         // getegid
 740         data8 0                         // acct
 741         data8 0                         // ioctl                // 1065
 742         data8 0                         // fcntl
 743         data8 0                         // umask
 744         data8 0                         // chroot
 745         data8 0                         // ustat
 746         data8 0                         // dup2                 // 1070
 747         data8 0                         // setreuid
 748         data8 0                         // setregid
 749         data8 0                         // getresuid
 750         data8 0                         // setresuid
 751         data8 0                         // getresgid            // 1075
 752         data8 0                         // setresgid
 753         data8 0                         // getgroups
 754         data8 0                         // setgroups
 755         data8 0                         // getpgid
 756         data8 0                         // setpgid              // 1080
 757         data8 0                         // setsid
 758         data8 0                         // getsid
 759         data8 0                         // sethostname
 760         data8 0                         // setrlimit
 761         data8 0                         // getrlimit            // 1085
 762         data8 0                         // getrusage
 763         data8 fsys_gettimeofday         // gettimeofday
 764         data8 0                         // settimeofday
 765         data8 0                         // select
 766         data8 0                         // poll                 // 1090
 767         data8 0                         // symlink
 768         data8 0                         // readlink
 769         data8 0                         // uselib
 770         data8 0                         // swapon
 771         data8 0                         // swapoff              // 1095
 772         data8 0                         // reboot
 773         data8 0                         // truncate
 774         data8 0                         // ftruncate
 775         data8 0                         // fchmod
 776         data8 0                         // fchown               // 1100
 777         data8 0                         // getpriority
 778         data8 0                         // setpriority
 779         data8 0                         // statfs
 780         data8 0                         // fstatfs
 781         data8 0                         // gettid               // 1105
 782         data8 0                         // semget
 783         data8 0                         // semop
 784         data8 0                         // semctl
 785         data8 0                         // msgget
 786         data8 0                         // msgsnd               // 1110
 787         data8 0                         // msgrcv
 788         data8 0                         // msgctl
 789         data8 0                         // shmget
 790         data8 0                         // shmat
 791         data8 0                         // shmdt                // 1115
 792         data8 0                         // shmctl
 793         data8 0                         // syslog
 794         data8 0                         // setitimer
 795         data8 0                         // getitimer
 796         data8 0                                                 // 1120
 797         data8 0
 798         data8 0
 799         data8 0                         // vhangup
 800         data8 0                         // lchown
 801         data8 0                         // remap_file_pages     // 1125
 802         data8 0                         // wait4
 803         data8 0                         // sysinfo
 804         data8 0                         // clone
 805         data8 0                         // setdomainname
 806         data8 0                         // newuname             // 1130
 807         data8 0                         // adjtimex
 808         data8 0
 809         data8 0                         // init_module
 810         data8 0                         // delete_module
 811         data8 0                                                 // 1135
 812         data8 0
 813         data8 0                         // quotactl
 814         data8 0                         // bdflush
 815         data8 0                         // sysfs
 816         data8 0                         // personality          // 1140
 817         data8 0                         // afs_syscall
 818         data8 0                         // setfsuid
 819         data8 0                         // setfsgid
 820         data8 0                         // getdents
 821         data8 0                         // flock                // 1145
 822         data8 0                         // readv
 823         data8 0                         // writev
 824         data8 0                         // pread64
 825         data8 0                         // pwrite64
 826         data8 0                         // sysctl               // 1150
 827         data8 0                         // mmap
 828         data8 0                         // munmap
 829         data8 0                         // mlock
 830         data8 0                         // mlockall
 831         data8 0                         // mprotect             // 1155
 832         data8 0                         // mremap
 833         data8 0                         // msync
 834         data8 0                         // munlock
 835         data8 0                         // munlockall
 836         data8 0                         // sched_getparam       // 1160
 837         data8 0                         // sched_setparam
 838         data8 0                         // sched_getscheduler
 839         data8 0                         // sched_setscheduler
 840         data8 0                         // sched_yield
 841         data8 0                         // sched_get_priority_max       // 1165
 842         data8 0                         // sched_get_priority_min
 843         data8 0                         // sched_rr_get_interval
 844         data8 0                         // nanosleep
 845         data8 0                         // nfsservctl
 846         data8 0                         // prctl                // 1170
 847         data8 0                         // getpagesize
 848         data8 0                         // mmap2
 849         data8 0                         // pciconfig_read
 850         data8 0                         // pciconfig_write
 851         data8 0                         // perfmonctl           // 1175
 852         data8 0                         // sigaltstack
 853         data8 0                         // rt_sigaction
 854         data8 0                         // rt_sigpending
 855         data8 fsys_rt_sigprocmask       // rt_sigprocmask
 856         data8 0                         // rt_sigqueueinfo      // 1180
 857         data8 0                         // rt_sigreturn
 858         data8 0                         // rt_sigsuspend
 859         data8 0                         // rt_sigtimedwait
 860         data8 0                         // getcwd
 861         data8 0                         // capget               // 1185
 862         data8 0                         // capset
 863         data8 0                         // sendfile
 864         data8 0
 865         data8 0
 866         data8 0                         // socket               // 1190
 867         data8 0                         // bind
 868         data8 0                         // connect
 869         data8 0                         // listen
 870         data8 0                         // accept
 871         data8 0                         // getsockname          // 1195
 872         data8 0                         // getpeername
 873         data8 0                         // socketpair
 874         data8 0                         // send
 875         data8 0                         // sendto
 876         data8 0                         // recv                 // 1200
 877         data8 0                         // recvfrom
 878         data8 0                         // shutdown
 879         data8 0                         // setsockopt
 880         data8 0                         // getsockopt
 881         data8 0                         // sendmsg              // 1205
 882         data8 0                         // recvmsg
 883         data8 0                         // pivot_root
 884         data8 0                         // mincore
 885         data8 0                         // madvise
 886         data8 0                         // newstat              // 1210
 887         data8 0                         // newlstat
 888         data8 0                         // newfstat
 889         data8 0                         // clone2
 890         data8 0                         // getdents64
 891         data8 0                         // getunwind            // 1215
 892         data8 0                         // readahead
 893         data8 0                         // setxattr
 894         data8 0                         // lsetxattr
 895         data8 0                         // fsetxattr
 896         data8 0                         // getxattr             // 1220
 897         data8 0                         // lgetxattr
 898         data8 0                         // fgetxattr
 899         data8 0                         // listxattr
 900         data8 0                         // llistxattr
 901         data8 0                         // flistxattr           // 1225
 902         data8 0                         // removexattr
 903         data8 0                         // lremovexattr
 904         data8 0                         // fremovexattr
 905         data8 0                         // tkill
 906         data8 0                         // futex                // 1230
 907         data8 0                         // sched_setaffinity
 908         data8 0                         // sched_getaffinity
 909         data8 fsys_set_tid_address      // set_tid_address
 910         data8 0                         // fadvise64_64
 911         data8 0                         // tgkill               // 1235
 912         data8 0                         // exit_group
 913         data8 0                         // lookup_dcookie
 914         data8 0                         // io_setup
 915         data8 0                         // io_destroy
 916         data8 0                         // io_getevents         // 1240
 917         data8 0                         // io_submit
 918         data8 0                         // io_cancel
 919         data8 0                         // epoll_create
 920         data8 0                         // epoll_ctl
 921         data8 0                         // epoll_wait           // 1245
 922         data8 0                         // restart_syscall
 923         data8 0                         // semtimedop
 924         data8 0                         // timer_create
 925         data8 0                         // timer_settime
 926         data8 0                         // timer_gettime        // 1250
 927         data8 0                         // timer_getoverrun
 928         data8 0                         // timer_delete
 929         data8 0                         // clock_settime
 930         data8 fsys_clock_gettime        // clock_gettime
 931         data8 0                         // clock_getres         // 1255
 932         data8 0                         // clock_nanosleep
 933         data8 0                         // fstatfs64
 934         data8 0                         // statfs64
 935         data8 0                         // mbind
 936         data8 0                         // get_mempolicy        // 1260
 937         data8 0                         // set_mempolicy
 938         data8 0                         // mq_open
 939         data8 0                         // mq_unlink
 940         data8 0                         // mq_timedsend
 941         data8 0                         // mq_timedreceive      // 1265
 942         data8 0                         // mq_notify
 943         data8 0                         // mq_getsetattr
 944         data8 0                         // kexec_load
 945         data8 0                         // vserver
 946         data8 0                         // waitid               // 1270
 947         data8 0                         // add_key
 948         data8 0                         // request_key
 949         data8 0                         // keyctl
 950         data8 0                         // ioprio_set
 951         data8 0                         // ioprio_get           // 1275
 952         data8 0                         // move_pages
 953         data8 0                         // inotify_init
 954         data8 0                         // inotify_add_watch
 955         data8 0                         // inotify_rm_watch
 956         data8 0                         // migrate_pages        // 1280
 957         data8 0                         // openat
 958         data8 0                         // mkdirat
 959         data8 0                         // mknodat
 960         data8 0                         // fchownat
 961         data8 0                         // futimesat            // 1285
 962         data8 0                         // newfstatat
 963         data8 0                         // unlinkat
 964         data8 0                         // renameat
 965         data8 0                         // linkat
 966         data8 0                         // symlinkat            // 1290
 967         data8 0                         // readlinkat
 968         data8 0                         // fchmodat
 969         data8 0                         // faccessat
 970         data8 0
 971         data8 0                                                 // 1295
 972         data8 0                         // unshare
 973         data8 0                         // splice
 974         data8 0                         // set_robust_list
 975         data8 0                         // get_robust_list
 976         data8 0                         // sync_file_range      // 1300
 977         data8 0                         // tee
 978         data8 0                         // vmsplice
 979         data8 0
 980         data8 fsys_getcpu               // getcpu               // 1304
 981
 982         // fill in zeros for the remaining entries
 983         .zero:
 984         .space fsyscall_table + 8*NR_syscalls - .zero, 0