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  */
  14
  15 #include <asm/asmmacro.h>
  16 #include <asm/errno.h>
  17 #include <asm/offsets.h>
  18 #include <asm/percpu.h>
  19 #include <asm/thread_info.h>
  20 #include <asm/sal.h>
  21 #include <asm/signal.h>
  22 #include <asm/system.h>
  23 #include <asm/unistd.h>
  24
  25 #include "entry.h"
  26
  27 /*
  28  * See Documentation/ia64/fsys.txt for details on fsyscalls.
  29  *
  30  * On entry to an fsyscall handler:
  31  *   r10        = 0 (i.e., defaults to "successful syscall return")
  32  *   r11        = saved ar.pfs (a user-level value)
  33  *   r15        = system call number
  34  *   r16        = "current" task pointer (in normal kernel-mode, this is in r13)
  35  *   r32-r39    = system call arguments
  36  *   b6         = return address (a user-level value)
  37  *   ar.pfs     = previous frame-state (a user-level value)
  38  *   PSR.be     = cleared to zero (i.e., little-endian byte order is in effect)
  39  *   all other registers may contain values passed in from user-mode
  40  *
  41  * On return from an fsyscall handler:
  42  *   r11        = saved ar.pfs (as passed into the fsyscall handler)
  43  *   r15        = system call number (as passed into the fsyscall handler)
  44  *   r32-r39    = system call arguments (as passed into the fsyscall handler)
  45  *   b6         = return address (as passed into the fsyscall handler)
  46  *   ar.pfs     = previous frame-state (as passed into the fsyscall handler)
  47  */
  48
  49 ENTRY(fsys_ni_syscall)
  50         .prologue
  51         .altrp b6
  52         .body
  53         mov r8=ENOSYS
  54         mov r10=-1
  55         FSYS_RETURN
  56 END(fsys_ni_syscall)
  57
  58 ENTRY(fsys_getpid)
  59         .prologue
  60         .altrp b6
  61         .body
  62         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
  63         ;;
  64         ld4 r9=[r9]
  65         add r8=IA64_TASK_TGID_OFFSET,r16
  66         ;;
  67         and r9=TIF_ALLWORK_MASK,r9
  68         ld4 r8=[r8]                             // r8 = current->tgid
  69         ;;
  70         cmp.ne p8,p0=0,r9
  71 (p8)    br.spnt.many fsys_fallback_syscall
  72         FSYS_RETURN
  73 END(fsys_getpid)
  74
  75 ENTRY(fsys_getppid)
  76         .prologue
  77         .altrp b6
  78         .body
  79         add r17=IA64_TASK_GROUP_LEADER_OFFSET,r16
  80         ;;
  81         ld8 r17=[r17]                           // r17 = current->group_leader
  82         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
  83         ;;
  84
  85         ld4 r9=[r9]
  86         add r17=IA64_TASK_REAL_PARENT_OFFSET,r17 // r17 = &current->group_leader->real_parent
  87         ;;
  88         and r9=TIF_ALLWORK_MASK,r9
  89
  90 1:      ld8 r18=[r17]                           // r18 = current->group_leader->real_parent
  91         ;;
  92         cmp.ne p8,p0=0,r9
  93         add r8=IA64_TASK_TGID_OFFSET,r18        // r8 = &current->group_leader->real_parent->tgid
  94         ;;
  95
  96         /*
  97          * The .acq is needed to ensure that the read of tgid has returned its data before
  98          * we re-check "real_parent".
  99          */
 100         ld4.acq r8=[r8]                         // r8 = current->group_leader->real_parent->tgid
 101 #ifdef CONFIG_SMP
 102         /*
 103          * Re-read current->group_leader->real_parent.
 104          */
 105         ld8 r19=[r17]                           // r19 = current->group_leader->real_parent
 106 (p8)    br.spnt.many fsys_fallback_syscall
 107         ;;
 108         cmp.ne p6,p0=r18,r19                    // did real_parent change?
 109         mov r19=0                       // i must not leak kernel bits...
 110 (p6)    br.cond.spnt.few 1b                     // yes -> redo the read of tgid and the check
 111         ;;
 112         mov r17=0                       // i must not leak kernel bits...
 113         mov r18=0                       // i must not leak kernel bits...
 114 #else
 115         mov r17=0                       // i must not leak kernel bits...
 116         mov r18=0                       // i must not leak kernel bits...
 117         mov r19=0                       // i must not leak kernel bits...
 118 #endif
 119         FSYS_RETURN
 120 END(fsys_getppid)
 121
 122 ENTRY(fsys_set_tid_address)
 123         .prologue
 124         .altrp b6
 125         .body
 126         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
 127         ;;
 128         ld4 r9=[r9]
 129         tnat.z p6,p7=r32                // check argument register for being NaT
 130         ;;
 131         and r9=TIF_ALLWORK_MASK,r9
 132         add r8=IA64_TASK_PID_OFFSET,r16
 133         add r18=IA64_TASK_CLEAR_CHILD_TID_OFFSET,r16
 134         ;;
 135         ld4 r8=[r8]
 136         cmp.ne p8,p0=0,r9
 137         mov r17=-1
 138         ;;
 139 (p6)    st8 [r18]=r32
 140 (p7)    st8 [r18]=r17
 141 (p8)    br.spnt.many fsys_fallback_syscall
 142         ;;
 143         mov r17=0                       // i must not leak kernel bits...
 144         mov r18=0                       // i must not leak kernel bits...
 145         FSYS_RETURN
 146 END(fsys_set_tid_address)
 147
 148 /*
 149  * Ensure that the time interpolator structure is compatible with the asm code
 150  */
 151 #if IA64_TIME_INTERPOLATOR_SOURCE_OFFSET !=0 || IA64_TIME_INTERPOLATOR_SHIFT_OFFSET != 2 \
 152         || IA64_TIME_INTERPOLATOR_JITTER_OFFSET != 3 || IA64_TIME_INTERPOLATOR_NSEC_OFFSET != 4
 153 #error fsys_gettimeofday incompatible with changes to struct time_interpolator
 154 #endif
 155 #define CLOCK_REALTIME 0
 156 #define CLOCK_MONOTONIC 1
 157 #define CLOCK_DIVIDE_BY_1000 0x4000
 158 #define CLOCK_ADD_MONOTONIC 0x8000
 159
 160 ENTRY(fsys_gettimeofday)
 161         .prologue
 162         .altrp b6
 163         .body
 164         mov r31 = r32
 165         tnat.nz p6,p0 = r33             // guard against NaT argument
 166 (p6)    br.cond.spnt.few .fail_einval
 167         mov r30 = CLOCK_DIVIDE_BY_1000
 168         ;;
 169 .gettime:
 170         // Register map
 171         // Incoming r31 = pointer to address where to place result
 172         //          r30 = flags determining how time is processed
 173         // r2,r3 = temp r4-r7 preserved
 174         // r8 = result nanoseconds
 175         // r9 = result seconds
 176         // r10 = temporary storage for clock difference
 177         // r11 = preserved: saved ar.pfs
 178         // r12 = preserved: memory stack
 179         // r13 = preserved: thread pointer
 180         // r14 = address of mask / mask
 181         // r15 = preserved: system call number
 182         // r16 = preserved: current task pointer
 183         // r17 = wall to monotonic use
 184         // r18 = time_interpolator->offset
 185         // r19 = address of wall_to_monotonic
 186         // r20 = pointer to struct time_interpolator / pointer to time_interpolator->address
 187         // r21 = shift factor
 188         // r22 = address of time interpolator->last_counter
 189         // r23 = address of time_interpolator->last_cycle
 190         // r24 = adress of time_interpolator->offset
 191         // r25 = last_cycle value
 192         // r26 = last_counter value
 193         // r27 = pointer to xtime
 194         // r28 = sequence number at the beginning of critcal section
 195         // r29 = address of seqlock
 196         // r30 = time processing flags / memory address
 197         // r31 = pointer to result
 198         // Predicates
 199         // p6,p7 short term use
 200         // p8 = timesource ar.itc
 201         // p9 = timesource mmio64
 202         // p10 = timesource mmio32
 203         // p11 = timesource not to be handled by asm code
 204         // p12 = memory time source ( = p9 | p10)
 205         // p13 = do cmpxchg with time_interpolator_last_cycle
 206         // p14 = Divide by 1000
 207         // p15 = Add monotonic
 208         //
 209         // Note that instructions are optimized for McKinley. McKinley can process two
 210         // bundles simultaneously and therefore we continuously try to feed the CPU
 211         // two bundles and then a stop.
 212         tnat.nz p6,p0 = r31     // branch deferred since it does not fit into bundle structure
 213         mov pr = r30,0xc000     // Set predicates according to function
 214         add r2 = TI_FLAGS+IA64_TASK_SIZE,r16
 215         movl r20 = time_interpolator
 216         ;;
 217         ld8 r20 = [r20]         // get pointer to time_interpolator structure
 218         movl r29 = xtime_lock
 219         ld4 r2 = [r2]           // process work pending flags
 220         movl r27 = xtime
 221         ;;      // only one bundle here
 222         ld8 r21 = [r20]         // first quad with control information
 223         and r2 = TIF_ALLWORK_MASK,r2
 224 (p6)    br.cond.spnt.few .fail_einval   // deferred branch
 225         ;;
 226         add r10 = IA64_TIME_INTERPOLATOR_ADDRESS_OFFSET,r20
 227         extr r3 = r21,32,32     // time_interpolator->nsec_per_cyc
 228         extr r8 = r21,0,16      // time_interpolator->source
 229         cmp.ne p6, p0 = 0, r2   // Fallback if work is scheduled
 230 (p6)    br.cond.spnt.many fsys_fallback_syscall
 231         ;;
 232         cmp.eq p8,p12 = 0,r8    // Check for cpu timer
 233         cmp.eq p9,p0 = 1,r8     // MMIO64 ?
 234         extr r2 = r21,24,8      // time_interpolator->jitter
 235         cmp.eq p10,p0 = 2,r8    // MMIO32 ?
 236         cmp.ltu p11,p0 = 2,r8   // function or other clock
 237 (p11)   br.cond.spnt.many fsys_fallback_syscall
 238         ;;
 239         setf.sig f7 = r3        // Setup for scaling of counter
 240 (p15)   movl r19 = wall_to_monotonic
 241 (p12)   ld8 r30 = [r10]
 242         cmp.ne p13,p0 = r2,r0   // need jitter compensation?
 243         extr r21 = r21,16,8     // shift factor
 244         ;;
 245 .time_redo:
 246         .pred.rel.mutex p8,p9,p10
 247         ld4.acq r28 = [r29]     // xtime_lock.sequence. Must come first for locking purposes
 248 (p8)    mov r2 = ar.itc         // CPU_TIMER. 36 clocks latency!!!
 249         add r22 = IA64_TIME_INTERPOLATOR_LAST_COUNTER_OFFSET,r20
 250 (p9)    ld8 r2 = [r30]          // readq(ti->address). Could also have latency issues..
 251 (p10)   ld4 r2 = [r30]          // readw(ti->address)
 252 (p13)   add r23 = IA64_TIME_INTERPOLATOR_LAST_CYCLE_OFFSET,r20
 253         ;;                      // could be removed by moving the last add upward
 254         ld8 r26 = [r22]         // time_interpolator->last_counter
 255 (p13)   ld8 r25 = [r23]         // time interpolator->last_cycle
 256         add r24 = IA64_TIME_INTERPOLATOR_OFFSET_OFFSET,r20
 257 (p15)   ld8 r17 = [r19],IA64_TIMESPEC_TV_NSEC_OFFSET
 258         ld8 r9 = [r27],IA64_TIMESPEC_TV_NSEC_OFFSET
 259         add r14 = IA64_TIME_INTERPOLATOR_MASK_OFFSET, r20
 260         ;;
 261         ld8 r18 = [r24]         // time_interpolator->offset
 262         ld8 r8 = [r27],-IA64_TIMESPEC_TV_NSEC_OFFSET    // xtime.tv_nsec
 263 (p13)   sub r3 = r25,r2 // Diff needed before comparison (thanks davidm)
 264         ;;
 265         ld8 r14 = [r14]         // time_interpolator->mask
 266 (p13)   cmp.gt.unc p6,p7 = r3,r0        // check if it is less than last. p6,p7 cleared
 267         sub r10 = r2,r26        // current_counter - last_counter
 268         ;;
 269 (p6)    sub r10 = r25,r26       // time we got was less than last_cycle
 270 (p7)    mov ar.ccv = r25        // more than last_cycle. Prep for cmpxchg
 271         ;;
 272         and r10 = r10,r14       // Apply mask
 273         ;;
 274         setf.sig f8 = r10
 275         nop.i 123
 276         ;;
 277 (p7)    cmpxchg8.rel r3 = [r23],r2,ar.ccv
 278 EX(.fail_efault, probe.w.fault r31, 3)  // This takes 5 cycles and we have spare time
 279         xmpy.l f8 = f8,f7       // nsec_per_cyc*(counter-last_counter)
 280 (p15)   add r9 = r9,r17         // Add wall to monotonic.secs to result secs
 281         ;;
 282 (p15)   ld8 r17 = [r19],-IA64_TIMESPEC_TV_NSEC_OFFSET
 283 (p7)    cmp.ne p7,p0 = r25,r3   // if cmpxchg not successful redo
 284         // simulate tbit.nz.or p7,p0 = r28,0
 285         and r28 = ~1,r28        // Make sequence even to force retry if odd
 286         getf.sig r2 = f8
 287         mf
 288         add r8 = r8,r18         // Add time interpolator offset
 289         ;;
 290         ld4 r10 = [r29]         // xtime_lock.sequence
 291 (p15)   add r8 = r8, r17        // Add monotonic.nsecs to nsecs
 292         shr.u r2 = r2,r21
 293         ;;              // overloaded 3 bundles!
 294         // End critical section.
 295         add r8 = r8,r2          // Add xtime.nsecs
 296         cmp4.ne.or p7,p0 = r28,r10
 297 (p7)    br.cond.dpnt.few .time_redo     // sequence number changed ?
 298         // Now r8=tv->tv_nsec and r9=tv->tv_sec
 299         mov r10 = r0
 300         movl r2 = 1000000000
 301         add r23 = IA64_TIMESPEC_TV_NSEC_OFFSET, r31
 302 (p14)   movl r3 = 2361183241434822607   // Prep for / 1000 hack
 303         ;;
 304 .time_normalize:
 305         mov r21 = r8
 306         cmp.ge p6,p0 = r8,r2
 307 (p14)   shr.u r20 = r8, 3               // We can repeat this if necessary just wasting some time
 308         ;;
 309 (p14)   setf.sig f8 = r20
 310 (p6)    sub r8 = r8,r2
 311 (p6)    add r9 = 1,r9                   // two nops before the branch.
 312 (p14)   setf.sig f7 = r3                // Chances for repeats are 1 in 10000 for gettod
 313 (p6)    br.cond.dpnt.few .time_normalize
 314         ;;
 315         // Divided by 8 though shift. Now divide by 125
 316         // The compiler was able to do that with a multiply
 317         // and a shift and we do the same
 318 EX(.fail_efault, probe.w.fault r23, 3)          // This also costs 5 cycles
 319 (p14)   xmpy.hu f8 = f8, f7                     // xmpy has 5 cycles latency so use it...
 320         ;;
 321         mov r8 = r0
 322 (p14)   getf.sig r2 = f8
 323         ;;
 324 (p14)   shr.u r21 = r2, 4
 325         ;;
 326 EX(.fail_efault, st8 [r31] = r9)
 327 EX(.fail_efault, st8 [r23] = r21)
 328         FSYS_RETURN
 329 .fail_einval:
 330         mov r8 = EINVAL
 331         mov r10 = -1
 332         FSYS_RETURN
 333 .fail_efault:
 334         mov r8 = EFAULT
 335         mov r10 = -1
 336         FSYS_RETURN
 337 END(fsys_gettimeofday)
 338
 339 ENTRY(fsys_clock_gettime)
 340         .prologue
 341         .altrp b6
 342         .body
 343         cmp4.ltu p6, p0 = CLOCK_MONOTONIC, r32
 344         // Fallback if this is not CLOCK_REALTIME or CLOCK_MONOTONIC
 345 (p6)    br.spnt.few fsys_fallback_syscall
 346         mov r31 = r33
 347         shl r30 = r32,15
 348         br.many .gettime
 349 END(fsys_clock_gettime)
 350
 351 /*
 352  * long fsys_rt_sigprocmask (int how, sigset_t *set, sigset_t *oset, size_t sigsetsize).
 353  */
 354 #if _NSIG_WORDS != 1
 355 # error Sorry, fsys_rt_sigprocmask() needs to be updated for _NSIG_WORDS != 1.
 356 #endif
 357 ENTRY(fsys_rt_sigprocmask)
 358         .prologue
 359         .altrp b6
 360         .body
 361
 362         add r2=IA64_TASK_BLOCKED_OFFSET,r16
 363         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
 364         cmp4.ltu p6,p0=SIG_SETMASK,r32
 365
 366         cmp.ne p15,p0=r0,r34                    // oset != NULL?
 367         tnat.nz p8,p0=r34
 368         add r31=IA64_TASK_SIGHAND_OFFSET,r16
 369         ;;
 370         ld8 r3=[r2]                             // read/prefetch current->blocked
 371         ld4 r9=[r9]
 372         tnat.nz.or p6,p0=r35
 373
 374         cmp.ne.or p6,p0=_NSIG_WORDS*8,r35
 375         tnat.nz.or p6,p0=r32
 376 (p6)    br.spnt.few .fail_einval                // fail with EINVAL
 377         ;;
 378 #ifdef CONFIG_SMP
 379         ld8 r31=[r31]                           // r31 <- current->sighand
 380 #endif
 381         and r9=TIF_ALLWORK_MASK,r9
 382         tnat.nz.or p8,p0=r33
 383         ;;
 384         cmp.ne p7,p0=0,r9
 385         cmp.eq p6,p0=r0,r33                     // set == NULL?
 386         add r31=IA64_SIGHAND_SIGLOCK_OFFSET,r31 // r31 <- current->sighand->siglock
 387 (p8)    br.spnt.few .fail_efault                // fail with EFAULT
 388 (p7)    br.spnt.many fsys_fallback_syscall      // got pending kernel work...
 389 (p6)    br.dpnt.many .store_mask                // -> short-circuit to just reading the signal mask
 390
 391         /* Argh, we actually have to do some work and _update_ the signal mask: */
 392
 393 EX(.fail_efault, probe.r.fault r33, 3)          // verify user has read-access to *set
 394 EX(.fail_efault, ld8 r14=[r33])                 // r14 <- *set
 395         mov r17=(1 << (SIGKILL - 1)) | (1 << (SIGSTOP - 1))
 396         ;;
 397
 398         rsm psr.i                               // mask interrupt delivery
 399         mov ar.ccv=0
 400         andcm r14=r14,r17                       // filter out SIGKILL & SIGSTOP
 401
 402 #ifdef CONFIG_SMP
 403         mov r17=1
 404         ;;
 405         cmpxchg4.acq r18=[r31],r17,ar.ccv       // try to acquire the lock
 406         mov r8=EINVAL                   // default to EINVAL
 407         ;;
 408         ld8 r3=[r2]                     // re-read current->blocked now that we hold the lock
 409         cmp4.ne p6,p0=r18,r0
 410 (p6)    br.cond.spnt.many .lock_contention
 411         ;;
 412 #else
 413         ld8 r3=[r2]                     // re-read current->blocked now that we hold the lock
 414         mov r8=EINVAL                   // default to EINVAL
 415 #endif
 416         add r18=IA64_TASK_PENDING_OFFSET+IA64_SIGPENDING_SIGNAL_OFFSET,r16
 417         add r19=IA64_TASK_SIGNAL_OFFSET,r16
 418         cmp4.eq p6,p0=SIG_BLOCK,r32
 419         ;;
 420         ld8 r19=[r19]                   // r19 <- current->signal
 421         cmp4.eq p7,p0=SIG_UNBLOCK,r32
 422         cmp4.eq p8,p0=SIG_SETMASK,r32
 423         ;;
 424         ld8 r18=[r18]                   // r18 <- current->pending.signal
 425         .pred.rel.mutex p6,p7,p8
 426 (p6)    or r14=r3,r14                   // SIG_BLOCK
 427 (p7)    andcm r14=r3,r14                // SIG_UNBLOCK
 428
 429 (p8)    mov r14=r14                     // SIG_SETMASK
 430 (p6)    mov r8=0                        // clear error code
 431         // recalc_sigpending()
 432         add r17=IA64_SIGNAL_GROUP_STOP_COUNT_OFFSET,r19
 433
 434         add r19=IA64_SIGNAL_SHARED_PENDING_OFFSET+IA64_SIGPENDING_SIGNAL_OFFSET,r19
 435         ;;
 436         ld4 r17=[r17]           // r17 <- current->signal->group_stop_count
 437 (p7)    mov r8=0                // clear error code
 438
 439         ld8 r19=[r19]           // r19 <- current->signal->shared_pending
 440         ;;
 441         cmp4.gt p6,p7=r17,r0    // p6/p7 <- (current->signal->group_stop_count > 0)?
 442 (p8)    mov r8=0                // clear error code
 443
 444         or r18=r18,r19          // r18 <- current->pending | current->signal->shared_pending
 445         ;;
 446         // r18 <- (current->pending | current->signal->shared_pending) & ~current->blocked:
 447         andcm r18=r18,r14
 448         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
 449         ;;
 450
 451 (p7)    cmp.ne.or.andcm p6,p7=r18,r0            // p6/p7 <- signal pending
 452         mov r19=0                                       // i must not leak kernel bits...
 453 (p6)    br.cond.dpnt.many .sig_pending
 454         ;;
 455
 456 1:      ld4 r17=[r9]                            // r17 <- current->thread_info->flags
 457         ;;
 458         mov ar.ccv=r17
 459         and r18=~_TIF_SIGPENDING,r17            // r18 <- r17 & ~(1 << TIF_SIGPENDING)
 460         ;;
 461
 462         st8 [r2]=r14                            // update current->blocked with new mask
 463         cmpxchg4.acq r8=[r9],r18,ar.ccv         // current->thread_info->flags <- r18
 464         ;;
 465         cmp.ne p6,p0=r17,r8                     // update failed?
 466 (p6)    br.cond.spnt.few 1b                     // yes -> retry
 467
 468 #ifdef CONFIG_SMP
 469         st4.rel [r31]=r0                        // release the lock
 470 #endif
 471         ssm psr.i
 472         ;;
 473
 474         srlz.d                                  // ensure psr.i is set again
 475         mov r18=0                                       // i must not leak kernel bits...
 476
 477 .store_mask:
 478 EX(.fail_efault, (p15) probe.w.fault r34, 3)    // verify user has write-access to *oset
 479 EX(.fail_efault, (p15) st8 [r34]=r3)
 480         mov r2=0                                        // i must not leak kernel bits...
 481         mov r3=0                                        // i must not leak kernel bits...
 482         mov r8=0                                // return 0
 483         mov r9=0                                        // i must not leak kernel bits...
 484         mov r14=0                                       // i must not leak kernel bits...
 485         mov r17=0                                       // i must not leak kernel bits...
 486         mov r31=0                                       // i must not leak kernel bits...
 487         FSYS_RETURN
 488
 489 .sig_pending:
 490 #ifdef CONFIG_SMP
 491         st4.rel [r31]=r0                        // release the lock
 492 #endif
 493         ssm psr.i
 494         ;;
 495         srlz.d
 496         br.sptk.many fsys_fallback_syscall      // with signal pending, do the heavy-weight syscall
 497
 498 #ifdef CONFIG_SMP
 499 .lock_contention:
 500         /* Rather than spinning here, fall back on doing a heavy-weight syscall.  */
 501         ssm psr.i
 502         ;;
 503         srlz.d
 504         br.sptk.many fsys_fallback_syscall
 505 #endif
 506 END(fsys_rt_sigprocmask)
 507
 508 ENTRY(fsys_fallback_syscall)
 509         .prologue
 510         .altrp b6
 511         .body
 512         /*
 513          * We only get here from light-weight syscall handlers.  Thus, we already
 514          * know that r15 contains a valid syscall number.  No need to re-check.
 515          */
 516         adds r17=-1024,r15
 517         movl r14=sys_call_table
 518         ;;
 519         rsm psr.i
 520         shladd r18=r17,3,r14
 521         ;;
 522         ld8 r18=[r18]                           // load normal (heavy-weight) syscall entry-point
 523         mov r29=psr                             // read psr (12 cyc load latency)
 524         mov r27=ar.rsc
 525         mov r21=ar.fpsr
 526         mov r26=ar.pfs
 527 END(fsys_fallback_syscall)
 528         /* FALL THROUGH */
 529 GLOBAL_ENTRY(fsys_bubble_down)
 530         .prologue
 531         .altrp b6
 532         .body
 533         /*
 534          * We get here for syscalls that don't have a lightweight
 535          * handler.  For those, we need to bubble down into the kernel
 536          * and that requires setting up a minimal pt_regs structure,
 537          * and initializing the CPU state more or less as if an
 538          * interruption had occurred.  To make syscall-restarts work,
 539          * we setup pt_regs such that cr_iip points to the second
 540          * instruction in syscall_via_break.  Decrementing the IP
 541          * hence will restart the syscall via break and not
 542          * decrementing IP will return us to the caller, as usual.
 543          * Note that we preserve the value of psr.pp rather than
 544          * initializing it from dcr.pp.  This makes it possible to
 545          * distinguish fsyscall execution from other privileged
 546          * execution.
 547          *
 548          * On entry:
 549          *      - normal fsyscall handler register usage, except
 550          *        that we also have:
 551          *      - r18: address of syscall entry point
 552          *      - r21: ar.fpsr
 553          *      - r26: ar.pfs
 554          *      - r27: ar.rsc
 555          *      - r29: psr
 556          *
 557          * We used to clear some PSR bits here but that requires slow
 558          * serialization.  Fortuntely, that isn't really necessary.
 559          * The rationale is as follows: we used to clear bits
 560          * ~PSR_PRESERVED_BITS in PSR.L.  Since
 561          * PSR_PRESERVED_BITS==PSR.{UP,MFL,MFH,PK,DT,PP,SP,RT,IC}, we
 562          * ended up clearing PSR.{BE,AC,I,DFL,DFH,DI,DB,SI,TB}.
 563          * However,
 564          *
 565          * PSR.BE : already is turned off in __kernel_syscall_via_epc()
 566          * PSR.AC : don't care (kernel normally turns PSR.AC on)
 567          * PSR.I  : already turned off by the time fsys_bubble_down gets
 568          *          invoked
 569          * PSR.DFL: always 0 (kernel never turns it on)
 570          * PSR.DFH: don't care --- kernel never touches f32-f127 on its own
 571          *          initiative
 572          * PSR.DI : always 0 (kernel never turns it on)
 573          * PSR.SI : always 0 (kernel never turns it on)
 574          * PSR.DB : don't care --- kernel never enables kernel-level
 575          *          breakpoints
 576          * PSR.TB : must be 0 already; if it wasn't zero on entry to
 577          *          __kernel_syscall_via_epc, the branch to fsys_bubble_down
 578          *          will trigger a taken branch; the taken-trap-handler then
 579          *          converts the syscall into a break-based system-call.
 580          */
 581         /*
 582          * Reading psr.l gives us only bits 0-31, psr.it, and psr.mc.
 583          * The rest we have to synthesize.
 584          */
 585 #       define PSR_ONE_BITS             ((3 << IA64_PSR_CPL0_BIT)       \
 586                                          | (0x1 << IA64_PSR_RI_BIT)     \
 587                                          | IA64_PSR_BN | IA64_PSR_I)
 588
 589         invala                                  // M0|1
 590         movl r14=ia64_ret_from_syscall          // X
 591
 592         nop.m 0
 593         movl r28=__kernel_syscall_via_break     // X    create cr.iip
 594         ;;
 595
 596         mov r2=r16                              // A    get task addr to addl-addressable register
 597         adds r16=IA64_TASK_THREAD_ON_USTACK_OFFSET,r16 // A
 598         mov r31=pr                              // I0   save pr (2 cyc)
 599         ;;
 600         st1 [r16]=r0                            // M2|3 clear current->thread.on_ustack flag
 601         addl r22=IA64_RBS_OFFSET,r2             // A    compute base of RBS
 602         add r3=TI_FLAGS+IA64_TASK_SIZE,r2       // A
 603         ;;
 604         ld4 r3=[r3]                             // M0|1 r3 = current_thread_info()->flags
 605         lfetch.fault.excl.nt1 [r22]             // M0|1 prefetch register backing-store
 606         nop.i 0
 607         ;;
 608         mov ar.rsc=0                            // M2   set enforced lazy mode, pl 0, LE, loadrs=0
 609         nop.m 0
 610         nop.i 0
 611         ;;
 612         mov r23=ar.bspstore                     // M2 (12 cyc) save ar.bspstore
 613         mov.m r24=ar.rnat                       // M2 (5 cyc) read ar.rnat (dual-issues!)
 614         nop.i 0
 615         ;;
 616         mov ar.bspstore=r22                     // M2 (6 cyc) switch to kernel RBS
 617         movl r8=PSR_ONE_BITS                    // X
 618         ;;
 619         mov r25=ar.unat                         // M2 (5 cyc) save ar.unat
 620         mov r19=b6                              // I0   save b6 (2 cyc)
 621         mov r20=r1                              // A    save caller's gp in r20
 622         ;;
 623         or r29=r8,r29                           // A    construct cr.ipsr value to save
 624         mov b6=r18                              // I0   copy syscall entry-point to b6 (7 cyc)
 625         addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r2 // A compute base of memory stack
 626
 627         mov r18=ar.bsp                          // M2   save (kernel) ar.bsp (12 cyc)
 628         cmp.ne pKStk,pUStk=r0,r0                // A    set pKStk <- 0, pUStk <- 1
 629         br.call.sptk.many b7=ia64_syscall_setup // B
 630         ;;
 631         mov ar.rsc=0x3                          // M2   set eager mode, pl 0, LE, loadrs=0
 632         mov rp=r14                              // I0   set the real return addr
 633         and r3=_TIF_SYSCALL_TRACEAUDIT,r3       // A
 634         ;;
 635         ssm psr.i                               // M2   we're on kernel stacks now, reenable irqs
 636         cmp.eq p8,p0=r3,r0                      // A
 637 (p10)   br.cond.spnt.many ia64_ret_from_syscall // B    return if bad call-frame or r15 is a NaT
 638
 639         nop.m 0
 640 (p8)    br.call.sptk.many b6=b6                 // B    (ignore return address)
 641         br.cond.spnt ia64_trace_syscall         // B
 642 END(fsys_bubble_down)
 643
 644         .rodata
 645         .align 8
 646         .globl fsyscall_table
 647
 648         data8 fsys_bubble_down
 649 fsyscall_table:
 650         data8 fsys_ni_syscall
 651         data8 0                         // exit                 // 1025
 652         data8 0                         // read
 653         data8 0                         // write
 654         data8 0                         // open
 655         data8 0                         // close
 656         data8 0                         // creat                // 1030
 657         data8 0                         // link
 658         data8 0                         // unlink
 659         data8 0                         // execve
 660         data8 0                         // chdir
 661         data8 0                         // fchdir               // 1035
 662         data8 0                         // utimes
 663         data8 0                         // mknod
 664         data8 0                         // chmod
 665         data8 0                         // chown
 666         data8 0                         // lseek                // 1040
 667         data8 fsys_getpid               // getpid
 668         data8 fsys_getppid              // getppid
 669         data8 0                         // mount
 670         data8 0                         // umount
 671         data8 0                         // setuid               // 1045
 672         data8 0                         // getuid
 673         data8 0                         // geteuid
 674         data8 0                         // ptrace
 675         data8 0                         // access
 676         data8 0                         // sync                 // 1050
 677         data8 0                         // fsync
 678         data8 0                         // fdatasync
 679         data8 0                         // kill
 680         data8 0                         // rename
 681         data8 0                         // mkdir                // 1055
 682         data8 0                         // rmdir
 683         data8 0                         // dup
 684         data8 0                         // pipe
 685         data8 0                         // times
 686         data8 0                         // brk                  // 1060
 687         data8 0                         // setgid
 688         data8 0                         // getgid
 689         data8 0                         // getegid
 690         data8 0                         // acct
 691         data8 0                         // ioctl                // 1065
 692         data8 0                         // fcntl
 693         data8 0                         // umask
 694         data8 0                         // chroot
 695         data8 0                         // ustat
 696         data8 0                         // dup2                 // 1070
 697         data8 0                         // setreuid
 698         data8 0                         // setregid
 699         data8 0                         // getresuid
 700         data8 0                         // setresuid
 701         data8 0                         // getresgid            // 1075
 702         data8 0                         // setresgid
 703         data8 0                         // getgroups
 704         data8 0                         // setgroups
 705         data8 0                         // getpgid
 706         data8 0                         // setpgid              // 1080
 707         data8 0                         // setsid
 708         data8 0                         // getsid
 709         data8 0                         // sethostname
 710         data8 0                         // setrlimit
 711         data8 0                         // getrlimit            // 1085
 712         data8 0                         // getrusage
 713         data8 fsys_gettimeofday         // gettimeofday
 714         data8 0                         // settimeofday
 715         data8 0                         // select
 716         data8 0                         // poll                 // 1090
 717         data8 0                         // symlink
 718         data8 0                         // readlink
 719         data8 0                         // uselib
 720         data8 0                         // swapon
 721         data8 0                         // swapoff              // 1095
 722         data8 0                         // reboot
 723         data8 0                         // truncate
 724         data8 0                         // ftruncate
 725         data8 0                         // fchmod
 726         data8 0                         // fchown               // 1100
 727         data8 0                         // getpriority
 728         data8 0                         // setpriority
 729         data8 0                         // statfs
 730         data8 0                         // fstatfs
 731         data8 0                         // gettid               // 1105
 732         data8 0                         // semget
 733         data8 0                         // semop
 734         data8 0                         // semctl
 735         data8 0                         // msgget
 736         data8 0                         // msgsnd               // 1110
 737         data8 0                         // msgrcv
 738         data8 0                         // msgctl
 739         data8 0                         // shmget
 740         data8 0                         // shmat
 741         data8 0                         // shmdt                // 1115
 742         data8 0                         // shmctl
 743         data8 0                         // syslog
 744         data8 0                         // setitimer
 745         data8 0                         // getitimer
 746         data8 0                                                 // 1120
 747         data8 0
 748         data8 0
 749         data8 0                         // vhangup
 750         data8 0                         // lchown
 751         data8 0                         // remap_file_pages     // 1125
 752         data8 0                         // wait4
 753         data8 0                         // sysinfo
 754         data8 0                         // clone
 755         data8 0                         // setdomainname
 756         data8 0                         // newuname             // 1130
 757         data8 0                         // adjtimex
 758         data8 0
 759         data8 0                         // init_module
 760         data8 0                         // delete_module
 761         data8 0                                                 // 1135
 762         data8 0
 763         data8 0                         // quotactl
 764         data8 0                         // bdflush
 765         data8 0                         // sysfs
 766         data8 0                         // personality          // 1140
 767         data8 0                         // afs_syscall
 768         data8 0                         // setfsuid
 769         data8 0                         // setfsgid
 770         data8 0                         // getdents
 771         data8 0                         // flock                // 1145
 772         data8 0                         // readv
 773         data8 0                         // writev
 774         data8 0                         // pread64
 775         data8 0                         // pwrite64
 776         data8 0                         // sysctl               // 1150
 777         data8 0                         // mmap
 778         data8 0                         // munmap
 779         data8 0                         // mlock
 780         data8 0                         // mlockall
 781         data8 0                         // mprotect             // 1155
 782         data8 0                         // mremap
 783         data8 0                         // msync
 784         data8 0                         // munlock
 785         data8 0                         // munlockall
 786         data8 0                         // sched_getparam       // 1160
 787         data8 0                         // sched_setparam
 788         data8 0                         // sched_getscheduler
 789         data8 0                         // sched_setscheduler
 790         data8 0                         // sched_yield
 791         data8 0                         // sched_get_priority_max       // 1165
 792         data8 0                         // sched_get_priority_min
 793         data8 0                         // sched_rr_get_interval
 794         data8 0                         // nanosleep
 795         data8 0                         // nfsservctl
 796         data8 0                         // prctl                // 1170
 797         data8 0                         // getpagesize
 798         data8 0                         // mmap2
 799         data8 0                         // pciconfig_read
 800         data8 0                         // pciconfig_write
 801         data8 0                         // perfmonctl           // 1175
 802         data8 0                         // sigaltstack
 803         data8 0                         // rt_sigaction
 804         data8 0                         // rt_sigpending
 805         data8 fsys_rt_sigprocmask       // rt_sigprocmask
 806         data8 0                         // rt_sigqueueinfo      // 1180
 807         data8 0                         // rt_sigreturn
 808         data8 0                         // rt_sigsuspend
 809         data8 0                         // rt_sigtimedwait
 810         data8 0                         // getcwd
 811         data8 0                         // capget               // 1185
 812         data8 0                         // capset
 813         data8 0                         // sendfile
 814         data8 0
 815         data8 0
 816         data8 0                         // socket               // 1190
 817         data8 0                         // bind
 818         data8 0                         // connect
 819         data8 0                         // listen
 820         data8 0                         // accept
 821         data8 0                         // getsockname          // 1195
 822         data8 0                         // getpeername
 823         data8 0                         // socketpair
 824         data8 0                         // send
 825         data8 0                         // sendto
 826         data8 0                         // recv                 // 1200
 827         data8 0                         // recvfrom
 828         data8 0                         // shutdown
 829         data8 0                         // setsockopt
 830         data8 0                         // getsockopt
 831         data8 0                         // sendmsg              // 1205
 832         data8 0                         // recvmsg
 833         data8 0                         // pivot_root
 834         data8 0                         // mincore
 835         data8 0                         // madvise
 836         data8 0                         // newstat              // 1210
 837         data8 0                         // newlstat
 838         data8 0                         // newfstat
 839         data8 0                         // clone2
 840         data8 0                         // getdents64
 841         data8 0                         // getunwind            // 1215
 842         data8 0                         // readahead
 843         data8 0                         // setxattr
 844         data8 0                         // lsetxattr
 845         data8 0                         // fsetxattr
 846         data8 0                         // getxattr             // 1220
 847         data8 0                         // lgetxattr
 848         data8 0                         // fgetxattr
 849         data8 0                         // listxattr
 850         data8 0                         // llistxattr
 851         data8 0                         // flistxattr           // 1225
 852         data8 0                         // removexattr
 853         data8 0                         // lremovexattr
 854         data8 0                         // fremovexattr
 855         data8 0                         // tkill
 856         data8 0                         // futex                // 1230
 857         data8 0                         // sched_setaffinity
 858         data8 0                         // sched_getaffinity
 859         data8 fsys_set_tid_address      // set_tid_address
 860         data8 0                         // fadvise64_64
 861         data8 0                         // tgkill               // 1235
 862         data8 0                         // exit_group
 863         data8 0                         // lookup_dcookie
 864         data8 0                         // io_setup
 865         data8 0                         // io_destroy
 866         data8 0                         // io_getevents         // 1240
 867         data8 0                         // io_submit
 868         data8 0                         // io_cancel
 869         data8 0                         // epoll_create
 870         data8 0                         // epoll_ctl
 871         data8 0                         // epoll_wait           // 1245
 872         data8 0                         // restart_syscall
 873         data8 0                         // semtimedop
 874         data8 0                         // timer_create
 875         data8 0                         // timer_settime
 876         data8 0                         // timer_gettime        // 1250
 877         data8 0                         // timer_getoverrun
 878         data8 0                         // timer_delete
 879         data8 0                         // clock_settime
 880         data8 fsys_clock_gettime        // clock_gettime
 881         data8 0                         // clock_getres         // 1255
 882         data8 0                         // clock_nanosleep
 883         data8 0                         // fstatfs64
 884         data8 0                         // statfs64
 885         data8 0
 886         data8 0                                                 // 1260
 887         data8 0
 888         data8 0                         // mq_open
 889         data8 0                         // mq_unlink
 890         data8 0                         // mq_timedsend
 891         data8 0                         // mq_timedreceive      // 1265
 892         data8 0                         // mq_notify
 893         data8 0                         // mq_getsetattr
 894         data8 0                         // kexec_load
 895         data8 0
 896         data8 0                                                 // 1270
 897         data8 0
 898         data8 0
 899         data8 0
 900         data8 0
 901         data8 0                                                 // 1275
 902         data8 0
 903         data8 0
 904         data8 0
 905         data8 0
 906
 907         .org fsyscall_table + 8*NR_syscalls     // guard against failures to increase NR_syscalls