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 #include "paravirt_inst.h"
  29
  30 /*
  31  * See Documentation/ia64/fsys.txt for details on fsyscalls.
  32  *
  33  * On entry to an fsyscall handler:
  34  *   r10        = 0 (i.e., defaults to "successful syscall return")
  35  *   r11        = saved ar.pfs (a user-level value)
  36  *   r15        = system call number
  37  *   r16        = "current" task pointer (in normal kernel-mode, this is in r13)
  38  *   r32-r39    = system call arguments
  39  *   b6         = return address (a user-level value)
  40  *   ar.pfs     = previous frame-state (a user-level value)
  41  *   PSR.be     = cleared to zero (i.e., little-endian byte order is in effect)
  42  *   all other registers may contain values passed in from user-mode
  43  *
  44  * On return from an fsyscall handler:
  45  *   r11        = saved ar.pfs (as passed into the fsyscall handler)
  46  *   r15        = system call number (as passed into the fsyscall handler)
  47  *   r32-r39    = system call arguments (as passed into the fsyscall handler)
  48  *   b6         = return address (as passed into the fsyscall handler)
  49  *   ar.pfs     = previous frame-state (as passed into the fsyscall handler)
  50  */
  51
  52 ENTRY(fsys_ni_syscall)
  53         .prologue
  54         .altrp b6
  55         .body
  56         mov r8=ENOSYS
  57         mov r10=-1
  58         FSYS_RETURN
  59 END(fsys_ni_syscall)
  60
  61 ENTRY(fsys_getpid)
  62         .prologue
  63         .altrp b6
  64         .body
  65         add r17=IA64_TASK_GROUP_LEADER_OFFSET,r16
  66         ;;
  67         ld8 r17=[r17]                           // r17 = current->group_leader
  68         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
  69         ;;
  70         ld4 r9=[r9]
  71         add r17=IA64_TASK_TGIDLINK_OFFSET,r17
  72         ;;
  73         and r9=TIF_ALLWORK_MASK,r9
  74         ld8 r17=[r17]                           // r17 = current->group_leader->pids[PIDTYPE_PID].pid
  75         ;;
  76         add r8=IA64_PID_LEVEL_OFFSET,r17
  77         ;;
  78         ld4 r8=[r8]                             // r8 = pid->level
  79         add r17=IA64_PID_UPID_OFFSET,r17        // r17 = &pid->numbers[0]
  80         ;;
  81         shl r8=r8,IA64_UPID_SHIFT
  82         ;;
  83         add r17=r17,r8                          // r17 = &pid->numbers[pid->level]
  84         ;;
  85         ld4 r8=[r17]                            // r8 = pid->numbers[pid->level].nr
  86         ;;
  87         mov r17=0
  88         ;;
  89         cmp.ne p8,p0=0,r9
  90 (p8)    br.spnt.many fsys_fallback_syscall
  91         FSYS_RETURN
  92 END(fsys_getpid)
  93
  94 ENTRY(fsys_getppid)
  95         .prologue
  96         .altrp b6
  97         .body
  98         add r17=IA64_TASK_GROUP_LEADER_OFFSET,r16
  99         ;;
 100         ld8 r17=[r17]                           // r17 = current->group_leader
 101         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
 102         ;;
 103
 104         ld4 r9=[r9]
 105         add r17=IA64_TASK_REAL_PARENT_OFFSET,r17 // r17 = &current->group_leader->real_parent
 106         ;;
 107         and r9=TIF_ALLWORK_MASK,r9
 108
 109 1:      ld8 r18=[r17]                           // r18 = current->group_leader->real_parent
 110         ;;
 111         cmp.ne p8,p0=0,r9
 112         add r8=IA64_TASK_TGID_OFFSET,r18        // r8 = &current->group_leader->real_parent->tgid
 113         ;;
 114
 115         /*
 116          * The .acq is needed to ensure that the read of tgid has returned its data before
 117          * we re-check "real_parent".
 118          */
 119         ld4.acq r8=[r8]                         // r8 = current->group_leader->real_parent->tgid
 120 #ifdef CONFIG_SMP
 121         /*
 122          * Re-read current->group_leader->real_parent.
 123          */
 124         ld8 r19=[r17]                           // r19 = current->group_leader->real_parent
 125 (p8)    br.spnt.many fsys_fallback_syscall
 126         ;;
 127         cmp.ne p6,p0=r18,r19                    // did real_parent change?
 128         mov r19=0                       // i must not leak kernel bits...
 129 (p6)    br.cond.spnt.few 1b                     // yes -> redo the read of tgid and the check
 130         ;;
 131         mov r17=0                       // i must not leak kernel bits...
 132         mov r18=0                       // i must not leak kernel bits...
 133 #else
 134         mov r17=0                       // i must not leak kernel bits...
 135         mov r18=0                       // i must not leak kernel bits...
 136         mov r19=0                       // i must not leak kernel bits...
 137 #endif
 138         FSYS_RETURN
 139 END(fsys_getppid)
 140
 141 ENTRY(fsys_set_tid_address)
 142         .prologue
 143         .altrp b6
 144         .body
 145         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
 146         add r17=IA64_TASK_TGIDLINK_OFFSET,r16
 147         ;;
 148         ld4 r9=[r9]
 149         tnat.z p6,p7=r32                // check argument register for being NaT
 150         ld8 r17=[r17]                           // r17 = current->pids[PIDTYPE_PID].pid
 151         ;;
 152         and r9=TIF_ALLWORK_MASK,r9
 153         add r8=IA64_PID_LEVEL_OFFSET,r17
 154         add r18=IA64_TASK_CLEAR_CHILD_TID_OFFSET,r16
 155         ;;
 156         ld4 r8=[r8]                             // r8 = pid->level
 157         add r17=IA64_PID_UPID_OFFSET,r17        // r17 = &pid->numbers[0]
 158         ;;
 159         shl r8=r8,IA64_UPID_SHIFT
 160         ;;
 161         add r17=r17,r8                          // r17 = &pid->numbers[pid->level]
 162         ;;
 163         ld4 r8=[r17]                            // r8 = pid->numbers[pid->level].nr
 164         ;;
 165         cmp.ne p8,p0=0,r9
 166         mov r17=-1
 167         ;;
 168 (p6)    st8 [r18]=r32
 169 (p7)    st8 [r18]=r17
 170 (p8)    br.spnt.many fsys_fallback_syscall
 171         ;;
 172         mov r17=0                       // i must not leak kernel bits...
 173         mov r18=0                       // i must not leak kernel bits...
 174         FSYS_RETURN
 175 END(fsys_set_tid_address)
 176
 177 #if IA64_GTOD_LOCK_OFFSET !=0
 178 #error fsys_gettimeofday incompatible with changes to struct fsyscall_gtod_data_t
 179 #endif
 180 #if IA64_ITC_JITTER_OFFSET !=0
 181 #error fsys_gettimeofday incompatible with changes to struct itc_jitter_data_t
 182 #endif
 183 #define CLOCK_REALTIME 0
 184 #define CLOCK_MONOTONIC 1
 185 #define CLOCK_DIVIDE_BY_1000 0x4000
 186 #define CLOCK_ADD_MONOTONIC 0x8000
 187
 188 ENTRY(fsys_gettimeofday)
 189         .prologue
 190         .altrp b6
 191         .body
 192         mov r31 = r32
 193         tnat.nz p6,p0 = r33             // guard against NaT argument
 194 (p6)    br.cond.spnt.few .fail_einval
 195         mov r30 = CLOCK_DIVIDE_BY_1000
 196         ;;
 197 .gettime:
 198         // Register map
 199         // Incoming r31 = pointer to address where to place result
 200         //          r30 = flags determining how time is processed
 201         // r2,r3 = temp r4-r7 preserved
 202         // r8 = result nanoseconds
 203         // r9 = result seconds
 204         // r10 = temporary storage for clock difference
 205         // r11 = preserved: saved ar.pfs
 206         // r12 = preserved: memory stack
 207         // r13 = preserved: thread pointer
 208         // r14 = address of mask / mask value
 209         // r15 = preserved: system call number
 210         // r16 = preserved: current task pointer
 211         // r17 = (not used)
 212         // r18 = (not used)
 213         // r19 = address of itc_lastcycle
 214         // r20 = struct fsyscall_gtod_data (= address of gtod_lock.sequence)
 215         // r21 = address of mmio_ptr
 216         // r22 = address of wall_time or monotonic_time
 217         // r23 = address of shift / value
 218         // r24 = address mult factor / cycle_last value
 219         // r25 = itc_lastcycle value
 220         // r26 = address clocksource cycle_last
 221         // r27 = (not used)
 222         // r28 = sequence number at the beginning of critcal section
 223         // r29 = address of itc_jitter
 224         // r30 = time processing flags / memory address
 225         // r31 = pointer to result
 226         // Predicates
 227         // p6,p7 short term use
 228         // p8 = timesource ar.itc
 229         // p9 = timesource mmio64
 230         // p10 = timesource mmio32 - not used
 231         // p11 = timesource not to be handled by asm code
 232         // p12 = memory time source ( = p9 | p10) - not used
 233         // p13 = do cmpxchg with itc_lastcycle
 234         // p14 = Divide by 1000
 235         // p15 = Add monotonic
 236         //
 237         // Note that instructions are optimized for McKinley. McKinley can
 238         // process two bundles simultaneously and therefore we continuously
 239         // try to feed the CPU two bundles and then a stop.
 240
 241         add r2 = TI_FLAGS+IA64_TASK_SIZE,r16
 242         tnat.nz p6,p0 = r31             // guard against Nat argument
 243 (p6)    br.cond.spnt.few .fail_einval
 244         movl r20 = fsyscall_gtod_data // load fsyscall gettimeofday data address
 245         ;;
 246         ld4 r2 = [r2]                   // process work pending flags
 247         movl r29 = itc_jitter_data      // itc_jitter
 248         add r22 = IA64_GTOD_WALL_TIME_OFFSET,r20        // wall_time
 249         add r21 = IA64_CLKSRC_MMIO_OFFSET,r20
 250         mov pr = r30,0xc000     // Set predicates according to function
 251         ;;
 252         and r2 = TIF_ALLWORK_MASK,r2
 253         add r19 = IA64_ITC_LASTCYCLE_OFFSET,r29
 254 (p15)   add r22 = IA64_GTOD_MONO_TIME_OFFSET,r20        // monotonic_time
 255         ;;
 256         add r26 = IA64_CLKSRC_CYCLE_LAST_OFFSET,r20     // clksrc_cycle_last
 257         cmp.ne p6, p0 = 0, r2   // Fallback if work is scheduled
 258 (p6)    br.cond.spnt.many fsys_fallback_syscall
 259         ;;
 260         // Begin critical section
 261 .time_redo:
 262         ld4.acq r28 = [r20]     // gtod_lock.sequence, Must take first
 263         ;;
 264         and r28 = ~1,r28        // And make sequence even to force retry if odd
 265         ;;
 266         ld8 r30 = [r21]         // clocksource->mmio_ptr
 267         add r24 = IA64_CLKSRC_MULT_OFFSET,r20
 268         ld4 r2 = [r29]          // itc_jitter value
 269         add r23 = IA64_CLKSRC_SHIFT_OFFSET,r20
 270         add r14 = IA64_CLKSRC_MASK_OFFSET,r20
 271         ;;
 272         ld4 r3 = [r24]          // clocksource mult value
 273         ld8 r14 = [r14]         // clocksource mask value
 274         cmp.eq p8,p9 = 0,r30    // use cpu timer if no mmio_ptr
 275         ;;
 276         setf.sig f7 = r3        // Setup for mult scaling of counter
 277 (p8)    cmp.ne p13,p0 = r2,r0   // need itc_jitter compensation, set p13
 278         ld4 r23 = [r23]         // clocksource shift value
 279         ld8 r24 = [r26]         // get clksrc_cycle_last value
 280 (p9)    cmp.eq p13,p0 = 0,r30   // if mmio_ptr, clear p13 jitter control
 281         ;;
 282         .pred.rel.mutex p8,p9
 283         MOV_FROM_ITC(p8, p6, r2, r10)   // CPU_TIMER. 36 clocks latency!!!
 284 (p9)    ld8 r2 = [r30]          // MMIO_TIMER. Could also have latency issues..
 285 (p13)   ld8 r25 = [r19]         // get itc_lastcycle value
 286         ld8 r9 = [r22],IA64_TIMESPEC_TV_NSEC_OFFSET     // tv_sec
 287         ;;
 288         ld8 r8 = [r22],-IA64_TIMESPEC_TV_NSEC_OFFSET    // tv_nsec
 289 (p13)   sub r3 = r25,r2         // Diff needed before comparison (thanks davidm)
 290         ;;
 291 (p13)   cmp.gt.unc p6,p7 = r3,r0 // check if it is less than last. p6,p7 cleared
 292         sub r10 = r2,r24        // current_cycle - last_cycle
 293         ;;
 294 (p6)    sub r10 = r25,r24       // time we got was less than last_cycle
 295 (p7)    mov ar.ccv = r25        // more than last_cycle. Prep for cmpxchg
 296         ;;
 297 (p7)    cmpxchg8.rel r3 = [r19],r2,ar.ccv
 298         ;;
 299 (p7)    cmp.ne p7,p0 = r25,r3   // if cmpxchg not successful
 300         ;;
 301 (p7)    sub r10 = r3,r24        // then use new last_cycle instead
 302         ;;
 303         and r10 = r10,r14       // Apply mask
 304         ;;
 305         setf.sig f8 = r10
 306         nop.i 123
 307         ;;
 308         // fault check takes 5 cycles and we have spare time
 309 EX(.fail_efault, probe.w.fault r31, 3)
 310         xmpy.l f8 = f8,f7       // nsec_per_cyc*(counter-last_counter)
 311         ;;
 312         getf.sig r2 = f8
 313         mf
 314         ;;
 315         ld4 r10 = [r20]         // gtod_lock.sequence
 316         shr.u r2 = r2,r23       // shift by factor
 317         ;;
 318         add r8 = r8,r2          // Add xtime.nsecs
 319         cmp4.ne p7,p0 = r28,r10
 320 (p7)    br.cond.dpnt.few .time_redo     // sequence number changed, redo
 321         // End critical section.
 322         // Now r8=tv->tv_nsec and r9=tv->tv_sec
 323         mov r10 = r0
 324         movl r2 = 1000000000
 325         add r23 = IA64_TIMESPEC_TV_NSEC_OFFSET, r31
 326 (p14)   movl r3 = 2361183241434822607   // Prep for / 1000 hack
 327         ;;
 328 .time_normalize:
 329         mov r21 = r8
 330         cmp.ge p6,p0 = r8,r2
 331 (p14)   shr.u r20 = r8, 3 // We can repeat this if necessary just wasting time
 332         ;;
 333 (p14)   setf.sig f8 = r20
 334 (p6)    sub r8 = r8,r2
 335 (p6)    add r9 = 1,r9           // two nops before the branch.
 336 (p14)   setf.sig f7 = r3        // Chances for repeats are 1 in 10000 for gettod
 337 (p6)    br.cond.dpnt.few .time_normalize
 338         ;;
 339         // Divided by 8 though shift. Now divide by 125
 340         // The compiler was able to do that with a multiply
 341         // and a shift and we do the same
 342 EX(.fail_efault, probe.w.fault r23, 3)  // This also costs 5 cycles
 343 (p14)   xmpy.hu f8 = f8, f7             // xmpy has 5 cycles latency so use it
 344         ;;
 345 (p14)   getf.sig r2 = f8
 346         ;;
 347         mov r8 = r0
 348 (p14)   shr.u r21 = r2, 4
 349         ;;
 350 EX(.fail_efault, st8 [r31] = r9)
 351 EX(.fail_efault, st8 [r23] = r21)
 352         FSYS_RETURN
 353 .fail_einval:
 354         mov r8 = EINVAL
 355         mov r10 = -1
 356         FSYS_RETURN
 357 .fail_efault:
 358         mov r8 = EFAULT
 359         mov r10 = -1
 360         FSYS_RETURN
 361 END(fsys_gettimeofday)
 362
 363 ENTRY(fsys_clock_gettime)
 364         .prologue
 365         .altrp b6
 366         .body
 367         cmp4.ltu p6, p0 = CLOCK_MONOTONIC, r32
 368         // Fallback if this is not CLOCK_REALTIME or CLOCK_MONOTONIC
 369 (p6)    br.spnt.few fsys_fallback_syscall
 370         mov r31 = r33
 371         shl r30 = r32,15
 372         br.many .gettime
 373 END(fsys_clock_gettime)
 374
 375 /*
 376  * long fsys_rt_sigprocmask (int how, sigset_t *set, sigset_t *oset, size_t sigsetsize).
 377  */
 378 #if _NSIG_WORDS != 1
 379 # error Sorry, fsys_rt_sigprocmask() needs to be updated for _NSIG_WORDS != 1.
 380 #endif
 381 ENTRY(fsys_rt_sigprocmask)
 382         .prologue
 383         .altrp b6
 384         .body
 385
 386         add r2=IA64_TASK_BLOCKED_OFFSET,r16
 387         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
 388         cmp4.ltu p6,p0=SIG_SETMASK,r32
 389
 390         cmp.ne p15,p0=r0,r34                    // oset != NULL?
 391         tnat.nz p8,p0=r34
 392         add r31=IA64_TASK_SIGHAND_OFFSET,r16
 393         ;;
 394         ld8 r3=[r2]                             // read/prefetch current->blocked
 395         ld4 r9=[r9]
 396         tnat.nz.or p6,p0=r35
 397
 398         cmp.ne.or p6,p0=_NSIG_WORDS*8,r35
 399         tnat.nz.or p6,p0=r32
 400 (p6)    br.spnt.few .fail_einval                // fail with EINVAL
 401         ;;
 402 #ifdef CONFIG_SMP
 403         ld8 r31=[r31]                           // r31 <- current->sighand
 404 #endif
 405         and r9=TIF_ALLWORK_MASK,r9
 406         tnat.nz.or p8,p0=r33
 407         ;;
 408         cmp.ne p7,p0=0,r9
 409         cmp.eq p6,p0=r0,r33                     // set == NULL?
 410         add r31=IA64_SIGHAND_SIGLOCK_OFFSET,r31 // r31 <- current->sighand->siglock
 411 (p8)    br.spnt.few .fail_efault                // fail with EFAULT
 412 (p7)    br.spnt.many fsys_fallback_syscall      // got pending kernel work...
 413 (p6)    br.dpnt.many .store_mask                // -> short-circuit to just reading the signal mask
 414
 415         /* Argh, we actually have to do some work and _update_ the signal mask: */
 416
 417 EX(.fail_efault, probe.r.fault r33, 3)          // verify user has read-access to *set
 418 EX(.fail_efault, ld8 r14=[r33])                 // r14 <- *set
 419         mov r17=(1 << (SIGKILL - 1)) | (1 << (SIGSTOP - 1))
 420         ;;
 421
 422         RSM_PSR_I(p0, r18, r19)                 // mask interrupt delivery
 423         andcm r14=r14,r17                       // filter out SIGKILL & SIGSTOP
 424         mov r8=EINVAL                   // default to EINVAL
 425
 426 #ifdef CONFIG_SMP
 427         // __ticket_spin_trylock(r31)
 428         ld4 r17=[r31]
 429         ;;
 430         mov.m ar.ccv=r17
 431         extr.u r9=r17,17,15
 432         adds r19=1,r17
 433         extr.u r18=r17,0,15
 434         ;;
 435         cmp.eq p6,p7=r9,r18
 436         ;;
 437 (p6)    cmpxchg4.acq r9=[r31],r19,ar.ccv
 438 (p6)    dep.z r20=r19,1,15              // next serving ticket for unlock
 439 (p7)    br.cond.spnt.many .lock_contention
 440         ;;
 441         cmp4.eq p0,p7=r9,r17
 442         adds r31=2,r31
 443 (p7)    br.cond.spnt.many .lock_contention
 444         ld8 r3=[r2]                     // re-read current->blocked now that we hold the lock
 445         ;;
 446 #else
 447         ld8 r3=[r2]                     // re-read current->blocked now that we hold the lock
 448 #endif
 449         add r18=IA64_TASK_PENDING_OFFSET+IA64_SIGPENDING_SIGNAL_OFFSET,r16
 450         add r19=IA64_TASK_SIGNAL_OFFSET,r16
 451         cmp4.eq p6,p0=SIG_BLOCK,r32
 452         ;;
 453         ld8 r19=[r19]                   // r19 <- current->signal
 454         cmp4.eq p7,p0=SIG_UNBLOCK,r32
 455         cmp4.eq p8,p0=SIG_SETMASK,r32
 456         ;;
 457         ld8 r18=[r18]                   // r18 <- current->pending.signal
 458         .pred.rel.mutex p6,p7,p8
 459 (p6)    or r14=r3,r14                   // SIG_BLOCK
 460 (p7)    andcm r14=r3,r14                // SIG_UNBLOCK
 461
 462 (p8)    mov r14=r14                     // SIG_SETMASK
 463 (p6)    mov r8=0                        // clear error code
 464         // recalc_sigpending()
 465         add r17=IA64_SIGNAL_GROUP_STOP_COUNT_OFFSET,r19
 466
 467         add r19=IA64_SIGNAL_SHARED_PENDING_OFFSET+IA64_SIGPENDING_SIGNAL_OFFSET,r19
 468         ;;
 469         ld4 r17=[r17]           // r17 <- current->signal->group_stop_count
 470 (p7)    mov r8=0                // clear error code
 471
 472         ld8 r19=[r19]           // r19 <- current->signal->shared_pending
 473         ;;
 474         cmp4.gt p6,p7=r17,r0    // p6/p7 <- (current->signal->group_stop_count > 0)?
 475 (p8)    mov r8=0                // clear error code
 476
 477         or r18=r18,r19          // r18 <- current->pending | current->signal->shared_pending
 478         ;;
 479         // r18 <- (current->pending | current->signal->shared_pending) & ~current->blocked:
 480         andcm r18=r18,r14
 481         add r9=TI_FLAGS+IA64_TASK_SIZE,r16
 482         ;;
 483
 484 (p7)    cmp.ne.or.andcm p6,p7=r18,r0            // p6/p7 <- signal pending
 485         mov r19=0                                       // i must not leak kernel bits...
 486 (p6)    br.cond.dpnt.many .sig_pending
 487         ;;
 488
 489 1:      ld4 r17=[r9]                            // r17 <- current->thread_info->flags
 490         ;;
 491         mov ar.ccv=r17
 492         and r18=~_TIF_SIGPENDING,r17            // r18 <- r17 & ~(1 << TIF_SIGPENDING)
 493         ;;
 494
 495         st8 [r2]=r14                            // update current->blocked with new mask
 496         cmpxchg4.acq r8=[r9],r18,ar.ccv         // current->thread_info->flags <- r18
 497         ;;
 498         cmp.ne p6,p0=r17,r8                     // update failed?
 499 (p6)    br.cond.spnt.few 1b                     // yes -> retry
 500
 501 #ifdef CONFIG_SMP
 502         // __ticket_spin_unlock(r31)
 503         st2.rel [r31]=r20
 504         mov r20=0                                       // i must not leak kernel bits...
 505 #endif
 506         SSM_PSR_I(p0, p9, r31)
 507         ;;
 508
 509         srlz.d                                  // ensure psr.i is set again
 510         mov r18=0                                       // i must not leak kernel bits...
 511
 512 .store_mask:
 513 EX(.fail_efault, (p15) probe.w.fault r34, 3)    // verify user has write-access to *oset
 514 EX(.fail_efault, (p15) st8 [r34]=r3)
 515         mov r2=0                                        // i must not leak kernel bits...
 516         mov r3=0                                        // i must not leak kernel bits...
 517         mov r8=0                                // return 0
 518         mov r9=0                                        // i must not leak kernel bits...
 519         mov r14=0                                       // i must not leak kernel bits...
 520         mov r17=0                                       // i must not leak kernel bits...
 521         mov r31=0                                       // i must not leak kernel bits...
 522         FSYS_RETURN
 523
 524 .sig_pending:
 525 #ifdef CONFIG_SMP
 526         // __ticket_spin_unlock(r31)
 527         st2.rel [r31]=r20                       // release the lock
 528 #endif
 529         SSM_PSR_I(p0, p9, r17)
 530         ;;
 531         srlz.d
 532         br.sptk.many fsys_fallback_syscall      // with signal pending, do the heavy-weight syscall
 533
 534 #ifdef CONFIG_SMP
 535 .lock_contention:
 536         /* Rather than spinning here, fall back on doing a heavy-weight syscall.  */
 537         SSM_PSR_I(p0, p9, r17)
 538         ;;
 539         srlz.d
 540         br.sptk.many fsys_fallback_syscall
 541 #endif
 542 END(fsys_rt_sigprocmask)
 543
 544 /*
 545  * fsys_getcpu doesn't use the third parameter in this implementation. It reads
 546  * current_thread_info()->cpu and corresponding node in cpu_to_node_map.
 547  */
 548 ENTRY(fsys_getcpu)
 549         .prologue
 550         .altrp b6
 551         .body
 552         ;;
 553         add r2=TI_FLAGS+IA64_TASK_SIZE,r16
 554         tnat.nz p6,p0 = r32                     // guard against NaT argument
 555         add r3=TI_CPU+IA64_TASK_SIZE,r16
 556         ;;
 557         ld4 r3=[r3]                             // M r3 = thread_info->cpu
 558         ld4 r2=[r2]                             // M r2 = thread_info->flags
 559 (p6)    br.cond.spnt.few .fail_einval           // B
 560         ;;
 561         tnat.nz p7,p0 = r33                     // I guard against NaT argument
 562 (p7)    br.cond.spnt.few .fail_einval           // B
 563 #ifdef CONFIG_NUMA
 564         movl r17=cpu_to_node_map
 565         ;;
 566 EX(.fail_efault, probe.w.fault r32, 3)          // M This takes 5 cycles
 567 EX(.fail_efault, probe.w.fault r33, 3)          // M This takes 5 cycles
 568         shladd r18=r3,1,r17
 569         ;;
 570         ld2 r20=[r18]                           // r20 = cpu_to_node_map[cpu]
 571         and r2 = TIF_ALLWORK_MASK,r2
 572         ;;
 573         cmp.ne p8,p0=0,r2
 574 (p8)    br.spnt.many fsys_fallback_syscall
 575         ;;
 576         ;;
 577 EX(.fail_efault, st4 [r32] = r3)
 578 EX(.fail_efault, st2 [r33] = r20)
 579         mov r8=0
 580         ;;
 581 #else
 582 EX(.fail_efault, probe.w.fault r32, 3)          // M This takes 5 cycles
 583 EX(.fail_efault, probe.w.fault r33, 3)          // M This takes 5 cycles
 584         and r2 = TIF_ALLWORK_MASK,r2
 585         ;;
 586         cmp.ne p8,p0=0,r2
 587 (p8)    br.spnt.many fsys_fallback_syscall
 588         ;;
 589 EX(.fail_efault, st4 [r32] = r3)
 590 EX(.fail_efault, st2 [r33] = r0)
 591         mov r8=0
 592         ;;
 593 #endif
 594         FSYS_RETURN
 595 END(fsys_getcpu)
 596
 597 ENTRY(fsys_fallback_syscall)
 598         .prologue
 599         .altrp b6
 600         .body
 601         /*
 602          * We only get here from light-weight syscall handlers.  Thus, we already
 603          * know that r15 contains a valid syscall number.  No need to re-check.
 604          */
 605         adds r17=-1024,r15
 606         movl r14=sys_call_table
 607         ;;
 608         RSM_PSR_I(p0, r26, r27)
 609         shladd r18=r17,3,r14
 610         ;;
 611         ld8 r18=[r18]                           // load normal (heavy-weight) syscall entry-point
 612         MOV_FROM_PSR(p0, r29, r26)              // read psr (12 cyc load latency)
 613         mov r27=ar.rsc
 614         mov r21=ar.fpsr
 615         mov r26=ar.pfs
 616 END(fsys_fallback_syscall)
 617         /* FALL THROUGH */
 618 GLOBAL_ENTRY(paravirt_fsys_bubble_down)
 619         .prologue
 620         .altrp b6
 621         .body
 622         /*
 623          * We get here for syscalls that don't have a lightweight
 624          * handler.  For those, we need to bubble down into the kernel
 625          * and that requires setting up a minimal pt_regs structure,
 626          * and initializing the CPU state more or less as if an
 627          * interruption had occurred.  To make syscall-restarts work,
 628          * we setup pt_regs such that cr_iip points to the second
 629          * instruction in syscall_via_break.  Decrementing the IP
 630          * hence will restart the syscall via break and not
 631          * decrementing IP will return us to the caller, as usual.
 632          * Note that we preserve the value of psr.pp rather than
 633          * initializing it from dcr.pp.  This makes it possible to
 634          * distinguish fsyscall execution from other privileged
 635          * execution.
 636          *
 637          * On entry:
 638          *      - normal fsyscall handler register usage, except
 639          *        that we also have:
 640          *      - r18: address of syscall entry point
 641          *      - r21: ar.fpsr
 642          *      - r26: ar.pfs
 643          *      - r27: ar.rsc
 644          *      - r29: psr
 645          *
 646          * We used to clear some PSR bits here but that requires slow
 647          * serialization.  Fortuntely, that isn't really necessary.
 648          * The rationale is as follows: we used to clear bits
 649          * ~PSR_PRESERVED_BITS in PSR.L.  Since
 650          * PSR_PRESERVED_BITS==PSR.{UP,MFL,MFH,PK,DT,PP,SP,RT,IC}, we
 651          * ended up clearing PSR.{BE,AC,I,DFL,DFH,DI,DB,SI,TB}.
 652          * However,
 653          *
 654          * PSR.BE : already is turned off in __kernel_syscall_via_epc()
 655          * PSR.AC : don't care (kernel normally turns PSR.AC on)
 656          * PSR.I  : already turned off by the time paravirt_fsys_bubble_down gets
 657          *          invoked
 658          * PSR.DFL: always 0 (kernel never turns it on)
 659          * PSR.DFH: don't care --- kernel never touches f32-f127 on its own
 660          *          initiative
 661          * PSR.DI : always 0 (kernel never turns it on)
 662          * PSR.SI : always 0 (kernel never turns it on)
 663          * PSR.DB : don't care --- kernel never enables kernel-level
 664          *          breakpoints
 665          * PSR.TB : must be 0 already; if it wasn't zero on entry to
 666          *          __kernel_syscall_via_epc, the branch to paravirt_fsys_bubble_down
 667          *          will trigger a taken branch; the taken-trap-handler then
 668          *          converts the syscall into a break-based system-call.
 669          */
 670         /*
 671          * Reading psr.l gives us only bits 0-31, psr.it, and psr.mc.
 672          * The rest we have to synthesize.
 673          */
 674 #       define PSR_ONE_BITS             ((3 << IA64_PSR_CPL0_BIT)       \
 675                                          | (0x1 << IA64_PSR_RI_BIT)     \
 676                                          | IA64_PSR_BN | IA64_PSR_I)
 677
 678         invala                                  // M0|1
 679         movl r14=ia64_ret_from_syscall          // X
 680
 681         nop.m 0
 682         movl r28=__kernel_syscall_via_break     // X    create cr.iip
 683         ;;
 684
 685         mov r2=r16                              // A    get task addr to addl-addressable register
 686         adds r16=IA64_TASK_THREAD_ON_USTACK_OFFSET,r16 // A
 687         mov r31=pr                              // I0   save pr (2 cyc)
 688         ;;
 689         st1 [r16]=r0                            // M2|3 clear current->thread.on_ustack flag
 690         addl r22=IA64_RBS_OFFSET,r2             // A    compute base of RBS
 691         add r3=TI_FLAGS+IA64_TASK_SIZE,r2       // A
 692         ;;
 693         ld4 r3=[r3]                             // M0|1 r3 = current_thread_info()->flags
 694         lfetch.fault.excl.nt1 [r22]             // M0|1 prefetch register backing-store
 695         nop.i 0
 696         ;;
 697         mov ar.rsc=0                            // M2   set enforced lazy mode, pl 0, LE, loadrs=0
 698 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 699         MOV_FROM_ITC(p0, p6, r30, r23)          // M    get cycle for accounting
 700 #else
 701         nop.m 0
 702 #endif
 703         nop.i 0
 704         ;;
 705         mov r23=ar.bspstore                     // M2 (12 cyc) save ar.bspstore
 706         mov.m r24=ar.rnat                       // M2 (5 cyc) read ar.rnat (dual-issues!)
 707         nop.i 0
 708         ;;
 709         mov ar.bspstore=r22                     // M2 (6 cyc) switch to kernel RBS
 710         movl r8=PSR_ONE_BITS                    // X
 711         ;;
 712         mov r25=ar.unat                         // M2 (5 cyc) save ar.unat
 713         mov r19=b6                              // I0   save b6 (2 cyc)
 714         mov r20=r1                              // A    save caller's gp in r20
 715         ;;
 716         or r29=r8,r29                           // A    construct cr.ipsr value to save
 717         mov b6=r18                              // I0   copy syscall entry-point to b6 (7 cyc)
 718         addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r2 // A compute base of memory stack
 719
 720         mov r18=ar.bsp                          // M2   save (kernel) ar.bsp (12 cyc)
 721         cmp.ne pKStk,pUStk=r0,r0                // A    set pKStk <- 0, pUStk <- 1
 722         br.call.sptk.many b7=ia64_syscall_setup // B
 723         ;;
 724 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 725         // mov.m r30=ar.itc is called in advance
 726         add r16=TI_AC_STAMP+IA64_TASK_SIZE,r2
 727         add r17=TI_AC_LEAVE+IA64_TASK_SIZE,r2
 728         ;;
 729         ld8 r18=[r16],TI_AC_STIME-TI_AC_STAMP   // time at last check in kernel
 730         ld8 r19=[r17],TI_AC_UTIME-TI_AC_LEAVE   // time at leave kernel
 731         ;;
 732         ld8 r20=[r16],TI_AC_STAMP-TI_AC_STIME   // cumulated stime
 733         ld8 r21=[r17]                           // cumulated utime
 734         sub r22=r19,r18                         // stime before leave kernel
 735         ;;
 736         st8 [r16]=r30,TI_AC_STIME-TI_AC_STAMP   // update stamp
 737         sub r18=r30,r19                         // elapsed time in user mode
 738         ;;
 739         add r20=r20,r22                         // sum stime
 740         add r21=r21,r18                         // sum utime
 741         ;;
 742         st8 [r16]=r20                           // update stime
 743         st8 [r17]=r21                           // update utime
 744         ;;
 745 #endif
 746         mov ar.rsc=0x3                          // M2   set eager mode, pl 0, LE, loadrs=0
 747         mov rp=r14                              // I0   set the real return addr
 748         and r3=_TIF_SYSCALL_TRACEAUDIT,r3       // A
 749         ;;
 750         SSM_PSR_I(p0, p6, r22)                  // M2   we're on kernel stacks now, reenable irqs
 751         cmp.eq p8,p0=r3,r0                      // A
 752 (p10)   br.cond.spnt.many ia64_ret_from_syscall // B    return if bad call-frame or r15 is a NaT
 753
 754         nop.m 0
 755 (p8)    br.call.sptk.many b6=b6                 // B    (ignore return address)
 756         br.cond.spnt ia64_trace_syscall         // B
 757 END(paravirt_fsys_bubble_down)
 758
 759         .rodata
 760         .align 8
 761         .globl paravirt_fsyscall_table
 762
 763         data8 paravirt_fsys_bubble_down
 764 paravirt_fsyscall_table:
 765         data8 fsys_ni_syscall
 766         data8 0                         // exit                 // 1025
 767         data8 0                         // read
 768         data8 0                         // write
 769         data8 0                         // open
 770         data8 0                         // close
 771         data8 0                         // creat                // 1030
 772         data8 0                         // link
 773         data8 0                         // unlink
 774         data8 0                         // execve
 775         data8 0                         // chdir
 776         data8 0                         // fchdir               // 1035
 777         data8 0                         // utimes
 778         data8 0                         // mknod
 779         data8 0                         // chmod
 780         data8 0                         // chown
 781         data8 0                         // lseek                // 1040
 782         data8 fsys_getpid               // getpid
 783         data8 fsys_getppid              // getppid
 784         data8 0                         // mount
 785         data8 0                         // umount
 786         data8 0                         // setuid               // 1045
 787         data8 0                         // getuid
 788         data8 0                         // geteuid
 789         data8 0                         // ptrace
 790         data8 0                         // access
 791         data8 0                         // sync                 // 1050
 792         data8 0                         // fsync
 793         data8 0                         // fdatasync
 794         data8 0                         // kill
 795         data8 0                         // rename
 796         data8 0                         // mkdir                // 1055
 797         data8 0                         // rmdir
 798         data8 0                         // dup
 799         data8 0                         // pipe
 800         data8 0                         // times
 801         data8 0                         // brk                  // 1060
 802         data8 0                         // setgid
 803         data8 0                         // getgid
 804         data8 0                         // getegid
 805         data8 0                         // acct
 806         data8 0                         // ioctl                // 1065
 807         data8 0                         // fcntl
 808         data8 0                         // umask
 809         data8 0                         // chroot
 810         data8 0                         // ustat
 811         data8 0                         // dup2                 // 1070
 812         data8 0                         // setreuid
 813         data8 0                         // setregid
 814         data8 0                         // getresuid
 815         data8 0                         // setresuid
 816         data8 0                         // getresgid            // 1075
 817         data8 0                         // setresgid
 818         data8 0                         // getgroups
 819         data8 0                         // setgroups
 820         data8 0                         // getpgid
 821         data8 0                         // setpgid              // 1080
 822         data8 0                         // setsid
 823         data8 0                         // getsid
 824         data8 0                         // sethostname
 825         data8 0                         // setrlimit
 826         data8 0                         // getrlimit            // 1085
 827         data8 0                         // getrusage
 828         data8 fsys_gettimeofday         // gettimeofday
 829         data8 0                         // settimeofday
 830         data8 0                         // select
 831         data8 0                         // poll                 // 1090
 832         data8 0                         // symlink
 833         data8 0                         // readlink
 834         data8 0                         // uselib
 835         data8 0                         // swapon
 836         data8 0                         // swapoff              // 1095
 837         data8 0                         // reboot
 838         data8 0                         // truncate
 839         data8 0                         // ftruncate
 840         data8 0                         // fchmod
 841         data8 0                         // fchown               // 1100
 842         data8 0                         // getpriority
 843         data8 0                         // setpriority
 844         data8 0                         // statfs
 845         data8 0                         // fstatfs
 846         data8 0                         // gettid               // 1105
 847         data8 0                         // semget
 848         data8 0                         // semop
 849         data8 0                         // semctl
 850         data8 0                         // msgget
 851         data8 0                         // msgsnd               // 1110
 852         data8 0                         // msgrcv
 853         data8 0                         // msgctl
 854         data8 0                         // shmget
 855         data8 0                         // shmat
 856         data8 0                         // shmdt                // 1115
 857         data8 0                         // shmctl
 858         data8 0                         // syslog
 859         data8 0                         // setitimer
 860         data8 0                         // getitimer
 861         data8 0                                                 // 1120
 862         data8 0
 863         data8 0
 864         data8 0                         // vhangup
 865         data8 0                         // lchown
 866         data8 0                         // remap_file_pages     // 1125
 867         data8 0                         // wait4
 868         data8 0                         // sysinfo
 869         data8 0                         // clone
 870         data8 0                         // setdomainname
 871         data8 0                         // newuname             // 1130
 872         data8 0                         // adjtimex
 873         data8 0
 874         data8 0                         // init_module
 875         data8 0                         // delete_module
 876         data8 0                                                 // 1135
 877         data8 0
 878         data8 0                         // quotactl
 879         data8 0                         // bdflush
 880         data8 0                         // sysfs
 881         data8 0                         // personality          // 1140
 882         data8 0                         // afs_syscall
 883         data8 0                         // setfsuid
 884         data8 0                         // setfsgid
 885         data8 0                         // getdents
 886         data8 0                         // flock                // 1145
 887         data8 0                         // readv
 888         data8 0                         // writev
 889         data8 0                         // pread64
 890         data8 0                         // pwrite64
 891         data8 0                         // sysctl               // 1150
 892         data8 0                         // mmap
 893         data8 0                         // munmap
 894         data8 0                         // mlock
 895         data8 0                         // mlockall
 896         data8 0                         // mprotect             // 1155
 897         data8 0                         // mremap
 898         data8 0                         // msync
 899         data8 0                         // munlock
 900         data8 0                         // munlockall
 901         data8 0                         // sched_getparam       // 1160
 902         data8 0                         // sched_setparam
 903         data8 0                         // sched_getscheduler
 904         data8 0                         // sched_setscheduler
 905         data8 0                         // sched_yield
 906         data8 0                         // sched_get_priority_max       // 1165
 907         data8 0                         // sched_get_priority_min
 908         data8 0                         // sched_rr_get_interval
 909         data8 0                         // nanosleep
 910         data8 0                         // nfsservctl
 911         data8 0                         // prctl                // 1170
 912         data8 0                         // getpagesize
 913         data8 0                         // mmap2
 914         data8 0                         // pciconfig_read
 915         data8 0                         // pciconfig_write
 916         data8 0                         // perfmonctl           // 1175
 917         data8 0                         // sigaltstack
 918         data8 0                         // rt_sigaction
 919         data8 0                         // rt_sigpending
 920         data8 fsys_rt_sigprocmask       // rt_sigprocmask
 921         data8 0                         // rt_sigqueueinfo      // 1180
 922         data8 0                         // rt_sigreturn
 923         data8 0                         // rt_sigsuspend
 924         data8 0                         // rt_sigtimedwait
 925         data8 0                         // getcwd
 926         data8 0                         // capget               // 1185
 927         data8 0                         // capset
 928         data8 0                         // sendfile
 929         data8 0
 930         data8 0
 931         data8 0                         // socket               // 1190
 932         data8 0                         // bind
 933         data8 0                         // connect
 934         data8 0                         // listen
 935         data8 0                         // accept
 936         data8 0                         // getsockname          // 1195
 937         data8 0                         // getpeername
 938         data8 0                         // socketpair
 939         data8 0                         // send
 940         data8 0                         // sendto
 941         data8 0                         // recv                 // 1200
 942         data8 0                         // recvfrom
 943         data8 0                         // shutdown
 944         data8 0                         // setsockopt
 945         data8 0                         // getsockopt
 946         data8 0                         // sendmsg              // 1205
 947         data8 0                         // recvmsg
 948         data8 0                         // pivot_root
 949         data8 0                         // mincore
 950         data8 0                         // madvise
 951         data8 0                         // newstat              // 1210
 952         data8 0                         // newlstat
 953         data8 0                         // newfstat
 954         data8 0                         // clone2
 955         data8 0                         // getdents64
 956         data8 0                         // getunwind            // 1215
 957         data8 0                         // readahead
 958         data8 0                         // setxattr
 959         data8 0                         // lsetxattr
 960         data8 0                         // fsetxattr
 961         data8 0                         // getxattr             // 1220
 962         data8 0                         // lgetxattr
 963         data8 0                         // fgetxattr
 964         data8 0                         // listxattr
 965         data8 0                         // llistxattr
 966         data8 0                         // flistxattr           // 1225
 967         data8 0                         // removexattr
 968         data8 0                         // lremovexattr
 969         data8 0                         // fremovexattr
 970         data8 0                         // tkill
 971         data8 0                         // futex                // 1230
 972         data8 0                         // sched_setaffinity
 973         data8 0                         // sched_getaffinity
 974         data8 fsys_set_tid_address      // set_tid_address
 975         data8 0                         // fadvise64_64
 976         data8 0                         // tgkill               // 1235
 977         data8 0                         // exit_group
 978         data8 0                         // lookup_dcookie
 979         data8 0                         // io_setup
 980         data8 0                         // io_destroy
 981         data8 0                         // io_getevents         // 1240
 982         data8 0                         // io_submit
 983         data8 0                         // io_cancel
 984         data8 0                         // epoll_create
 985         data8 0                         // epoll_ctl
 986         data8 0                         // epoll_wait           // 1245
 987         data8 0                         // restart_syscall
 988         data8 0                         // semtimedop
 989         data8 0                         // timer_create
 990         data8 0                         // timer_settime
 991         data8 0                         // timer_gettime        // 1250
 992         data8 0                         // timer_getoverrun
 993         data8 0                         // timer_delete
 994         data8 0                         // clock_settime
 995         data8 fsys_clock_gettime        // clock_gettime
 996         data8 0                         // clock_getres         // 1255
 997         data8 0                         // clock_nanosleep
 998         data8 0                         // fstatfs64
 999         data8 0                         // statfs64
1000         data8 0                         // mbind
1001         data8 0                         // get_mempolicy        // 1260
1002         data8 0                         // set_mempolicy
1003         data8 0                         // mq_open
1004         data8 0                         // mq_unlink
1005         data8 0                         // mq_timedsend
1006         data8 0                         // mq_timedreceive      // 1265
1007         data8 0                         // mq_notify
1008         data8 0                         // mq_getsetattr
1009         data8 0                         // kexec_load
1010         data8 0                         // vserver
1011         data8 0                         // waitid               // 1270
1012         data8 0                         // add_key
1013         data8 0                         // request_key
1014         data8 0                         // keyctl
1015         data8 0                         // ioprio_set
1016         data8 0                         // ioprio_get           // 1275
1017         data8 0                         // move_pages
1018         data8 0                         // inotify_init
1019         data8 0                         // inotify_add_watch
1020         data8 0                         // inotify_rm_watch
1021         data8 0                         // migrate_pages        // 1280
1022         data8 0                         // openat
1023         data8 0                         // mkdirat
1024         data8 0                         // mknodat
1025         data8 0                         // fchownat
1026         data8 0                         // futimesat            // 1285
1027         data8 0                         // newfstatat
1028         data8 0                         // unlinkat
1029         data8 0                         // renameat
1030         data8 0                         // linkat
1031         data8 0                         // symlinkat            // 1290
1032         data8 0                         // readlinkat
1033         data8 0                         // fchmodat
1034         data8 0                         // faccessat
1035         data8 0
1036         data8 0                                                 // 1295
1037         data8 0                         // unshare
1038         data8 0                         // splice
1039         data8 0                         // set_robust_list
1040         data8 0                         // get_robust_list
1041         data8 0                         // sync_file_range      // 1300
1042         data8 0                         // tee
1043         data8 0                         // vmsplice
1044         data8 0
1045         data8 fsys_getcpu               // getcpu               // 1304
1046
1047         // fill in zeros for the remaining entries
1048         .zero:
1049         .space paravirt_fsyscall_table + 8*NR_syscalls - .zero, 0