# HG changeset patch
# User awilliam@xxxxxxxxxxxx
# Date 1168973505 25200
# Node ID 7a2c224a9252bb9ca6ada21cf372f22f37ad98fe
# Parent 1d72428a0fab5b8a3256c88968fd9253e7b30180
[IA64] Add fsys.S to sparse tree
>From 2.6.16.33
Signed-off-by: Alex Williamson <alex.williamson@xxxxxx>
---
linux-2.6-xen-sparse/arch/ia64/kernel/fsys.S | 884 +++++++++++++++++++++++++++
1 files changed, 884 insertions(+)
diff -r 1d72428a0fab -r 7a2c224a9252
linux-2.6-xen-sparse/arch/ia64/kernel/fsys.S
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/linux-2.6-xen-sparse/arch/ia64/kernel/fsys.S Tue Jan 16 11:51:45
2007 -0700
@@ -0,0 +1,884 @@
+/*
+ * This file contains the light-weight system call handlers
(fsyscall-handlers).
+ *
+ * Copyright (C) 2003 Hewlett-Packard Co
+ * David Mosberger-Tang <davidm@xxxxxxxxxx>
+ *
+ * 25-Sep-03 davidm Implement fsys_rt_sigprocmask().
+ * 18-Feb-03 louisk Implement fsys_gettimeofday().
+ * 28-Feb-03 davidm Fixed several bugs in fsys_gettimeofday(). Tuned it
some more,
+ * probably broke it along the way... ;-)
+ * 13-Jul-04 clameter Implement fsys_clock_gettime and revise
fsys_gettimeofday to make
+ * it capable of using memory based clocks without
falling back to C code.
+ */
+
+#include <asm/asmmacro.h>
+#include <asm/errno.h>
+#include <asm/asm-offsets.h>
+#include <asm/percpu.h>
+#include <asm/thread_info.h>
+#include <asm/sal.h>
+#include <asm/signal.h>
+#include <asm/system.h>
+#include <asm/unistd.h>
+
+#include "entry.h"
+
+/*
+ * See Documentation/ia64/fsys.txt for details on fsyscalls.
+ *
+ * On entry to an fsyscall handler:
+ * r10 = 0 (i.e., defaults to "successful syscall return")
+ * r11 = saved ar.pfs (a user-level value)
+ * r15 = system call number
+ * r16 = "current" task pointer (in normal kernel-mode, this is in r13)
+ * r32-r39 = system call arguments
+ * b6 = return address (a user-level value)
+ * ar.pfs = previous frame-state (a user-level value)
+ * PSR.be = cleared to zero (i.e., little-endian byte order is in effect)
+ * all other registers may contain values passed in from user-mode
+ *
+ * On return from an fsyscall handler:
+ * r11 = saved ar.pfs (as passed into the fsyscall handler)
+ * r15 = system call number (as passed into the fsyscall handler)
+ * r32-r39 = system call arguments (as passed into the fsyscall handler)
+ * b6 = return address (as passed into the fsyscall handler)
+ * ar.pfs = previous frame-state (as passed into the fsyscall handler)
+ */
+
+ENTRY(fsys_ni_syscall)
+ .prologue
+ .altrp b6
+ .body
+ mov r8=ENOSYS
+ mov r10=-1
+ FSYS_RETURN
+END(fsys_ni_syscall)
+
+ENTRY(fsys_getpid)
+ .prologue
+ .altrp b6
+ .body
+ add r9=TI_FLAGS+IA64_TASK_SIZE,r16
+ ;;
+ ld4 r9=[r9]
+ add r8=IA64_TASK_TGID_OFFSET,r16
+ ;;
+ and r9=TIF_ALLWORK_MASK,r9
+ ld4 r8=[r8] // r8 = current->tgid
+ ;;
+ cmp.ne p8,p0=0,r9
+(p8) br.spnt.many fsys_fallback_syscall
+ FSYS_RETURN
+END(fsys_getpid)
+
+ENTRY(fsys_getppid)
+ .prologue
+ .altrp b6
+ .body
+ add r17=IA64_TASK_GROUP_LEADER_OFFSET,r16
+ ;;
+ ld8 r17=[r17] // r17 = current->group_leader
+ add r9=TI_FLAGS+IA64_TASK_SIZE,r16
+ ;;
+
+ ld4 r9=[r9]
+ add r17=IA64_TASK_REAL_PARENT_OFFSET,r17 // r17 =
¤t->group_leader->real_parent
+ ;;
+ and r9=TIF_ALLWORK_MASK,r9
+
+1: ld8 r18=[r17] // r18 =
current->group_leader->real_parent
+ ;;
+ cmp.ne p8,p0=0,r9
+ add r8=IA64_TASK_TGID_OFFSET,r18 // r8 =
¤t->group_leader->real_parent->tgid
+ ;;
+
+ /*
+ * The .acq is needed to ensure that the read of tgid has returned its
data before
+ * we re-check "real_parent".
+ */
+ ld4.acq r8=[r8] // r8 =
current->group_leader->real_parent->tgid
+#ifdef CONFIG_SMP
+ /*
+ * Re-read current->group_leader->real_parent.
+ */
+ ld8 r19=[r17] // r19 =
current->group_leader->real_parent
+(p8) br.spnt.many fsys_fallback_syscall
+ ;;
+ cmp.ne p6,p0=r18,r19 // did real_parent change?
+ mov r19=0 // i must not leak kernel bits...
+(p6) br.cond.spnt.few 1b // yes -> redo the read of tgid
and the check
+ ;;
+ mov r17=0 // i must not leak kernel bits...
+ mov r18=0 // i must not leak kernel bits...
+#else
+ mov r17=0 // i must not leak kernel bits...
+ mov r18=0 // i must not leak kernel bits...
+ mov r19=0 // i must not leak kernel bits...
+#endif
+ FSYS_RETURN
+END(fsys_getppid)
+
+ENTRY(fsys_set_tid_address)
+ .prologue
+ .altrp b6
+ .body
+ add r9=TI_FLAGS+IA64_TASK_SIZE,r16
+ ;;
+ ld4 r9=[r9]
+ tnat.z p6,p7=r32 // check argument register for being NaT
+ ;;
+ and r9=TIF_ALLWORK_MASK,r9
+ add r8=IA64_TASK_PID_OFFSET,r16
+ add r18=IA64_TASK_CLEAR_CHILD_TID_OFFSET,r16
+ ;;
+ ld4 r8=[r8]
+ cmp.ne p8,p0=0,r9
+ mov r17=-1
+ ;;
+(p6) st8 [r18]=r32
+(p7) st8 [r18]=r17
+(p8) br.spnt.many fsys_fallback_syscall
+ ;;
+ mov r17=0 // i must not leak kernel bits...
+ mov r18=0 // i must not leak kernel bits...
+ FSYS_RETURN
+END(fsys_set_tid_address)
+
+/*
+ * Ensure that the time interpolator structure is compatible with the asm code
+ */
+#if IA64_TIME_INTERPOLATOR_SOURCE_OFFSET !=0 ||
IA64_TIME_INTERPOLATOR_SHIFT_OFFSET != 2 \
+ || IA64_TIME_INTERPOLATOR_JITTER_OFFSET != 3 ||
IA64_TIME_INTERPOLATOR_NSEC_OFFSET != 4
+#error fsys_gettimeofday incompatible with changes to struct time_interpolator
+#endif
+#define CLOCK_REALTIME 0
+#define CLOCK_MONOTONIC 1
+#define CLOCK_DIVIDE_BY_1000 0x4000
+#define CLOCK_ADD_MONOTONIC 0x8000
+
+ENTRY(fsys_gettimeofday)
+ .prologue
+ .altrp b6
+ .body
+ mov r31 = r32
+ tnat.nz p6,p0 = r33 // guard against NaT argument
+(p6) br.cond.spnt.few .fail_einval
+ mov r30 = CLOCK_DIVIDE_BY_1000
+ ;;
+.gettime:
+ // Register map
+ // Incoming r31 = pointer to address where to place result
+ // r30 = flags determining how time is processed
+ // r2,r3 = temp r4-r7 preserved
+ // r8 = result nanoseconds
+ // r9 = result seconds
+ // r10 = temporary storage for clock difference
+ // r11 = preserved: saved ar.pfs
+ // r12 = preserved: memory stack
+ // r13 = preserved: thread pointer
+ // r14 = address of mask / mask
+ // r15 = preserved: system call number
+ // r16 = preserved: current task pointer
+ // r17 = wall to monotonic use
+ // r18 = time_interpolator->offset
+ // r19 = address of wall_to_monotonic
+ // r20 = pointer to struct time_interpolator / pointer to
time_interpolator->address
+ // r21 = shift factor
+ // r22 = address of time interpolator->last_counter
+ // r23 = address of time_interpolator->last_cycle
+ // r24 = adress of time_interpolator->offset
+ // r25 = last_cycle value
+ // r26 = last_counter value
+ // r27 = pointer to xtime
+ // r28 = sequence number at the beginning of critcal section
+ // r29 = address of seqlock
+ // r30 = time processing flags / memory address
+ // r31 = pointer to result
+ // Predicates
+ // p6,p7 short term use
+ // p8 = timesource ar.itc
+ // p9 = timesource mmio64
+ // p10 = timesource mmio32
+ // p11 = timesource not to be handled by asm code
+ // p12 = memory time source ( = p9 | p10)
+ // p13 = do cmpxchg with time_interpolator_last_cycle
+ // p14 = Divide by 1000
+ // p15 = Add monotonic
+ //
+ // Note that instructions are optimized for McKinley. McKinley can
process two
+ // bundles simultaneously and therefore we continuously try to feed the
CPU
+ // two bundles and then a stop.
+ tnat.nz p6,p0 = r31 // branch deferred since it does not fit into
bundle structure
+ mov pr = r30,0xc000 // Set predicates according to function
+ add r2 = TI_FLAGS+IA64_TASK_SIZE,r16
+ movl r20 = time_interpolator
+ ;;
+ ld8 r20 = [r20] // get pointer to time_interpolator structure
+ movl r29 = xtime_lock
+ ld4 r2 = [r2] // process work pending flags
+ movl r27 = xtime
+ ;; // only one bundle here
+ ld8 r21 = [r20] // first quad with control information
+ and r2 = TIF_ALLWORK_MASK,r2
+(p6) br.cond.spnt.few .fail_einval // deferred branch
+ ;;
+ add r10 = IA64_TIME_INTERPOLATOR_ADDRESS_OFFSET,r20
+ extr r3 = r21,32,32 // time_interpolator->nsec_per_cyc
+ extr r8 = r21,0,16 // time_interpolator->source
+ cmp.ne p6, p0 = 0, r2 // Fallback if work is scheduled
+(p6) br.cond.spnt.many fsys_fallback_syscall
+ ;;
+ cmp.eq p8,p12 = 0,r8 // Check for cpu timer
+ cmp.eq p9,p0 = 1,r8 // MMIO64 ?
+ extr r2 = r21,24,8 // time_interpolator->jitter
+ cmp.eq p10,p0 = 2,r8 // MMIO32 ?
+ cmp.ltu p11,p0 = 2,r8 // function or other clock
+(p11) br.cond.spnt.many fsys_fallback_syscall
+ ;;
+ setf.sig f7 = r3 // Setup for scaling of counter
+(p15) movl r19 = wall_to_monotonic
+(p12) ld8 r30 = [r10]
+ cmp.ne p13,p0 = r2,r0 // need jitter compensation?
+ extr r21 = r21,16,8 // shift factor
+ ;;
+.time_redo:
+ .pred.rel.mutex p8,p9,p10
+ ld4.acq r28 = [r29] // xtime_lock.sequence. Must come first for
locking purposes
+(p8) mov r2 = ar.itc // CPU_TIMER. 36 clocks latency!!!
+ add r22 = IA64_TIME_INTERPOLATOR_LAST_COUNTER_OFFSET,r20
+(p9) ld8 r2 = [r30] // readq(ti->address). Could also have latency
issues..
+(p10) ld4 r2 = [r30] // readw(ti->address)
+(p13) add r23 = IA64_TIME_INTERPOLATOR_LAST_CYCLE_OFFSET,r20
+ ;; // could be removed by moving the last add
upward
+ ld8 r26 = [r22] // time_interpolator->last_counter
+(p13) ld8 r25 = [r23] // time interpolator->last_cycle
+ add r24 = IA64_TIME_INTERPOLATOR_OFFSET_OFFSET,r20
+(p15) ld8 r17 = [r19],IA64_TIMESPEC_TV_NSEC_OFFSET
+ ld8 r9 = [r27],IA64_TIMESPEC_TV_NSEC_OFFSET
+ add r14 = IA64_TIME_INTERPOLATOR_MASK_OFFSET, r20
+ ;;
+ ld8 r18 = [r24] // time_interpolator->offset
+ ld8 r8 = [r27],-IA64_TIMESPEC_TV_NSEC_OFFSET // xtime.tv_nsec
+(p13) sub r3 = r25,r2 // Diff needed before comparison (thanks davidm)
+ ;;
+ ld8 r14 = [r14] // time_interpolator->mask
+(p13) cmp.gt.unc p6,p7 = r3,r0 // check if it is less than last. p6,p7
cleared
+ sub r10 = r2,r26 // current_counter - last_counter
+ ;;
+(p6) sub r10 = r25,r26 // time we got was less than last_cycle
+(p7) mov ar.ccv = r25 // more than last_cycle. Prep for cmpxchg
+ ;;
+ and r10 = r10,r14 // Apply mask
+ ;;
+ setf.sig f8 = r10
+ nop.i 123
+ ;;
+(p7) cmpxchg8.rel r3 = [r23],r2,ar.ccv
+EX(.fail_efault, probe.w.fault r31, 3) // This takes 5 cycles and we have
spare time
+ xmpy.l f8 = f8,f7 // nsec_per_cyc*(counter-last_counter)
+(p15) add r9 = r9,r17 // Add wall to monotonic.secs to result secs
+ ;;
+(p15) ld8 r17 = [r19],-IA64_TIMESPEC_TV_NSEC_OFFSET
+(p7) cmp.ne p7,p0 = r25,r3 // if cmpxchg not successful redo
+ // simulate tbit.nz.or p7,p0 = r28,0
+ and r28 = ~1,r28 // Make sequence even to force retry if odd
+ getf.sig r2 = f8
+ mf
+ add r8 = r8,r18 // Add time interpolator offset
+ ;;
+ ld4 r10 = [r29] // xtime_lock.sequence
+(p15) add r8 = r8, r17 // Add monotonic.nsecs to nsecs
+ shr.u r2 = r2,r21
+ ;; // overloaded 3 bundles!
+ // End critical section.
+ add r8 = r8,r2 // Add xtime.nsecs
+ cmp4.ne.or p7,p0 = r28,r10
+(p7) br.cond.dpnt.few .time_redo // sequence number changed ?
+ // Now r8=tv->tv_nsec and r9=tv->tv_sec
+ mov r10 = r0
+ movl r2 = 1000000000
+ add r23 = IA64_TIMESPEC_TV_NSEC_OFFSET, r31
+(p14) movl r3 = 2361183241434822607 // Prep for / 1000 hack
+ ;;
+.time_normalize:
+ mov r21 = r8
+ cmp.ge p6,p0 = r8,r2
+(p14) shr.u r20 = r8, 3 // We can repeat this if necessary just
wasting some time
+ ;;
+(p14) setf.sig f8 = r20
+(p6) sub r8 = r8,r2
+(p6) add r9 = 1,r9 // two nops before the branch.
+(p14) setf.sig f7 = r3 // Chances for repeats are 1 in 10000
for gettod
+(p6) br.cond.dpnt.few .time_normalize
+ ;;
+ // Divided by 8 though shift. Now divide by 125
+ // The compiler was able to do that with a multiply
+ // and a shift and we do the same
+EX(.fail_efault, probe.w.fault r23, 3) // This also costs 5 cycles
+(p14) xmpy.hu f8 = f8, f7 // xmpy has 5 cycles latency so
use it...
+ ;;
+ mov r8 = r0
+(p14) getf.sig r2 = f8
+ ;;
+(p14) shr.u r21 = r2, 4
+ ;;
+EX(.fail_efault, st8 [r31] = r9)
+EX(.fail_efault, st8 [r23] = r21)
+ FSYS_RETURN
+.fail_einval:
+ mov r8 = EINVAL
+ mov r10 = -1
+ FSYS_RETURN
+.fail_efault:
+ mov r8 = EFAULT
+ mov r10 = -1
+ FSYS_RETURN
+END(fsys_gettimeofday)
+
+ENTRY(fsys_clock_gettime)
+ .prologue
+ .altrp b6
+ .body
+ cmp4.ltu p6, p0 = CLOCK_MONOTONIC, r32
+ // Fallback if this is not CLOCK_REALTIME or CLOCK_MONOTONIC
+(p6) br.spnt.few fsys_fallback_syscall
+ mov r31 = r33
+ shl r30 = r32,15
+ br.many .gettime
+END(fsys_clock_gettime)
+
+/*
+ * long fsys_rt_sigprocmask (int how, sigset_t *set, sigset_t *oset, size_t
sigsetsize).
+ */
+#if _NSIG_WORDS != 1
+# error Sorry, fsys_rt_sigprocmask() needs to be updated for _NSIG_WORDS != 1.
+#endif
+ENTRY(fsys_rt_sigprocmask)
+ .prologue
+ .altrp b6
+ .body
+
+ add r2=IA64_TASK_BLOCKED_OFFSET,r16
+ add r9=TI_FLAGS+IA64_TASK_SIZE,r16
+ cmp4.ltu p6,p0=SIG_SETMASK,r32
+
+ cmp.ne p15,p0=r0,r34 // oset != NULL?
+ tnat.nz p8,p0=r34
+ add r31=IA64_TASK_SIGHAND_OFFSET,r16
+ ;;
+ ld8 r3=[r2] // read/prefetch
current->blocked
+ ld4 r9=[r9]
+ tnat.nz.or p6,p0=r35
+
+ cmp.ne.or p6,p0=_NSIG_WORDS*8,r35
+ tnat.nz.or p6,p0=r32
+(p6) br.spnt.few .fail_einval // fail with EINVAL
+ ;;
+#ifdef CONFIG_SMP
+ ld8 r31=[r31] // r31 <- current->sighand
+#endif
+ and r9=TIF_ALLWORK_MASK,r9
+ tnat.nz.or p8,p0=r33
+ ;;
+ cmp.ne p7,p0=0,r9
+ cmp.eq p6,p0=r0,r33 // set == NULL?
+ add r31=IA64_SIGHAND_SIGLOCK_OFFSET,r31 // r31 <-
current->sighand->siglock
+(p8) br.spnt.few .fail_efault // fail with EFAULT
+(p7) br.spnt.many fsys_fallback_syscall // got pending kernel work...
+(p6) br.dpnt.many .store_mask // -> short-circuit to just
reading the signal mask
+
+ /* Argh, we actually have to do some work and _update_ the signal mask:
*/
+
+EX(.fail_efault, probe.r.fault r33, 3) // verify user has read-access
to *set
+EX(.fail_efault, ld8 r14=[r33]) // r14 <- *set
+ mov r17=(1 << (SIGKILL - 1)) | (1 << (SIGSTOP - 1))
+ ;;
+
+ rsm psr.i // mask interrupt delivery
+ mov ar.ccv=0
+ andcm r14=r14,r17 // filter out SIGKILL & SIGSTOP
+
+#ifdef CONFIG_SMP
+ mov r17=1
+ ;;
+ cmpxchg4.acq r18=[r31],r17,ar.ccv // try to acquire the lock
+ mov r8=EINVAL // default to EINVAL
+ ;;
+ ld8 r3=[r2] // re-read current->blocked now that we
hold the lock
+ cmp4.ne p6,p0=r18,r0
+(p6) br.cond.spnt.many .lock_contention
+ ;;
+#else
+ ld8 r3=[r2] // re-read current->blocked now that we
hold the lock
+ mov r8=EINVAL // default to EINVAL
+#endif
+ add r18=IA64_TASK_PENDING_OFFSET+IA64_SIGPENDING_SIGNAL_OFFSET,r16
+ add r19=IA64_TASK_SIGNAL_OFFSET,r16
+ cmp4.eq p6,p0=SIG_BLOCK,r32
+ ;;
+ ld8 r19=[r19] // r19 <- current->signal
+ cmp4.eq p7,p0=SIG_UNBLOCK,r32
+ cmp4.eq p8,p0=SIG_SETMASK,r32
+ ;;
+ ld8 r18=[r18] // r18 <- current->pending.signal
+ .pred.rel.mutex p6,p7,p8
+(p6) or r14=r3,r14 // SIG_BLOCK
+(p7) andcm r14=r3,r14 // SIG_UNBLOCK
+
+(p8) mov r14=r14 // SIG_SETMASK
+(p6) mov r8=0 // clear error code
+ // recalc_sigpending()
+ add r17=IA64_SIGNAL_GROUP_STOP_COUNT_OFFSET,r19
+
+ add
r19=IA64_SIGNAL_SHARED_PENDING_OFFSET+IA64_SIGPENDING_SIGNAL_OFFSET,r19
+ ;;
+ ld4 r17=[r17] // r17 <- current->signal->group_stop_count
+(p7) mov r8=0 // clear error code
+
+ ld8 r19=[r19] // r19 <- current->signal->shared_pending
+ ;;
+ cmp4.gt p6,p7=r17,r0 // p6/p7 <- (current->signal->group_stop_count
> 0)?
+(p8) mov r8=0 // clear error code
+
+ or r18=r18,r19 // r18 <- current->pending |
current->signal->shared_pending
+ ;;
+ // r18 <- (current->pending | current->signal->shared_pending) &
~current->blocked:
+ andcm r18=r18,r14
+ add r9=TI_FLAGS+IA64_TASK_SIZE,r16
+ ;;
+
+(p7) cmp.ne.or.andcm p6,p7=r18,r0 // p6/p7 <- signal pending
+ mov r19=0 // i must not leak
kernel bits...
+(p6) br.cond.dpnt.many .sig_pending
+ ;;
+
+1: ld4 r17=[r9] // r17 <-
current->thread_info->flags
+ ;;
+ mov ar.ccv=r17
+ and r18=~_TIF_SIGPENDING,r17 // r18 <- r17 & ~(1 <<
TIF_SIGPENDING)
+ ;;
+
+ st8 [r2]=r14 // update current->blocked with
new mask
+ cmpxchg4.acq r8=[r9],r18,ar.ccv // current->thread_info->flags
<- r18
+ ;;
+ cmp.ne p6,p0=r17,r8 // update failed?
+(p6) br.cond.spnt.few 1b // yes -> retry
+
+#ifdef CONFIG_SMP
+ st4.rel [r31]=r0 // release the lock
+#endif
+ ssm psr.i
+ ;;
+
+ srlz.d // ensure psr.i is set again
+ mov r18=0 // i must not leak
kernel bits...
+
+.store_mask:
+EX(.fail_efault, (p15) probe.w.fault r34, 3) // verify user has write-access
to *oset
+EX(.fail_efault, (p15) st8 [r34]=r3)
+ mov r2=0 // i must not leak
kernel bits...
+ mov r3=0 // i must not leak
kernel bits...
+ mov r8=0 // return 0
+ mov r9=0 // i must not leak
kernel bits...
+ mov r14=0 // i must not leak
kernel bits...
+ mov r17=0 // i must not leak
kernel bits...
+ mov r31=0 // i must not leak
kernel bits...
+ FSYS_RETURN
+
+.sig_pending:
+#ifdef CONFIG_SMP
+ st4.rel [r31]=r0 // release the lock
+#endif
+ ssm psr.i
+ ;;
+ srlz.d
+ br.sptk.many fsys_fallback_syscall // with signal pending, do the
heavy-weight syscall
+
+#ifdef CONFIG_SMP
+.lock_contention:
+ /* Rather than spinning here, fall back on doing a heavy-weight
syscall. */
+ ssm psr.i
+ ;;
+ srlz.d
+ br.sptk.many fsys_fallback_syscall
+#endif
+END(fsys_rt_sigprocmask)
+
+ENTRY(fsys_fallback_syscall)
+ .prologue
+ .altrp b6
+ .body
+ /*
+ * We only get here from light-weight syscall handlers. Thus, we
already
+ * know that r15 contains a valid syscall number. No need to re-check.
+ */
+ adds r17=-1024,r15
+ movl r14=sys_call_table
+ ;;
+ rsm psr.i
+ shladd r18=r17,3,r14
+ ;;
+ ld8 r18=[r18] // load normal (heavy-weight)
syscall entry-point
+ mov r29=psr // read psr (12 cyc load
latency)
+ mov r27=ar.rsc
+ mov r21=ar.fpsr
+ mov r26=ar.pfs
+END(fsys_fallback_syscall)
+ /* FALL THROUGH */
+GLOBAL_ENTRY(fsys_bubble_down)
+ .prologue
+ .altrp b6
+ .body
+ /*
+ * We get here for syscalls that don't have a lightweight
+ * handler. For those, we need to bubble down into the kernel
+ * and that requires setting up a minimal pt_regs structure,
+ * and initializing the CPU state more or less as if an
+ * interruption had occurred. To make syscall-restarts work,
+ * we setup pt_regs such that cr_iip points to the second
+ * instruction in syscall_via_break. Decrementing the IP
+ * hence will restart the syscall via break and not
+ * decrementing IP will return us to the caller, as usual.
+ * Note that we preserve the value of psr.pp rather than
+ * initializing it from dcr.pp. This makes it possible to
+ * distinguish fsyscall execution from other privileged
+ * execution.
+ *
+ * On entry:
+ * - normal fsyscall handler register usage, except
+ * that we also have:
+ * - r18: address of syscall entry point
+ * - r21: ar.fpsr
+ * - r26: ar.pfs
+ * - r27: ar.rsc
+ * - r29: psr
+ *
+ * We used to clear some PSR bits here but that requires slow
+ * serialization. Fortuntely, that isn't really necessary.
+ * The rationale is as follows: we used to clear bits
+ * ~PSR_PRESERVED_BITS in PSR.L. Since
+ * PSR_PRESERVED_BITS==PSR.{UP,MFL,MFH,PK,DT,PP,SP,RT,IC}, we
+ * ended up clearing PSR.{BE,AC,I,DFL,DFH,DI,DB,SI,TB}.
+ * However,
+ *
+ * PSR.BE : already is turned off in __kernel_syscall_via_epc()
+ * PSR.AC : don't care (kernel normally turns PSR.AC on)
+ * PSR.I : already turned off by the time fsys_bubble_down gets
+ * invoked
+ * PSR.DFL: always 0 (kernel never turns it on)
+ * PSR.DFH: don't care --- kernel never touches f32-f127 on its own
+ * initiative
+ * PSR.DI : always 0 (kernel never turns it on)
+ * PSR.SI : always 0 (kernel never turns it on)
+ * PSR.DB : don't care --- kernel never enables kernel-level
+ * breakpoints
+ * PSR.TB : must be 0 already; if it wasn't zero on entry to
+ * __kernel_syscall_via_epc, the branch to fsys_bubble_down
+ * will trigger a taken branch; the taken-trap-handler then
+ * converts the syscall into a break-based system-call.
+ */
+ /*
+ * Reading psr.l gives us only bits 0-31, psr.it, and psr.mc.
+ * The rest we have to synthesize.
+ */
+# define PSR_ONE_BITS ((3 << IA64_PSR_CPL0_BIT) \
+ | (0x1 << IA64_PSR_RI_BIT) \
+ | IA64_PSR_BN | IA64_PSR_I)
+
+ invala // M0|1
+ movl r14=ia64_ret_from_syscall // X
+
+ nop.m 0
+ movl r28=__kernel_syscall_via_break // X create cr.iip
+ ;;
+
+ mov r2=r16 // A get task addr to
addl-addressable register
+ adds r16=IA64_TASK_THREAD_ON_USTACK_OFFSET,r16 // A
+ mov r31=pr // I0 save pr (2 cyc)
+ ;;
+ st1 [r16]=r0 // M2|3 clear
current->thread.on_ustack flag
+ addl r22=IA64_RBS_OFFSET,r2 // A compute base of RBS
+ add r3=TI_FLAGS+IA64_TASK_SIZE,r2 // A
+ ;;
+ ld4 r3=[r3] // M0|1 r3 =
current_thread_info()->flags
+ lfetch.fault.excl.nt1 [r22] // M0|1 prefetch register
backing-store
+ nop.i 0
+ ;;
+ mov ar.rsc=0 // M2 set enforced lazy mode,
pl 0, LE, loadrs=0
+ nop.m 0
+ nop.i 0
+ ;;
+ mov r23=ar.bspstore // M2 (12 cyc) save ar.bspstore
+ mov.m r24=ar.rnat // M2 (5 cyc) read ar.rnat
(dual-issues!)
+ nop.i 0
+ ;;
+ mov ar.bspstore=r22 // M2 (6 cyc) switch to kernel
RBS
+ movl r8=PSR_ONE_BITS // X
+ ;;
+ mov r25=ar.unat // M2 (5 cyc) save ar.unat
+ mov r19=b6 // I0 save b6 (2 cyc)
+ mov r20=r1 // A save caller's gp in r20
+ ;;
+ or r29=r8,r29 // A construct cr.ipsr value
to save
+ mov b6=r18 // I0 copy syscall
entry-point to b6 (7 cyc)
+ addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r2 // A compute base of
memory stack
+
+ mov r18=ar.bsp // M2 save (kernel) ar.bsp
(12 cyc)
+ cmp.ne pKStk,pUStk=r0,r0 // A set pKStk <- 0, pUStk
<- 1
+ br.call.sptk.many b7=ia64_syscall_setup // B
+ ;;
+ mov ar.rsc=0x3 // M2 set eager mode, pl 0,
LE, loadrs=0
+ mov rp=r14 // I0 set the real return addr
+ and r3=_TIF_SYSCALL_TRACEAUDIT,r3 // A
+ ;;
+ ssm psr.i // M2 we're on kernel stacks
now, reenable irqs
+ cmp.eq p8,p0=r3,r0 // A
+(p10) br.cond.spnt.many ia64_ret_from_syscall // B return if bad
call-frame or r15 is a NaT
+
+ nop.m 0
+(p8) br.call.sptk.many b6=b6 // B (ignore return address)
+ br.cond.spnt ia64_trace_syscall // B
+END(fsys_bubble_down)
+
+ .rodata
+ .align 8
+ .globl fsyscall_table
+
+ data8 fsys_bubble_down
+fsyscall_table:
+ data8 fsys_ni_syscall
+ data8 0 // exit // 1025
+ data8 0 // read
+ data8 0 // write
+ data8 0 // open
+ data8 0 // close
+ data8 0 // creat // 1030
+ data8 0 // link
+ data8 0 // unlink
+ data8 0 // execve
+ data8 0 // chdir
+ data8 0 // fchdir // 1035
+ data8 0 // utimes
+ data8 0 // mknod
+ data8 0 // chmod
+ data8 0 // chown
+ data8 0 // lseek // 1040
+ data8 fsys_getpid // getpid
+ data8 fsys_getppid // getppid
+ data8 0 // mount
+ data8 0 // umount
+ data8 0 // setuid // 1045
+ data8 0 // getuid
+ data8 0 // geteuid
+ data8 0 // ptrace
+ data8 0 // access
+ data8 0 // sync // 1050
+ data8 0 // fsync
+ data8 0 // fdatasync
+ data8 0 // kill
+ data8 0 // rename
+ data8 0 // mkdir // 1055
+ data8 0 // rmdir
+ data8 0 // dup
+ data8 0 // pipe
+ data8 0 // times
+ data8 0 // brk // 1060
+ data8 0 // setgid
+ data8 0 // getgid
+ data8 0 // getegid
+ data8 0 // acct
+ data8 0 // ioctl // 1065
+ data8 0 // fcntl
+ data8 0 // umask
+ data8 0 // chroot
+ data8 0 // ustat
+ data8 0 // dup2 // 1070
+ data8 0 // setreuid
+ data8 0 // setregid
+ data8 0 // getresuid
+ data8 0 // setresuid
+ data8 0 // getresgid // 1075
+ data8 0 // setresgid
+ data8 0 // getgroups
+ data8 0 // setgroups
+ data8 0 // getpgid
+ data8 0 // setpgid // 1080
+ data8 0 // setsid
+ data8 0 // getsid
+ data8 0 // sethostname
+ data8 0 // setrlimit
+ data8 0 // getrlimit // 1085
+ data8 0 // getrusage
+ data8 fsys_gettimeofday // gettimeofday
+ data8 0 // settimeofday
+ data8 0 // select
+ data8 0 // poll // 1090
+ data8 0 // symlink
+ data8 0 // readlink
+ data8 0 // uselib
+ data8 0 // swapon
+ data8 0 // swapoff // 1095
+ data8 0 // reboot
+ data8 0 // truncate
+ data8 0 // ftruncate
+ data8 0 // fchmod
+ data8 0 // fchown // 1100
+ data8 0 // getpriority
+ data8 0 // setpriority
+ data8 0 // statfs
+ data8 0 // fstatfs
+ data8 0 // gettid // 1105
+ data8 0 // semget
+ data8 0 // semop
+ data8 0 // semctl
+ data8 0 // msgget
+ data8 0 // msgsnd // 1110
+ data8 0 // msgrcv
+ data8 0 // msgctl
+ data8 0 // shmget
+ data8 0 // shmat
+ data8 0 // shmdt // 1115
+ data8 0 // shmctl
+ data8 0 // syslog
+ data8 0 // setitimer
+ data8 0 // getitimer
+ data8 0 // 1120
+ data8 0
+ data8 0
+ data8 0 // vhangup
+ data8 0 // lchown
+ data8 0 // remap_file_pages // 1125
+ data8 0 // wait4
+ data8 0 // sysinfo
+ data8 0 // clone
+ data8 0 // setdomainname
+ data8 0 // newuname // 1130
+ data8 0 // adjtimex
+ data8 0
+ data8 0 // init_module
+ data8 0 // delete_module
+ data8 0 // 1135
+ data8 0
+ data8 0 // quotactl
+ data8 0 // bdflush
+ data8 0 // sysfs
+ data8 0 // personality // 1140
+ data8 0 // afs_syscall
+ data8 0 // setfsuid
+ data8 0 // setfsgid
+ data8 0 // getdents
+ data8 0 // flock // 1145
+ data8 0 // readv
+ data8 0 // writev
+ data8 0 // pread64
+ data8 0 // pwrite64
+ data8 0 // sysctl // 1150
+ data8 0 // mmap
+ data8 0 // munmap
+ data8 0 // mlock
+ data8 0 // mlockall
+ data8 0 // mprotect // 1155
+ data8 0 // mremap
+ data8 0 // msync
+ data8 0 // munlock
+ data8 0 // munlockall
+ data8 0 // sched_getparam // 1160
+ data8 0 // sched_setparam
+ data8 0 // sched_getscheduler
+ data8 0 // sched_setscheduler
+ data8 0 // sched_yield
+ data8 0 // sched_get_priority_max // 1165
+ data8 0 // sched_get_priority_min
+ data8 0 // sched_rr_get_interval
+ data8 0 // nanosleep
+ data8 0 // nfsservctl
+ data8 0 // prctl // 1170
+ data8 0 // getpagesize
+ data8 0 // mmap2
+ data8 0 // pciconfig_read
+ data8 0 // pciconfig_write
+ data8 0 // perfmonctl // 1175
+ data8 0 // sigaltstack
+ data8 0 // rt_sigaction
+ data8 0 // rt_sigpending
+ data8 fsys_rt_sigprocmask // rt_sigprocmask
+ data8 0 // rt_sigqueueinfo // 1180
+ data8 0 // rt_sigreturn
+ data8 0 // rt_sigsuspend
+ data8 0 // rt_sigtimedwait
+ data8 0 // getcwd
+ data8 0 // capget // 1185
+ data8 0 // capset
+ data8 0 // sendfile
+ data8 0
+ data8 0
+ data8 0 // socket // 1190
+ data8 0 // bind
+ data8 0 // connect
+ data8 0 // listen
+ data8 0 // accept
+ data8 0 // getsockname // 1195
+ data8 0 // getpeername
+ data8 0 // socketpair
+ data8 0 // send
+ data8 0 // sendto
+ data8 0 // recv // 1200
+ data8 0 // recvfrom
+ data8 0 // shutdown
+ data8 0 // setsockopt
+ data8 0 // getsockopt
+ data8 0 // sendmsg // 1205
+ data8 0 // recvmsg
+ data8 0 // pivot_root
+ data8 0 // mincore
+ data8 0 // madvise
+ data8 0 // newstat // 1210
+ data8 0 // newlstat
+ data8 0 // newfstat
+ data8 0 // clone2
+ data8 0 // getdents64
+ data8 0 // getunwind // 1215
+ data8 0 // readahead
+ data8 0 // setxattr
+ data8 0 // lsetxattr
+ data8 0 // fsetxattr
+ data8 0 // getxattr // 1220
+ data8 0 // lgetxattr
+ data8 0 // fgetxattr
+ data8 0 // listxattr
+ data8 0 // llistxattr
+ data8 0 // flistxattr // 1225
+ data8 0 // removexattr
+ data8 0 // lremovexattr
+ data8 0 // fremovexattr
+ data8 0 // tkill
+ data8 0 // futex // 1230
+ data8 0 // sched_setaffinity
+ data8 0 // sched_getaffinity
+ data8 fsys_set_tid_address // set_tid_address
+ data8 0 // fadvise64_64
+ data8 0 // tgkill // 1235
+ data8 0 // exit_group
+ data8 0 // lookup_dcookie
+ data8 0 // io_setup
+ data8 0 // io_destroy
+ data8 0 // io_getevents // 1240
+ data8 0 // io_submit
+ data8 0 // io_cancel
+ data8 0 // epoll_create
+ data8 0 // epoll_ctl
+ data8 0 // epoll_wait // 1245
+ data8 0 // restart_syscall
+ data8 0 // semtimedop
+ data8 0 // timer_create
+ data8 0 // timer_settime
+ data8 0 // timer_gettime // 1250
+ data8 0 // timer_getoverrun
+ data8 0 // timer_delete
+ data8 0 // clock_settime
+ data8 fsys_clock_gettime // clock_gettime
+
+ // fill in zeros for the remaining entries
+ .zero:
+ .space fsyscall_table + 8*NR_syscalls - .zero, 0
_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog
|
Home