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-rw-r--r--arch/ia64/kernel/entry.S26
1 files changed, 16 insertions, 10 deletions
diff --git a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S
index e49ad8c..ca2bb95 100644
--- a/arch/ia64/kernel/entry.S
+++ b/arch/ia64/kernel/entry.S
@@ -1156,6 +1156,9 @@ skip_rbs_switch:
* r31 = current->thread_info->flags
* On exit:
* p6 = TRUE if work-pending-check needs to be redone
+ *
+ * Interrupts are disabled on entry, reenabled depend on work, and
+ * disabled on exit.
*/
.work_pending_syscall:
add r2=-8,r2
@@ -1164,16 +1167,16 @@ skip_rbs_switch:
st8 [r2]=r8
st8 [r3]=r10
.work_pending:
- tbit.z p6,p0=r31,TIF_NEED_RESCHED // current_thread_info()->need_resched==0?
+ tbit.z p6,p0=r31,TIF_NEED_RESCHED // is resched not needed?
(p6) br.cond.sptk.few .notify
#ifdef CONFIG_PREEMPT
(pKStk) dep r21=-1,r0,PREEMPT_ACTIVE_BIT,1
;;
(pKStk) st4 [r20]=r21
- ssm psr.i // enable interrupts
#endif
+ ssm psr.i // enable interrupts
br.call.spnt.many rp=schedule
-.ret9: cmp.eq p6,p0=r0,r0 // p6 <- 1
+.ret9: cmp.eq p6,p0=r0,r0 // p6 <- 1 (re-check)
rsm psr.i // disable interrupts
;;
#ifdef CONFIG_PREEMPT
@@ -1182,13 +1185,13 @@ skip_rbs_switch:
(pKStk) st4 [r20]=r0 // preempt_count() <- 0
#endif
(pLvSys)br.cond.sptk.few .work_pending_syscall_end
- br.cond.sptk.many .work_processed_kernel // re-check
+ br.cond.sptk.many .work_processed_kernel
.notify:
(pUStk) br.call.spnt.many rp=notify_resume_user
-.ret10: cmp.ne p6,p0=r0,r0 // p6 <- 0
+.ret10: cmp.ne p6,p0=r0,r0 // p6 <- 0 (don't re-check)
(pLvSys)br.cond.sptk.few .work_pending_syscall_end
- br.cond.sptk.many .work_processed_kernel // don't re-check
+ br.cond.sptk.many .work_processed_kernel
.work_pending_syscall_end:
adds r2=PT(R8)+16,r12
@@ -1196,7 +1199,7 @@ skip_rbs_switch:
;;
ld8 r8=[r2]
ld8 r10=[r3]
- br.cond.sptk.many .work_processed_syscall // re-check
+ br.cond.sptk.many .work_processed_syscall
END(ia64_leave_kernel)
@@ -1234,9 +1237,12 @@ GLOBAL_ENTRY(ia64_invoke_schedule_tail)
END(ia64_invoke_schedule_tail)
/*
- * Setup stack and call do_notify_resume_user(). Note that pSys and pNonSys need to
- * be set up by the caller. We declare 8 input registers so the system call
- * args get preserved, in case we need to restart a system call.
+ * Setup stack and call do_notify_resume_user(), keeping interrupts
+ * disabled.
+ *
+ * Note that pSys and pNonSys need to be set up by the caller.
+ * We declare 8 input registers so the system call args get preserved,
+ * in case we need to restart a system call.
*/
ENTRY(notify_resume_user)
.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)