alpha: simplify TIF_NEED_RESCHED handling
In case we have both NEED_RESCHED and SIGPENDING/NOTIFY_RESUME,
handle the latter first. We'll get to original priorities in
the next commit, but now that allows to simplify the treatment
of NEED_RESCHED-only case nicely. Namely, now there no need to
preserve the data for restarts across the call of schedule() in
$work_resched; we can get there only if we had either returned
from syscall without SIGPENDING (in which case we should've
had no restart-worthy return value and want no restarts) or
already got through do_notify_resume() call (in which case we
want no restarts anymore). So we can just slap 0 into $19
instead of preserving it (and $20).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S
index 2a359c9..802108b 100644
--- a/arch/alpha/kernel/entry.S
+++ b/arch/alpha/kernel/entry.S
@@ -372,26 +372,18 @@
.align 4
.ent work_pending
work_pending:
- and $5, _TIF_NEED_RESCHED, $2
- beq $2, $work_notifysig
+ and $5, _TIF_NOTIFY_RESUME | _TIF_SIGPENDING, $2
+ bne $2, $work_notifysig
$work_resched:
- subq $sp, 16, $sp
- stq $19, 0($sp) /* save syscall nr */
- stq $20, 8($sp) /* and error indication (a3) */
+ /*
+ * We can get here only if we returned from syscall without SIGPENDING
+ * or got through work_notifysig already. Either case means no syscall
+ * restarts for us, so let $19 and $20 burn.
+ */
jsr $26, schedule
- ldq $19, 0($sp)
- ldq $20, 8($sp)
- addq $sp, 16, $sp
- /* Make sure need_resched and sigpending don't change between
- sampling and the rti. */
- lda $16, 7
- call_pal PAL_swpipl
- ldl $5, TI_FLAGS($8)
- and $5, _TIF_WORK_MASK, $2
- beq $2, restore_all
- and $5, _TIF_NEED_RESCHED, $2
- bne $2, $work_resched
+ mov 0, $19
+ br ret_to_user
$work_notifysig:
mov $sp, $16
