From 987ad70a4d90cf0e70dba43ece02c2e2219e092c Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 10 Jul 2007 11:24:18 +0200 Subject: [S390] system call optimization. After the in-kernel system call has been remove the system call path can be optimized. The problem state bit of the old psw is always set between system_call and sysc_do_svc. SAVE_ALL_SVC uses this information to avoid two instructions. Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/entry64.S | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'arch/s390/kernel/entry64.S') diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S index 685f11faa4bc..2a7b1304418b 100644 --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -99,6 +99,11 @@ _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK | _TIF_NEED_RESCHED | \ larl %r13,system_call .endm + .macro SAVE_ALL_SVC psworg,savearea + la %r12,\psworg + lg %r15,__LC_KERNEL_STACK # problem state -> load ksp + .endm + .macro SAVE_ALL_SYNC psworg,savearea la %r12,\psworg tm \psworg+1,0x01 # test problem state bit @@ -207,7 +212,7 @@ system_call: STORE_TIMER __LC_SYNC_ENTER_TIMER sysc_saveall: SAVE_ALL_BASE __LC_SAVE_AREA - SAVE_ALL_SYNC __LC_SVC_OLD_PSW,__LC_SAVE_AREA + SAVE_ALL_SVC __LC_SVC_OLD_PSW,__LC_SAVE_AREA CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA llgh %r7,__LC_SVC_INT_CODE # get svc number from lowcore #ifdef CONFIG_VIRT_CPU_ACCOUNTING -- cgit v1.2.3