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| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2007-07-10 11:24:18 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2007-07-10 11:24:51 +0200 |
| commit | 987ad70a4d90cf0e70dba43ece02c2e2219e092c (patch) | |
| tree | 5597a511a31647acd7a11160d9db60a53f388d80 /arch/s390/kernel/entry64.S | |
| parent | 3d62149f025134cd69c2fef2a2ccfac3c3c2054f (diff) | |
| download | blackbird-obmc-linux-987ad70a4d90cf0e70dba43ece02c2e2219e092c.tar.gz blackbird-obmc-linux-987ad70a4d90cf0e70dba43ece02c2e2219e092c.zip | |
[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 <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/entry64.S')
| -rw-r--r-- | arch/s390/kernel/entry64.S | 7 |
1 files changed, 6 insertions, 1 deletions
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 |
