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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/entry.S | |
| parent | [S390] dasd: Avoid compile warnings on !CONFIG_DASD_PROFILE (diff) | |
| download | linux-987ad70a4d90cf0e70dba43ece02c2e2219e092c.tar.xz 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/entry.S')
| -rw-r--r-- | arch/s390/kernel/entry.S | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 6234c6978a1f..bc7ff3658c3d 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -107,6 +107,11 @@ STACK_SIZE = 1 << STACK_SHIFT l %r13,__LC_SVC_NEW_PSW+4 # load &system_call to %r13 .endm + .macro SAVE_ALL_SVC psworg,savearea + la %r12,\psworg + l %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 @@ -218,7 +223,7 @@ 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 lh %r7,0x8a # get svc number from lowcore #ifdef CONFIG_VIRT_CPU_ACCOUNTING |