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author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2013-04-24 10:20:43 +0200 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2013-04-26 09:07:01 +0200 |
commit | dc7ee00d4771b3218b10e09e1071ee6eb176d381 (patch) | |
tree | 18eb16aa67cadf8d4bb880b8443563d2fb47cf43 /arch/s390/kernel/setup.c | |
parent | b8668fd0a7e1b59ff4fd33b65e7f6d46b2d3cf1c (diff) | |
download | op-kernel-dev-dc7ee00d4771b3218b10e09e1071ee6eb176d381.zip op-kernel-dev-dc7ee00d4771b3218b10e09e1071ee6eb176d381.tar.gz |
s390: lowcore stack pointer offsets
Store the stack pointers in the lowcore for the kernel stack, the async
stack and the panic stack with the offset required for the first user.
This avoids an unnecessary add instruction on the system call path.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/setup.c')
-rw-r--r-- | arch/s390/kernel/setup.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index 2926885..0f419c5 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -377,11 +377,14 @@ static void __init setup_lowcore(void) PSW_MASK_DAT | PSW_MASK_MCHECK; lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler; lc->clock_comparator = -1ULL; - lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE; + lc->kernel_stack = ((unsigned long) &init_thread_union) + + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); lc->async_stack = (unsigned long) - __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE; + __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + + ASYNC_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); lc->panic_stack = (unsigned long) - __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE; + __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + + PAGE_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); lc->current_task = (unsigned long) init_thread_union.thread_info.task; lc->thread_info = (unsigned long) &init_thread_union; lc->machine_flags = S390_lowcore.machine_flags; |