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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2014-01-23 11:18:36 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-02-21 08:50:14 +0100 |
| commit | 4f41c2b4567dbfb7ff93e5c552b869e2865bcd9d (patch) | |
| tree | 5845eccdb038c5e1bc90a0aaf8919f2a65fa8096 /arch/s390/kernel/setup.c | |
| parent | cfa785e623577cdad2aa721acb23bd3a95eced9a (diff) | |
| download | blackbird-obmc-linux-4f41c2b4567dbfb7ff93e5c552b869e2865bcd9d.tar.gz blackbird-obmc-linux-4f41c2b4567dbfb7ff93e5c552b869e2865bcd9d.zip | |
s390/uaccess: get rid of indirect function calls
There are only two uaccess variants on s390 left: the version that is used
if the mvcos instruction is available, and the page table walk variant.
So there is no need for expensive indirect function calls.
By default the mvcos variant will be called. If the mvcos instruction is not
available it will call the page table walk variant.
For minimal performance impact the "if (mvcos_is_available)" is implemented
with a jump label, which will be a six byte nop on machines with mvcos.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
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, 0 insertions, 9 deletions
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index 09e2f468f48b..91ea00955db7 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -47,7 +47,6 @@ #include <linux/compat.h> #include <asm/ipl.h> -#include <asm/uaccess.h> #include <asm/facility.h> #include <asm/smp.h> #include <asm/mmu_context.h> @@ -65,12 +64,6 @@ #include "entry.h" /* - * User copy operations. - */ -struct uaccess_ops uaccess; -EXPORT_SYMBOL(uaccess); - -/* * Machine setup.. */ unsigned int console_mode = 0; @@ -1009,8 +1002,6 @@ void __init setup_arch(char **cmdline_p) init_mm.end_data = (unsigned long) &_edata; init_mm.brk = (unsigned long) &_end; - uaccess = MACHINE_HAS_MVCOS ? uaccess_mvcos : uaccess_pt; - parse_early_param(); detect_memory_layout(memory_chunk, memory_end); os_info_init(); |
