diff options
author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2012-06-05 09:59:52 +0200 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2012-06-14 09:09:02 +0200 |
commit | fbe765680d1fe9d08187ea4dad5041a7955a2c3a (patch) | |
tree | cfa5ba11106bb5535552cf6b29ff6aa81f32c606 /arch/s390/include/asm/processor.h | |
parent | 72f6e3a8bc956fddf6e004ae9b804977d1458e77 (diff) |
s390/smp: make absolute lowcore / cpu restart parameter accesses more robust
Setting the cpu restart parameters is done in three different fashions:
- directly setting the four parameters individually
- copying the four parameters with memcpy (using 4 * sizeof(long))
- copying the four parameters using a private structure
In addition code in entry*.S relies on a certain order of the restart
members of struct _lowcore.
Make all of this more robust to future changes by adding a
mem_absolute_assign(dest, val) define, which assigns val to dest
using absolute addressing mode. Also the load multiple instructions
in entry*.S have been split into separate load instruction so the
order of the struct _lowcore members doesn't matter anymore.
In addition move the prototypes of memcpy_real/absolute from uaccess.h
to processor.h. These memcpy* variants are not related to uaccess at all.
string.h doesn't seem to match as well, so lets use processor.h.
Also replace the eight byte array in struct _lowcore which represents a
misaliged u64 with a u64. The compiler will always create code that
handles the misaligned u64 correctly.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/processor.h')
-rw-r--r-- | arch/s390/include/asm/processor.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 20d0585cf905..f1700c5c8884 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -348,4 +348,14 @@ extern void (*s390_base_ext_handler_fn)(void); ".previous\n" #endif +extern int memcpy_real(void *, void *, size_t); +extern void memcpy_absolute(void *, void *, size_t); + +#define mem_assign_absolute(dest, val) { \ + __typeof__(dest) __tmp = (val); \ + \ + BUILD_BUG_ON(sizeof(__tmp) != sizeof(val)); \ + memcpy_absolute(&(dest), &__tmp, sizeof(__tmp)); \ +} + #endif /* __ASM_S390_PROCESSOR_H */ |