diff options
| author | Mohan Kumar M <mohan@in.ibm.com> | 2007-03-21 08:51:32 +0300 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2007-03-22 07:01:43 +0300 |
| commit | b4aea36b7956eeebfc56314ce0944db1441255ce (patch) | |
| tree | a0c84f25e1f5a2ef0af624871e8f892654fd79a4 /arch/powerpc/platforms/pseries/hvCall.S | |
| parent | f144e7c7272bf527c380bffaa5e789dc28a09d8d (diff) | |
| download | linux-b4aea36b7956eeebfc56314ce0944db1441255ce.tar.xz | |
[POWERPC] Avoid hypervisor statistics calculation in real mode
kexec invokes plpar_hcall hypervisor call in real mode. plpar_hcall
refers to per cpu variables for accounting hypervisor statistics.
These variables may not be in the RMO region, so accesses to them
in real mode may result in a data storage exception.
This fixes this problem by using a new plpar_hcall_raw function which
does not update the hypervisor call statistics. Thanks to Anton for
suggesting this idea.
Signed-off-by: Mohan Kumar M <mohan@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/platforms/pseries/hvCall.S')
| -rw-r--r-- | arch/powerpc/platforms/pseries/hvCall.S | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/hvCall.S b/arch/powerpc/platforms/pseries/hvCall.S index 5c7e38789897..1501b0a9e749 100644 --- a/arch/powerpc/platforms/pseries/hvCall.S +++ b/arch/powerpc/platforms/pseries/hvCall.S @@ -123,6 +123,40 @@ _GLOBAL(plpar_hcall) blr /* return r3 = status */ +/* + * plpar_hcall_raw can be called in real mode. kexec/kdump need some + * hypervisor calls to be executed in real mode. So plpar_hcall_raw + * does not access the per cpu hypervisor call statistics variables, + * since these variables may not be present in the RMO region. + */ +_GLOBAL(plpar_hcall_raw) + HMT_MEDIUM + + mfcr r0 + stw r0,8(r1) + + std r4,STK_PARM(r4)(r1) /* Save ret buffer */ + + mr r4,r5 + mr r5,r6 + mr r6,r7 + mr r7,r8 + mr r8,r9 + mr r9,r10 + + HVSC /* invoke the hypervisor */ + + ld r12,STK_PARM(r4)(r1) + std r4, 0(r12) + std r5, 8(r12) + std r6, 16(r12) + std r7, 24(r12) + + lwz r0,8(r1) + mtcrf 0xff,r0 + + blr /* return r3 = status */ + _GLOBAL(plpar_hcall9) HMT_MEDIUM |