From b4aea36b7956eeebfc56314ce0944db1441255ce Mon Sep 17 00:00:00 2001 From: Mohan Kumar M <mohan@in.ibm.com> Date: Wed, 21 Mar 2007 11:21:32 +0530 Subject: [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> --- include/asm-powerpc/hvcall.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include') diff --git a/include/asm-powerpc/hvcall.h b/include/asm-powerpc/hvcall.h index 60977806d2..62efd9d7a4 100644 --- a/include/asm-powerpc/hvcall.h +++ b/include/asm-powerpc/hvcall.h @@ -236,6 +236,20 @@ long plpar_hcall_norets(unsigned long opcode, ...); #define PLPAR_HCALL_BUFSIZE 4 long plpar_hcall(unsigned long opcode, unsigned long *retbuf, ...); +/** + * plpar_hcall_raw: - Make a hypervisor call without calculating hcall stats + * @opcode: The hypervisor call to make. + * @retbuf: Buffer to store up to 4 return arguments in. + * + * This call supports up to 6 arguments and 4 return arguments. Use + * PLPAR_HCALL_BUFSIZE to size the return argument buffer. + * + * Used when phyp interface needs to be called in real mode. Similar to + * plpar_hcall, but plpar_hcall_raw works in real mode and does not + * calculate hypervisor call statistics. + */ +long plpar_hcall_raw(unsigned long opcode, unsigned long *retbuf, ...); + /** * plpar_hcall9: - Make a pseries hypervisor call with up to 9 return arguments * @opcode: The hypervisor call to make. -- cgit v1.2.2