leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

[POWERPC] Avoid hypervisor statistics calculation in real mode

Browse Source 
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>
This commit is contained in:
Mohan Kumar M
2007-03-21 11:21:32 +05:30
committed by Paul Mackerras
parent f144e7c727
commit b4aea36b79
4 changed files with 65 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
include/asm-powerpc/hvcall.h
View File

@@ -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.