Haren Myneni <ha...@linux.vnet.ibm.com> writes: > On 06/03/2018 03:48 AM, Michael Ellerman wrote: >> Haren Myneni <ha...@linux.vnet.ibm.com> writes: >>> NX can set 3rd bit in CR register for XER[SO] (Summation overflow) >>> which is not related to paste request. The current paste function >>> returns failure for the successful request when this bit is set. >>> So mask this bit and check the proper return status. >>> >>> Fixes: 2392c8c8c045 ("powerpc/powernv/vas: Define copy/paste interfaces") >>> Cc: sta...@vger.kernel.org # v4.14+ >>> Signed-off-by: Haren Myneni <ha...@us.ibm.com> >>> >>> diff --git a/arch/powerpc/platforms/powernv/copy-paste.h >>> b/arch/powerpc/platforms/powernv/copy-paste.h >>> index c9a5036..82392e3 100644 >>> --- a/arch/powerpc/platforms/powernv/copy-paste.h >>> +++ b/arch/powerpc/platforms/powernv/copy-paste.h >>> @@ -9,7 +9,8 @@ >>> #include <asm/ppc-opcode.h> >>> >>> #define CR0_SHIFT 28 >>> -#define CR0_MASK 0xF >>> +#define CR0_MASK 0xE /* 3rd bit undefined or set for XER[SO] */ >>> + >>> /* >>> * Copy/paste instructions: >>> * >> >> Unfortunately this no longer applies to my next branch, because those >> macros have been moved out of this header as part of an unrelated patch. >> >> The following patch should work instead, can you please confirm by >> testing it? >> >> diff --git a/arch/powerpc/platforms/powernv/copy-paste.h >> b/arch/powerpc/platforms/powernv/copy-paste.h >> index 3fa62de96d9c..c46a326776cf 100644 >> --- a/arch/powerpc/platforms/powernv/copy-paste.h >> +++ b/arch/powerpc/platforms/powernv/copy-paste.h >> @@ -41,5 +41,7 @@ static inline int vas_paste(void *paste_address, int >> offset) >> : "b" (offset), "b" (paste_address) >> : "memory", "cr0"); >> >> - return (cr >> CR0_SHIFT) & CR0_MASK; >> + >> + /* We mask with 0xE to ignore SO */ >> + return (cr >> CR0_SHIFT) & 0xE; >> } > > Tested with this patch and it works.
Thanks. I sent a new version to the list and will apply that. cheers