On 11/22/2012 07:39 PM, Michael Neuling wrote: > Haren Myneni <ha...@linux.vnet.ibm.com> wrote: > >> [PATCH 5/6] powerpc: Macros for saving/restore PPR >> >> Several macros are defined for saving and restore user defined PPR value. >> >> Signed-off-by: Haren Myneni <ha...@us.ibm.com> >> --- >> arch/powerpc/include/asm/exception-64s.h | 29 >> +++++++++++++++++++++++++++++ >> arch/powerpc/include/asm/ppc_asm.h | 25 +++++++++++++++++++++++++ >> arch/powerpc/include/asm/reg.h | 1 + >> 3 files changed, 55 insertions(+), 0 deletions(-) >> >> diff --git a/arch/powerpc/include/asm/exception-64s.h >> b/arch/powerpc/include/asm/exception-64s.h >> index bfd3f1f..880ef7d 100644 >> --- a/arch/powerpc/include/asm/exception-64s.h >> +++ b/arch/powerpc/include/asm/exception-64s.h >> @@ -62,6 +62,35 @@ >> #define EXC_HV H >> #define EXC_STD >> >> +/* >> + * PPR save/restore macros used in exceptions_64s.S >> + * Used for P7 or later processors >> + */ >> +#define SAVE_PPR(area, ra, rb) >> \ >> +BEGIN_FTR_SECTION_NESTED(940) >> \ >> + ld ra,PACACURRENT(r13); \ >> + ld rb,area+EX_PPR(r13); /* Read PPR from paca */ \ >> + std rb,TASKTHREADPPR(ra); \ >> +END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,940) >> + >> +#define RESTORE_PPR_PACA(area, ra) \ >> +BEGIN_FTR_SECTION_NESTED(941) >> \ >> + ld ra,area+EX_PPR(r13); \ >> + mtspr SPRN_PPR,ra; \ >> +END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,941) >> + > > Can you add some documentation here on why we should use the different > versions. > > I'm trying to read the next patch and it's not clear to my why some have > HMT_MEDIUM_NO_PPR and other times HMT_MEDIUM and others > HTM_MEDIUM_HAS_PPR. > > Looks like HTM_MEDIUM_NO_PPR sets the priority to medium on systems > where we can't save/restore the PPR, hence it can be called earlier in > the exception handler before we have free GPRs. HTM_MEDIUM_HAS_PPR > saves the priority on systems where it can, and then sets the priority > to medium. > > Maybe we should change the names > HTM_MEDIUM_NO_PPR => HTM_MEDIUM_PPR_DISCARD and > HTM_MEDIUM_HAS_PPR => HTM_MEDIUM_PPR_SAVE > But now I'm heading into bike shedding territory... plus I think I > suggested the names you have currently, so I'm feeling a bit dumb now > :-)
No problem, We can change these macro names if HTM_MEDIUM_PPR_DISCARD/ HTM_MEDIUM_PPR_SAVE gives better description. Right, HTM_MEDIUM_NO_PPR is used on systems where we do not save/restore PPR. So the behaviour is same as before - just increases the priority. HTM_MEDIUM_HAS_PPR will be executed on systems where CPU_FTR_HAS_PPR is enabled. I will write some comments around these macros to make it clear. We can also name them HMT_MEDIUM_CPU_NO_PPR_SAVE and HMT_MEDIUM_CPU_HAS_PPR_SAVE since we are enabling PPR save/restore using CPU_FTR macro. Otherwise I will follow with your suggestions. Thanks Haren > Mikey > >> +#define HMT_MEDIUM_NO_PPR \ >> +BEGIN_FTR_SECTION_NESTED(942) >> \ >> + HMT_MEDIUM; \ >> +END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,0,942) /*non P7*/ >> + >> +#define HMT_MEDIUM_HAS_PPR(area, ra) >> \ >> +BEGIN_FTR_SECTION_NESTED(943) >> \ >> + mfspr ra,SPRN_PPR; \ >> + std ra,area+EX_PPR(r13); \ >> + HMT_MEDIUM; \ >> +END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,943) >> + >> #define __EXCEPTION_PROLOG_1(area, extra, vec) >> \ >> GET_PACA(r13); \ >> std r9,area+EX_R9(r13); /* save r9 - r12 */ \ > > >> diff --git a/arch/powerpc/include/asm/ppc_asm.h >> b/arch/powerpc/include/asm/ppc_asm.h >> index 376e36d..52649cc 100644 >> --- a/arch/powerpc/include/asm/ppc_asm.h >> +++ b/arch/powerpc/include/asm/ppc_asm.h >> @@ -389,6 +389,31 @@ END_FTR_SECTION_IFCLR(CPU_FTR_601) >> FTR_SECTION_ELSE_NESTED(848); \ >> mtocrf (FXM), RS; \ >> ALT_FTR_SECTION_END_NESTED_IFCLR(CPU_FTR_NOEXECUTE, 848) >> + >> +/* >> + * PPR restore macros used in entry_64.S >> + * Used for P7 or later processors >> + */ >> +#define HMT_MEDIUM_LOW_HAS_PPR >> \ >> +BEGIN_FTR_SECTION_NESTED(944) >> \ >> + HMT_MEDIUM_LOW; \ >> +END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,944) >> + >> +#define SET_DEFAULT_THREAD_PPR(ra, rb) >> \ >> +BEGIN_FTR_SECTION_NESTED(945) >> \ >> + lis ra,0xc; /* default ppr=3 */ \ >> + ld rb,PACACURRENT(r13); \ >> + sldi ra,ra,32; /* 11- 13 bits are used for ppr */ \ >> + std ra,TASKTHREADPPR(rb); \ >> +END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,945) >> + >> +#define RESTORE_PPR(ra, rb) \ >> +BEGIN_FTR_SECTION_NESTED(946) >> \ >> + ld ra,PACACURRENT(r13); \ >> + ld rb,TASKTHREADPPR(ra); \ >> + mtspr SPRN_PPR,rb; /* Restore PPR */ \ >> +END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,946) >> + >> #endif >> >> /* >> diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h >> index d24c141..1723be3 100644 >> --- a/arch/powerpc/include/asm/reg.h >> +++ b/arch/powerpc/include/asm/reg.h >> @@ -287,6 +287,7 @@ >> #define SPRN_DBAT6U 0x23C /* Data BAT 6 Upper Register */ >> #define SPRN_DBAT7L 0x23F /* Data BAT 7 Lower Register */ >> #define SPRN_DBAT7U 0x23E /* Data BAT 7 Upper Register */ >> +#define SPRN_PPR 0x380 /* SMT Thread status Register */ >> >> #define SPRN_DEC 0x016 /* Decrement Register */ >> #define SPRN_DER 0x095 /* Debug Enable Regsiter */ >> -- >> 1.7.1 >> >> >> >> _______________________________________________ >> Linuxppc-dev mailing list >> Linuxppc-dev@lists.ozlabs.org >> https://lists.ozlabs.org/listinfo/linuxppc-dev >> _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
