[PATCH 2/3] powerpc: Load Monitor Register Support
This enables new registers, LMRR and LMSER, that can trigger an EBB in userspace code when a monitored load (via the new ldmx instruction) loads memory from a monitored space. This facility is controlled by a new FSCR bit, LM. This patch disables the control bit on CPU setup and enables that bit when a facility unavailable exception is taken for using it. On context switch, this bit is then used to determine whether the two relevant registers are saved and restored. This is done lazily for performance reasons. Signed-off-by: Jack Miller --- arch/powerpc/include/asm/processor.h | 2 ++ arch/powerpc/include/asm/reg.h| 5 + arch/powerpc/kernel/cpu_setup_power.S | 3 ++- arch/powerpc/kernel/process.c | 20 arch/powerpc/kernel/traps.c | 4 5 files changed, 33 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index 009fab1..2bb822b 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -314,6 +314,8 @@ struct thread_struct { unsigned long mmcr2; unsignedmmcr0; unsignedused_ebb; + unsigned long lmrr; + unsigned long lmser; #endif }; diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 7972c9f..ab98ca4 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -282,6 +282,8 @@ #define SPRN_HRMOR 0x139 /* Real mode offset register */ #define SPRN_HSRR0 0x13A /* Hypervisor Save/Restore 0 */ #define SPRN_HSRR1 0x13B /* Hypervisor Save/Restore 1 */ +#define SPRN_LMRR 0x32D /* Load Monitor Region Register */ +#define SPRN_LMSER 0x32E /* Load Monitor Section Enable Register */ #define SPRN_IC0x350 /* Virtual Instruction Count */ #define SPRN_VTB 0x351 /* Virtual Time Base */ #define SPRN_LDBAR 0x352 /* LD Base Address Register */ @@ -291,6 +293,7 @@ #define SPRN_PMCR 0x374 /* Power Management Control Register */ /* HFSCR and FSCR bit numbers are the same */ +#define FSCR_LM_LG 11 /* Enable Load Monitor Registers */ #define FSCR_TAR_LG8 /* Enable Target Address Register */ #define FSCR_EBB_LG7 /* Enable Event Based Branching */ #define FSCR_TM_LG 5 /* Enable Transactional Memory */ @@ -300,10 +303,12 @@ #define FSCR_VECVSX_LG 1 /* Enable VMX/VSX */ #define FSCR_FP_LG 0 /* Enable Floating Point */ #define SPRN_FSCR 0x099 /* Facility Status & Control Register */ +#define FSCR_LM __MASK(FSCR_LM_LG) #define FSCR_TAR __MASK(FSCR_TAR_LG) #define FSCR_EBB __MASK(FSCR_EBB_LG) #define FSCR_DSCR__MASK(FSCR_DSCR_LG) #define SPRN_HFSCR 0xbe/* HV=1 Facility Status & Control Register */ +#define HFSCR_LM __MASK(FSCR_LM_LG) #define HFSCR_TAR__MASK(FSCR_TAR_LG) #define HFSCR_EBB__MASK(FSCR_EBB_LG) #define HFSCR_TM __MASK(FSCR_TM_LG) diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S index 584e119..a232930 100644 --- a/arch/powerpc/kernel/cpu_setup_power.S +++ b/arch/powerpc/kernel/cpu_setup_power.S @@ -157,7 +157,8 @@ __init_LPCR: __init_FSCR: mfspr r3,SPRN_FSCR - ori r3,r3,FSCR_TAR|FSCR_DSCR|FSCR_EBB + ori r3,r3,FSCR_LM|FSCR_TAR|FSCR_DSCR|FSCR_EBB + xorir3,r3,FSCR_LM mtspr SPRN_FSCR,r3 blr diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 00bf6f5..f0061ec 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1005,6 +1005,14 @@ static inline void save_sprs(struct thread_struct *t) */ t->tar = mfspr(SPRN_TAR); } + + if (cpu_has_feature(CPU_FTR_ARCH_300)) { + /* Conditionally save Load Monitor registers, if enabled */ + if (t->fscr & FSCR_LM) { + t->lmrr = mfspr(SPRN_LMRR); + t->lmser = mfspr(SPRN_LMSER); + } + } #endif } @@ -1041,6 +1049,16 @@ static inline void restore_sprs(struct thread_struct *old_thread, if (old_thread->tar != new_thread->tar) mtspr(SPRN_TAR, new_thread->tar); } + + if (cpu_has_feature(CPU_FTR_ARCH_300)) { + /* Conditionally restore Load Monitor registers, if enabled */ + if (new_thread->fscr & FSCR_LM) { + if (old_thread->lmrr != new_thread->lmrr); + mtspr(SPRN_LMRR, new_thread->lmrr); + if (old_thread->lmser != new_thread->lmser); + mtspr(SPRN_LMSER, new_thread->lmser); + } + } #endif } @@ -1566,6 +1584,8 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) regs->gp
Re: [PATCH 2/3] powerpc: Load Monitor Register Support
Hi Jack, [auto build test ERROR on powerpc/next] [also build test ERROR on v4.6-rc4 next-20160418] [if your patch is applied to the wrong git tree, please drop us a note to help improving the system] url: https://github.com/0day-ci/linux/commits/Jack-Miller/powerpc-Complete-FSCR-context-switch/20160419-031650 base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next config: powerpc-allnoconfig (attached as .config) reproduce: wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree make.cross ARCH=powerpc All errors (new ones prefixed by >>): arch/powerpc/kernel/process.c: In function 'start_thread': >> arch/powerpc/kernel/process.c:1615:17: error: 'struct thread_struct' has no >> member named 'fscr' current->thread.fscr &= ~FSCR_LM; ^ vim +1615 arch/powerpc/kernel/process.c 1609 if (cpu_has_feature(CPU_FTR_TM)) 1610 regs->msr |= MSR_TM; 1611 current->thread.tm_tfhar = 0; 1612 current->thread.tm_texasr = 0; 1613 current->thread.tm_tfiar = 0; 1614 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ > 1615 current->thread.fscr &= ~FSCR_LM; 1616 } 1617 EXPORT_SYMBOL(start_thread); 1618 --- 0-DAY kernel test infrastructureOpen Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation .config.gz Description: Binary data ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
[PATCH 2/3] powerpc: Load Monitor Register Support
This enables new registers, LMRR and LMSER, that can trigger an EBB in userspace code when a monitored load (via the new ldmx instruction) loads memory from a monitored space. This facility is controlled by a new FSCR bit, LM. This patch disables the control bit on CPU setup and enables that bit when a facility unavailable exception is taken for using it. On context switch, this bit is then used to determine whether the two relevant registers are saved and restored. This is done lazily for performance reasons. Signed-off-by: Jack Miller --- arch/powerpc/include/asm/processor.h | 2 ++ arch/powerpc/include/asm/reg.h| 5 + arch/powerpc/kernel/cpu_setup_power.S | 3 ++- arch/powerpc/kernel/process.c | 19 +++ arch/powerpc/kernel/traps.c | 4 5 files changed, 32 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index 009fab1..2bb822b 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -314,6 +314,8 @@ struct thread_struct { unsigned long mmcr2; unsignedmmcr0; unsignedused_ebb; + unsigned long lmrr; + unsigned long lmser; #endif }; diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 7972c9f..ab98ca4 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -282,6 +282,8 @@ #define SPRN_HRMOR 0x139 /* Real mode offset register */ #define SPRN_HSRR0 0x13A /* Hypervisor Save/Restore 0 */ #define SPRN_HSRR1 0x13B /* Hypervisor Save/Restore 1 */ +#define SPRN_LMRR 0x32D /* Load Monitor Region Register */ +#define SPRN_LMSER 0x32E /* Load Monitor Section Enable Register */ #define SPRN_IC0x350 /* Virtual Instruction Count */ #define SPRN_VTB 0x351 /* Virtual Time Base */ #define SPRN_LDBAR 0x352 /* LD Base Address Register */ @@ -291,6 +293,7 @@ #define SPRN_PMCR 0x374 /* Power Management Control Register */ /* HFSCR and FSCR bit numbers are the same */ +#define FSCR_LM_LG 11 /* Enable Load Monitor Registers */ #define FSCR_TAR_LG8 /* Enable Target Address Register */ #define FSCR_EBB_LG7 /* Enable Event Based Branching */ #define FSCR_TM_LG 5 /* Enable Transactional Memory */ @@ -300,10 +303,12 @@ #define FSCR_VECVSX_LG 1 /* Enable VMX/VSX */ #define FSCR_FP_LG 0 /* Enable Floating Point */ #define SPRN_FSCR 0x099 /* Facility Status & Control Register */ +#define FSCR_LM __MASK(FSCR_LM_LG) #define FSCR_TAR __MASK(FSCR_TAR_LG) #define FSCR_EBB __MASK(FSCR_EBB_LG) #define FSCR_DSCR__MASK(FSCR_DSCR_LG) #define SPRN_HFSCR 0xbe/* HV=1 Facility Status & Control Register */ +#define HFSCR_LM __MASK(FSCR_LM_LG) #define HFSCR_TAR__MASK(FSCR_TAR_LG) #define HFSCR_EBB__MASK(FSCR_EBB_LG) #define HFSCR_TM __MASK(FSCR_TM_LG) diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S index 584e119..a232930 100644 --- a/arch/powerpc/kernel/cpu_setup_power.S +++ b/arch/powerpc/kernel/cpu_setup_power.S @@ -157,7 +157,8 @@ __init_LPCR: __init_FSCR: mfspr r3,SPRN_FSCR - ori r3,r3,FSCR_TAR|FSCR_DSCR|FSCR_EBB + ori r3,r3,FSCR_LM|FSCR_TAR|FSCR_DSCR|FSCR_EBB + xorir3,r3,FSCR_LM mtspr SPRN_FSCR,r3 blr diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 00bf6f5..3e91bd6 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1005,6 +1005,14 @@ static inline void save_sprs(struct thread_struct *t) */ t->tar = mfspr(SPRN_TAR); } + + if (cpu_has_feature(CPU_FTR_ARCH_300)) { + /* Conditionally save Load Monitor registers, if enabled */ + if (t->fscr & FSCR_LM) { + t->lmrr = mfspr(SPRN_LMRR); + t->lmser = mfspr(SPRN_LMSER); + } + } #endif } @@ -1041,6 +1049,16 @@ static inline void restore_sprs(struct thread_struct *old_thread, if (old_thread->tar != new_thread->tar) mtspr(SPRN_TAR, new_thread->tar); } + + if (cpu_has_feature(CPU_FTR_ARCH_300)) { + /* Conditionally restore Load Monitor registers, if enabled */ + if (new_thread->fscr & FSCR_LM) { + if (old_thread->lmrr != new_thread->lmrr); + mtspr(SPRN_LMRR, new_thread->lmrr); + if (old_thread->lmser != new_thread->lmser); + mtspr(SPRN_LMSER, new_thread->lmser); + } + } #endif } @@ -1592,6 +1610,7 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) current->thread.t
Re: [PATCH 2/3] powerpc: Load Monitor Register Support
Thanks, yeah, that's more readable and more correct. I'll change it in the next spin. - Jack On Tue, Apr 12, 2016 at 12:40 AM, Segher Boessenkool wrote: > Hi, > > On Mon, Apr 11, 2016 at 01:57:44PM -0500, Jack Miller wrote: >> __init_FSCR: >> mfspr r3,SPRN_FSCR >> + andi. r3,r3,(~FSCR_LM)@L >> ori r3,r3,FSCR_TAR|FSCR_DSCR|FSCR_EBB >> mtspr SPRN_FSCR,r3 >> blr > > This clears the top 48 bits as well. Shouldn't matter currently; but > more robust (and easier to read, if you know the idiom) is > > ori r3,r3,FSCR_LM|FSCR_TAR|FSCR_DSCR|FSCR_EBB > xorir3,r3,FSCR_LM > > > Segher ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 2/3] powerpc: Load Monitor Register Support
Hi, On Mon, Apr 11, 2016 at 01:57:44PM -0500, Jack Miller wrote: > __init_FSCR: > mfspr r3,SPRN_FSCR > + andi. r3,r3,(~FSCR_LM)@L > ori r3,r3,FSCR_TAR|FSCR_DSCR|FSCR_EBB > mtspr SPRN_FSCR,r3 > blr This clears the top 48 bits as well. Shouldn't matter currently; but more robust (and easier to read, if you know the idiom) is ori r3,r3,FSCR_LM|FSCR_TAR|FSCR_DSCR|FSCR_EBB xorir3,r3,FSCR_LM Segher ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
[PATCH 2/3] powerpc: Load Monitor Register Support
This enables new registers, LMRR and LMSER, that can trigger an EBB in userspace code when a monitored load (via the new ldmx instruction) loads memory from a monitored space. This facility is controlled by a new FSCR bit, LM. This patch disables the control bit on CPU setup and enables that bit when a facility unavailable exception is taken for using it. On context switch, this bit is then used to determine whether the two relevant registers are saved and restored. This is done lazily for performance reasons. Signed-off-by: Jack Miller --- arch/powerpc/include/asm/processor.h | 2 ++ arch/powerpc/include/asm/reg.h| 5 + arch/powerpc/kernel/cpu_setup_power.S | 1 + arch/powerpc/kernel/process.c | 19 +++ arch/powerpc/kernel/traps.c | 4 5 files changed, 31 insertions(+) diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index 009fab1..2bb822b 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -314,6 +314,8 @@ struct thread_struct { unsigned long mmcr2; unsignedmmcr0; unsignedused_ebb; + unsigned long lmrr; + unsigned long lmser; #endif }; diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 7972c9f..ab98ca4 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -282,6 +282,8 @@ #define SPRN_HRMOR 0x139 /* Real mode offset register */ #define SPRN_HSRR0 0x13A /* Hypervisor Save/Restore 0 */ #define SPRN_HSRR1 0x13B /* Hypervisor Save/Restore 1 */ +#define SPRN_LMRR 0x32D /* Load Monitor Region Register */ +#define SPRN_LMSER 0x32E /* Load Monitor Section Enable Register */ #define SPRN_IC0x350 /* Virtual Instruction Count */ #define SPRN_VTB 0x351 /* Virtual Time Base */ #define SPRN_LDBAR 0x352 /* LD Base Address Register */ @@ -291,6 +293,7 @@ #define SPRN_PMCR 0x374 /* Power Management Control Register */ /* HFSCR and FSCR bit numbers are the same */ +#define FSCR_LM_LG 11 /* Enable Load Monitor Registers */ #define FSCR_TAR_LG8 /* Enable Target Address Register */ #define FSCR_EBB_LG7 /* Enable Event Based Branching */ #define FSCR_TM_LG 5 /* Enable Transactional Memory */ @@ -300,10 +303,12 @@ #define FSCR_VECVSX_LG 1 /* Enable VMX/VSX */ #define FSCR_FP_LG 0 /* Enable Floating Point */ #define SPRN_FSCR 0x099 /* Facility Status & Control Register */ +#define FSCR_LM __MASK(FSCR_LM_LG) #define FSCR_TAR __MASK(FSCR_TAR_LG) #define FSCR_EBB __MASK(FSCR_EBB_LG) #define FSCR_DSCR__MASK(FSCR_DSCR_LG) #define SPRN_HFSCR 0xbe/* HV=1 Facility Status & Control Register */ +#define HFSCR_LM __MASK(FSCR_LM_LG) #define HFSCR_TAR__MASK(FSCR_TAR_LG) #define HFSCR_EBB__MASK(FSCR_EBB_LG) #define HFSCR_TM __MASK(FSCR_TM_LG) diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S index 584e119..0474856 100644 --- a/arch/powerpc/kernel/cpu_setup_power.S +++ b/arch/powerpc/kernel/cpu_setup_power.S @@ -157,6 +157,7 @@ __init_LPCR: __init_FSCR: mfspr r3,SPRN_FSCR + andi. r3,r3,(~FSCR_LM)@L ori r3,r3,FSCR_TAR|FSCR_DSCR|FSCR_EBB mtspr SPRN_FSCR,r3 blr diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 0c7e797..e39af31 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1005,6 +1005,14 @@ static inline void save_sprs(struct thread_struct *t) */ t->tar = mfspr(SPRN_TAR); } + + if (cpu_has_feature(CPU_FTR_ARCH_300)) { + /* Conditionally save Load Monitor registers, if enabled */ + if (t->fscr & FSCR_LM) { + t->lmrr = mfspr(SPRN_LMRR); + t->lmser = mfspr(SPRN_LMSER); + } + } #endif } @@ -1046,7 +1054,16 @@ static inline void restore_sprs(struct thread_struct *old_thread, if (old_thread->fscr != new_thread->fscr) mtspr(SPRN_FSCR, new_thread->fscr); + } + if (cpu_has_feature(CPU_FTR_ARCH_300)) { + /* Conditionally restore Load Monitor registers, if enabled */ + if (new_thread->fscr & FSCR_LM) { + if (old_thread->lmrr != new_thread->lmrr); + mtspr(SPRN_LMRR, new_thread->lmrr); + if (old_thread->lmser != new_thread->lmser); + mtspr(SPRN_LMSER, new_thread->lmser); + } } #endif } @@ -1573,6 +1590,8 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) regs->gpr[2] = 0; regs->msr = MSR_USER32; } + +