diff options
Diffstat (limited to 'arch/powerpc/kernel/process.c')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 92 |
1 files changed, 80 insertions, 12 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 75b6676c1a0b..3aabed4a60a9 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -742,6 +742,73 @@ void restore_tm_state(struct pt_regs *regs) #define __switch_to_tm(prev) #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ +static inline void save_sprs(struct thread_struct *t) +{ +#ifdef CONFIG_ALTIVEC + if (cpu_has_feature(cpu_has_feature(CPU_FTR_ALTIVEC))) + t->vrsave = mfspr(SPRN_VRSAVE); +#endif +#ifdef CONFIG_PPC_BOOK3S_64 + if (cpu_has_feature(CPU_FTR_DSCR)) + t->dscr = mfspr(SPRN_DSCR); + + if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + t->bescr = mfspr(SPRN_BESCR); + t->ebbhr = mfspr(SPRN_EBBHR); + t->ebbrr = mfspr(SPRN_EBBRR); + + t->fscr = mfspr(SPRN_FSCR); + + /* + * Note that the TAR is not available for use in the kernel. + * (To provide this, the TAR should be backed up/restored on + * exception entry/exit instead, and be in pt_regs. FIXME, + * this should be in pt_regs anyway (for debug).) + */ + t->tar = mfspr(SPRN_TAR); + } +#endif +} + +static inline void restore_sprs(struct thread_struct *old_thread, + struct thread_struct *new_thread) +{ +#ifdef CONFIG_ALTIVEC + if (cpu_has_feature(CPU_FTR_ALTIVEC) && + old_thread->vrsave != new_thread->vrsave) + mtspr(SPRN_VRSAVE, new_thread->vrsave); +#endif +#ifdef CONFIG_PPC_BOOK3S_64 + if (cpu_has_feature(CPU_FTR_DSCR)) { + u64 dscr = get_paca()->dscr_default; + u64 fscr = old_thread->fscr & ~FSCR_DSCR; + + if (new_thread->dscr_inherit) { + dscr = new_thread->dscr; + fscr |= FSCR_DSCR; + } + + if (old_thread->dscr != dscr) + mtspr(SPRN_DSCR, dscr); + + if (old_thread->fscr != fscr) + mtspr(SPRN_FSCR, fscr); + } + + if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + if (old_thread->bescr != new_thread->bescr) + mtspr(SPRN_BESCR, new_thread->bescr); + if (old_thread->ebbhr != new_thread->ebbhr) + mtspr(SPRN_EBBHR, new_thread->ebbhr); + if (old_thread->ebbrr != new_thread->ebbrr) + mtspr(SPRN_EBBRR, new_thread->ebbrr); + + if (old_thread->tar != new_thread->tar) + mtspr(SPRN_TAR, new_thread->tar); + } +#endif +} + struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *new) { @@ -751,17 +818,16 @@ struct task_struct *__switch_to(struct task_struct *prev, struct ppc64_tlb_batch *batch; #endif + new_thread = &new->thread; + old_thread = ¤t->thread; + WARN_ON(!irqs_disabled()); - /* Back up the TAR and DSCR across context switches. - * Note that the TAR is not available for use in the kernel. (To - * provide this, the TAR should be backed up/restored on exception - * entry/exit instead, and be in pt_regs. FIXME, this should be in - * pt_regs anyway (for debug).) - * Save the TAR and DSCR here before we do treclaim/trecheckpoint as - * these will change them. + /* + * We need to save SPRs before treclaim/trecheckpoint as these will + * change a number of them. */ - save_early_sprs(&prev->thread); + save_sprs(&prev->thread); __switch_to_tm(prev); @@ -844,10 +910,6 @@ struct task_struct *__switch_to(struct task_struct *prev, #endif /* CONFIG_HAVE_HW_BREAKPOINT */ #endif - - new_thread = &new->thread; - old_thread = ¤t->thread; - #ifdef CONFIG_PPC64 /* * Collect processor utilization data per process @@ -883,6 +945,10 @@ struct task_struct *__switch_to(struct task_struct *prev, last = _switch(old_thread, new_thread); + /* Need to recalculate these after calling _switch() */ + old_thread = &last->thread; + new_thread = ¤t->thread; + #ifdef CONFIG_PPC_BOOK3S_64 if (current_thread_info()->local_flags & _TLF_LAZY_MMU) { current_thread_info()->local_flags &= ~_TLF_LAZY_MMU; @@ -891,6 +957,8 @@ struct task_struct *__switch_to(struct task_struct *prev, } #endif /* CONFIG_PPC_BOOK3S_64 */ + restore_sprs(old_thread, new_thread); + return last; } |