/* * Switch a MMU context. * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 1996, 1997, 1998, 1999 by Ralf Baechle * Copyright (C) 1999 Silicon Graphics, Inc. */ #ifndef _ASM_MMU_CONTEXT_H #define _ASM_MMU_CONTEXT_H #include <linux/errno.h> #include <linux/sched.h> #include <linux/slab.h> #include <asm/cacheflush.h> #include <asm/tlbflush.h> #ifdef CONFIG_MIPS_MT_SMTC #include <asm/mipsmtregs.h> #include <asm/smtc.h> #endif /* SMTC */ /* * For the fast tlb miss handlers, we keep a per cpu array of pointers * to the current pgd for each processor. Also, the proc. id is stuffed * into the context register. */ extern unsigned long pgd_current[]; #define TLBMISS_HANDLER_SETUP_PGD(pgd) \ pgd_current[smp_processor_id()] = (unsigned long)(pgd) #ifdef CONFIG_32BIT #define TLBMISS_HANDLER_SETUP() \ write_c0_context((unsigned long) smp_processor_id() << 25); \ TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir) #endif #ifdef CONFIG_64BIT #define TLBMISS_HANDLER_SETUP() \ write_c0_context((unsigned long) smp_processor_id() << 26); \ TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir) #endif #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) #define ASID_INC 0x40 #define ASID_MASK 0xfc0 #elif defined(CONFIG_CPU_R8000) #define ASID_INC 0x10 #define ASID_MASK 0xff0 #elif defined(CONFIG_CPU_RM9000) #define ASID_INC 0x1 #define ASID_MASK 0xfff /* SMTC/34K debug hack - but maybe we'll keep it */ #elif defined(CONFIG_MIPS_MT_SMTC) #define ASID_INC 0x1 extern unsigned long smtc_asid_mask; #define ASID_MASK (smtc_asid_mask) #define HW_ASID_MASK 0xff /* End SMTC/34K debug hack */ #else /* FIXME: not correct for R6000 */ #define ASID_INC 0x1 #define ASID_MASK 0xff #endif #define cpu_context(cpu, mm) ((mm)->context[cpu]) #define cpu_asid(cpu, mm) (cpu_context((cpu), (mm)) & ASID_MASK) #define asid_cache(cpu) (cpu_data[cpu].asid_cache) static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) { } /* * All unused by hardware upper bits will be considered * as a software asid extension. */ #define ASID_VERSION_MASK ((unsigned long)~(ASID_MASK|(ASID_MASK-1))) #define ASID_FIRST_VERSION ((unsigned long)(~ASID_VERSION_MASK) + 1) #ifndef CONFIG_MIPS_MT_SMTC /* Normal, classic MIPS get_new_mmu_context */ static inline void get_new_mmu_context(struct mm_struct *mm, unsigned long cpu) { unsigned long asid = asid_cache(cpu); if (! ((asid += ASID_INC) & ASID_MASK) ) { if (cpu_has_vtag_icache) flush_icache_all(); local_flush_tlb_all(); /* start new asid cycle */ if (!asid) /* fix version if needed */ asid = ASID_FIRST_VERSION; } cpu_context(cpu, mm) = asid_cache(cpu) = asid; } #else /* CONFIG_MIPS_MT_SMTC */ #define get_new_mmu_context(mm,cpu) smtc_get_new_mmu_context((mm),(cpu)) #endif /* CONFIG_MIPS_MT_SMTC */ /* * Initialize the context related info for a new mm_struct * instance. */ static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm) { int i; for (i = 0; i < num_online_cpus(); i++) cpu_context(i, mm) = 0; return 0; } static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) { unsigned int cpu = smp_processor_id(); unsigned long flags; #ifdef CONFIG_MIPS_MT_SMTC unsigned long oldasid; unsigned long mtflags; int mytlb = (smtc_status & SMTC_TLB_SHARED) ? 0 : cpu_data[cpu].vpe_id; local_irq_save(flags); mtflags = dvpe(); #else /* Not SMTC */ local_irq_save(flags); #endif /* CONFIG_MIPS_MT_SMTC */ /* Check if our ASID is of an older version and thus invalid */ if ((cpu_context(cpu, next) ^ asid_cache(cpu)) & ASID_VERSION_MASK) get_new_mmu_context(next, cpu); #ifdef CONFIG_MIPS_MT_SMTC /* * If the EntryHi ASID being replaced happens to be * the value flagged at ASID recycling time as having * an extended life, clear the bit showing it being * in use by this "CPU", and if that's the last bit, * free up the ASID value for use and flush any old * instances of it from the TLB. */ oldasid = (read_c0_entryhi() & ASID_MASK); if(smtc_live_asid[mytlb][oldasid]) { smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu); if(smtc_live_asid[mytlb][oldasid] == 0) smtc_flush_tlb_asid(oldasid); } /* * Tread softly on EntryHi, and so long as we support * having ASID_MASK smaller than the hardware maximum, * make sure no "soft" bits become "hard"... */ write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK) | (cpu_context(cpu, next) & ASID_MASK)); ehb(); /* Make sure it propagates to TCStatus */ evpe(mtflags); #else write_c0_entryhi(cpu_context(cpu, next)); #endif /* CONFIG_MIPS_MT_SMTC */ TLBMISS_HANDLER_SETUP_PGD(next->pgd); /* * Mark current->active_mm as not "active" anymore. * We don't want to mislead possible IPI tlb flush routines. */ cpu_clear(cpu, prev->cpu_vm_mask); cpu_set(cpu, next->cpu_vm_mask); local_irq_restore(flags); } /* * Destroy context related info for an mm_struct that is about * to be put to rest. */ static inline void destroy_context(struct mm_struct *mm) { } #define deactivate_mm(tsk,mm) do { } while (0) /* * After we have set current->mm to a new value, this activates * the context for the new mm so we see the new mappings. */ static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next) { unsigned long flags; unsigned int cpu = smp_processor_id(); #ifdef CONFIG_MIPS_MT_SMTC unsigned long oldasid; unsigned long mtflags; int mytlb = (smtc_status & SMTC_TLB_SHARED) ? 0 : cpu_data[cpu].vpe_id; #endif /* CONFIG_MIPS_MT_SMTC */ local_irq_save(flags); /* Unconditionally get a new ASID. */ get_new_mmu_context(next, cpu); #ifdef CONFIG_MIPS_MT_SMTC /* See comments for similar code above */ mtflags = dvpe(); oldasid = read_c0_entryhi() & ASID_MASK; if(smtc_live_asid[mytlb][oldasid]) { smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu); if(smtc_live_asid[mytlb][oldasid] == 0) smtc_flush_tlb_asid(oldasid); } /* See comments for similar code above */ write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK) | (cpu_context(cpu, next) & ASID_MASK)); ehb(); /* Make sure it propagates to TCStatus */ evpe(mtflags); #else write_c0_entryhi(cpu_context(cpu, next)); #endif /* CONFIG_MIPS_MT_SMTC */ TLBMISS_HANDLER_SETUP_PGD(next->pgd); /* mark mmu ownership change */ cpu_clear(cpu, prev->cpu_vm_mask); cpu_set(cpu, next->cpu_vm_mask); local_irq_restore(flags); } /* * If mm is currently active_mm, we can't really drop it. Instead, * we will get a new one for it. */ static inline void drop_mmu_context(struct mm_struct *mm, unsigned cpu) { unsigned long flags; #ifdef CONFIG_MIPS_MT_SMTC unsigned long oldasid; /* Can't use spinlock because called from TLB flush within DVPE */ unsigned int prevvpe; int mytlb = (smtc_status & SMTC_TLB_SHARED) ? 0 : cpu_data[cpu].vpe_id; #endif /* CONFIG_MIPS_MT_SMTC */ local_irq_save(flags); if (cpu_isset(cpu, mm->cpu_vm_mask)) { get_new_mmu_context(mm, cpu); #ifdef CONFIG_MIPS_MT_SMTC /* See comments for similar code above */ prevvpe = dvpe(); oldasid = (read_c0_entryhi() & ASID_MASK); if (smtc_live_asid[mytlb][oldasid]) { smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu); if(smtc_live_asid[mytlb][oldasid] == 0) smtc_flush_tlb_asid(oldasid); } /* See comments for similar code above */ write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK) | cpu_asid(cpu, mm)); ehb(); /* Make sure it propagates to TCStatus */ evpe(prevvpe); #else /* not CONFIG_MIPS_MT_SMTC */ write_c0_entryhi(cpu_asid(cpu, mm)); #endif /* CONFIG_MIPS_MT_SMTC */ } else { /* will get a new context next time */ #ifndef CONFIG_MIPS_MT_SMTC cpu_context(cpu, mm) = 0; #else /* SMTC */ int i; /* SMTC shares the TLB (and ASIDs) across VPEs */ for (i = 0; i < num_online_cpus(); i++) { if((smtc_status & SMTC_TLB_SHARED) || (cpu_data[i].vpe_id == cpu_data[cpu].vpe_id)) cpu_context(i, mm) = 0; } #endif /* CONFIG_MIPS_MT_SMTC */ } local_irq_restore(flags); } #endif /* _ASM_MMU_CONTEXT_H */