diff options
Diffstat (limited to 'arch/mips/include/asm/mmu_context.h')
| -rw-r--r-- | arch/mips/include/asm/mmu_context.h | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h new file mode 100644 index 0000000..d7f3eb0 --- /dev/null +++ b/arch/mips/include/asm/mmu_context.h @@ -0,0 +1,297 @@ +/* + * 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 */ +#include <asm-generic/mm_hooks.h> + +/* + * 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_each_online_cpu(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_each_online_cpu(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 */ |
