|  | /* | 
|  | * 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 */ |