| /* | 
 |  * 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 */ |