arch/mips/include/asm/mmu_context.h - arm/linux-arm64-legacy - Git at Google

 /*
  * 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/smp.h>
 #include <linux/slab.h>
 #include <asm/cacheflush.h>
 #include <asm/hazards.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>

 #define TLBMISS_HANDLER_SETUP_PGD(pgd)					\
 do {									\
 	extern void tlbmiss_handler_setup_pgd(unsigned long);		\
 	tlbmiss_handler_setup_pgd((unsigned long)(pgd));		\
 } while (0)

 #ifdef CONFIG_MIPS_PGD_C0_CONTEXT
 #define TLBMISS_HANDLER_SETUP()						\
 	do {								\
 		TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);		\
 		write_c0_xcontext((unsigned long) smp_processor_id() <<	\
 						SMP_CPUID_REGSHIFT);	\
 	} while (0)

 #else /* !CONFIG_MIPS_PGD_C0_CONTEXT: using  pgd_current*/

 /*
  * 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()						\
 	write_c0_context((unsigned long) smp_processor_id() <<		\
 						SMP_CPUID_REGSHIFT);	\
 	back_to_back_c0_hazard();					\
 	TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)
 #endif /* CONFIG_MIPS_PGD_C0_CONTEXT*/
 #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_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.asid[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)
 {
 	extern void kvm_local_flush_tlb_all(void);
 	unsigned long asid = asid_cache(cpu);

 	if (! ((asid += ASID_INC) & ASID_MASK) ) {
 		if (cpu_has_vtag_icache)
 			flush_icache_all();
 #ifdef CONFIG_KVM
 		kvm_local_flush_tlb_all();      /* start new asid cycle */
 #else
 		local_flush_tlb_all();	/* start new asid cycle */
 #endif
 		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_possible_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_asid(cpu, next));
 	ehb(); /* Make sure it propagates to TCStatus */
 	evpe(mtflags);
 #else
 	write_c0_entryhi(cpu_asid(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.
 	 */
 	cpumask_clear_cpu(cpu, mm_cpumask(prev));
 	cpumask_set_cpu(cpu, mm_cpumask(next));

 	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_asid(cpu, next));
 	ehb(); /* Make sure it propagates to TCStatus */
 	evpe(mtflags);
 #else
 	write_c0_entryhi(cpu_asid(cpu, next));
 #endif /* CONFIG_MIPS_MT_SMTC */
 	TLBMISS_HANDLER_SETUP_PGD(next->pgd);

 	/* mark mmu ownership change */
 	cpumask_clear_cpu(cpu, mm_cpumask(prev));
 	cpumask_set_cpu(cpu, mm_cpumask(next));

 	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 (cpumask_test_cpu(cpu, mm_cpumask(mm)))  {
 		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 */
	/*
	* 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/smp.h>
	#include <linux/slab.h>
	#include <asm/cacheflush.h>
	#include <asm/hazards.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>

	#define TLBMISS_HANDLER_SETUP_PGD(pgd) \
	do { \
	extern void tlbmiss_handler_setup_pgd(unsigned long); \
	tlbmiss_handler_setup_pgd((unsigned long)(pgd)); \
	} while (0)

	#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
	#define TLBMISS_HANDLER_SETUP() \
	do { \
	TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir); \
	write_c0_xcontext((unsigned long) smp_processor_id() << \
	SMP_CPUID_REGSHIFT); \
	} while (0)

	#else /* !CONFIG_MIPS_PGD_C0_CONTEXT: using pgd_current*/

	/*
	* 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() \
	write_c0_context((unsigned long) smp_processor_id() << \
	SMP_CPUID_REGSHIFT); \
	back_to_back_c0_hazard(); \
	TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)
	#endif /* CONFIG_MIPS_PGD_C0_CONTEXT*/
	#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_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.asid[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)
	{
	extern void kvm_local_flush_tlb_all(void);
	unsigned long asid = asid_cache(cpu);

	if (! ((asid += ASID_INC) & ASID_MASK) ) {
	if (cpu_has_vtag_icache)
	flush_icache_all();
	#ifdef CONFIG_KVM
	kvm_local_flush_tlb_all(); /* start new asid cycle */
	#else
	local_flush_tlb_all(); /* start new asid cycle */
	#endif
	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_possible_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_asid(cpu, next));
	ehb(); /* Make sure it propagates to TCStatus */
	evpe(mtflags);
	#else
	write_c0_entryhi(cpu_asid(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.
	*/
	cpumask_clear_cpu(cpu, mm_cpumask(prev));
	cpumask_set_cpu(cpu, mm_cpumask(next));

	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_asid(cpu, next));
	ehb(); /* Make sure it propagates to TCStatus */
	evpe(mtflags);
	#else
	write_c0_entryhi(cpu_asid(cpu, next));
	#endif /* CONFIG_MIPS_MT_SMTC */
	TLBMISS_HANDLER_SETUP_PGD(next->pgd);

	/* mark mmu ownership change */
	cpumask_clear_cpu(cpu, mm_cpumask(prev));
	cpumask_set_cpu(cpu, mm_cpumask(next));

	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 (cpumask_test_cpu(cpu, mm_cpumask(mm))) {
	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 */