LXR linux/arch/powerpc/include/asm/mmu

   1#ifndef __ASM_POWERPC_MMU_CONTEXT_H
   2#define __ASM_POWERPC_MMU_CONTEXT_H
   3#ifdef __KERNEL__
   4
   5#include <linux/kernel.h>
   6#include <linux/mm.h>
   7#include <linux/sched.h>
   8#include <linux/spinlock.h>
   9#include <asm/mmu.h>    
  10#include <asm/cputable.h>
  11#include <asm-generic/mm_hooks.h>
  12#include <asm/cputhreads.h>
  13
  14/*
  15 * Most if the context management is out of line
  16 */
  17extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
  18extern void destroy_context(struct mm_struct *mm);
  19
  20extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
  21extern void switch_stab(struct task_struct *tsk, struct mm_struct *mm);
  22extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
  23extern void set_context(unsigned long id, pgd_t *pgd);
  24
  25#ifdef CONFIG_PPC_BOOK3S_64
  26extern int __init_new_context(void);
  27extern void __destroy_context(int context_id);
  28static inline void mmu_context_init(void) { }
  29#else
  30extern unsigned long __init_new_context(void);
  31extern void __destroy_context(unsigned long context_id);
  32extern void mmu_context_init(void);
  33#endif
  34
  35/*
  36 * switch_mm is the entry point called from the architecture independent
  37 * code in kernel/sched.c
  38 */
  39static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  40                             struct task_struct *tsk)
  41{
  42        /* Mark this context has been used on the new CPU */
  43        cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
  44
  45        /* 32-bit keeps track of the current PGDIR in the thread struct */
  46#ifdef CONFIG_PPC32
  47        tsk->thread.pgdir = next->pgd;
  48#endif /* CONFIG_PPC32 */
  49
  50        /* 64-bit Book3E keeps track of current PGD in the PACA */
  51#ifdef CONFIG_PPC_BOOK3E_64
  52        get_paca()->pgd = next->pgd;
  53#endif
  54        /* Nothing else to do if we aren't actually switching */
  55        if (prev == next)
  56                return;
  57
  58        /* We must stop all altivec streams before changing the HW
  59         * context
  60         */
  61#ifdef CONFIG_ALTIVEC
  62        if (cpu_has_feature(CPU_FTR_ALTIVEC))
  63                asm volatile ("dssall");
  64#endif /* CONFIG_ALTIVEC */
  65
  66        /* The actual HW switching method differs between the various
  67         * sub architectures.
  68         */
  69#ifdef CONFIG_PPC_STD_MMU_64
  70        if (cpu_has_feature(CPU_FTR_SLB))
  71                switch_slb(tsk, next);
  72        else
  73                switch_stab(tsk, next);
  74#else
  75        /* Out of line for now */
  76        switch_mmu_context(prev, next);
  77#endif
  78
  79}
  80
  81#define deactivate_mm(tsk,mm)   do { } while (0)
  82
  83/*
  84 * After we have set current->mm to a new value, this activates
  85 * the context for the new mm so we see the new mappings.
  86 */
  87static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
  88{
  89        unsigned long flags;
  90
  91        local_irq_save(flags);
  92        switch_mm(prev, next, current);
  93        local_irq_restore(flags);
  94}
  95
  96/* We don't currently use enter_lazy_tlb() for anything */
  97static inline void enter_lazy_tlb(struct mm_struct *mm,
  98                                  struct task_struct *tsk)
  99{
 100        /* 64-bit Book3E keeps track of current PGD in the PACA */
 101#ifdef CONFIG_PPC_BOOK3E_64
 102        get_paca()->pgd = NULL;
 103#endif
 104}
 105
 106#endif /* __KERNEL__ */
 107#endif /* __ASM_POWERPC_MMU_CONTEXT_H */
 108