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