arch/powerpc/include/asm/mmu_context.h

   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  */
  17 extern void mmu_context_init(void);
  18 extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
  19 extern void destroy_context(struct mm_struct *mm);
  20
  21 extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
  22 extern void switch_stab(struct task_struct *tsk, struct mm_struct *mm);
  23 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
  24 extern void set_context(unsigned long id, pgd_t *pgd);
  25
  26 /*
  27  * switch_mm is the entry point called from the architecture independent
  28  * code in kernel/sched.c
  29  */
  30 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  31                              struct task_struct *tsk)
  32 {
  33         /* Mark this context has been used on the new CPU */
  34         cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
  35
  36         /* 32-bit keeps track of the current PGDIR in the thread struct */
  37 #ifdef CONFIG_PPC32
  38         tsk->thread.pgdir = next->pgd;
  39 #endif /* CONFIG_PPC32 */
  40
  41         /* Nothing else to do if we aren't actually switching */
  42         if (prev == next)
  43                 return;
  44
  45         /* We must stop all altivec streams before changing the HW
  46          * context
  47          */
  48 #ifdef CONFIG_ALTIVEC
  49         if (cpu_has_feature(CPU_FTR_ALTIVEC))
  50                 asm volatile ("dssall");
  51 #endif /* CONFIG_ALTIVEC */
  52
  53         /* The actual HW switching method differs between the various
  54          * sub architectures.
  55          */
  56 #ifdef CONFIG_PPC_STD_MMU_64
  57         if (cpu_has_feature(CPU_FTR_SLB))
  58                 switch_slb(tsk, next);
  59         else
  60                 switch_stab(tsk, next);
  61 #else
  62         /* Out of line for now */
  63         switch_mmu_context(prev, next);
  64 #endif
  65
  66 }
  67
  68 #define deactivate_mm(tsk,mm)   do { } while (0)
  69
  70 /*
  71  * After we have set current->mm to a new value, this activates
  72  * the context for the new mm so we see the new mappings.
  73  */
  74 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
  75 {
  76         unsigned long flags;
  77
  78         local_irq_save(flags);
  79         switch_mm(prev, next, current);
  80         local_irq_restore(flags);
  81 }
  82
  83 /* We don't currently use enter_lazy_tlb() for anything */
  84 static inline void enter_lazy_tlb(struct mm_struct *mm,
  85                                   struct task_struct *tsk)
  86 {
  87 }
  88
  89 #endif /* __KERNEL__ */
  90 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */