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