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 static inline void mmu_context_init(void) { }
  27 #else
  28 extern 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  */
  35 static 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  */
  83 static 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 */
  93 static 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 */