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 unsigned long __init_new_context(void);
  31 extern void __destroy_context(unsigned long context_id);
  32 extern 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  */
  39 static 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  */
  87 static 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 */
  97 static 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 */