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 extern void switch_cop(struct mm_struct *next);
  36 extern int use_cop(unsigned long acop, struct mm_struct *mm);
  37 extern void drop_cop(unsigned long acop, struct mm_struct *mm);
  38
  39 /*
  40  * switch_mm is the entry point called from the architecture independent
  41  * code in kernel/sched.c
  42  */
  43 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  44                              struct task_struct *tsk)
  45 {
  46         /* Mark this context has been used on the new CPU */
  47         cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
  48
  49         /* 32-bit keeps track of the current PGDIR in the thread struct */
  50 #ifdef CONFIG_PPC32
  51         tsk->thread.pgdir = next->pgd;
  52 #endif /* CONFIG_PPC32 */
  53
  54         /* 64-bit Book3E keeps track of current PGD in the PACA */
  55 #ifdef CONFIG_PPC_BOOK3E_64
  56         get_paca()->pgd = next->pgd;
  57 #endif
  58         /* Nothing else to do if we aren't actually switching */
  59         if (prev == next)
  60                 return;
  61
  62 #ifdef CONFIG_PPC_ICSWX
  63         /* Switch coprocessor context only if prev or next uses a coprocessor */
  64         if (prev->context.acop || next->context.acop)
  65                 switch_cop(next);
  66 #endif /* CONFIG_PPC_ICSWX */
  67
  68         /* We must stop all altivec streams before changing the HW
  69          * context
  70          */
  71 #ifdef CONFIG_ALTIVEC
  72         if (cpu_has_feature(CPU_FTR_ALTIVEC))
  73                 asm volatile ("dssall");
  74 #endif /* CONFIG_ALTIVEC */
  75
  76         /* The actual HW switching method differs between the various
  77          * sub architectures.
  78          */
  79 #ifdef CONFIG_PPC_STD_MMU_64
  80         if (mmu_has_feature(MMU_FTR_SLB))
  81                 switch_slb(tsk, next);
  82         else
  83                 switch_stab(tsk, next);
  84 #else
  85         /* Out of line for now */
  86         switch_mmu_context(prev, next);
  87 #endif
  88
  89 }
  90
  91 #define deactivate_mm(tsk,mm)   do { } while (0)
  92
  93 /*
  94  * After we have set current->mm to a new value, this activates
  95  * the context for the new mm so we see the new mappings.
  96  */
  97 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
  98 {
  99         unsigned long flags;
 100
 101         local_irq_save(flags);
 102         switch_mm(prev, next, current);
 103         local_irq_restore(flags);
 104 }
 105
 106 /* We don't currently use enter_lazy_tlb() for anything */
 107 static inline void enter_lazy_tlb(struct mm_struct *mm,
 108                                   struct task_struct *tsk)
 109 {
 110         /* 64-bit Book3E keeps track of current PGD in the PACA */
 111 #ifdef CONFIG_PPC_BOOK3E_64
 112         get_paca()->pgd = NULL;
 113 #endif
 114 }
 115
 116 #endif /* __KERNEL__ */
 117 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */