include/asm-powerpc/mmu_context.h

   1 #ifndef __ASM_POWERPC_MMU_CONTEXT_H
   2 #define __ASM_POWERPC_MMU_CONTEXT_H
   3
   4 #ifndef CONFIG_PPC64
   5 #include <asm-ppc/mmu_context.h>
   6 #else
   7
   8 #include <linux/kernel.h>
   9 #include <linux/mm.h>
  10 #include <asm/mmu.h>
  11 #include <asm/cputable.h>
  12
  13 /*
  14  * Copyright (C) 2001 PPC 64 Team, IBM Corp
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License
  18  * as published by the Free Software Foundation; either version
  19  * 2 of the License, or (at your option) any later version.
  20  */
  21
  22 /*
  23  * Getting into a kernel thread, there is no valid user segment, mark
  24  * paca->pgdir NULL so that SLB miss on user addresses will fault
  25  */
  26 static inline void enter_lazy_tlb(struct mm_struct *mm,
  27                                   struct task_struct *tsk)
  28 {
  29 #ifdef CONFIG_PPC_64K_PAGES
  30         get_paca()->pgdir = NULL;
  31 #endif /* CONFIG_PPC_64K_PAGES */
  32 }
  33
  34 #define NO_CONTEXT      0
  35 #define MAX_CONTEXT     (0x100000-1)
  36
  37 extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
  38 extern void destroy_context(struct mm_struct *mm);
  39
  40 extern void switch_stab(struct task_struct *tsk, struct mm_struct *mm);
  41 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
  42
  43 /*
  44  * switch_mm is the entry point called from the architecture independent
  45  * code in kernel/sched.c
  46  */
  47 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  48                              struct task_struct *tsk)
  49 {
  50         if (!cpu_isset(smp_processor_id(), next->cpu_vm_mask))
  51                 cpu_set(smp_processor_id(), next->cpu_vm_mask);
  52
  53         /* No need to flush userspace segments if the mm doesnt change */
  54 #ifdef CONFIG_PPC_64K_PAGES
  55         if (prev == next && get_paca()->pgdir == next->pgd)
  56                 return;
  57 #else
  58         if (prev == next)
  59                 return;
  60 #endif /* CONFIG_PPC_64K_PAGES */
  61
  62 #ifdef CONFIG_ALTIVEC
  63         if (cpu_has_feature(CPU_FTR_ALTIVEC))
  64                 asm volatile ("dssall");
  65 #endif /* CONFIG_ALTIVEC */
  66
  67         if (cpu_has_feature(CPU_FTR_SLB))
  68                 switch_slb(tsk, next);
  69         else
  70                 switch_stab(tsk, next);
  71 }
  72
  73 #define deactivate_mm(tsk,mm)   do { } while (0)
  74
  75 /*
  76  * After we have set current->mm to a new value, this activates
  77  * the context for the new mm so we see the new mappings.
  78  */
  79 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
  80 {
  81         unsigned long flags;
  82
  83         local_irq_save(flags);
  84         switch_mm(prev, next, current);
  85         local_irq_restore(flags);
  86 }
  87
  88 #endif /* CONFIG_PPC64 */
  89 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */