include/asm-powerpc/mmu_context.h

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