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 <linux/sched.h>
  12 #include <asm/mmu.h>
  13 #include <asm/cputable.h>
  14 #include <asm-generic/mm_hooks.h>
  15
  16 /*
  17  * Copyright (C) 2001 PPC 64 Team, IBM Corp
  18  *
  19  * This program is free software; you can redistribute it and/or
  20  * modify it under the terms of the GNU General Public License
  21  * as published by the Free Software Foundation; either version
  22  * 2 of the License, or (at your option) any later version.
  23  */
  24
  25 static inline void enter_lazy_tlb(struct mm_struct *mm,
  26                                   struct task_struct *tsk)
  27 {
  28 }
  29
  30 /*
  31  * The proto-VSID space has 2^35 - 1 segments available for user mappings.
  32  * Each segment contains 2^28 bytes.  Each context maps 2^44 bytes,
  33  * so we can support 2^19-1 contexts (19 == 35 + 28 - 44).
  34  */
  35 #define NO_CONTEXT      0
  36 #define MAX_CONTEXT     ((1UL << 19) - 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         if (prev == next)
  56                 return;
  57
  58 #ifdef CONFIG_ALTIVEC
  59         if (cpu_has_feature(CPU_FTR_ALTIVEC))
  60                 asm volatile ("dssall");
  61 #endif /* CONFIG_ALTIVEC */
  62
  63         if (cpu_has_feature(CPU_FTR_SLB))
  64                 switch_slb(tsk, next);
  65         else
  66                 switch_stab(tsk, next);
  67 }
  68
  69 #define deactivate_mm(tsk,mm)   do { } while (0)
  70
  71 /*
  72  * After we have set current->mm to a new value, this activates
  73  * the context for the new mm so we see the new mappings.
  74  */
  75 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
  76 {
  77         unsigned long flags;
  78
  79         local_irq_save(flags);
  80         switch_mm(prev, next, current);
  81         local_irq_restore(flags);
  82 }
  83
  84 #endif /* CONFIG_PPC64 */
  85 #endif /* __KERNEL__ */
  86 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */